JP2022139823A - Optical sensor, control method for optical sensor, and control program for optical sensor - Google Patents

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 LT being visible 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; and a light projection adjustment unit that recognizes, as an indication direction, a specific direction in which, among detection results based on detection signals obtained by driving the optical axis adjustment element to sequentially project the detection light in a plurality of preset specific directions, a detection result evaluated such that the detection light is blocked is obtained, and adjusts a light projection direction of the detection light projected for inspection of an objected to be inspected on the basis of, the recognized indication direction.SELECTED DRAWING: Figure 4

Description

The present invention relates to an optical sensor, an optical sensor control method, and an optical sensor control program.

2. Description of the Related Art Optical sensors that detect the presence or absence of an inspection object and the distance to it are known. For example, Patent Literature 1 discloses a ToF (Time of Flight) sensor that detects distance by measuring the time it takes for detection light projected onto an inspection object to be reflected and returned.

JP 2017-53769 A

An optical sensor is installed in a production line, and is sometimes used to measure a characteristic shape portion of a part flowing through the production line to determine the type and quality of the article. When utilized in this manner, optical sensors are often attached to structures associated with the manufacturing line 300, but may not always be attached near the object to be inspected. Therefore, in recent years, a wide-range type optical sensor with a detection range of several meters has also been developed. However, with the wide-range type optical sensor, if even a slight angular error occurs during installation, the detected light will deviate from the target portion of the inspection object. When an optical sensor is attached via a mounting device, it is difficult to precisely adjust the optical axis of the detection light, and the operator must check the spot of the detection light while loosening and tightening the mounting device, which is a cumbersome task. was there.

The present invention has been made to solve such problems, and provides an optical sensor or the like that does not require complicated optical axis adjustment work even when detecting a relatively distant detection target. It provides.

An optical sensor according to a first aspect of the present invention comprises a light projecting element that projects visible detection light, an optical axis adjustment element that adjusts the optical axis of the detection light projected from the light projecting element, A light-receiving element that receives the detection light reflected by the object and outputs a detection signal, and a detection signal that is obtained by sequentially projecting the detection light in a plurality of predetermined specific directions by driving the optical axis adjustment element. Among the detection results based on the detection method, the specific direction in which the detection result that the detection light is evaluated as being blocked is recognized as the indicated direction, and based on the recognized indicated direction, light is emitted for inspection of the inspection object. and a light projection adjustment unit that adjusts the light projection direction. According to the optical sensor configured in this way, the user can indicate the projection direction of the detection light to be projected for inspection of the inspection target simply by blocking the detection light in a specific direction with, for example, a fingertip. Therefore, it is possible to save the trouble of readjusting the orientation of the optical sensor and improve the workability.

In the optical sensor described above, the light projection adjustment unit sequentially projects light in a plurality of specific directions and the currently set projection direction as one cycle. In the case of projecting light in the light direction, the mode of light projection may be changed. By making the modes of light projection different in this way, the user can easily recognize the role of each detection light projected from one light projecting element.

In the above optical sensor, each of the plurality of specific directions may be set at the end of the range adjustable by the optical axis adjustment element. By setting the end of the adjustable range in this way, the user can easily recognize within which range the detection light projected for inspection of the inspection object can be adjusted.

In the above optical sensor, if there is a specific direction in which the light-receiving element cannot detect the reflected detection signal, the light projection adjustment unit detects the detection signal in the specific direction. You may make it move in the possible direction. If the specific direction is moved in this way, the detection light in any specific direction forms a spot on the object, so that the user can easily find the optical axis of the detection light in the specific direction and give a direction indication. Cheap.

In the above optical sensor, the light projection adjustment unit moves in at least one of a plurality of predetermined specific directions or a plurality of specific directions based on the distance to the object detected in the light projection direction. can be By moving in this way, it is possible to maintain an appropriate interval between detected light beams in a specific direction regardless of the distance from the optical sensor, so that the user can easily give a direction indication. At this time, if the plurality of specific directions is not at the end of the range adjustable by the optical axis adjusting element, the light projection adjusting section may project light in the end direction to indicate the range. By projecting light toward the end in this way, the user can easily recognize the range in which the detection light projected for inspection of the inspection object can be adjusted.

In the above-mentioned optical sensor, the light projection adjustment unit produces a detection result that is evaluated to indicate that the detection light in two or more specific directions out of the detection light projected in each of the plurality of specific directions is successively and sequentially blocked. is obtained, the projection direction of the detection light projected for inspection of the inspection object may be adjusted based on the order in which the two or more specific directions are blocked. This aspect also allows the user to intuitively and easily give directions. At this time, when the light projection adjustment unit adjusts the light projection direction based on the order of blocking, it is preferable to stop the adjustment of the light projection direction for a preset set time. By providing such a stop period, erroneous detection due to reciprocation of the user's hand can be prevented.

In the above optical sensor, the light projection adjustment unit adjusts the light projection direction when all of the detection results obtained by sequentially projecting light in a plurality of specific directions are evaluation results indicating that the detected light is blocked. may be confirmed. In this way, if the confirmation instruction is accepted following the direction instruction, the user does not need to operate the optical sensor to issue the confirmation instruction, so workability can be expected to be improved.

In the above-mentioned optical sensor, the light projection adjustment unit outputs detection results obtained by sequentially projecting light in a plurality of specific directions, and the detection results are such that all of the detection light in a preset combination is blocked. In this case, the projection direction may be determined. Further, the light emission adjustment unit emits the detection light as the final light emission for accepting the confirmation instruction, and when the detection result indicates that the detection light of the final light emission is blocked, changes the light projection direction. You can confirm. Even in such a mode, the user does not need to operate the optical sensor to issue a confirmation instruction, so workability can be expected to be improved.

In the above optical sensor, the plurality of specific directions are set for each of the plurality of discrete points defined so as to cover at least a part of the range adjustable by the optical axis adjustment element, and the projection adjustment The unit may recognize the specific direction in which the detection result evaluated that the detected light is blocked at the closest distance is obtained as the pointing direction, and may determine the projection direction as the pointing direction. With such an indication method, the direction of projection can be indicated more directly.

A method for controlling an optical sensor according to a second aspect of the present invention includes 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 target A control method for an optical sensor provided with a light receiving element for receiving detection light reflected by an object and outputting a detection signal, wherein the detection light is directed in a plurality of predetermined specific directions by driving the optical axis adjustment element. Among the detection results based on the detection signals obtained by projecting light in a plurality of specific directions in the step of sequentially projecting light onto the target and the step of projecting light, a detection result evaluated as blocking the detection light was obtained. It has a recognition step of recognizing a specific direction as a pointing direction, and an adjusting step of adjusting the projection direction of the detection light projected for inspecting the inspection target based on the pointing direction recognized in the recognition step.

A control program for an optical sensor according to a third aspect of the present invention includes a light projecting element that projects detection light, and 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 detection light reflected by an object and outputs a detection signal. Among the detection results based on the detection signals obtained by projecting light in a plurality of specific directions in each of the projection step of sequentially projecting light in a specific direction and the projection step, the detection result evaluated as the detection light being blocked is obtained. a recognition step of recognizing the specified direction as a pointing direction; and an adjusting step of adjusting the projection direction of the detection light projected for inspection of the inspection object based on the pointing direction recognized in the recognition step. to execute.

Even in the second and third aspects, as in the first aspect, it is possible to easily indicate the projection direction of the detection light emitted for inspection of the inspection object, so that the optical sensor can This eliminates the trouble of readjusting the orientation, and improves workability.

INDUSTRIAL APPLICABILITY 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 relatively distant detection target.

1 is an external perspective view of an optical sensor; FIG. 1 is a system configuration diagram of an optical sensor; FIG. It is a figure explaining the light projection of the instruction|indication light projection and adjustment light projection with respect to a preliminary|backup workpiece|work. It is a figure explaining the adjustment method in the case of moving adjustment projection rightward. It is a figure explaining the adjustment method in the case of moving adjustment projection downward. It is a figure explaining the determination method which determines the light projection direction of adjustment light projection to an inspection direction. It is a figure which shows a mode that an inspection target is inspected. It is a figure which shows a mode that the projection direction of instruction|indication light projection is automatically adjusted according to the shape of a target object. It is a figure which shows a mode that the projection direction of instruction|indication light projection is automatically adjusted according to the distance of a target object. FIG. 10 is a diagram showing how boundary projection is performed in addition to instruction projection. It is a figure explaining other instruction|indication methods which move adjustment projection light. FIG. 10 is a diagram for explaining another method of determining the direction of projection of adjusted light to be in the inspection direction; It is a figure explaining the adjustment method which determines an inspection direction directly, without light-projecting adjustment light. It is a flow figure explaining the processing procedure of a control part.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described through embodiments of the invention, but the invention according to the scope of claims is not limited to the following embodiments. Moreover, not all the configurations described in the embodiments are essential as means for solving the problems.

FIG. 1 is an external perspective view of an optical sensor 100. FIG. The optical sensor 100 according to the present embodiment is a sensor that detects the presence or absence of a partial shape of a workpiece to be inspected, the distance to a specific location, and the like, and is installed and used in a manufacturing line of a factory, for example. _The optical sensor ₁₀₀ projects detection light L1 toward the work and receives detection light L2 that is reflected back from the work. The optical sensor 100 described below is a ToF sensor that detects distance information by measuring the round trip time of detection light. _The optical sensor 100 outputs undetected information indicating that the workpiece is not detected when the detection light _L2 cannot be received, and outputs distance information when the detection light L2 is received.

The detection light L ₁ is transmitted through a transmission window 102 provided on one surface of the housing 101 and projected. Although the details will be described later, the optical sensor 100 includes an optical axis adjusting element that adjusts the projection direction of the detection light L ₁ projected from the light projecting element. The optical axis adjustment element can deflect the optical axis of the detection light L1 in _two orthogonal directions (the X-axis direction and the Y-axis direction in the drawing) at a predetermined pitch. Specifically, the optical axis of the detection light L ₁ can be aligned in any direction (x _m , y _n ) indicated by dots within the deflectable range R as shown.

Further, the optical sensor ₁₀₀ can detect the distance in the range from _Dn to _Df along the projection direction of the detection light L1. That is, the range indicated by halftone dots in the figure is the detectable range V. If the work does not exist in this range, the optical sensor 100 outputs non-detection information. Output the distance information to the ₁ reflection point.

An operation button 150 is provided on one surface of the housing 101, and the operation button 150 receives an operation from the user. A display panel 160 is provided on one surface of the housing 101, and the display panel 160 displays the determined inspection direction and the like, as will be described later. A cable 103 is connected to a PLC or a PC as external devices, and transmits output signals to these devices. 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 FIG. 1 are used to indicate the directions of the constituent elements shown in each drawing.

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

The light projecting element 120 is a laser diode that emits laser light in a wavelength band of visible light (eg, red light of 635 nm to 680 nm), and is controlled by the control unit 110 to a specific frequency (eg, 12 MHz) for detection. Light L ₁ is emitted. 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 be used.

The optical axis adjustment element 130 is an element that adjusts the optical axis of the detection light L ₁ projected from the light projecting element 120, as described above. In this embodiment, as the optical axis adjustment element 130, a liquid crystal device is used that realizes deflection by applying a voltage to a liquid crystal cell to control on/off. Specifically, the liquid crystal device is formed by laminating a liquid crystal diffraction grating in which liquid crystal cells are arranged (for example, the journal "Optics" Vol. 30 No. 1: "Research Trends in Liquid Crystal Optical Devices" p. This device 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 according to the signal. In addition, as the optical axis adjustment element 130, a MEMS mirror, an optical phased array, an electro-optic crystal, or the like can be used.

The light receiving element 140 is, for example, a CMOS sensor having photoelectric conversion pixels arranged two-dimensionally, converts the received detection light L ₂ into an electric signal, and transmits the electric signal to the control unit 110 . _In the drawing, 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, but in reality they are the same optical path as shown in _FIG . For example, _a dichroic mirror is used to separate the optical path of the detection light _L2 toward the light receiving element 140 from the optical path of the detection light L1. In addition, since the optical axis adjustment element 130 is accommodated in the housing 101 together with the light emitting element 120 and the light receiving element 140, it is necessary to provide _a movable portion outside the housing 101 for adjusting the optical axis of the detection light L1. There is no Therefore, since the housing 101 can be directly fixed to a structure associated with a manufacturing line, for example, the optical sensor 100 can be easily installed and is less susceptible to accidental contact by an operator.

The operation button 150 is an operation member that receives 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 cooperates with the control unit 110 and functions as a reception unit that receives 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.

The display panel 160 is, for example, a liquid crystal panel, and displays the setting state of the optical sensor 100, distance information as detection results, non-detection information, and the like. As a device indicating the setting state of the optical sensor 100, an LED or the like may be provided. The input/output IF 170 is an interface for exchanging information with an external device via the cable 103, and includes, for example, an Ethernet (registered trademark) unit and a LAN unit. Note that 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 a wireless LAN or Bluetooth (registered trademark).

The control unit 110 can also receive, via the input/output IF 170, an operation performed by a user on an external operation panel and a control signal output by a PLC, which is an external device. For example, when the user operates the operation panel to issue an instruction to start inspecting a workpiece, the input/output IF 170 functions as a reception unit that cooperates with the control unit 110 to receive an instruction to start inspection.

The storage unit 180 is a non-volatile storage medium, and is configured by flash memory, for example. The storage unit 180 can store various parameter values, functions, lookup tables, etc. 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 initial detection distance detected at the start of the adjustment mode and the determined inspection direction of the detection light L1.

The control unit 110 also serves 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 to sequentially project the detection light L ₁ in _a plurality of predetermined specific directions. A specific direction in which a detection result evaluated to be obtained is recognized as _a pointing direction, and the projection direction of the detection light L1 projected for inspection of the inspection workpiece is adjusted based on the recognized pointing direction. Further, when inspecting a work to be inspected, the optical axis adjustment element ₁₃₀ is driven so that the detection light L1 is projected in the inspection direction thus adjusted and determined. The distance calculation unit 112 calculates the time difference between the projected detection light L1 and the received detection light L2 using, for example, the _phase difference between the _two , and converts it into the distance to the preliminary work or inspection work. The control unit 110 can data-structure the calculation result of the distance calculation unit 112 and output it as distance information. Alternatively, when the light receiving element 140 does not receive the detection light L2, it is possible to output prescribed non _- detection information.

The user switches the optical sensor 100 to the adjustment mode via the operation button ₁₅₀ or the like, and performs adjustment work for determining the inspection direction to which the detection light L1 should be directed. The procedure will be specifically described below.

FIG. 3 is a diagram for explaining projection of instruction lights _IU , _IR , _ID , and _IL and adjustment light _LT onto the preliminary workpiece 210. As shown in FIG. The optical sensor 100 is fixed to a structure associated with the production line toward 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 intended inspection object, on the production line 300 so that the target inspection point 211 is positioned around the inspection position. Here, the inspection point 211 only needs to be included in the deflectable range of the detection light L ₁ , and the user can place the preliminary work 210 on the production line 300 at an approximate location without paying much attention. good.

It is desirable that the spare workpiece 210 is a reference product in which the inspection point 211 is determined to be good. In this embodiment, it is assumed that it is inspected whether the hexagonal screws are properly fastened to the works that are successively passed through the manufacturing line 300 . In this case, it is desirable that the inspection point 211 is the screw head of the hexagonal screw, and that the hexagonal screw is correctly tightened in the preliminary work 210 as well.

With the optical sensor 100 and the spare workpiece 210 thus installed, the user operates the operation button 150 or the like to switch the optical sensor 100 to the adjustment mode. When the optical sensor 100 is switched to the adjustment mode, the optical sensor 100 sequentially and repeatedly executes the instruction light projections _IU , _IR , _ID , _IL and the adjustment light projection _LT . The adjustment projection light L _T is adjustment target light that is projected in a temporary inspection direction for determining the projection direction (inspection direction) of the detection light L ₁ for inspecting the inspection object. The adjustment projection light LT is directed to the center of the _deflectable range R, for example, at the start of the adjustment mode.

The instruction lights _IU , IR, _ID , and IL are projected toward four directions of the _deflectable range _R , respectively, in order to receive an instruction from the user to adjust the projection direction of the adjustment light _LT . It is an indication detection light. In this embodiment, as shown in the figure, the instruction projection light _IU is positioned at the midpoint of the upper side of the boundary of the deflectable range _R , and the instruction projection light IR is positioned at the midpoint of the right side of the boundary of the deflectable range R. I _D is projected toward the middle point of the lower side of the boundary of the _deflectable range R, and the instruction light IL is projected toward the middle point of the left side of the boundary of the deflectable range R, respectively. That is, in this embodiment, as a plurality of specific directions in which the instruction light is projected, the four directions of up, down, left, and right, which are the ends of the adjustable range with respect to the center of the deflectable range R, are set. The plurality of specific directions is not limited to this. For example, directions at the four corners of the boundary of the deflectable range R may be set, or eight directions may be set by adding the four directions of the present embodiment. .

The light projection adjustment unit 111 sequentially deflects the detection light _{L 1} emitted from the light projecting element 120 to perform instruction light projection I _U →instruction light projection I _R →instruction light projection I _D →instruction light projection IL →adjustment. Light projection is repeated with light projection _LT as one cycle. Specifically, the light is sequentially switched so that each projection continues for 0.01 seconds, for example. Since the detection light L ₁ is visible light, the user can visually recognize the spots S _U , S _R , SP _D , _{S L} , and S _T formed on the preliminary work 210 by these light projections. At the start of the adjustment mode, the adjusted projection light L _T is arranged such that the spot S _T is positioned in the interior surrounded by the spots S _U , S _R , SP _D and _{S L} , particularly at the center of the interior surrounded. is preferably adjusted. When adjusted in this way, the user can intuitively grasp the roles of the instruction projection lights _IU , _IR , _ID , and _IL and the adjustment projection lights _LT , and furthermore, the subsequent adjustment allows the user to understand the spot Even if SP _T is moved, the deflection amount and deflection direction of the adjustment projected light L _T can be easily grasped.

Here, the light projection adjustment unit ₁₁₁ distinguishes between the spot _SPT of the adjusted projection light _LT and the spots _SPU , _SPR , SPD, and _SPL of the instruction light projections _IU , _IR , _ID , and _IL . As shown, the _modes of projection of adjustment light _LT and instruction light _IU , _IR , _ID , and IL are made different. Specifically, it is possible to cooperate with the control unit 110 to control the light projection of the light projecting element 120 to increase the emission intensity with respect to the adjusted projection light L _T or to blink the light. By making the modes of light projection different in this way, the user can easily recognize the roles of the respective light projections even though the detection light L ₁ is projected from one light projection element 120 .

When the adjustment mode is started, the projection adjustment unit 111 causes the distance calculation unit 112 to calculate the distances to each of the instruction _{projections IU} , _IR , _ID , and IL executed at the start. The projection adjustment unit 111 stores these calculation results in the storage unit 180 as the initial detection distances D _U , D _R , D _D and D _L .

FIG. 4 is a diagram for explaining an adjustment method when moving the adjustment projection light _LT to the right. When the adjustment mode is started as described above, until the adjustment mode ends, the light projection adjustment unit 111 performs the command projection _IU → command light projection I _R → command light projection I _D → command light projection _IL → The projection of the adjustment projection light _LT is repeated. The distance calculation unit 112 calculates the detection distances for the command projection _{lights IU} , _IR , _ID , and IL in synchronization with the respective light projections. In this state, for example, when the user sticks his or her index finger into the optical path of the projection light I _R as shown in the figure, the spot SP _R is formed on the index finger of the user, and the projection light I _R is blocked by the index finger, and is positioned behind it. (indicated by the dashed line). The distance calculator 112 calculates the distance D _R ' to the index finger with respect to the pointing light I _R .

When the calculation result is handed over to the light projection adjustment unit 111, the light projection adjustment unit 111 evaluates that the instruction light projection I _R is blocked based on the comparison with the initial detection distance D _R . Since the command projection light I _R is projected toward the right side with respect to the center of the deflectable range R, the projection adjustment unit 111, based on the evaluation result, sets the adjusted projection light _LT to the projection direction at that time. to the right by a preset amount of deflection. When the user sticks his or her index finger into the optical path of the instruction light I _R for a while, the adjustment light L _T is gradually deflected to the right and eventually reaches above the inspection point 211 . The user withdraws the index finger from the optical path of the instruction light _IR at the right timing.

FIG. 5 is a diagram for explaining an adjustment method for moving the adjustment projection light _LT downward. Continuing from FIG. 4, for example, when the user sticks his or her index finger into the optical path of the instruction light _{ID as shown in the figure, the spot SP D is} formed on the user's index finger, and the distance calculation unit 112 calculates the instruction light _ID , the distance D _D ' to the index finger is calculated.

When the calculation result is handed over to the light projection adjustment unit 111, the light projection adjustment unit 111 evaluates that the instruction light projection I _D has been blocked from comparison with the initial detection distance D _D . Since the command projection light I _D is projected downward with respect to the center of the deflectable range R, the projection adjustment unit 111 determines the adjusted projection light L _T from the evaluation result as the projected light at that time. The direction is deflected downward by a preset amount of deflection. When the user sticks his or her index finger into the optical path of the instruction light _ID for a while, the adjustment light L _T is gradually deflected downward and eventually reaches the inspection point 211 . The user withdraws the index finger from the optical path of the instruction light _ID at the right timing.

FIG. 6 is a diagram for explaining a determination method for determining the projection direction of the adjustment projection light _LT to be the inspection direction. After the adjusted projection light L _T reaches the inspection point 211 as described above, the user determines the projection direction as the inspection direction. Specifically, for example, as shown in the figure, the confirm button of the operation buttons 150 is pressed to confirm. When the projection direction of the adjustment projection light L _T at that time is determined as the inspection direction, the projection adjustment unit 111 stores the direction coordinates (x _T , y _T ) indicating the inspection direction in the storage unit 180 . The light projection adjustment unit 111 performs the determined inspection light L _C for a certain period of time in a mode different from the light projection mode of the adjustment light L _T . Specifically, it is possible to cooperate with the control unit 110 to control the light projection of the light projecting element 120 to increase the emission intensity with respect to the adjusted projection light L _T or to blink the light. As a result, a highly visible spot SP _C is formed at the inspection location 211, and the user can confirm the inspection location. Once the inspection direction is determined in this way, the user can repeatedly loosen or tighten the mounting device while checking the spot of the detection light even when detecting a detection target relatively far from the optical sensor 100 . It is possible to omit complicated work such as

FIG. 7 is a diagram showing how an inspection workpiece 290, which is an object to be inspected, is inspected. After the inspection direction is determined as described above, the user removes the spare work 210 and operates the manufacturing line 300 so that the target inspection works 290 flow sequentially. Upon receiving the inspection start instruction, the light projection adjustment unit 111 reads the direction coordinates (x _T , y _T ) stored in the storage unit 180 and fixes the projection direction of the inspection light L _C to that direction. The control unit 110 emits the inspection light LC every time the workpiece ₂₉₀ to be inspected reaches a specified position on the production line 300, causes the detection process to be executed, and outputs the detection result to an external device.

Here, a case of simply outputting the detection distance of the inspection point 221 as the detection result will be described. As shown in the figure, the hexagonal screw is correctly tightened in a certain workpiece 290a to be inspected, and the optical sensor 100 outputs the distance D _a to the external device as the detected distance at the inspection point 291a. The external device confirms that the distance D _a is within the allowable range and judges it as "accepted". On the other hand, the hexagon screw is floating due to insufficient tightening of the next workpiece 290b to be inspected, and the optical sensor 100 outputs the distance D _b to the external device as the detection distance at the inspection point 291b. The external device confirms that the distance D _b is not included in the allowable range, and determines "fail". In this manner, the optical sensor 100 can be used to determine whether the workpiece 290 to be inspected is good or bad. The optical sensor 100 may make pass/fail judgment and output the result to an external device.

Next, some modifications will be described. FIG. 8 is a diagram showing, as a first modified example, how the projection direction of the instruction light is automatically adjusted according to the shape of the preliminary work 220 that is the object.

In the embodiments described with reference to FIGS. 3 to 6, the projection directions of the instruction lights _IU , IR, _ID , and IL are set at the ends (boundaries) of the _deflectable range _R. FIG. However, depending on the shape of the object, there may be no reflective surface at the location where the pointing light is projected, making it impossible to form a spot. _In such a case, the light receiving element 140 cannot detect the detection light L2, which is the reflected light, and the distance calculation section 112 outputs the result of distance non-calculation. In addition, the user cannot visually recognize in which direction the instructional light projection is being performed, and it is difficult to block such instructional light projection.

Therefore, the light projection adjustment unit 111 performs adjustment to gradually move the light projection direction toward the inside of the deflectable range R for the instructed light projection for which the distance was not calculated. Specifically, for example, as shown in the figure, when a result of distance non-calculation is obtained for the initial instruction light projection _IU , the light projection adjustment unit 111 causes the instruction light projection _IU to be deflected by the preset deflection. Deflect downward by the amount. In this case, the downward direction for the pointing light _IU is the center direction of the deflectable range R. As shown in FIG. If the distance cannot be calculated again after the deflection, the instruction projection light _IU is further deflected downward by a preset deflection amount. Such processing is repeated until the spot S _U is formed on the preliminary work 210 and the adjustment of the projection direction of the instruction light I _U is finished when the distance detection is successful.

If the spot S _U is formed on the preliminary work 210 in this way, the distance calculator 112 can calculate the initial detection distance D _U and the user can recognize the optical path of the instruction light I _U. Similarly, when the distance is not calculated for the instruction _lights I _R , I _D , and IL, the light projection direction is gradually deflected toward the center of the deflectable range R, thereby automatically perform reconciliation.

It should be noted that the direction of deflection does not have to be the center direction of the deflectable range R. In addition, the instruction light beams other than the instruction light beams for which the distance calculation result is not obtained are also deflected so that the respective instruction light beams maintain the relative relationship in the vertical and horizontal directions and form a spot on the preliminary work 210 . good too. By executing the automatic adjustment in this way, any pointing light can form a spot on the preliminary work 210, so that the user can easily find the optical path of each pointing light and give direction instructions. .

FIG. 9 is a diagram showing, as a second modified example, how the projection direction of the instruction light is automatically adjusted according to the distance of the preliminary work 210, which is the object. As shown in FIG. 1, the deflectable range R increases as the distance from the optical sensor 100 increases. Therefore, when the production line 300 is far from the optical sensor 100, the deflectable range R becomes large with respect to the object. The distance cannot be calculated in many cases. Moreover, even if the distance can be calculated, the intervals between the spots formed by the respective spots are widened, making it difficult for the user to perform the operation of blocking the respective optical paths.

Therefore, the light projection adjustment unit 111 adjusts each light projection based on the distance to the backup workpiece 210 detected by at least one of the instruction light projections _IU , _IR , _ID , and _IL or the adjusted light projection _LT . Adjust direction. For example, when the distance D _P is detected by the spot SP _T formed by the adjusted projection light L _T as shown in the figure, the designated projection frame S is determined according to the size predetermined for the distance D _P. Then, the projection directions of the instruction lights _IU , _IR , _ID , and IL are adjusted so as to match the directions of the instruction light projection frame _S in the vertical and horizontal directions.

In this manner, if the instruction light projection frame S is set inside the deflectable range R according to the distance of the preliminary work 210 and the direction of projection of the instruction light is adjusted, the respective spots on the preliminary work 210 are appropriately aligned. can be expected to be formed at regular intervals. It becomes easier for the user to perform the operation of blocking each optical path. In addition, when there is instruction light projection for which the result of distance calculation is not calculated even if the projection direction of the instruction light projection is adjusted in this way, the example of FIG. 8 is applied to the instruction light projection, and The light projection direction may be adjusted.

FIG. 10 is a diagram showing a third modified example in which boundary light projections P _a , P _b , P _c , and P _d are performed in addition to instruction light projections I _U , I _R , I _D , and I _L . be. If the designated light projection frame S is set inside the deflectable range R according to the distance of the preliminary work 210 as in the example of FIG. 9, it becomes difficult for the user to recognize within which range the adjusted projection light _LT can be moved. . Therefore, the light projection adjustment unit 111 provides instruction light projection boundaries for indicating the _adjustable range separately from the instruction light projection _IU , _IR , _ID , and IL for receiving the movement instruction of the adjustment light projection _LT . Light projections P _a , P _b , P _c , P _d are further performed.

As shown in the figure, if the preliminary work 230 is relatively large, the boundary projection lights P _a , P _b , P _c , and P _d that are projected toward the four corners of the deflectable range R are projected onto the surface of the preliminary work 230 . Spots SP _a , SP _b , SP _c , SP _d can be formed. By visually recognizing the spots SP _a , SP _b , SP _c , and SP _d thus formed, the user can recognize the range in which the adjusted projected light _LT can be moved.

The light projection adjustment unit 111 sequentially deflects the detection light _{L 1} emitted from the light projecting element 120 so that, for example, the instruction light _IU →the instruction light I _R →the instruction light I _D →the instruction light IL →adjustment light L _T →boundary light P _a →boundary light P _b →boundary light P _c →boundary light P _d is repeated as one cycle. Alternatively, the frequency of boundary light projection may be reduced, for example, by making the frequency of boundary light projection half the frequency of instruction light projection. Further, the emission intensity of the boundary light emission may be lowered or the lighting time may be shortened with respect to the instruction light emission.

When boundary projection is performed in this way, the user can easily make adjustments when moving the adjustment projection light _LT beyond the instruction projection frame S. FIG. For example, as shown in the figure, this is convenient when the adjustment projection light _LT is moved to an inspection point 231 existing outside the instruction projection frame S.

FIG. 11 is a diagram for explaining another instruction method for moving the adjustment projection light _LT as a fourth modification. In each of the embodiments described so far, the user was made to recognize the pointing direction by blocking one of the projecting light beams, but in the fourth modified example, each of the projecting light beams is continuously blocked, The direction indication is recognized by the order of blocking. FIGS. 11(A) to 11(C) are diagrams showing how one of the instruction light projections is blocked in order as time elapses.

Specifically, it shows how the user shakes his palm from top to bottom, and FIG. 11A shows how the instruction light _IU is blocked in the initial stage. After that, as shown in FIG. 11( _B ), the _palm blocks the projected light I _R and IL as well as the projected light I _U , and eventually, as shown in FIG. block the Note that FIG. 11C shows a state in which I _R is also blocked at the same time. When the light projection adjustment unit 111 receives from the distance calculation unit 112 such a calculation result that can be evaluated as being sequentially blocked over time, it recognizes that the palm has been swung from top to bottom, and adjusts the projection light L _T . The light is deflected downward from the light projection direction at that time by a preset deflection amount. Similarly, when it is recognized that the palm is shaken from bottom to top, the adjusted light emission _LT is directed upward, and when it is recognized that the palm is shaken from right to left, the adjusted light emission _LT is directed to the left and left to right. When it is recognized that it has been swung to the right, it deflects the adjusted projection light _LT to the right by a preset amount of deflection.

For example, if you try to shake your palm continuously from top to bottom, you will also have to shake your palm continuously from bottom to top. is performed once, recognition of the indicated direction is stopped for a preset set time (for example, 1 second). Once the user shakes the palm to recognize the pointing direction, the user returns the palm to the initial position while recognition of the pointing direction is stopped.

FIG. 12 is a diagram for explaining another determination method for determining the projection direction of the adjustment projection light _LT to be the inspection direction as a fifth modification. This modified example is compatible with the fourth modified example, but is not limited to this, and can be combined with any of the previous embodiments.

In the example of FIG. 6 described above, after the adjusted projected light L _T reaches the inspection point 211, the user operates the operation button 150 to confirm the projected light direction as the inspection direction. In this modification, after the adjustment projection light _LT reaches the inspection point 211, as shown in the figure, the user _blocks all of the instruction projection lights _IU , _IR , _ID , and IL at the same time. , the light projection direction is determined as the inspection direction.

When the light projection adjustment unit 111 receives from the distance calculation unit 112 a calculation result in which all of the instructed light projections _IU , IR, _ID , and _IL are blocked, the light projection adjustment unit 111 determines the adjusted projection light _L Set the projection direction of _T to the inspection direction. That is, the direction coordinates (x _T , y _T ) indicating the inspection direction are stored in the storage unit 180 . In this way, if the confirmation instruction is accepted following the direction instruction, the user does not need to operate the operation button 150 of the optical sensor 100 to issue the confirmation instruction, so that an improvement in workability can be expected. .

It should be noted that the method of detecting the definite indication is not limited to the method of detecting that all of the indication lights _IU , _IR , _ID , and _IL are blocked at the same time, and various other methods can be adopted. . For example, when it is detected that all of a _preset combination of instruction lights _IU , _IR , _ID , and IL are blocked, the adjustment light _LT is emitted at that time. The direction may be determined to be the inspection direction. For example, in the combination of the instruction lights _IU and _ID , it is considered rare that they are blocked at the same time. can be recognized as Further, apart from the instruction light emission, the confirmation light emission for accepting the confirmation instruction may be performed. When the determined projected light is blocked, the projection direction of the adjusted projected light _LT at that time is determined to be the inspection direction. The determined light projection is preferably performed in a direction away from the direction of the instruction light projection.

FIG. 13 is a diagram for explaining an adjustment method for directly determining the inspection direction without emitting adjustment light L _T as a sixth modification. In any of the embodiments described so far, the instruction lights _IU , _IR , _ID , and IL are _projected in four directions (or more) to receive the instruction to move the adjustment light _LT . and detected that one of them was blocked and deflected stepwise in that direction. In this modified example, the projection direction of the instruction projection light _IM is set for each of the lattice points defined in the deflectable range R. FIG. Then, the light projection adjustment unit 111 recognizes the projection direction of the instruction light _IM for which the detection result is evaluated as being the closest and blocked as the instruction direction, and immediately changes the instruction direction to the inspection direction. Determined as

More specifically, as shown in FIG. 13A, the light projection adjustment unit 111 drives the optical axis adjustment element 130 so that the lattice points set in the deflection range R are linearly drawn from the upper left to the lower right. _In this manner, the detection light L1 is sequentially deflected and projected. Each projection for the lattice point is designated as the designated projection I _M . For example, when the user wants to set the screw head of the hexagonal screw, which is the inspection point 211, in the inspection direction, one of the instruction projection lights _IM that irradiates the screw head is the most optical one compared to the other instruction projection lights _IM . Stick out your index finger so as to block it near the sensor 100 . Then, the light projection adjustment unit 111 recognizes the instruction projection light _IM as the instruction direction, and determines it as the inspection direction for inspecting the inspection object.

FIG. 13(B) shows how the determined inspection light _{L C} is projected for a certain period of time in a mode different from the light projection mode of the instruction light IM. Specifically, it is possible to cooperate with the control unit 110 to control the light projection of the light projecting element 120 to increase the emission intensity with respect to the adjusted projection light L _T or to blink the light. According to such an adjustment method, it is possible to omit the work of adjusting the projection direction of the adjustment projection light _LT through a plurality of instruction steps, so that the inspection direction can be determined more directly and in a short time. can be done.

In the illustrated example, the projection direction of the instruction light IM is set for each of the lattice points defined in the _deflectable range R, but the setting of the projection direction of the instruction light _IM is limited to this. do not have. The projection direction of the instruction light _IM may be set for each of a plurality of discrete points defined so as to cover at least a part of the deflectable range R.

Next, the processing procedure of the control unit 110 will be described using the embodiment described with reference to FIGS. 3 to 7 as a representative example. FIG. 14 is a flowchart for explaining the processing procedure of the control unit 110. As shown in FIG. The flow starts when the adjustment mode is selected with the optical sensor 100 fixed to a structure associated with the production line 300 and the preliminary workpiece 210 placed on the production line 300 .

In step S101, the light projection adjustment unit 111 performs instruction projection I _U toward the upper boundary of the deflectable range R → instruction projection I _R toward the right side of the boundary → instruction projection _ID toward the lower side of the boundary → boundary The instruction light I _L directed toward the left side is sequentially projected, and the distance calculation unit 112 is caused to calculate the distance to each of them. The projection adjustment unit 111 stores these calculation results in the storage unit 180 as the initial detection distances D _U , D _R , D _D and D _L .

Subsequently, the process proceeds to step _S102 , and the light projection adjustment unit 111 sequentially executes instruction projection _IU →instruction projection _IR →instruction projection _ID →instruction projection IL. Then, in step S103, it is determined whether or not any instruction light has been blocked. Specifically, the detection distances D _U ', D _R ', D _D ', and D _L ' calculated for the respective light projections are threshold values from the initial detection distances D _U , D _R , D _D , and D _L . It is determined whether or not it has been blocked by whether or not the length has shortened beyond .

If it is determined that neither of them is blocked, the process proceeds to step S104, the light projection adjustment unit 111 projects the adjusted projection light _LT in the same direction as the previous time, and the process proceeds to step S106. When it is determined that any one of them has been blocked, the light projection adjustment unit 111 updates the orientation of the adjusted projection light L _T in the direction indicated by the blocked instruction light projection, and proceeds to step S106.

Proceeding to step S<b>106 , the light projection adjustment unit 111 confirms whether or not a confirmation instruction has been received via the operation button 150 . If no confirmation instruction has been received, the process returns to step S102 to continue the adjustment mode. If the confirmation instruction is accepted, the projection direction of the adjustment projection light L _T at that time is confirmed as the inspection direction, the direction coordinates (x _T , y _T ) indicating the inspection direction are stored in the storage unit 180, and the adjustment mode is entered. , and proceeds to step S107.

Upon receiving the instruction to start inspection in step S107, the control unit 110 reads the direction coordinates (x _T , y _T ) stored in the storage unit 180 and fixes the projection direction of the inspection light L _C to that direction. . Then, in step S108, inspection light L _C is emitted every time the work 290 to be inspected reaches a specified position on the manufacturing line 300, detection processing is executed, and the detection result is output to an external device. When the inspection of the planned number of works flowing on the production line 300 is completed, the series of processes is completed.

The optical sensor 100 described above is not limited to the ToF sensor that detects distance information by measuring the round-trip time of the detected light. A triangulation sensor that detects distance information may be used. _When employing an optical axis adjustment element in a triangulation sensor, for example, _a lookup table that associates the measurement distance with the projection direction of the detection light L1 and the light reception position of the detection light L2 should be prepared in advance. For example, distance information can be generated as a detection result. Further, in the above-described embodiments, detection of distance information for judging the quality of an object to be inspected has been described, but the usage of the output distance information is not limited to the quality judgment. For example, it is conceivable to use a characteristic partial shape as an inspection object and detect the distance to determine the type of the inspection object.

[Note]
a light projecting element (120) for projecting detection light (L ₁ ), which is visible light;
an optical axis adjusting element (130) for adjusting the optical axis of the detection light (L ₁ ) projected from the light projecting element (120);
a light receiving element (140) that receives the detection light (L ₂ ) reflected by the object and outputs a detection signal;
Among detection results based on the detection signals obtained by sequentially projecting the detection light (L ₁ ) in a plurality of predetermined specific directions by driving the optical axis adjustment element (130), the detection light Projection of the detection light (L ₁ ) for inspecting the inspection object (290) by recognizing the specific direction in which the detection result evaluated as being blocked (L ₁ ) is obtained as the pointing direction. An optical sensor (100) comprising a light projection adjustment section (111) that adjusts based on the indicated direction that has been recognized.

DESCRIPTION OF SYMBOLS 100... Optical sensor, 101... Housing, 102... Transmission window, 103... Cable, 110... Control part, 111... Light emission adjustment part, 112... Distance calculation part, 120... Light emission element, 130... Optical axis adjustment element , 140... light receiving element, 150... operation button, 160... display panel, 170... input/output IF, 180... storage section, 210, 220, 230... preliminary work, 211, 231... inspection location, 290, 290a, 290b... inspection Workpiece 291a, 291b Inspection point 300 Production line

Claims (14)

a light projecting element that projects detection light that is visible light;
an optical axis adjusting 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 the object and outputs a detection signal;
Among detection results based on the detection signals obtained by sequentially projecting the detection light in a plurality of predetermined specific directions by driving the optical axis adjusting element, it is evaluated that the detection light is blocked. a light projection adjustment unit that recognizes a specific direction from which a detection result is obtained as a designated direction, and adjusts the projection direction of the detection light projected for inspection of the inspection object based on the recognized designated direction; optical sensor. The light projection adjustment unit sequentially projects the light in the plurality of specific directions and the currently set light projection direction as one cycle, and projects light in the plurality of specific directions and in the light projection direction. 2. The optical sensor according to claim 1, wherein the light is projected in different ways. 3. The optical sensor according to claim 1, wherein each of the plurality of specific directions is set at an end of a range adjustable by the optical axis adjustment element. When there is a specific direction in which the reflected detection signal cannot be detected by the light-receiving element among the plurality of predetermined specific directions, the light projection adjustment unit adjusts the detection light projected in the specific direction. 4. The optical sensor according to any one of claims 1 to 3, wherein the detection signal is deflected in a detectable direction. The light projection adjustment unit projects the detection light in each of the plurality of specific directions based on at least one of the plurality of predetermined specific directions or a distance to an object detected in the light projection direction. 5. An optical sensor according to any one of claims 1 to 4, which deflects the . 6. When the plurality of specific directions are directions inside a range adjustable by the optical axis adjusting element, the light projection adjusting section projects light toward the end to indicate the range. The optical sensor according to . The light projection adjustment unit obtains a detection result evaluated that the detection light in two or more specific directions out of the detection light projected in each of the plurality of specific directions is successively and sequentially blocked. 7. The optical sensor of any one of claims 1 to 6, wherein, if any, the direction of light projection is adjusted based on the order in which the two or more specific directions are blocked. 8. The optical system according to claim 7, wherein, when the light projection adjustment unit adjusts the light projection direction based on the order of blocking, the adjustment of the light projection direction is stopped for a preset time. sensor. The light projection adjustment unit determines the light projection direction when all of the detection results obtained by sequentially projecting light in the plurality of specific directions are detection results that indicate that the detection light is blocked. Optical sensor according to any one of claims 1 to 8. When the light projection adjustment unit evaluates that all of the detection light beams of a preset combination among the detection results obtained by sequentially projecting light in the plurality of specific directions are blocked, 9. The optical sensor according to any one of claims 1 to 8, wherein the light projection direction is determined. The light projection adjustment unit projects the detection light as final light projection for accepting a final instruction, and if the detection result indicates that the detection light of the final light projection is blocked, the light projection adjustment unit 9. Optical sensor according to any one of the preceding claims, for determining the direction of light. The plurality of specific directions are set for each of a plurality of discrete points defined to cover at least a part of the range adjustable by the optical axis adjustment element,
2. The light projection adjusting unit recognizes a specific direction in which a detection result evaluated that the detected light is blocked at the closest point is obtained as the designated direction, and determines the projected light direction as the designated direction. Optical sensor as described. an optical axis adjusting element for adjusting an optical axis of the detection light projected from the light emitting element; and receiving the detection light reflected by the object to generate a detection signal. A control method for an optical sensor comprising a light receiving element that outputs
a light projecting step of sequentially projecting the detection light in a plurality of preset specific directions by driving the optical axis adjustment element;
Among the detection results based on the detection signals obtained by projecting light in each of the plurality of specific directions in the light projecting step, a specific direction in which a detection result evaluated to indicate that the detection light is blocked is defined as a pointing direction. a recognition step of recognizing;
and an adjusting step of adjusting a projection direction of the detection light projected for inspecting the inspection target based on the pointing direction recognized in the recognition step. an optical axis adjusting element for adjusting an optical axis of the detection light projected from the light emitting element; and receiving the detection light reflected by the object to generate a detection signal. A control program for an optical sensor comprising a light receiving element that outputs,
a light projecting step of sequentially projecting the detection light in a plurality of preset specific directions by driving the optical axis adjustment element;
Among the detection results based on the detection signals obtained by projecting light in each of the plurality of specific directions in the light projecting step, a specific direction in which a detection result evaluated to indicate that the detection light is blocked is defined as a pointing direction. a recognition step of recognizing;
A control program for an optical sensor that causes a computer to execute an adjustment step of adjusting the projection direction of the detection light projected for inspection of the inspection target based on the pointing direction recognized in the recognition step.

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