Fastening tool, fastening method and multi-optical axis photoelectric sensor

Abstract

The ease of optical axis alignment is improved when a light curtain is attached to a mounting tool. The mounting tool is a component for attaching a light curtain housing to a base, with the housing forming a plurality of optical axes along a longitudinal direction. The housing includes a side wall section that is essentially parallel to the optical axes in cross-sectional view and orthogonal to the longitudinal direction.The fastening tool comprises a base part that is attached to the base and receives the housing from a front side, a temporary fastening part that temporarily secures the housing to the base part by elastic support, and a complete fastening element that fully fixes a rotational position of the housing about an axis and an upper-lower position in the longitudinal direction by pressing the housing in a state where it is temporarily attached to the base part. The base part includes rotation limiting elements that bear against the side wall section of the housing to restrict the rotation of the housing about the axis within a confined range in a state where the housing is temporarily attached to the base part.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The invention relates to a fastening tool, a fastening method and a multi-optical-axis photoelectric sensor. 2. Description of the state of the art

[0002] A light curtain is an aspect of a multi-optical-axis photoelectric sensor. The light curtain detects a person or object depending on whether a multitude of optical axes formed between a light emitter and a light receiver are blocked.

[0003] The light curtain is attached to a base (base column) using a mounting tool. The main functions of the mounting tool are to adjust the optical axes between the light source and the light receiver to obtain the desired amount of light in all optical axes, and to secure the light curtain so that it does not shift due to impact or similar hazards.

[0004] Note that in the optical axis alignment described above, the up-and-down movement of the light curtain along a longitudinal direction (axis direction) and the rotation of the light curtain around the axis are performed separately. As a general procedure, the light curtain is first positioned in an up-and-down direction relative to the mounting tool, and then the light curtain is temporarily attached to the mounting tool in the set up-and-down position.

[0005] Subsequently, after the rotational position of the light curtain around the axis has been set, the light curtain is fully fixed to the mounting tool in the set rotational position.

[0006] In addition, there is a state-of-the-art fastening tool that attaches the housing of a light curtain to the fastening tool by means of a screw fastening.

[0007] For example, in a multi-optical-axis photoelectric sensor JP2003-242868A, the upper-lower position of a light curtain can be adjusted by loosening a first bolt, and the upper-lower position of the light curtain is fixed by tightening the first bolt. Furthermore, the rotational position of the light curtain around an axis can be adjusted by tightening a second bolt, and the rotational position of the light curtain around the axis is fixed by loosening the second bolt.

[0008] With the state-of-the-art fastening tool described above, it is easy to use a metal part, thus simplifying the securing force. However, since a variety of screw fastening operations are required, it is difficult to say that its usability is high. For example, it is not easy to adjust the optical axis of the light curtain while switching back and forth between adjusting the upper-lower position and the rotation position with the state-of-the-art fastening tool.

[0009] In particular, with the prior art fastening tool described above, once the second screw is loosened, the housing of the light curtain can rotate freely around its axis. Therefore, adjusting the optical axis can be very difficult for an inexperienced operator.

[0010] Note that some prior art fastening tools have a cylindrical surface with a slightly smaller diameter than a columnar light curtain and temporarily secure the light curtain, which is fitted (inserted) into the cylindrical surface, by means of elastic support. With this configuration, it is easy to temporarily secure the light curtain, and it is also easy to switch between adjusting the upper-lower position and the rotational position. However, since it is difficult to assume a metal part, it is difficult to ensure a secure fastening force. Furthermore, since the rotational movement around the axis is not limited, it is not easy to adjust the rotational position. BRIEF SUMMARY OF THE INVENTION

[0011] In view of the problems mentioned above, one objective of the invention is to improve the simplicity of optical axis alignment when a light curtain is attached to a mounting tool.

[0012] A fastening tool according to the invention is, for example, a fastening tool for attaching a housing of a light curtain to a base, wherein the light curtain forms a plurality of optical axes along a longitudinal direction, wherein the housing has a side wall section which, in cross-sectional view, is orthogonal to the longitudinal direction and substantially parallel to the optical axes, wherein the fastening tool comprises a base part with a rear surface or a side surface attached to the base and configured to receive the housing from a front, temporary fastening elements configured to temporarily fasten the housing to the base part by elastic support, and a complete fastening element configured to establish a rotational position of the housing about an axis and an upper-lower position in the longitudinal direction by pressing the housing in a state.to fully fix the housing when it is temporarily attached to the base part. The base part includes rotation limiting elements that restrict the rotation of the housing around its axis to a predetermined range by bearing against the side wall section of the housing when the housing is temporarily attached to the base part.

[0013] Please note that other features, elements, steps, benefits and characteristics will be more clearly evident from the following detailed description and the accompanying drawings.

[0014] According to the invention, when the housing of the light curtain is temporarily attached to the mounting tool, the rotation angle of the housing about the axis is limited to a predetermined range by the rotation limiting section. Accordingly, the user can adjust the optical axis about the axis of the light curtain within this range, thus facilitating optical axis alignment. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a diagram illustrating a schematic configuration of a light curtain; Fig. Figure 2 is a perspective view illustrating the overall configuration of a light source; Fig. Figure 3 is a front view illustrating the overall configuration of the light emitter; Fig. Figure 4 is a perspective view illustrating one end of the light source; Fig. 5 is a functional block diagram of the light curtain; Fig. Figure 6 is a diagram illustrating a first embodiment of the light emitter; Fig. 7 is a diagram illustrating an example arrangement of indicator lamp sources according to the first embodiment; Fig. Figure 8 is a diagram illustrating a relationship between a light emission color and an operating mode; Fig. 9 is a diagram illustrating an arrangement example of indicator lamp sources according to a second embodiment; Fig. 10 is a diagram illustrating a display pattern example according to the second embodiment; Fig. 11 is a diagram illustrating an arrangement example and a display pattern example of indicator lamp sources according to a third embodiment; Fig. 12 is a diagram illustrating an arrangement example and a display pattern example of indicator lamp sources according to a fourth embodiment; Fig. Figure 13 is a diagram illustrating a relationship between an average amount of light received and a display pattern; Fig. Figure 14 is a diagram illustrating a relationship between a minimum amount of light received and a display pattern; Fig. 15 is a diagram illustrating an illuminated image (first example) of a light curtain; Fig. Figure 16 is a diagram illustrating an illuminated image (second example) of a light curtain; Fig. Figure 17 is a functional block diagram of a light curtain with a display pattern control function; Fig. 18 is a diagram illustrating a processing flow of the display pattern control; Fig. Figure 19 is a perspective view illustrating a resin-type fastening tool; Fig. Figure 20 is a four-view diagram illustrating the resin-type fastening tool; Fig. 21 is a diagram illustrating a scene in which a resin-type fastening tool is attached to a base; Fig. 22 is a diagram illustrating a scene in which a housing is attached to the resin-type fastening tool; Fig. Figure 23 is a cross-sectional view illustrating an external shape of the housing; Fig. Figure 24 is a cross-sectional view illustrating a scene in which the casing is attached to the front; Fig. Figure 25 is a cross-sectional view illustrating a scene in which the rotation of the casing is restricted; Fig. Figure 26 is a perspective view illustrating a metal-type fastening tool; Fig. Figure 27 is a four-view diagram illustrating the metal-type fastening tool; Fig. 28 is a diagram illustrating a scene in which the metal-type fastening tool is attached to the base; and Fig. Figure 29 is a diagram illustrating a scene in which the housing is attached to the metal-type fastening tool. DETAILED DESCRIPTION OF PREFERRED EXECUTION FORMS <lichtvorhang>

[0015] Fig. Figure 1 is a diagram illustrating a schematic configuration of a light curtain. The light curtain 1 of the present configuration example is an aspect of a multi-optical-axis photoelectric sensor and generally comprises a pair of a light transmitter 100 and a light receiver 200.

[0016] The light curtain 1 detects a person or object depending on whether at least one of a plurality of optical axes (six optical axes Oax1 to Oax6 in this drawing), which are formed at intervals between the light transmitter 100 and the light receiver 200, which are arranged in parallel, is blocked. For example, the light curtain 1 is provided at an entrance or the like of a hazardous area in which a hazard source such as a press is located and can be used as a safety device to detect the intrusion or presence of a worker.

[0017] The projector 100 and the light receiver 200 each include extended (up to 2 m or more) housings 110 and 210 and associated cables 120 and 220.

[0018] The housing 110 comprises a hollow metal housing 111 extending in a longitudinal direction and hollow end caps 112 and 113 (corresponding to end pieces), each connected to both ends of the metal housing 111. Similarly, the housing 210 comprises a hollow metal housing 211 extending in a longitudinal direction and hollow end caps 212 and 213 (corresponding to end pieces), each connected to both ends of the metal housing 211. In the present embodiment, the longitudinal direction is a direction that is substantially parallel to a direction in which the plurality of optical axes formed between the light emitter 100 and the light receiver 200 are spaced apart.

[0019] As described above, if the metal housings 111 and 211 are assumed to have high stiffness as the housings for housings 110 and 210, the extended housings 110 and 210 are less likely to deform. Accordingly, adjusting the arrangement (for example, adjusting the angle for the parallel arrangement of both housings) of the light transmitter 100 and the light receiver 200 becomes relatively simple. Note that, for example, a cost-effective and lightweight aluminum extrusion product can be used as the metal housings 111 and 211. In this case, the metal housings 111 and 211 all have the same cross-section, regardless of where the metal housings are cut in an extrusion direction (= longitudinal direction).

[0020] Each of the end caps 112, 113, 212, and 213 can be formed by injection molding using a resin material or by die casting using a metal material such as zinc. Note that interfaces with cables 120 and 220 can be mounted on the underside of end caps 113 and 213 in this drawing. Therefore, end caps 113 and 213 can be larger than end caps 112 and 212 in this drawing. <lichtsender>

[0021] Fig. 2 and Fig. Figure 3 shows a perspective view and a front view, illustrating the overall configuration of the light transmitter 100. Furthermore, Fig. 4 a perspective view illustrating one end of light transmitter 100.

[0022] As described above, the light projector 100 comprises the housing 110 and the cable 120. Furthermore, the housing 110 includes the metal housing 111 and the end caps 112 and 113. The light projector 100 also includes a front cover 130, indicator lamps 140, and bumpers 150.

[0023] The front cover 130 is an elongated translucent plate attached to cover a front opening (detection window) of the housing 110. Light projection elements 161 to 166 are arranged at equal intervals along a longitudinal direction in the front opening of the housing 110 to form the plurality of optical axes Oax1 to Oax6. That is, the front cover 130 is attached to the housing 110 to intersect the plurality of optical axes Oax1 to Oax6. The front cover 130 can be an extruded translucent resin plate (acrylic plate or similar) or a glass plate.The translucent properties of the element used as the front cover 130 in the present embodiment relate to translucency such that light rays from the light projection elements 161 to 166, which form the plurality of optical axes Oax1 to Oax6, are not excessively scattered from the optical axes and are received by light receiving elements 261 to 266, to be described later, with a certain amount of light or more. As described above, since the translucent element is used for the front cover 130, a worker can visually detect the light projection elements 161 to 166 through the front cover 130.

[0024] Note that the light projection element (the light projection element 166 in Fig. 3), which corresponds to at least one optical axis among the plurality of optical axes Oax1 to Oax6, can be arranged in the end cap 113. That is, the light projection elements 161 to 166 can be arranged at equal intervals longitudinally over the entire area from one end to the other of the light transmitter 100. In addition, the cable 120 can originate from a rear (or side) surface of the end cap 113 instead of from a bottom surface of the end cap 113. With such a configuration, the light transmitter 100 can be installed close to an installation surface (floor surface or the like). Accordingly, a dead space-free design can be achieved.

[0025] The indicator lamps 140 are controlled to be switched on or off with a light emission color that corresponds, for example, to an operating state of the light curtain 1 (an optical axis detection state, a self-diagnostic result, or the like) or to a work instruction regarding the insertion and removal of an object. That is, the indicator lamp 140 functions as an operating indicator light or as a work instruction light. Accordingly, the worker can visually recognize the operating state or work instruction of the light curtain 1 by looking at the indicator lamps 140 of the light curtain 1.

[0026] In particular, the indicator lamps 140 are arranged outwards from an outer surface of at least one of the front cover 130 and the housing 110 along a longitudinal direction, or are formed in series with the front cover 130 (details of the structure are described later). Referring to this drawing, the indicator lamps 140 are provided on both sides of the front cover 130. With the indicator lamps 140 arranged or formed in this way, it is possible to provide a clearly visible display without compromising the rigidity of the housing 110. More precisely, the indicator lamp 140 is an elongated extruded product and is arranged such that its longitudinal direction runs parallel to the longitudinal direction of the housing 110.Note that the indicator lamps 140 can be arranged along the longitudinal direction of the housing 110, and that a manufacturing method for this is not limited to extrusion, and that the shape of the indicator lamp 140 need not be elongated. For example, a variety of elements functioning as the indicator lamps 140 can be arranged along the longitudinal direction of the housing 110.

[0027] Furthermore, the indicator lamp 140 is a light-diffusing element that scatters incident light from an indicator lamp source 170 (not shown), which is housed inside the casing 110, in various directions. More precisely, the indicator lamp 140 contains a light-diffusing element that scatters light in different directions. In the configuration where the light-diffusing element, as the indicator lamp 140, contains the light-diffusing element, a clearly visible display can be achieved even when the number of indicator lamp light sources 170 is small relative to the surface area of ​​the indicator lamp 140, because the indicator lamp 140 can be illuminated relatively uniformly. In the present embodiment, the indicator lamp 140 is milky white because it is made of a transparent resin to which fine particles have been added.In a case where a base resin is not transparent but has a specific color, the specific color is mixed with a milky white resin. In a case where the indicator lamp 140 is made of a milky white resin (silicone or the like), in addition to the configuration in which the light-diffusing element contains the light-diffusing body, it is possible to achieve a relatively uniform illumination of the indicator lamp 140. The light-diffusing element, in the case of the indicator lamp 140, can be an element that scatters the light from the indicator lamp source 170 in such a way that the light can be visually detected from more directions, or an element that scatters the light from the indicator lamp source 170 to such an extent that it is difficult to visually discern a contour of the indicator lamp source 170 from the outside of the indicator lamp 140.For example, a light-diffusing element with a machined surface for diffusing light from the indicator lamp source 170 (indicator lamp 140) can be arranged. For example, embossing is a known surface treatment for diffusing light. In the configuration where the light-diffusing element with the machined surface is arranged as the indicator lamp 140, it is easy to manufacture such an element if it contains an area where light is relatively easily scattered and an area where light is relatively less easily scattered.

[0028] The bumpers 150 protrude outwards from an area of ​​the outer surface of the front cover 130, which intersects the plurality of optical axes Oax1 to Oax6, and are arranged along the longitudinal direction of the housing 110 (details of a structure will be described later).

[0029] Referring to this drawing, a pair of bumpers 150 are designed to project from both sides of the front cover 130. That is, the front cover 130 is arranged in a narrow valley that is wedged between the pair of bumpers 150 (twin bumpers proposed by the applicant of the present application), which are positioned on either side of it and project forward. Thus, even if the object collides with a front face of the light emitter 100, the impact is absorbed by the bumpers 150. Accordingly, the front cover 130 is less likely to be damaged. Note that the bumper 150 can be made of a hard material such as metal.

[0030] Furthermore, a configuration of the light receiver 200 is essentially similar to a configuration of the light transmitter 100. Accordingly, the description of Fig. Sections 2 to 4 describe the configuration of the light receiver 200 by reading the light transmitter 100 and the light projection elements 161 to 166 in conjunction with the light receiver 200 and the light receiving elements 261 to 266, respectively, and by replacing the reference numerals in other 100 series with corresponding reference numerals in 200 series. The same applies to the following description.

[0031] Fig. Figure 5 is a functional block diagram of the light curtain 1. In the light curtain 1 of the present configuration example, the light transmitter 100 comprises the indicator lamps 140, the light projection elements 161 to 166, the indicator lamp source 170, a control circuit 181 and a communication circuit 182.

[0032] The light projection elements 161 to 166 are arranged at equal intervals with a predetermined spacing along the longitudinal direction of the light source 100. The light projection elements 161 to 166 sequentially project a plurality of light beams to form the plurality of optical axes Oax1 to Oax6 in the direction of the light receiver 200 (in particular the light receiving elements 261 to 266) in a time-division multiplexing procedure based on a light projection control signal input by the control circuit 181. Note that the light projection elements 161 to 166 can, for example, be light-emitting diodes emitting infrared light beams.

[0033] The indicator lamp source 170 supplies light to the indicator lamps 140 based on a display control signal input from the control circuit 181. The indicator lamp source 170 can be switched between a variety of light emission colors (for example, red, green, and orange) in accordance with the operating state of the light curtain 1, the work instructions, or the like.

[0034] Note that the indicator lamp source 170 can be switched on in pulses at a time offset from a light projection or light reception time of each of the plurality of optical axes Oax1 to Oax6. According to such switch-on or switch-off control, interference with the detection of the optical axis by the indicator lamp source 170 can be suppressed.

[0035] The indicator lamp 140 diffuses light that enters from the indicator lamp source 170 in various directions. The worker can visually recognize the operating status of the light curtain 1, the work instructions, or similar information by looking at the indicator lamps 140.

[0036] In response to an instruction from the light receiver 200, the control circuit 181 generates the light projection control signal to sequentially drive the light projection elements 161 to 166 using time-division multiplexing. Furthermore, the control circuit 181 generates the display control signal to switch the display lamp source 170 on or off in each light emission color. The control circuit 181 also exchanges various types of information with the communication circuit 182.

[0037] The communication circuit 182 performs wired or wireless communication with the light receiver 200 (in particular the communication circuit 282). For example, the communication circuit 182 receives input information regarding the operating state (an optical axis detection state, a self-diagnostic result, and the like) of the light curtain 1 from the light receiver 200 and transmits the information to the control circuit 181.

[0038] On the other hand, the light receiver 200 comprises an indicator lamp 240, light receiving elements 261 to 266, an indicator lamp source 270, a control circuit 281, a communication circuit 282, an output circuit 283 and an input circuit 284.

[0039] The light receiving elements 261 to 266 are arranged at equal intervals along the longitudinal direction of the light receiver 200, with the same spacing as the light projection elements 161 to 166. The light receiving elements 261 to 266 sequentially receive multiple light beams to form multiple optical axes Oax1 to Oax6 in a time-division multiplexing procedure based on a light receiving control signal input from the control circuit 281. Note that the light receiving elements 261 to 266 can be, for example, photodiodes or phototransistors that output electrical signals corresponding to a received amount of infrared light.

[0040] The indicator lamp source 270 provides light for display in the direction of the indicator lamp 240 based on a display control signal input from the control circuit 281. Similar to the indicator lamp source 170, the indicator lamp source 270 can be switched between a variety of light emission colors (for example, red, green, and orange), in accordance with the operating state of the light curtain 1, the work instructions, or the like.

[0041] Note that the indicator lamp source 270 can be switched on in pulses at a time offset from the light projection or light reception time of each of the plurality of optical axes Oax1 to Oax6. According to such switch-on or switch-off control, interference with the detection of the optical axis by the indicator lamp source 270 can be suppressed.

[0042] Additionally, a case is considered in which the indicator lamp source 270 is continuously switched on. In this case, it is desirable to provide a saturation prevention circuit (= a subtraction circuit for a DC component) so that the electrical signals output by the light receiving elements 261 to 266 are not saturated, even when DC light from the indicator lamp source 270 is received by the light receiving elements 261 to 266.

[0043] The indicator lamp 240 scatters light incident from the indicator lamp source 270 in various directions. The worker can visually recognize the operating status of the light curtain 1, the work instructions, or the like by looking at the indicator lamp 240.

[0044] Furthermore, since the indicator lamps 140 and 240 are each provided on both the light transmitter 100 and the light receiver 200, a clearly visible display can be carried out.

[0045] Control circuit 281 generates the light reception control signal to sequentially activate the light receiving elements 261 to 266 in a time-division multiplexing procedure, synchronized with the activation time of each of the light projection elements 161 to 166. Furthermore, control circuit 281 generates the display control signal to switch the display lamp source 270 on or off in each light emission color. Control circuit 281 also exchanges various types of information with communication circuit 282, output circuit 283, and input circuit 284.

[0046] Furthermore, the control circuit 281 monitors the light incidence or light shielding state of each of the plurality of optical axes Oax1 to Oax6. For example, the control circuit 281 can output an operating permit signal (ON signal) when all of the plurality of optical axes Oax1 to Oax6 are in the light incidence state. Conversely, the control circuit 281 can output an operating denial signal (OFF signal) when at least one of the plurality of optical axes Oax1 to Oax6 is in the light shielding state.

[0047] Furthermore, the control circuit 281 can have a self-diagnostic function to monitor whether the light incidence or light shielding state of each of the plurality of optical axes Oax1 to Oax6 is being monitored correctly. Note that, as a self-diagnostic method, for example, the control circuit 281 and the output circuit 283 (for example, an output signal switching device [OSSD] output) can be multiplexed, and the agreement or mismatch of the multiplexed signals can be determined.

[0048] For example, if the multiplexed signals match, an OK diagnosis is made (a diagnostic result indicating that the condition can be monitored correctly). Conversely, if the multiplexed signals do not match, an NG diagnosis is made (a diagnostic result indicating that the condition cannot be monitored correctly). Note that in a case where the NG diagnosis is made, the disable signal (OFF signal) can be output regardless of the light incidence condition of each of the multiple optical axes Oax1 to Oax6.

[0049] Note that information that can be used for safety control is safety information, and general information that cannot be used for safety control is non-safety information. For example, the OSSD output is part of the safety information. The signal used to turn on or off each of the indicator lamp sources 170 and 270 can be a signal indicating safety information or a signal indicating non-safety information.

[0050] The communication circuit 282 performs wired or wireless communication with the light transmitter 100 (in particular with the communication circuit 182). For example, the communication circuit 282 receives an input of information regarding the operating state (an optical axis detection state, a self-diagnostic result, and the like) of the light curtain 1 from the control circuit 281 and transmits the information to the light transmitter 100.

[0051] Output circuit 283 performs wired or wireless communication with an external device (for example, a safety controller). For example, output circuit 283 receives an input regarding the operating status (an optical axis detection state, a self-diagnostic result, or the like) of the light curtain 1 from control circuit 281 and transmits the information to an external device.

[0052] The input circuit 284 performs wired or wireless communication with an external device (for example, a safety controller). For example, the input circuit 284 receives an input of a work instruction regarding the insertion and removal of an object from an external device and transmits the work instruction to the control circuit 281. <Erste Ausführungsform>

[0053] Fig. Figure 6 is a diagram (= a schematic sectional view, where a metal housing 111 of a light emitter 100 is cut at any position in the longitudinal direction) illustrating a first embodiment of the light emitter 100. The light emitter 100 of the present embodiment comprises a housing 110 (only one metal housing 111 is shown in this drawing), a front cover 130, indicator lamps 140, a bumper 150, an indicator lamp source 170, a substrate 190, and a light shielding plate 191.

[0054] The metal housing 111 is an extruded product extending longitudinally along the light emitter 100. With reference to this drawing, the metal housing 111 comprises a body 111a, a pair of first projecting strips 111b, and a pair of second projecting strips 111c.

[0055] Body 111a is a hollow body with a U-shaped cross-section and an opening on one upper side (= a front side of the light source 100). The indicator lamp source 170, the substrate 190, and the light shielding plate 191 are housed within the interior of body 111a.

[0056] The first pair of projecting strips 111b extends from the inner surfaces of the left and right side walls of the body 111a toward an inner side of the opening. That is, the first pair of projecting strips 111b are arranged such that they face each other at a predetermined distance and clamp an optical axis intersection region X (a region that intersects a plurality of optical axes Oax1 to Oax6). Note that the first pair of projecting strips 111b act as cover fixing elements to support the front cover 130. As described above, a translucent element is used for the front cover 130, provided that the translucent element is located at least within the optical axis intersection region X and does not interfere with the optical axes Oax1 to Oax6.For example, in the present embodiment, a part that comes into contact with the pair of first projecting strips 111b need not necessarily have light-transmitting properties.

[0057] The pair of second projecting strips 111c extends further upwards in the drawing from the upper ends of the left and right side walls of the body 111a. Furthermore, each of the pair of second projecting strips 111c has a distal end that is bent towards the inside of the opening. Note that the pair of second projecting strips 111c acts as the bumpers 150 for protecting the front cover 130. That is, in the present embodiment, the bumpers 150 described above are formed from the metal housing 111. Accordingly, the strength of the light transmitter 100 can be improved.

[0058] The front cover 130 is supported (suspended) at both ends by the pair of first projecting strips 111b. The front cover 130 allows light rays forming the plurality of optical axes Oax1 to Oax6 to pass through the optical axis intersection area X. A process to improve liquid resistance is carried out between the front cover 130 and the pair of first projecting strips 111b (see thick line α). For example, a process is carried out to accommodate a seal and fix it with a liquid-resistant adhesive. As described later, since the adhesive properties between the front cover 130 and the first projecting strips 111b are improved by the indicator lamps 140, the liquid resistance is further enhanced.

[0059] The indicator lamps 140 are arranged on both sides of the front cover 130, adjacent to the bumpers 150. Referring to this drawing, the indicator lamps 140 are arranged along the longitudinal direction of the light source 100 in areas that are clamped between the first projecting strips 111b and the distal ends (curved sections) of the second projecting strips 111c, that is, in areas that are clamped between the bumpers 150 and the front cover 130.

[0060] Note that the indicator lamp 140 scatters the light entering from the indicator lamp source 170 via the front cover 130 in various directions. For example, the indicator lamp 140 may have a taper to refract and scatter the light entering from the indicator lamp source 170 towards the inside of the opening.

[0061] With the indicator lamps 140 arranged in this way, it is easy to see even from one side of the light source 100. Accordingly, in the small-format (small-caliber) light curtain 1, which uses the metal housing 111, it is possible to implement a highly visible display without compromising the rigidity of the housing 110. In particular, in a case where the pair of bumpers 150 are designed to protrude from both sides of the front cover 130, the effect of the above arrangement on improved visibility can be more noticeable.

[0062] Furthermore, in the light transmitter 100 of the present embodiment, the indicator lamps 140 also function as pressure elements for pressing and securing the front cover 130 downwards (i.e., in one direction towards the first projecting strips 111b). Accordingly, since the adhesion properties between the front cover 130 and the first projecting strip 111b are improved, the liquid resistance can be enhanced by preventing liquid from penetrating the interior of the metal housing 111. Note that it is desirable for the indicator lamps 140 to possess sufficient elasticity to function as pressure elements.

[0063] The indicator lamp source 170 is mounted on a main surface (i.e., a surface facing the front cover 130) of the substrate 190. The indicator lamp source 170 supplies light for display in the direction of the indicator lamps 140 via the front cover 130. With reference to this drawing, the light emitted by the indicator lamp source 170 passes between the pair of first projecting strips 111b without being shielded by the pair of first projecting strips 111b and is supplied to the indicator lamps 140 via the front cover 130.

[0064] Note that the number of indicator lamp sources 170 is not limited. For example, multiple indicator lamp sources 170 can be arranged intermittently or in series along the longitudinal direction of the light source 100.

[0065] Furthermore, the indicator lamp source 170 can include a lens for controlling the direction of the emitted light. For example, a lens can be provided that is optically designed to reduce the propagation angle of the light in a left-right direction in this drawing and to increase the propagation angle of the light in a depth direction in this drawing. According to such a lens, it is possible to reduce the number of indicator lamp sources 170 while suppressing interference with the multiple optical axes Oax1 to Oax6.

[0066] Note that one type of lens can be a point-symmetric lens (single-lens arrangement) or a cylindrical lens (row arrangement by extrusion product).

[0067] The light-shielding plate 191 is provided between the indicator lamp source 170 and the optical axis intersection area X. Accordingly, since the light from the indicator lamp source 170 is shielded in the direction of the optical axis intersection area X, the light emitted by the indicator lamp source 170 is less likely to interfere with the plurality of optical axes Oax1 to Oax6.

[0069] Furthermore, a case is considered in which the optical axes Oax1 to Oax6 are formed by infrared light and visible light (red light, green light, orange light, or the like) is emitted by the indicator lamp source 170. In this case, a filter that transmits infrared light and blocks visible light can be provided in the light receiver 200.In particular, in a case where the indicator lamps 240 are provided in the light receiver 200, a filter that transmits infrared light and blocks visible light can be arranged so that it does not block the display of the indicator lamps 240. Filters can be provided in the light receiving elements 261 to 266, or a filter can be provided in a lens that directs light to the light receiving elements 261 to 266.

[0068] Fig. Figure 7 is a diagram illustrating an example arrangement of the indicator lamp sources 170 according to the first embodiment. As shown in this drawing, the light projection elements 161 to 166 can be arranged at equal intervals along a longitudinal direction of the substrate 190 in a central region 190a of the substrate 190. Alternatively, the indicator lamp sources 170 can be arranged at equal intervals along the longitudinal direction of the substrate 190 in an end region 190b of the substrate 190.

[0069] In particular, the light projection elements 161 to 166 and the indicator lamp sources 170 can be arranged such that their positions are offset from one another in the longitudinal direction of the substrate 190 (staggered). According to such an arrangement, mutual interference between the light projection elements 161 to 166 and the indicator lamp sources 170 is suppressed.

[0070] Note that the number and arrangement of the indicator lamp sources 170 are not limited to the arrangement example in this drawing. For example, the number of indicator lamp sources 170 can be reduced so that the light beams supplied to the indicator lamps 140 exhibit some unevenness. <anzeigeinhalt>

[0071] Fig. Figure 8 is a diagram illustrating the relationship between the light emission color of indicator lamp 140 and an operating mode. As shown in this diagram, indicator lamp 140 can be switched to any of the operating indicator lamp modes and work instruction lamp modes. For example, a control signal for switching the operating mode of indicator lamp 140 could be a 2-bit (four values) digital signal input into input circuit 284.

[0072] First, a case is described in which the indicator lamp 140 is set to the operating indicator lamp mode. When the operating indicator lamp mode is set, the indicator lamp 140 is controlled to be switched on or off with a light emission color corresponding to the operating state of the light curtain 1.

[0073] Referring to this diagram, for example, when the light curtain 1 is in a normal state (for example, a state in which all of the plurality of optical axes Oax1 to Oax6 are not shielded), the indicator lamp 140 is illuminated in green. Conversely, when the light curtain 1 is in an abnormal state (for example, an emergency stop state in which at least one of the plurality of optical axes Oax1 to Oax6 is shielded), the indicator lamp 140 is illuminated in red. Furthermore, the indicator lamp 140 flashes red when the light curtain 1 is in an alarm notification state (for example, an NG diagnostic state triggered by a self-diagnostic function).

[0074] Next, a case is described in which the indicator lamp 140 is set to the work instruction lamp mode. When the work instruction lamp mode is set, the indicator lamp 140 is controlled to turn on or off with a light emission color that corresponds to the work instruction signal received by the input circuit 284.

[0075] Regarding this diagram, for example, when the work instruction signal indicates a "work permission" state, indicator lamp 140 illuminates green. Conversely, when the work instruction signal indicates a "work refusal" state, indicator lamp 140 illuminates red. Additionally, when the work instruction signal indicates "self-diagnosis," indicator lamp 140 flashes red. Note that in work instruction lamp mode, indicator lamp 140 may illuminate orange. The method for using an illuminated state may vary depending on the user.

[0076] Furthermore, in a case where the light curtain 1 is used in an environment where the light emission of the indicator lamp 140 is not desirable, the indicator lamp 140 can be permanently switched off. <Betrachtung zur Reduzierung der Lichtempfangsmenge auf der optischen Achse>

[0077] As described above, the light curtain comprises two light emitters and one light receiver, and the multiple light projection and receiving elements are arranged along a single axis. When using the light curtain, the light emitters and receivers are positioned parallel to each other, and an angle is adjusted to ensure that a sufficient amount of light passes through all elements. The greater the distance between the light emitters and receivers, the more difficult it is to determine if the alignment is correct, and the more difficult it is to see the display. Therefore, adjusting the angle is challenging.

[0078] The light curtain can be used in harsh environments, such as those exposed to dirt or impacts. Therefore, a bumper-shaped cover protrudes from the front of the detection unit to protect it. However, preventing dirt from accumulating on the front cover is challenging. If dirt accumulates and the light-receiving elements cannot receive sufficient light, the optical axis is in a light-shielding state, and there is a possibility that the device's activation will be blocked by the light curtain's safety output. Therefore, regular maintenance to clean the front cover's glass surface is necessary to prevent any impact on the optical axis's detection performance.

[0079] In environments where dirt accumulates, the light curtain must be installed to ensure a certain level of light reception on the optical axis, with a margin to compensate for a decrease in light reception due to dirt (i.e., a light reception level for each optical axis that serves as a criterion for determining whether the optical axis is in the light-shielding state or not). Furthermore, maintenance is required before the optical axis enters the light-shielding state by verifying a decrease in light reception over time.

[0080] In response to the aforementioned requirements, a model exists that can confirm the amount of light received along the optical axis by the body of the light curtain. For example, in one existing model, the magnitude of the light received along the optical axis is expressed by the number of a multitude of illuminated light-emitting diodes (LEDs) or by a seven-segment display. However, these displays are small and difficult to read from a distance. Therefore, it can be difficult to verify the display when setting up the light curtain. Furthermore, even during operation of the light curtain, it is difficult to notice a decrease in the amount of light received along the optical axis unless the small display described above is considered and confirmed.

[0081] On the other hand, large-format indicator lamps 140 and 240 are provided in the light curtain 1, which has been described so far in the present specification, so that an activation state of the light curtain 1 can be easily visually recognized, while both size reduction and high visibility are achieved.

[0082] In view of the above considerations, a novel embodiment is proposed below in which a display which is locked with the amount of light received on the optical axis can be carried out with high visibility by the indicator lamps 140 and 240. <Zweite Ausführungsform>

[0083] Fig. Figure 9 is a diagram illustrating an example arrangement of an indicator lamp source according to a second embodiment. In the present embodiment, several (two in this drawing) substrates 190 with identical structure are cascaded along a longitudinal direction. With such a configuration, a light curtain 1 can be easily extended by simply increasing the number of cascades of the substrates 190.

[0084] In this drawing, which illustrates a light transmitter 100, light projection elements 161 to 166 can be arranged at equal intervals along the longitudinal direction of the substrate 190 in a central area 190a of the substrate 190, similar to the one described above. Fig. 7. Referring to this drawing, the light projection elements 161 to 163 are arranged on the substrate 190 on a right-hand side of the drawing in a sequence shown, from right-hand to left-hand side. Conversely, on the substrate 190 on a left-hand side of the drawing, the light projection elements 164 to 166 are arranged in a sequence shown, from right-hand to left-hand side. Note that if a configuration of a light receiver 200 is understood, each of the light projection elements 161 to 166 can be read as light receiving elements 261 to 266.

[0085] On the other hand, the indicator lamp light sources 170 can be arranged at equal intervals along the longitudinal direction of the substrate 190 in an end region 190b of the substrate 190. In particular, the indicator lamp light sources 170 can be distinguished as indicator lamp light sources 170a, 170b, and 170c, depending on the difference in each control system. With reference to this drawing, the indicator lamp light sources 170a, 170b, and 170c are arranged on two substrates 190 in the sequence shown, from left to right of the drawing. Note that, although not shown in this drawing, the light curtain 1 includes an OSSD indicator lamp whose display aspect changes according to an OSSD output, separate from the indicator lamp source 170. Thus, the display aspect of the indicator lamp source 170 changes to indicate light receiving states of the light receiving elements 261 to 266.

[0086] As described above, the light projection elements 161 to 163 (or 164 to 166) and the indicator lamp sources 170a, 170b and 170c are arranged as a single unit on the common substrate 190. In particular, the indicator lamp sources 170a, 170b and 170c are unified as a set of three light sources.

[0087] Note that, as a modification, the light projection elements 161 to 163 (or 164 to 166) and the control lamp light sources 170a, 170b and 170c can be separate units. That is, a unit in which the light projection elements 161 to 163 (or 164 to 166) are arranged and a unit in which the control lamp light sources 170a, 170b and 170c are arranged can be independent of each other.

[0088] Fig. Figure 10 is a diagram illustrating a display pattern example according to the second embodiment. In the upper part of this drawing, an "on state" is shown. In this "on state," the indicator lamp sources 170a are switched on, and both the indicator lamp sources 170b and 170c are switched off. Accordingly, a display pattern is obtained in which "one on, two off" is repeated from the left to the right side of the drawing.

[0089] In the central part of this drawing, an "off-on state" is depicted. In this "off-on state," both indicator lamp sources 170a and 170b are switched on, and indicator lamp source 170c is switched off. Accordingly, a display pattern is obtained in which "switching on two, switching off one" is repeated from the left to the right side of the drawing.

[0090] The lower part of this drawing shows an "ABC-on state". In this "ABC-on state", all indicator lamp sources 170a, 170b and 170c are switched on.

[0091] As described above, in a display pattern example according to the present embodiment, the indicator lamp sources 170a, 170b, and 170c are switched on intermittently. Accordingly, the display pattern is switched to one of the three patterns mentioned above based on the amount of light received on the optical axis, and thus the amount of light received on the optical axis can only be distinguished by observing the large indicator lamps 140 and 240. As a result, the light curtain 1 is provided, which can be easily adjusted at the time of initial setup and exhibits high maintainability. <Dritte Ausführungsform>

[0092] Fig. Figure 11 is a diagram illustrating an arrangement example and a display pattern example of indicator lamp sources according to a third embodiment. In the present embodiment, two indicator lamp sources 170a, two indicator lamp sources 170b, and two indicator lamp sources 170c are arranged as a single unit on a common substrate 190. That is, the indicator lamp sources 170a, 170b, and 170c are unified as a set of six light sources.

[0093] With regard to this drawing, two indicator lamp sources 170a, two indicator lamp sources 170b and two indicator lamp sources 170c are arranged on the substrate 190 in a sequence shown from a left side to a right side of the drawing.

[0094] The upper part of this drawing depicts an "on state." In this "on state," indicator lamp sources 170a are switched on, and both indicator lamp sources 170b and 170c are switched off. Accordingly, a display pattern is obtained in which "two on, four off" is repeated from the left to the right side of the drawing.

[0095] In the central part of this drawing, an "off-on state" is depicted. In this "off-on state," both indicator lamp sources 170a and 170b are switched on, and indicator lamp sources 170c are switched off. Accordingly, a display pattern is obtained in which "four on, two off" is repeated from the left to the right side of the paper surface.

[0096] The lower part of this drawing shows an "ABC-on state". In this "ABC-on state", all indicator lamp sources 170a, 170b and 170c are switched on.

[0097] Note that in the second embodiment described above ( Fig. 10) the number of indicator lamp sources 170a, 170b and 170c in a non-switched-on state (off state) is increased or decreased by one for each display pattern, such as 2, 1 and 0.

[0098] On the other hand, in the arrangement example of the indicator lamp sources and the display pattern example according to the present embodiment, the number of indicator lamp sources 170a, 170b and 170c in the off state is increased or decreased by two for each display pattern, such as 4, 2 and 0. Accordingly, in comparison with the second embodiment described above ( Fig. 10) A large difference in distance exists between the light sources to be switched on intermittently. As a result, the switching of the display pattern (and the change in the amount of light received on the optical axis) is easily detected by the light diffuser. <Vierte Ausführungsform>

[0099] Fig. Figure 12 is a diagram illustrating an arrangement example and a display pattern example of indicator lamp light sources according to a fourth embodiment. Similar to the second embodiment described above ( Fig. 10) In the present embodiment, indicator lamp light sources 170a, 170b and 170c are unified as a set of three. However, the order of the indicator lamp light sources 170a, 170b and 170c differs for each substrate 190.

[0100] Referring to this drawing, the control lamp light sources 170a, 170b, and 170c are arranged on the substrate 190 on the left side of the drawing in a sequence shown from left to right. Conversely, the control lamp light sources 170a, 170b, and 170c are arranged on the substrate 190 on the right side of this drawing in a sequence shown from right to left.

[0101] The upper part of this drawing depicts an "on state." In this "on state," indicator lamp sources 170a are switched on, and both indicator lamp sources 170b and 170c are switched off. Accordingly, a display pattern is obtained in which "switching on one, switching off four, switching on one" is repeated from the left to the right side of the drawing.

[0102] A lower part of this drawing depicts a "BC-on state". In this "BC-on state", indicator lamp source 170a is switched on, and both indicator lamp sources 170b and 170c are switched off. Accordingly, a display pattern is obtained in which "one off, four on, one off" is repeated from the left to the right side of the drawing.

[0103] As described above, in the arrangement example and the display pattern example of the indicator lamp sources according to the present embodiment, the number of indicator lamp sources 170a, 170b, and 170c in the off state is increased or decreased by two, such as 4, 2, and 0, for each display pattern, while maintaining a set of three units. Accordingly, similar to the third embodiment described above ( Fig. 11), the switching of the display pattern (and the change in the amount of light received on the optical axis) is easily detected. <Beziehung zwischen Lichtempfangsmenge auf der optischen Achse und Anzeigemuster>

[0104] Fig. Figure 13 is a diagram illustrating the relationship between the amount of light received on the optical axis (average light received) and the display pattern. The amount of light received on the optical axis is converted by an analog-to-digital converter and compared to a threshold value. An average value (= average light received) of the light received values ​​on the optical axes can be used as a criterion for determining the display pattern.

[0105] First, an ON state of the OSSD indicates a state in which a condition, namely that "the light reception levels of all optical axes are at least a first threshold," is met for the light-receiving elements 261 to 266, and the OSSD output is ON. In the present embodiment, for the sake of simplicity, a state in which the light-receiving elements 261 to 266 meet the condition and the OSSD output can be switched on is defined as the determining ON state, and the determining ON state is a state in which "the light reception levels of all optical axes are at least the first threshold." The first threshold is identical to a threshold for determining whether each individual optical axis is in the light-shielding state or not.Therefore, the average light reception in this state is high to a certain extent and cannot be low enough to be considered "complete light blocking". That is, since the light reception values ​​of all optical axes are at or above the first threshold, the average light reception cannot fall below the first threshold.

[0106] Accordingly, the "OFF" indication, when the average light reception falls below the first threshold, can be understood as an indication where the light reception elements 261 to 266 do not meet the condition that "the light reception values ​​of all optical axes correspond to or exceed the first threshold," that is, they are only in a determined OFF state. A horizontal axis is introduced in this drawing to illustrate this indication. The horizontal axis shows the result of the individual light reception determination for each optical axis (= the number of optical axes that were determined to be in the light-shielding state by individual determination of the optical axis).Note that an OFF state of the OSSD indicates a state in which the condition that "the light reception levels of all optical axes correspond to the first threshold or more" is not met for the light reception elements 261 to 266, and the OSSD output is OFF. For the sake of simplicity, in the present embodiment, a state in which the light reception elements 261 to 266 do not meet the condition that "the light reception levels of all optical axes correspond to the first threshold or more"—that is, a state in which "the light reception levels of at least one or more optical axes are below the first threshold"—is considered the determined OFF state. That is, in the determined ON state, the number of optical axes in the light-shielding state is 0. Conversely, in the determined OFF state, the number of optical axes in the light-shielding state is 1 or more.

[0107] Note that the individual determination of light reception for each optical axis is only performed in the determination-ON state (indicator color: green) and the determination-OFF state (indicator color: red). Therefore, in a flowchart described later, performing this determination is the same step as comparing the average light reception with the threshold value.

[0108] Furthermore, in the ON and OFF states, a threshold value is shifted as a criterion for switching the number of indicator lamp sources 170a, 170b, and 170c that are switched on. First, the ON state is described. As described above, the ON state is a state in which the light received by all optical axes is at or above the first threshold value. Therefore, in the ON state, threshold values ​​for switching the number of indicator lamp sources that are switched on (a fourth and a fifth threshold value in this diagram) are provided in a range where the average light received is relatively high.

[0109] Referring to this diagram, if the average light received is lower than the fourth threshold in the ON state, one green light is illuminated (= a state in which only indicator lamp 170a is illuminated in green). If the average light received is higher than the fourth threshold and lower than the fifth threshold, two green lights are illuminated (= a state in which indicator lamp sources 170a and 170b are illuminated in green). If the average light received is higher than the fifth threshold, three green lights are illuminated (= a state in which indicator lamp sources 170a, 170b, and 170c are illuminated in green). That is, as the average light received increases, the number of illuminated green lights also increases.

[0110] Note that the amount of light received on each optical axis decreases with increasing distance between the light source 100 and the light receiver 200. Although the light source 100 and the light receiver 200 are positioned parallel and can normally receive light without impurities, it is also conceivable that the amount of light received decreases simply due to an increase in the distance between the light source 100 and the light receiver 200.

[0111] If the number of indicator lamp sources 170a, 170b, and 170c that are switched on is reduced in such a situation, information regarding installation and maintenance cannot be transmitted correctly. Therefore, it is desirable to adjust the threshold to extend the range in which the number of indicator lamp sources 170a, 170b, and 170c that are switched on is 3. Referring to this drawing, in the ON state, the fifth threshold for switching the number of indicator lamp sources 170a, 170b, and 170c that are switched on is set relatively low between three and two.

[0112] Next, the off-determination state is described. Switching the display pattern in the off-determination state is useful when light transmitter 100 and light receiver 200 are installed. For example, consider a case where the installation positions of light transmitters 100 and 200 are set starting from the off state, in which the number of illuminated indicator lamp sources is 0. In this case, to capture the directional dependence of the setting (i.e., whether the installation positions are close to the correct installation positions or not), it is desirable for the display pattern to switch even if the average amount of light received increases or decreases slightly.

[0113] Thus, in the OFF state, the thresholds (the first, second, and third thresholds in this drawing) are provided for switching the number of indicator lamp sources turned on in an area where the average amount of light received is relatively low. For example, a relationship between the thresholds can be first threshold < second threshold < third threshold < fourth threshold < fifth threshold, as shown in this drawing. In the embodiment shown in this drawing, neither the first, second, nor third threshold affects the switching of the number of indicator lamp sources turned on in the ON state.

[0114] Regarding this diagram, if the average light received is lower than the first threshold in the OFF state, the state becomes the OFF state (a state in which indicator lamp sources 170a, 170b, and 170c are off), as described above. If the average light received is higher than the first threshold and lower than the second threshold, one red light is switched on (a state in which only indicator lamp source 170a is switched on in red). If the average light received is higher than the second threshold and lower than the third threshold, two red lights are switched on (a state in which indicator lamp sources 170a and 170b are switched on in red).If the average light reception is higher than the third threshold, three red lights are switched on (= a state in which the indicator lamp sources 170a, 170b and 170c are switched on in red). That is, if the average light reception increases, the number of switched-on red lights increases.

[0115] As described above, the purpose of switching the display pattern according to the amount of light received on the optical axis differs between the ON and OFF states. Specifically, it is assumed that switching the display pattern to green light in the ON state is useful for detecting dirt accumulation (maintenance requirements) after the light curtain 1 has been operating. Conversely, switching the display pattern to red light in the OFF state is useful for aligning the optical axis when the light curtain 1 is installed. Therefore, to set individually optimal thresholds for the ON and OFF states, it is desirable to shift the thresholds between these states.

[0116] Contrary to the description above, it is also advantageous to align the thresholds between the ON state and the OFF state. For example, in this diagram, from the perspective of the average light intake, "one green light is on" in the ON state and "three red lights are on (or two red lights are on)" in the OFF state are adjacent. Therefore, if the optical axis is blocked and the ON state is switched to the OFF state while maintaining the average light intake, the display pattern will change from "one green light is on" to "three red lights are on (or two with red lights on)."

[0117] This means that if one focuses solely on the number of lights illuminated, the display pattern may be switched with a feeling of unease, as the number of illuminated lights increases even though the optical axis is shielded. Therefore, if the priority is to convey the amount of light received on the optical axis in an easily understandable manner, it can be said that it is desirable to adjust the thresholds between the ON and OFF states in such a way that a reverse effect in the number of illuminated lights does not occur.

[0118] Fig. Figure 14 is a diagram illustrating the relationship between the amount of light received on the optical axis (minimum amount of light) and the display pattern. As shown in this diagram, the determining criterion for the display pattern can be a minimum value (= minimum amount of light) of the amount of light received on each optical axis.

[0119] In this case, for example, a first threshold, a second threshold, and a third threshold are defined as threshold settings. A relationship between the thresholds can be: first threshold < second threshold < third threshold.

[0120] Regarding this diagram, if the minimum light level is lower than the first threshold, three red lights are illuminated (= a state in which indicator lamp sources 170a, 170b, and 170c are illuminated in red). This state corresponds to the off-determination state. As described above, in the off-determination state, the number of illuminated red lights is fixed at three. If the minimum light level is higher than the first threshold and lower than the second threshold, one green light is illuminated (= a state in which only indicator lamp source 170a is illuminated in green). If the minimum light level is higher than the second threshold and lower than the third threshold, two green lights are illuminated (= a state in which indicator lamp sources 170a and 170b are illuminated in green).If the minimum light level is higher than the third threshold, three green lights are switched on (= a state in which indicator lamp sources 170a, 170b and 170c are switched on in green). That is, if the minimum light level increases, the number of switched-on green lights also increases.

[0121] As described above, an average value (= average amount of light received) of the amounts of light received in the optical axes can be assumed as a determining criterion for determining the display pattern, or the minimum value (= minimum amount of light received) can be assumed. <Eingeschaltetes Bild>

[0122] Fig. Figure 15 is a diagram illustrating an illuminated image (first example) of the light curtain 1. This drawing shows the second embodiment described above ( Fig. 9 and Fig. 10) as an example arrangement and display pattern of the indicator lamp sources 170a, 170b and 170c. Furthermore, the relationship between the amount of light received on the optical axis and the display pattern is based on the above with reference to Fig. The switching control described in section 13 of the display pattern was applied.

[0123] First, the operating-OFF state (four states on the left side of this diagram) is described. In a complete light-shielding state, the light curtain 1 is switched off (= a state in which the indicator lamp sources 170a, 170b, and 170c are switched off). At a low light level, one red light is switched on (= a state in which only the indicator lamp source 170a is switched on in red). At a medium light level, two red lights are switched on (= a state in which the indicator lamp sources 170a and 170b are switched on in red). At a high light level, three red lights are switched on (= a state in which the indicator lamp sources 170a, 170b, and 170c are switched on in red).

[0124] Next, the determining ON state (three states on the right side of this diagram) is described. At low light level, one green light is switched on (= a state in which only indicator lamp 170a is switched on in green). At medium light level, two green lights are switched on (= a state in which indicator lamp sources 170a and 170b are switched on in green). At high light level, three green lights are switched on (= a state in which indicator lamp sources 170a, 170b, and 170c are switched on in green).

[0125] Note that a light diffuser is positioned over each of the indicator lamp sources 170a, 170b, and 170c. Therefore, it is desirable to adjust the arrangement and display pattern of the indicator lamp sources 170a, 170b, and 170c so that the switching of the display pattern can also be detected by the light diffuser. This point is also as described above.

[0126] Fig. Figure 16 is a diagram illustrating an illuminated image (second example) of the light curtain 1. In this drawing, a bar graph of the light curtain 1 is displayed according to the amount of light received on the optical axis. Specifically, each of the three substrates 190x, 190y, and 190z, which are cascaded along the longitudinal direction of the light curtain 1 (more precisely, a group of indicator lamp sources 170 embedded therein), is controlled as an individual unit to be switched on or off.

[0127] First, the operating-OFF state (four states on the left side of this diagram) is described. In a complete light-shielding state, light curtain 1 is switched off (= a state in which substrates 190x, 190y, and 190z are switched off). At low light levels, 1 / 3 of light curtain 1 is switched on with a red bar (= only substrate 190x is switched on in red). At medium light levels, 2 / 3 of light curtain 1 is switched on with a red bar (= a state in which substrates 190x and 190y are switched on in red). At high light levels, the entire light curtain 1 (3 / 3) is switched on with a red bar (= a state in which substrates 190x, 190y, and 190z are switched on in red).

[0128] Next, the determining ON state (three states on the right side of this drawing) is described. At low light intensity, 1 / 3 of light curtain 1 is switched on with a green bar (= only substrate 190x is switched on in green). At medium light intensity, 2 / 3 of light curtain 1 is switched on with a green bar (= substrates 190x and 190y are switched on in green). At high light intensity, the entire light curtain 1 (3 / 3) is switched on with a green bar (= a state in which substrates 190x, 190y, and 190z are switched on in green).

[0129] As described above, in the activated image of the second example ( Fig. 16) The switching of the display pattern according to the amount of light received on the optical axis is easier to perceive compared to the first example described above ( Fig. 15) Note that in a case where the above-described turned-on image is realized based on the configuration in which the multiple substrates 190x, 190y and 190z are cascaded, the degree of design difficulty and cost may increase. <Modifikation des Anzeigemusters entsprechend der Lichtempfangsmenge auf der optischen Achse>

[0130] The above description illustrates a configuration where the number (specifically, the interval between interruptions) of the 170 illuminated indicator lamp sources is switched according to the amount of light received on the optical axis. However, various other modifications are conceivable.

[0131] For example, the timing of the indicator lamp 140 (e.g., whether it is constantly switched on, flashes at 1-second intervals, or flashes at 2-second intervals) can be changed in accordance with the amount of light received on the optical axis. Furthermore, the amount or color of light emitted by the indicator lamp 140 can also be changed in accordance with the amount of light received on the optical axis. In a case where these aspects are considered, it is not necessary to individually control the multiple indicator lamp sources 170 when switching the display pattern. Therefore, for example, an optical fiber can be used as the indicator lamp 140. <Funktionsblock (mit Anzeigemustersteuerfunktion)>

[0132] Fig. Figure 17 is a functional block diagram of light curtain 1 with a display pattern control function. Note that in this drawing, with reference to the above described Fig. 5, Control systems of the indicator lamp sources 170a, 170b and 170c and the indicator lamp sources 270a, 270b and 270c instead of light emission and light reception systems of the optical axes Oax1 to Oax6 are the focus.

[0133] Furthermore, according to the second embodiment described above ( Fig. 9 and Fig. 10) the indicator lamp sources 170a, 170b and 170c and the indicator lamp sources 270a, 270b and 270c arranged as a set of three in the sequence shown (in the order a, b, c, a, b and c from the top of this drawing).

[0134] Control circuit 181 controls the two indicator lamp sources 170a by means of a common control signal. The same applies to indicator lamp sources 170b and 170c. Furthermore, control circuit 281 controls the two indicator lamp sources 270a by means of a common control signal. The same applies to indicator lamp sources 270b and 270c.

[0135] Note that the light received by each of the optical axes Oax1 to Oax6 is compared with the threshold value in the control circuit 281. In this case, the control circuit 281 may contain an analog-to-digital converter that converts an analog signal output by each of the light receiving elements 261 to 266 into a digital signal. Furthermore, the control circuit 281 may contain a computation circuit that calculates an average value (= average light received) or a minimum value (= minimum light received) from the light received by each of the optical axes Oax1 to Oax6.

[0136] Control circuit 281 performs on / off control of each of the indicator lamp sources 270a, 270b, and 270c based on a comparison between the average light received (or the minimum light received) and the threshold value. Additionally, control circuit 281 transmits the comparison result to control circuit 181 via communication circuits 282 and 182. Control circuit 181 then performs on / off control of each of the indicator lamp sources 170a, 170b, and 170c based on the comparison result transmitted by control circuit 281. <verarbeitungsablauf>

[0137] Fig. Figure 18 is a diagram illustrating a processing flow of the display pattern control based on the average amount of light received. When the processing flow of this drawing is started, in step S1 the optical axis to be driven, Oax(i) (where i = 1, 2, ..., and imax(6), and an initial setting value is i = 1), is set.

[0138] In the subsequent step S2, the light projection element 161 is switched on. That is, first the light projection element 161 is switched on to form the optical axis Oax1.

[0139] In step S3, it is determined whether the amount of light received Li in the light receiving element 26i is greater than the first threshold. Note that, as described above, the first threshold corresponds to the threshold for determining whether each of the optical axes Oax1 to Oax6 is in the light-shielding state. The process then proceeds to step S4 if a "yes" determination is made. Conversely, the process proceeds to step S8 if a "no" determination is made. In step S8, the safety output (OSSD) is switched to the OFF state without waiting for the display pattern control to complete. This allows for the immediate shutdown of a hazard such as a press. Furthermore, in step S8, in addition to switching the safety output (OSSD) to the OFF state, the display aspect of the OSSD indicator lamp can be changed accordingly.Note that steps S3 and S8 are not directly related to the display pattern control. Therefore, steps S3 and S8 are represented by dashed lines in this drawing.

[0140] If a YES determination is made in step S3, the amount of light received Li is recorded in a register or the like in step S4.

[0141] In the subsequent step S5, it is determined whether the optical axis is the final optical axis (that is, i = imax(6)). The process then continues to step S6 if a "yes" determination is made. Conversely, the process returns to step S1 after incrementing the variable i by one (++i) if a "no" determination is made. Steps S1 through S5 are then repeated until a "yes" determination is made in step S5.

[0142] If a "yes" determination is made in step S5, a comparison is performed in step S6 between the average value (= average light reception quantity) or the minimum value (= minimum light reception quantity) of the light reception quantities and the multitude of threshold values. The comparison in this step was carried out with reference to the above-described Fig. 13 and Fig. 14 described. Therefore, the superfluous description is omitted.

[0143] In the subsequent step S7, the switched-on state (display pattern) of each of the indicator lamps 140 and 240 is updated according to the comparison result obtained in step S6. The process then returns to step S1, and the sequence of processing is repeated.

[0144] Note that this diagram is drawn with the understanding that in step S6, a comparison processing can be performed between the average value (= average light received quantity) of the light received quantities and the multitude of threshold values. That is, the comparison processing in step S6 is not performed for each optical axis, but after recording the light received quantities for all optical axes.

[0145] However, in a case where the comparison processing is performed between the minimum value (= minimum light received quantity) and the multitude of threshold values, step S5 can be omitted. That is, the comparison processing in step S6 can be performed sequentially for each optical axis without waiting for the light received quantities of all optical axes to be recorded.

[0146] For example, if the amount of light received by the first light receiving element 261 is the second threshold or less, it is sufficient to switch to a green light (= a state in which only the indicator lamp source 170a is switched on in green) without comparing the amount of light received by each of the other light receiving elements 262 to 266 with the threshold (see Fig. 14). Accordingly, the subsequent comparison processing can be omitted. <zusammenfassung>

[0147] In the above described Fig. In sections 9 to 18, the light curtain 1 with the function of switching the display pattern according to the amount of light received on the optical axis was proposed. Briefly, this configuration can be expressed as: “A light curtain comprising a housing with a metal casing in which an element of a pair consisting of a light-projecting element and a light-receiving element, forming a plurality of optical axes, is arranged along a longitudinal direction inside and extends in the longitudinal direction, and end pieces connected to both ends of the metal casing to form the plurality of optical axes at intervals from one another; a cover that allows light from the light projection element to pass through and is attached to the housing in such a way that it intersects the multitude of optical axes; an indicator lamp, which is a light-diffusing element, arranged outwards from an outer surface of at least one of the cover and the housing along the longitudinal direction or formed in series with the cover; and a source of indicator lamps, which is housed inside the casing and which supplies light for display in the direction of the indicator lamp, wherein, when an operating indicator lamp mode is set, the indicator lamp source performs a turn-on or turn-off control in a display pattern corresponding to a light emission color corresponding to an operating state of the light curtain and a light reception quantity of the light receiving element. <Befestigungswerkzeug (Harztyp)>

[0148] The following describes a resin-type fastening tool 2A with reference to Fig. 19 to 22 described in detail. Fig. 19 and Fig. Figure 20 is a perspective view and a four-view diagram illustrating the fastening tool 2A. Fig. Figure 21 is a diagram illustrating a scene in which the fastening tool 2A is attached to a base 3. Fig. Figure 22 is a diagram illustrating a scene in which the housing 110 of the light source 100, which forms the light curtain 1, is attached to the mounting tool 2A. In each drawing, the longitudinal direction of the light curtain 1 is the X-axis, a transverse direction is the Y-axis, and a thickness direction (depth direction) is the Z-axis. Note that in the following description, the housing 110 of the light source 100 can be read as the housing 210 of the light receiver 200.

[0149] The mounting tool 2A corresponds to a device for attaching the light curtain 1 to the base 3. As described above, the multi-optical-axis photoelectric sensor, which includes the mounting tool 2A and the light curtain 1 attached to the mounting tool 2A, can be installed on the base 3.

[0150] The fastening tool 2A comprises as its main components a base part 310, temporary fastening elements 320 and a complete fastening element 330.

[0151] The base part 310 is a plastic part with a back surface or a side surface that is attached to the base 3 and receives the housing 110 from a front. The base part 310 comprises a bottom part 311 and upright parts 312 and 313. The bottom part 311 can be formed in a rectangular shape in the xy-plane view. The upright parts 312 and 313 can be raised in a Z-axis direction from both end positions of the bottom part 311 in a Y-axis direction. The base part 310 can, for example, be formed in an essentially U-shape with a front opening in the yz-plane view.

[0152] A through-hole 311a, through which a screw passes in the Z-axis direction, is provided in the base part 311. Furthermore, a through-hole 312a, through which the screw passes in the Y-axis direction, is provided in the upright part 312. The base part 310 is screwed to the base 3 through the through-hole 311a or 312a. That is, the rear surface or the side surface of the base part 310 attached to the base 3 can be understood as the outer side surface of the base part 311 or the upright part 312. Each of the through-holes 311a and 312a can be formed in a shape in which the screw position can be arbitrarily set. For example, the through-hole 311a can be formed in an oval shape whose longitudinal direction is the Y-axis direction in the XY top view. Furthermore, the through hole 312a can be formed in an oval shape, the longitudinal direction of which is the Z-axis direction in the XZ top view.Note that multiple through holes 311a and multiple through holes 312a may be provided.

[0153] A through-hole 313a, into which a tool such as a hex key is inserted in the direction of the y-axis, can be provided in the upright part 313. The through-hole 313a can be located opposite the through-hole 312a. The through-hole 313a can be larger than the through-hole 312a. With this configuration, it is easy to screw the base part 310 to the base 3 through the through-hole 312a.

[0154] A groove 313b parallel to an X-axis direction, that is, the longitudinal direction of the light curtain 1, can be provided on the outer side surface of the upright part 313. Its technical significance will be described later.

[0155] The temporary fasteners 320 are elements that temporarily attach the housing 110 to the base part 310 by means of elastic support. The base part 310 and the temporary fasteners 320 can be molded as one-piece plastic parts. The temporary fasteners 320 can be provided at both end positions of the base part 311 in the X-axis direction. The temporary fasteners 320 can be a finger-shaped leaf spring bent along an outer contour of the housing 110 to support the housing 110 together with the base part 310 at a minimum of three points.

[0156] The complete fastening element 330 is an element that fixes a rotational position of the housing 110 about an axis and an upper-lower position in the longitudinal direction by pressing the housing 110 and the temporary fastening elements 320 inwards, in a state in which the housing 110 is temporarily attached to the base part 310. The complete fastening element 330 can be a metal part independent of the base part 310 and the temporary fastening elements 320.

[0157] The complete fastening element 330 is screwed to a front end of the upright part 312 by a screw 331 extending in the Z-axis direction. When the screw 331 is loosened, the rotational position and the upper-lower position of the housing 110 can be adjusted. Conversely, when the screw 331 is tightened, the rotational position and the upper-lower position of the housing 110 are fixed. The upright part 312 acts as a receiving element for the screw 331. Accordingly, the wall thickness of the upright part 312 in the Y-axis direction is designed to be greater than the wall thickness of the upright part 313 in the Y-axis direction. <Befestigungsarbeit (Überblick)>

[0158] Next, an overview of the installation process for the light curtain 1 using the installation tool 2A is described. First, in a first step, as described above, the following steps are taken: Fig. As shown in Figure 21, the fastening tool 2A is screwed onto the base 3. Then, in a second step, as described above, Fig. Figure 22 shows that the housing 110 is temporarily attached to the base part 310 of the fastening tool 2A. Finally, in a third step, after the rotational position of the housing 110 about the axis and the upper-lower position in the longitudinal direction have been set, the housing 110 is completely fixed to the base part 310 of the fastening tool 2A. <Gehäuse (Metallgehäuse)>

[0159] Fig. Figure 23 is a cross-sectional view illustrating the external shape of the housing 110 (specifically, the metal housing 111). Note that this drawing shows a cross-section when the housing 110 is vertically cut at any position along its length; that is, a zy cross-section orthogonal to the longitudinal direction is drawn. As shown in this drawing, the housing 110 comprises side wall sections Pa and Pb and arc sections Pc to Pf.

[0160] The side wall sections Pa and Pb are essentially parallel to the optical axis Oax in the zy-sectional view of the housing 110. The side wall sections Pa and Pb are designed to be line-symmetrical to each other with respect to the optical axis Oax. Each of the arc sections Pc to Pf forms part of a circumference C in the zy-sectional view of the housing 110. The arc sections Pc and Pd are designed to be line-symmetrical to each other with respect to the optical axis Oax. The arc sections Pe and Pf are designed to be line-symmetrical with respect to the optical axis Oax. The arc sections Pc and Pd are located in front of the side wall sections Pa and Pb, that is, on a front face of the housing 110. The arc sections Pe and Pf are located behind the side wall sections Pa and Pb, respectively, that is, on a rear face of the housing 110.

[0161] In the housing 110 of this configuration example, the housing is mounted so that it is directly gripped by the mounting tool 2A. Accordingly, it is not necessary to form a suitable mounting groove on a rear surface of the housing 110. Note that in a general configuration where the suitable mounting groove is formed in the housing 110, it is necessary to increase the strength of the rear surface portion where the suitable mounting groove is formed, and the size of the housing 110 is increased. On the other hand, in the housing 110 of this configuration example, since there is no limitation regarding the strength of the rear surface portion, the size of the housing 110 can be reduced.

[0162] Furthermore, as described above, the housing 110 of the present configuration example comprises the arc sections Pc to Pf. Accordingly, the housing 110 is rotated about the X-axis in a state where it is temporarily attached to the fastening tool 2A, and thus the rotational position of the housing 110 can be adjusted voluntarily. The fastening procedure for the housing 110 will be described in detail later.

[0163] Note that a groove 111d parallel to the X-axis direction, i.e., the longitudinal direction of the housing 110, may be provided on the outer side surface of the housing 110. Its technical significance will be described later. <Befestigungsarbeit (Details)>

[0164] Fig. Figure 24 is a cross-sectional view illustrating a scene in which the housing 110 is attached to the fastening tool 2A with the front facing forward. This drawing can be considered an α-α cross-section in the manner described above. Fig. 22 can be understood.

[0165] First, a temporary mounting of the housing 110 is described. The base part 310 and the temporary mounting elements 320 support the housing 110 at a minimum of three points. For example, in a case where the mounting tool 2A is attached to the housing 110 in a state where the optical axis Oax is parallel to the Z-axis, that is, in a state where the housing 110 is facing forward, inner surfaces of the base part 311 in the base part 310 can be supports P1 and P2. Referring to this drawing, support P1 is adjacent to the arc part Pe, and support P2 is adjacent to the arc part Pf. In addition, an inner surface of a fingertip in the temporary mounting part 320 can be an elastic support P0. Referring to this drawing, the elastic support P0 is adjacent to the arc part Pd.

[0166] The elastic support P0 elastically supports the housing 110 by pre-tensioning the arc section Pf inwards. Thus, the fastening force of the housing 110, that is, the normal force acting between the elastic support P0 and the arc section Pd, is lower than in a case where the temporary fastening element 320 does not have spring properties. Accordingly, the housing 110 is temporarily fastened in a state where its rotational position about the axis and its upper-lower position in the longitudinal direction can be adjusted by a frictional force acting between the elastic support P0 and the arc section Pd. That is, the housing 110 can be temporarily fastened without requiring screw fastening, simply by fitting it into the fastening tool 2A.

[0167] Furthermore, the base part 310 comprises rotation limiting elements P4 and P5. Each of the rotation limiting elements P4 and P5 is formed by an inner surface parallel to the X-axis direction, that is, an inner surface parallel to a front-back direction of the base part 310, below the inner surfaces of the base part 310 facing the housing 110. With reference to this drawing, the rotation limiting elements P4 and P5 can each be formed by inner surfaces of the upright parts 312 and 313, respectively. As described above, the rotation limiting elements P4 and P5 can be provided on both sides of a space for receiving the housing 110, in order to be opposite the side wall sections Pa and Pb of the housing 110.

[0168] The rotation limiting section P4 or P5 limits a rotation angle θ of the housing 110 about the X-axis to a predetermined limiting range, for example -θlim ≤ θ ≤ +θlim, by bearing against the side wall section Pa or Pb of the housing 110 in a state in which the housing 110 is temporarily attached to the base part 310.

[0169] However, if the limiting range of the rotation angle θ is too narrow, the optical axis alignment may be inadequate. Conversely, if the limiting range of the rotation angle θ is too wide, the ease of handling the optical axis alignment may be impaired. Considering such a compromise, the limiting range of the rotation angle θ can, for example, be set within ±30° (-30° ≤ θ ≤ +30°). More suitable, the limiting range may be within ±20° (-20° ≤ θ ≤ +20°). Ideally, the limiting range should be within 410° (-10° ≤ θ < +10°).

[0170] Note that in a case where the rotation angle θ lies within the restriction range, for example, in a case where θ = 0° as shown in this drawing, the rotation limiting elements P4 and P5 do not abut the side wall sections Pa and Pb of the housing 110. Such a condition can be understood as a state in which the rotation angle θ is not restricted.

[0171] Fig. Figure 25 is a cross-sectional view illustrating a scene in which the rotation of the housing 110 is limited. As shown in this drawing, when the housing 110 is rotated clockwise about the X-axis by a rotation angle θlim, that is, when θ = +θlim, the rotation limiting element P4 abuts the side wall section Pa. Consequently, the housing 110 cannot rotate further clockwise. In this state, the arc portion Pf of the housing 110 can abut not only the support P2 of the base part 310, but also the support P3. That is, the base part 310 and the temporary fasteners 320 support the housing 110 at five points: supports P1 to P3, the rotation limiting element P4, and the elastic support P0.

[0172] Furthermore, in a state where the housing 110 is rotated counterclockwise about the X-axis by the rotation angle θlim, that is, in a state where θ = -θlim (although this is not shown again), the rotation limiting element P5 abuts the side wall section Pb of the housing 110. As a result, the housing 110 cannot rotate any further counterclockwise.

[0173] Note that, as in Fig. 24 and Fig. Figure 25 shows that grooves 111d and 313b are provided parallel to the longitudinal direction of the light curtain 1, respectively, on the outer side surface of the housing 110 and the outer side surface of the upright part 313. These grooves 111d and 313b can serve as markers to identify whether the housing 110 is attached to the fastening tool 2A in a forward-facing position.

[0174] For example, as in Fig. Figure 24 shows that the worker performing the fastening work of the light curtain 1 can see at a glance that the housing 110 is opposite the fastening tool 2A by confirming that the relative positions of the grooves 111d and 313b in the Z-axis direction are the same.

[0175] Subsequently, a complete fastening operation of the housing 110 will be carried out with reference to Fig. 24 and Fig. 25. After the rotational position and the upper-lower position of the housing 110 are set, the screw 331 is tightened, thus attaching the complete fastening element 330 to the base part 310. As a result, the housing 110 is supported at least at three points by the supports P1 and P2 of the base part 310 and the complete fastening element 330, which has no spring properties. With this configuration, the housing 110 can be completely fixed by screw fastening. Accordingly, the fastening of the light curtain 1 is simplified compared to the prior art.

[0176] Note that the complete fastener 330 is preferably made of metal rather than resin. With this configuration, the complete fastener 330 is less prone to deformation during full fastening by screw fixing or when used at high temperatures. Accordingly, the fastening force of the housing 110 can be improved.

[0177] Furthermore, the temporary fasteners 320 and the full fastener 330 can be designed such that the pressing directions with respect to the housing 110 are identical. With this configuration, it is less likely that the rotational position and the upper-lower position set at the time of temporary fastening will be displaced at the time of full fastening.

[0178] In particular, the coefficient of friction of the inner surface of the base part 310 is desirablely greater than the coefficient of friction of a surface of each of the temporary fasteners 320 and the complete fastener 330. More precisely, machining to increase the coefficients of friction, for example embossing, can only be carried out on parts that can be the supports P1 to P3 and the rotation limiting elements P4 and P5 described above, that is, the inner surfaces of the bottom part 311 and the upright parts 312 and 313 in the base part 310.

[0179] With this configuration, it is less likely that the base part 310 and the housing 110 will slide, and it is more likely that the temporary fasteners 320, the full fastener 330, and the housing 110 will slide. As a result, it is less likely that the housing 110 will rotate about the X-axis while the full fastener 330 is pressed against the housing 110 by screw fastening during the full fastening operation. Accordingly, it is less likely that the rotational position set at the time of temporary fastening will shift at the time of full fastening. <Befestigungswerkzeug (Metalltyp)>

[0180] Next, a metal-type fastening tool 2B is described with reference to Fig. 26 to 29 described in detail. Fig. 26 and Fig. Figures 27 are a perspective view and a four-view illustration depicting the fastening tool 2B. Fig. Figure 28 is a diagram illustrating a scene in which the fastening tool 2B is attached to the base 3. Fig. Figure 29 is a diagram illustrating a scene in which the housing 110 of the light source 100, which forms the light curtain 1, is attached to the mounting tool 2B. In each drawing, the longitudinal direction of the light curtain 1 is an X-axis, a transverse direction is a Y-axis, and a thickness direction (depth direction) is a Z-axis.

[0181] Fastening tool 2B comprises as its main components a base part 410, temporary fasteners 420, and a complete fastener 430, similar to fastening tool 2A described above. Note that fastening tool 2B has a fundamentally similar configuration to fastening tool 2A. Therefore, in the description of fastening tool 2A above, the reference numbers in the 300 series assigned to the components of fastening tool 2A can be read as reference numbers in the 400 series to be understood as a description of fastening tool 2B. Thus, the following description primarily describes a characteristic configuration of fastening tool 2B; in other words, its differences from fastening tool 2A.

[0182] In the fastening tool 2B, not only the complete fastening element 430, but also the base part 410 and the temporary fastening elements 420 are made of metal. For example, the temporary fastening elements 420 can be metal springs. The metal fastening tool 2B is superior to the resin fastening tool 2A in heat resistance and impact resistance.

[0183] The base part 410, the temporary fasteners 420, and the complete fastener 430 can be separate metal parts. The temporary fastener 420 can be attached to the base part 410 with a screw 421. The base part can be made of aluminum, die-cast zinc, or the like. The temporary fastener 420 can be made of SUS304, phosphor bronze, or the like.

[0184] Note that with the plastic fastening tool 2A, only the bottom portion 411 of the base part 410 and the inner surfaces of the upright parts 412 and 413 can be machined to increase the coefficient of friction, for example, by shot blasting. With this configuration, the base part 410 and the housing 110 are less likely to slide, and the temporary fasteners 420, the full fastener 430, and the housing 110 are more likely to slide. As a result, the housing 110 is less likely to rotate about the X-axis, while the full fastener 430 is pressed against the housing 110 by screw fastening during the full fastening operation. Accordingly, the rotational position set at the time of temporary fastening is less likely to change at the time of full fastening.

[0185] Furthermore, one surface of the fastening tool 2B can undergo a coating treatment. This configuration can help prevent damage to the housing 110. <Andere Modifikationen>

[0186] Note that, in addition to the embodiments mentioned above, various modifications to different technical features disclosed in this specification may be made without departing from the spirit of the invention. That is to say, the embodiments mentioned above are in every respect exemplary and not limiting, and the technical scope of the invention is defined by the claims and includes all modifications that fall within the meaning and scope defined by the claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2003-242868A

[0007] < / zusammenfassung> < / verarbeitungsablauf> < / anzeigeinhalt> < / lichtsender> < / lichtvorhang>

Images