JP2012164670A - Multiple optical axis photoelectric sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiple optical axis photoelectric sensor which can make a dangerous region easily recognizable to prevent intrusion into the dangerous region.SOLUTION: A first display element 31a may be shaped like a triangle, etc. other than a rectangle. The first display element 31a may be installed in only the vicinity of opposite ends of a floodlight element 7. The first display element 31a may be formed in two or more shapes. The first display element 31a may be installed one for each floodlight element 7. The first display element 31a may be installed still closer to an edge than a floodlight element 7 at the farthest edge. The first display element 31a only needs to be installed on a center line Z1 and may have its center displaced (offset) from the center line Z1.

Description

The present invention relates to a multi-optical axis photoelectric sensor that forms a light curtain for detecting a human body or the like entering a predetermined area, and more particularly to an indicator.

In order to ensure human safety from a machine that is regarded as a danger source such as a press machine, a multi-optical axis photoelectric sensor that detects a human body or the like is frequently used in a path through which a person can enter the danger source. The multi-optical axis photoelectric sensor includes a projector having a large number of light projecting elements arranged in a row and a light receiver having a number of light receiving elements receiving a light beam from the light projecting elements arranged in a row. A light curtain is formed by a plurality of optical axis rows that divide the danger area, and when a light-blocking object enters the light curtain, the light axis is detected and the safety source is forcibly stopped to ensure safety. Therefore, a shut-off command signal for shutting off the power source of a motor or the like that drives the danger source is output.

In recent multi-optical axis photoelectric sensors, infrared light is often used as the light projecting element. In this case, the multi-optical axis photoelectric sensor has only two thin casings, and the dangerous area is difficult to understand. If the worker knows that it is a dangerous area, safety will increase.

From this point of view, a multi-optical axis photoelectric sensor has been proposed in which a plurality of display units are provided on the side surface different from the light projecting / receiving surface of the casing over almost the entire length of the light projecting / receiving device. However, in this prior art, when the casing is covered with a metal cover to protect the multi-optical axis photoelectric sensor, the indicator becomes invisible.

On the other hand, a multi-optical axis photoelectric sensor in which a display element is provided on the light projecting / receiving surface over almost the entire length of the projector is also known (Patent Document 1).

Japanese Patent Laid-Open No. 11-345548

However, in this prior art, since the display element is provided in parallel with the optical axis array of the light projecting element, the light projecting surface tends to be wide.
In addition, since the display elements are displaced from the optical axis array, it is impossible to know an accurate dangerous area.

Accordingly, an object of the present invention is to provide a multi-optical axis photoelectric sensor that makes it easy to understand the dangerous area and prevents the dangerous area from entering.

In order to achieve the above object, each of the first inventions has a casing which is long in one direction, and a plurality of optical axes are arranged in a line apart from each other from one end to the other end along the longitudinal direction of the casing. In a multi-optical axis photoelectric sensor that includes a projector and a light receiver, and detects an object according to a light incident / light-shielding state of the optical axis, it drives a light projecting element that is built in the projector and constitutes the optical axis. A light projecting circuit, a light receiving circuit built in the light receiver for processing a signal from a light receiving element constituting the optical axis, and a light receiving circuit in which all optical axes are in a light incident state based on a signal from the light receiving circuit. A state output circuit that outputs a binary signal corresponding to a first state and a second state in which at least one optical axis is in a light-blocking state, and the failure of the light projecting circuit, the light receiving circuit, and the state output circuit is diagnosed Diagnostic means, and the projector and the receiver. The device includes a first display unit including a plurality of display elements arranged at positions that do not interfere with the optical axis on the row of optical axis rows arranged in the one row, and the light projector and / or the light receiver includes: A second display unit comprising a plurality of display elements arranged at positions not interfering with the optical axis outside the optical axis array arranged in the one line, and the multi-optical axis photoelectric sensor includes the optical axis array. In order to indicate, the plurality of display elements of the first display unit are turned on in the first state, and when the diagnosis means diagnoses a failure, the plurality of display elements of the second display unit are predetermined. A display control unit for displaying the diagnosis contents by the lighting pattern.

In the first aspect of the present invention, the display elements provided on the optical axis array are turned on when the intruder is detected, that is, during the normal operation, in the first state where all the optical axes are in the incident state. For this reason, since the dangerous area is easily understood by an operator or the like, entry into the dangerous area can be prevented in advance.
Further, since the display elements of the first display section are arranged on the optical axis row, it is possible to know the dangerous area accurately and there is no possibility that the light emitting / receiving surface becomes wide.

In the first invention, the light projector and the light receiver are provided with a plurality of optical axis modules integrally including two or more optical axes, and the optical axis module is based on the number of the optical axes integrally included. Alternatively, a small number of display elements of the first display unit may be provided.
In this case, the light emitting / receiving elements and the display elements are integrated into a module, so that productivity is improved and the number of display elements in the first display section can be reduced, thereby reducing costs. Can be planned.

The first invention further includes an optical axis module integrally including at least one optical axis and a first communication line connecting the plurality of optical axis modules, and the display element of the first display unit And a plurality of display modules smaller than the number of the optical axis modules, and a second communication line connecting the plurality of display modules.
Thus, by providing a display module different from the optical axis module and providing a second communication line different from the first communication line between the optical axis modules, standardization of parts becomes easy.

In the first invention, each of the light projector and the light receiver includes a first optical axis module integrally including at least one optical axis, and at least one optical axis having a configuration different from that of the first optical axis module. And a plurality of second optical axis modules integrally connected to each other, and the first optical axis module may further include a display element of the first display unit.
In this case, since the first optical axis module on which the display element is mounted is provided in addition to the second optical axis module, the number of parts is reduced, so that productivity is improved.

Means to solve the problem:
On the other hand, the second invention has a casing that is long in one direction, and a light projector and a light receiver in which a plurality of optical axes are arranged in a line apart from each other from one end to the other end along the longitudinal direction of the casing. A multi-optical axis photoelectric sensor that detects an object according to a light incident / light-shielding state of the optical axis, and a light projecting circuit that is built in the light projector and drives a light projecting element that constitutes the optical axis; A light receiving circuit that is built in the light receiver and processes a signal from a light receiving element constituting the optical axis, and a first state in which all the optical axes are in a light incident state based on a signal from the light receiving circuit, and at least A state output circuit that outputs a binary signal corresponding to a second state in which one optical axis is in a light-blocking state, and a diagnosis unit that diagnoses a failure in the light projecting circuit, the light receiving circuit, and the state output circuit The projector and the light receiver are arranged in the row. A display unit comprising a plurality of display elements arranged at positions that do not interfere with the optical axis on the optical axis array, wherein the multi-optical axis photoelectric sensor is configured to display the optical axis array. The plurality of display elements of the display unit are turned on when in the first state, and when the diagnosis unit diagnoses a failure, the plurality of display elements of the display unit are in the first state predetermined. Has a display control unit for displaying diagnostic contents by different lighting patterns.

Effect of the invention:
In the second invention, similar to the first invention, there are advantages such as prevention of entry into the dangerous area.

Best Mode for Carrying Out the Invention:
In the second invention, the light projector and the light receiver include a plurality of optical axis modules integrally including two or more optical axes, and the optical axis module is based on the number of the optical axes integrally included. There may be few display elements of the display unit.
In this case, productivity can be improved and costs can be reduced.

In the present invention, the display elements arranged on the rows of the optical axis rows may be provided at or near both ends in the longitudinal direction of the casing.
In this case, since up to both end portions in the longitudinal direction of the casing are displayed as the dangerous area, the area is accurately recognized in the longitudinal direction.

In the present invention, display elements disposed on the optical axis array may be disposed between the both ends.
In this case, the danger area can be easily recognized.

In the present invention, the display elements disposed on the optical axis array may be disposed between the optical axes and disposed along the center line of the optical axis array.

In the present invention, the display elements arranged on the rows of the optical axis rows may be arranged at a substantially equal pitch.

In the present invention, at least one of the optical axes may be arranged closer to the end of the display element provided at both ends.
In this case, an undetectable dead space is unlikely to occur at the end portion.

In the present invention, the casing may include end casings at both ends and an intermediate casing therebetween, and display elements provided at the both ends may be provided in the end casing.
In this case, the detection area can be recognized up to the end.

In the present invention, the display element arranged on the row of the optical axis rows may be lit even when the optical axes match at the time of attachment.
In this case, since the light is turned on at the time of attachment, that is, at the time of adjusting the optical axis, the adjustment becomes easy.

In the first aspect of the present invention, the multi-optical axis photoelectric sensor is configured such that the state output circuit has at least one optical axis based on a signal from the light receiving circuit and a first state in which all the optical axes are in the incident state. A normal mode for outputting a binary signal corresponding to the second state in which the light is blocked, and a mute mode for outputting a signal corresponding to the first state regardless of the incident / shielded state of the optical axis. In the normal mode, the display control unit lights the plurality of display elements of the first display unit in the first state to indicate the optical axis array, and displays the state on the second display unit. Information indicating an output state of the output circuit, and in the mute mode, the plurality of display elements of the first display unit are turned on in the first state to indicate the optical axis array, 2 Information indicating mute mode on the display and the front Output state of the status output circuit may be displayed and information indicating.

On the other hand, in the second aspect of the invention, the multi-optical axis photoelectric sensor includes at least one of the state output circuit and the first state in which all the optical axes are in a light incident state based on a signal from the light receiving circuit. A normal mode for outputting a binary signal corresponding to the second state in which the optical axis is in a light shielding state, and a mute mode for outputting a signal corresponding to the first state regardless of the light incident / light shielding state of the optical axis. The display control unit lights the plurality of display elements of the display unit in the first state to indicate the optical axis array in the normal mode, and displays the display unit in the mute mode. Information indicating the mute mode may be displayed on the screen.

In these cases, it is easy to understand whether or not the mute mode is set.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 4 show a first embodiment.
In FIG. 2, the multi-optical axis photoelectric sensor 1 has a pair of light projectors / receivers 2 and 3, and the light projector 2 and the light receiver 3 are connected to each other via a communication line or a signal line L1. The light emitters / receivers 2 and 3 can be added in series via communication lines or signal lines, and the optical axis modules M1 are connected to each other.

In FIG. 3, the light projector 2 has an elongated casing 4, and N light projecting elements 7 are arranged in the casing 4 in a line along the longitudinal direction Z at equal intervals.

Similarly, the light receiver 3 has an elongated casing 4 in which the same number of light receiving elements 8 as the light projecting elements 7 are arranged at equal intervals in a line along the longitudinal direction Z thereof. The distance between the adjacent light receiving elements 8 is the same as the distance between the light projecting elements 7 of the projector 2.

The light projector 2 and the light receiver 3 are arranged so as to face each other on the same plane. From each light projecting element 7 of the light projector 2 toward the light receiving element 8 of the corresponding light receiver 3, for example, a light beam made of infrared rays. Is fired, a safety light curtain is formed between the projector 2 and the light receiver 3. Reference numeral 10 shown in FIG. 1 indicates an optical axis.

The light projecting element 7 is formed of, for example, a light emitting diode that emits infrared light. On the other hand, the light receiving element 8 is formed of, for example, a photodiode that receives the infrared light. A condensing lens (not shown) is provided in front of each of the light projecting element 7 and the light receiving element 8.

The light projector 2 includes N light projecting elements 7 such as the light emitting diodes, N light projecting circuits 12 that individually drive the N light projecting elements 7, and these N light projecting circuits 12. It has the element switching circuit 13 which scans by division | segmentation, and the light projection control circuit 14 which controls the light projector 2 entirely. The light projection control circuit 14 receives the clock signal from the clock generation circuit 15 and generates a light projection timing for sequentially causing the N light projecting elements 7 to emit light.

The projector 2 includes a communication control circuit 17 that controls communication with the light receiver 3, for example, transmission / reception of timing signals, and also controls communication with other additional projectors. In response to an instruction from the light receiver 3, the N light projecting circuits 12 are sequentially activated, so that the light projecting elements 7 on the first optical axis 10 to the Nth light projecting element 7 are turned on one after another. As a result, the projector 2 sequentially emits light beams from the first optical axis 10 to the Nth optical axis 10 at a predetermined projection timing toward the light receiver 3.

The light receiver 3 scans the N light receiving elements 8 such as light receiving diodes, the N light receiving circuits 18 that individually drive the N light receiving elements 8, and the N light receiving circuits 18 in a time division manner. It has an element switching circuit 19 and a light receiving control unit 20 that controls the light receiver 3 as a whole. The light receiving control unit 20 receives the clock signal from the clock generation circuit 21 and sequentially activates the N light receiving elements 8. To do.

The light receiver 3 also includes a communication control circuit 23 for controlling communication with the projector 2, for example, transmission / reception of timing signals, and for controlling communication with other additionally installed light receivers 3. The unit 20 receives the timing signal from the projector 2 and receives the light from the first light receiving element 8 so that it can capture the output from the light receiving element 8 corresponding to the light beam sequentially emitted from the projector 2. The axis 10 to the Nth optical axis 10 are sequentially activated.

Arrangement of the projector 2 and the light receiver 3:
The light projector 2 and the light receiver 3 can be arranged in various shapes with the light projector 2 and the light receiver 3 as a pair. For example, in the case of a press machine or the like, it may be provided in a U shape so as to surround the press machine, and in an object having a conveyor, it may be provided at the entrance and the exit of the conveyor.

Modules M1-M3:
As shown in FIG. 2, the projector 2 includes one or a plurality of optical axis modules M1 and one projection control module M2. The optical axis modules M1 on the light projecting side are connected to each other in series via the connector 6. One end of the connected optical axis module M1 is connected to the light projection control module M2 via the connector 6.
On the other hand, the light receiver 3 includes one or a plurality of optical axis modules M1 and one light reception control module M3. The optical axis modules M1 on the light receiving side are connected to each other in series via the connector 6. One end of the connected optical axis module M1 is connected to the light reception control module M3 via the connector 6.
The light projection control module M2 and the light reception control module M3 are each connected to the input / output unit 5 via the communication line or the signal line L1.

Optical axis module M1:
As shown in FIG. 1, the optical axis module M1 includes a first display element 31a and a first display control unit 31b for driving the first display element 31a together with the light projecting element 7 or the light receiving element 8 described above. Is provided. Therefore, the optical axis module M1 has two or more optical axes 10 integrally.
The first display element 31a is made of, for example, a light emitting diode that can selectively emit one of red and green. The number of the first display elements 31a is smaller than the number of the optical axes (in this embodiment, one first display element 31a per one optical axis module M1).

Projection control module M2:
The light projection control module M2 is a kind of the optical axis module, and in addition to the same elements and circuits as the optical axis module M1 on the light projection side, the input / output unit 5, the light projection control circuit 14, and the clock generation circuit 15 And a communication control circuit 17.

Light reception control module M3:
The light reception control module M3 is one type of the optical axis module, and in addition to the same elements and circuits as the optical axis module M1 on the light reception side, the input / output unit 5, the light reception control unit 20, the clock generation circuit 21, and communication It has a control circuit 23, and further includes a second display section 32 composed of a plurality of second display elements 32a, and a second display control section 32b that drives the second display elements 32a. The second display element 32a is made of, for example, a light emitting diode capable of selectively emitting either red or green.

In FIG. 1, for convenience of illustration, only one optical axis module M1 is shown for each of the projector 2 and the light receiver 3. However, as shown in FIGS. 2, 3, and 8, the optical axis module M1 is shown. Can be expanded arbitrarily.

Signal lines L11 to L14:
As shown in FIG. 1, the first display control unit 31b on the light projecting side is connected to each other via a signal line L11 and is also connected to the light projecting control circuit 14 of the light projecting control module M2.
The element switching circuit 13 on the light projecting side is connected to each other via the signal line L13 and is also connected to the light projecting control circuit 14.
The first display control unit 31b on the light receiving side is connected to each other via the signal line L11 and is also connected to the light receiving control unit 20 of the light receiving control module M3.
The element switching circuits 19 on the light receiving side are connected to each other via the signal line L14 and to the light receiving control unit 20.
The second display control unit 32b of the light reception control module M3 is connected to the light reception control unit 20 through the signal line L12.

Casing 4:
As shown in FIG. 3, the projector 2 and the light receiver 3 are configured such that the modules M <b> 1 to M <b> 3 are accommodated in a casing 4. As shown to Fig.4 (a), the casing 4 is comprised by the end casing 40 of the both ends, and the intermediate casing 41 between them. The casing 4 has a substantially U-shaped or U-shaped cross section.

As shown in FIG. 3, the light-projecting casing 4 accommodates one or a plurality of optical axis modules M1 and also accommodates a light projection control module M2 at one end. The casing 4 on the light receiving side accommodates one or a plurality of optical axis modules M1, and accommodates the light receiving control module M3 at one end.
The light projecting control module M2 and the light receiving control module M3 do not need to be provided with the light projecting element 7, the light receiving element 8, and the like.

Arrangement of the first display element 31a:
The light emitting side casing 4 and the light receiving side casing 4 in FIG. 3 are installed so that the light projecting element 7 and the light receiving element 8 face each other.
The light projecting element 7 and the light receiving element 8 are arranged in a line with respect to the longitudinal direction Z. The first display unit 31 composed of the plurality of first display elements 31 a is arranged on the optical axis row of the light projecting element 7 to the light receiving element 8 and at a position where it does not interfere with the optical axis 10. That is, the first display element 31a is disposed between the optical axes 10 and 10 and is disposed on the center line Z1 of the optical axis array.

The first display elements 31a are arranged at a substantially equal pitch on the center line Z1 of the optical axis row. As shown in FIGS. 4A and 4B, the first display element 31a is provided in the vicinity of both ends in the longitudinal direction Z of the projector 2 or the light receiver 3, and is also disposed between the both ends. ing. The first display element 31 a provided at both ends of the casing 4 is provided in each end casing 40. The center line Z1 is provided at the center in the width direction X of the casing 4 of the light projector / receiver 2 or 3.

As shown in FIG. 3, the light projecting elements 7 to 8 are arranged closer to the ends than the first display elements 31 a provided at both ends in the longitudinal direction Z of the light projectors 2 to 3. Therefore, the optical axis 10 is disposed closer to the end than the first display elements 31a at both ends.

Arrangement of the second display element 32a:
The second display unit 32 composed of the plurality of second display elements 32 a is outside the row on the center line Z <b> 1 of the optical axis row arranged in the row of the light receiver 3 and at a position where it does not interfere with the light receiving element 8. Arranged. In addition, the 2nd display part 32 may be provided in the light projector 2, and may be provided in both the light projector 2 and the light receiver 3. FIG.

Input / output unit 5:
The input / output unit 5 has a function as a controller and a function of inputting / outputting signals to / from the outside. The input / output unit 5 incorporates safety and non-safety output control circuits (not shown), and signals are output from these output control circuits to a safety control device and a non-safety control device such as a press machine.

The light reception control unit 20 of the light reception control module M3 in FIG. 1 includes a state output circuit 33 and a diagnosis unit 34.
The input / output unit 5 controls each device of the projector 2 and the light receiver 3 and other devices such as a press connected to the input / output unit 5 based on the signal output from the light reception control unit 20. Do. For example, the multi-optical axis photoelectric sensor 1 may include a normal mode, a mute mode, an optical axis setting mode, a diagnostic mode, and the like described below.

Normal mode;
The normal mode is a mode in which an object is detected according to the light incident / light shielding state of the optical axis 10. In the normal mode, the state output circuit 33 in FIG. 1 is based on a signal from the light receiving circuit 18 output via the element switching circuit 19 and at least one of the first state in which all the optical axes 10 are in the incident state. The binary signal corresponding to the second state in which the optical axis 10 is in the light-shielding state is output to the input / output unit 5.

In the normal mode, the input / output unit 5 indicates the detection area formed by the optical axis 10 via the display control units 31b and 32b, respectively, based on the received binary signal. The first display unit 31 is turned on, and information indicating the output state of the state output circuit 33 is displayed on the second display unit 32.

In the normal mode, the input / output unit 5 lights the first display element 31a in a predetermined pattern based on the state signal from the state output circuit 33.

For example, when the input / output unit 5 receives a binary signal corresponding to the first state, all the first display elements 31a may be lit in green.
On the other hand, when the input / output unit 5 receives a binary signal corresponding to the second state, the input / output unit 5 immediately stops a danger source such as a press connected to the input / output unit 5. At the same time, the input / output unit 5 turns off the first display elements 31a of the light-shielded optical axis modules M1 to M3 and turns off the other first display elements 31a of the optical axis modules M1 to M3 that receive light. It may be lit red. At the same time, the input / output unit 5 may light the second display element 32a in red.

An example of the lighting pattern will be described with reference to FIG.
As shown in FIGS. 8A and 8B, all optical axes 101
When -10n is incident, all the first display elements 31a1 to 31am are lit in green. Thereby, the dangerous area becomes clear.

When the optical axis 101 at one end is incident and at least one of the remaining optical axes 102-10n is shielded, the first display element 31a1 at the other end is lit in red ( Hereinafter referred to as “red lighting”). Similarly, the optical axis 10n at the other end is incident and the remaining optical axis 101
When one or more of -10n-1 are shielded from light, the first display element 31am at the other end is lit red. If both the optical axes 10n and 101 are incident and one or more of the intermediate optical axes 102 to 10n-1 are shielded, all intermediate first display elements 31a2 to 31 am-1 are used. Lights up red.

When the optical axis 101 at one end is shielded from light, the first display element 31a1 at the one end and all intermediate first display elements 31a2 to 31 am-1 are turned off. Similarly, when the optical axis 10n at the other end is shielded from light, the first display element 31am at the other end and all the intermediate first display elements 31a2 to 31 am-1 are turned off.

That is, when only the optical axis 101 at one end is incident, only the first display element 31a1 at the one end is lit red, and the remaining first display elements 31a2 to 31am are turned off. Similarly, when only the optical axis 10n at the other end is incident, only the first display element 31am at the other end is lit red, and the remaining display elements 31a1 to 31 am-1 are turned off.

In the case of this lighting pattern, when the multi-optical axis photoelectric sensor 1 is installed, while the lighting state of the first display elements 31a1 to 31am is observed, one (or the other) optical axis 101 (10n) is matched, By matching the (or one) optical axis 10n (10 1), the optical axis adjustment of the light projecting and receiving units 2 and 3 is facilitated.

As another lighting pattern, when there is a portion where the optical axis is shifted, the first display element 31a of the shifted optical axis modules M1 to M3 is turned off, and the optical axis is matched with the optical axis. The first display elements 31a of the modules M1 to M3 may be lit in red. Furthermore, when all the optical axes match, all the first display elements 31a may be lit in green.
These lighting patterns are also useful when adjusting the optical axis.

This multi-optical axis photoelectric sensor 1 can diagnose failures of the light projecting circuit 12, the light receiving circuit 18, and the status output circuit 33. The diagnostic means 34 transmits the presence / absence of a failure in the circuits 12, 18, 33 to the input / output unit 5.

In the diagnostic mode, the input / output unit 5 lights the first display element 31a in a predetermined pattern based on the diagnostic signal from the diagnostic means 34.
For example, when a diagnostic signal indicating that any one of the circuits 12, 18, and 33 has failed, all the first display elements 31a may blink in red. Further, the input / output unit 5 may notify the operator of the failed part or state by turning on the second display element 32a with a predetermined lighting pattern.

Mute mode;
The mute mode is a mode in which the safety function of the safety light curtain is temporarily disabled when the workpiece passes through the safety light curtain including the optical axis 10. In the mute mode, the state output circuit 33 outputs a signal corresponding to the first state to the input / output unit 5 regardless of whether the optical axis is incident or blocked.

In the mute mode, the input / output unit 5 turns on the plurality of first display elements 31a of the first display unit 31 to indicate the optical axis row, and the information and state indicating the mute mode on the second display unit 32 Information indicating the output state of the output circuit 33 is displayed.
For example, in the mute mode, all the first display elements 31a may be lit in green and the second display element 32a may be blinked in green so that the operator is notified of the mute state.

It should be noted that various patterns other than those described above can be adopted as the lighting color, lighting pattern, blinking pattern, and the like of the first display unit 31 and the second display unit 32 in each mode. Moreover, you may enable it for the customer who purchased the multi-optical axis photoelectric sensor 1 to set an original pattern. Furthermore, when the functions of the multi-optical axis photoelectric sensor 1, such as mute, interlock release waiting, and override, are executed, a lighting pattern or blinking pattern corresponding to the function may be adopted.

FIG. 5 shows a second embodiment.
As shown in FIG. 5, each light axis module M10 is provided with one light projecting element 7 or light receiving element 8. Each display module M11 is provided with one first display element 31a.
The present multi-optical axis photoelectric sensor includes a flat cable 45 in which first and second communication lines L21 and L22 are incorporated, and first and second optical fibers for fixing the optical axis module M10 and the display module M11 to the flat cable 45, respectively. Fixtures 46 and 47 are provided.

A plurality of the optical axis modules M10 are fixed to the flat cable 45 by the first fixing tool 46, and a smaller number of display modules M11 than the optical axis module M1 are fixed by the second fixing tool 47.
The first fixture 46 is provided with a first communication line L21 that connects the plurality of optical axis modules M10 and a second communication line L22 that electrically connects the plurality of display modules M11.
Other configurations are the same as those of the first embodiment, and the description thereof is omitted.
The optical axis module M10 may be provided with two or more light projecting elements 7 to light receiving elements 8.

FIG. 6 shows a third embodiment.
As shown in FIG. 6, the first optical axis module M <b> 10 is provided with a light projecting element 7 or a light receiving element 8. On the other hand, the second optical axis module M20 is provided with a light projecting element 7 to a light receiving element 8 and a first display element 31a.
A plurality of first optical axis modules M10 are fixed to the flat cable 45 by the first fixtures 46, and a smaller number of second optical axis modules M20 than the optical axis modules M10 are fixed by the first fixtures 46. Is done.
Other configurations are the same as those of the second embodiment, and the description thereof is omitted.
The first and / or second optical axis modules M10 and M20 may be provided with two or more light projecting elements 7 to light receiving elements 8.

FIG. 7 shows another example of the arrangement of the first display elements 31a.
As shown in FIG. 7A, the shape of the first display element 31a may be a triangle other than a square.
As shown in FIG. 7B, the first display element 31 a may be provided only in the vicinity of both ends of the light projecting element 7.
As shown in FIG. 7C, the first display element 31a may be formed in two or more types.
As shown in FIG. 7D, the first display element 31 a may be provided for each light projecting element 7.
As shown in FIG. 7E, the first display element 31a may be provided closer to the end than the endmost light projecting element 7.
As shown in FIG. 7F, the first display element 31a may be provided on the center line Z1, and may be misaligned (offset) with respect to the center line Z1.

FIG. 9 shows an example of the layout of the multi-optical axis photoelectric sensor 1.
The multi-optical axis photoelectric sensor 1 may have two projectors 2 and 2 and light receivers 3 and 3 each formed into a L shape indicated by a solid line or a gate shape (a U-shape) indicated by a two-dot chain line. . In such a case, when the optical axis 10 is provided on the center line Z1 in the width direction X as in this embodiment, the pitch P between the optical axes 10 and 10 is the same as that of the straight line Li portion in the corner portion Co. It becomes easy to make the pitch P constant.

In the above-described embodiment, the input / output unit 5 is provided in the light receiver 3, but in the present invention, the input / output unit 5 is not necessarily provided, and the function of the input / output unit 5 is provided as shown in FIG. The controller 5 </ b> B may be provided externally or may be incorporated in the projector 2.

The present invention can be applied to a multi-optical axis photoelectric sensor that forms a light curtain for detecting a human body or the like entering a predetermined area.

It is a schematic block diagram which shows the light projector / receiver concerning Example 1 of the multi-optical axis photoelectric sensor of this invention. It is a schematic block diagram of a multi-optical axis photoelectric sensor. It is a schematic perspective view of a multi-optical axis photoelectric sensor. (A) is a disassembled perspective view which shows a light projector or a light receiver, (b) is a schematic perspective view which shows a light projector or a light receiver. 6 is a schematic perspective view showing a module of a multi-optical axis photoelectric sensor of Example 2. FIG. 6 is a schematic perspective view showing a module of a multi-optical axis photoelectric sensor of Example 3. FIG. It is a schematic front view of the light projector which shows other examples, such as arrangement | positioning of a display element. (A) is a plane | planar conceptual diagram of the light projector (receiver) for demonstrating the lighting pattern of a display element, (b) is a chart which shows the lighting pattern. It is a planar conceptual diagram of a projector (receiver) showing an example of the layout of a multi-optical axis photoelectric sensor. FIG. 6 is a schematic configuration diagram showing a module of a multi-optical axis photoelectric sensor of Example 4.

1: multi-optical axis photoelectric sensor 2: projector 3: light receiver 4: casing 40: end casing 41: intermediate casing 7: light projecting element 8: light receiving element 10: optical axis 12: light projecting circuit 14: light projecting control circuit 18 : Light receiving circuit 20: light receiving control unit 31: first display unit 31 a: (first) display element 31 b: first display control unit 32: second display unit 32 a: (second) display element 32 b: second display control unit 33: status output circuit 34: diagnostic means L1: signal line L21: first communication line L22: second communication lines M1 to M3: optical axis module M10: first optical axis module M20: second optical axis module M11: display module Z1: Center line

Claims (3)

Each has a long casing in one direction, and includes a projector and a light receiver in which a plurality of optical axes are arranged in a line apart from each other along the longitudinal direction of the casing, and according to the incident / light-shielding state of the optical axis In the multi-optical axis photoelectric sensor that detects objects by
The light projector and the light receiver are composed of a plurality of display elements arranged on the row of optical axis rows arranged in the row, and the optical axis adjustment is arranged such that the plurality of display elements are arranged along the optical axis row. For display,
The display element on one end side of the display unit is lit according to the incident light of the optical axis at one end, and the display element on the other end side is lit according to the incident light of the optical axis at the other end. Axis photoelectric sensor.   The multi-optical axis photoelectric sensor further includes a failure display unit composed of a plurality of display elements for displaying a failure content of the multi-optical axis photoelectric sensor, and the lighting pattern of the plurality of display elements of the failure display unit The multi-optical axis photoelectric sensor according to claim 1, wherein the failure content is notified. The multi-optical axis photoelectric sensor according to claim 1, wherein the width of the display element of the optical axis adjustment display unit is wider than the width of the optical axis.

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