JP2002140967A - Multiple optical axis photoelectric switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multiple optical axis photoelectric switch, capable of easily adjusting an optical axis without causing a cost increase. SOLUTION: As for this multiple optical axis photoelectric switch, since all light intercepting elements are divided into four groups of light intercepting elements 41-44, and the display parts 31-34 corresponding to them are provided, the number of display parts for adjusting optical axes can be reduced in comparison with a conventional one equipped with a display lamp for adjusting the optical axis for every light intercepting element. Since a laser beam source used in the one with a laser pointer is not separately required, a manufacturing cost can be also suppressed. In addition, the display parts can be brought close to their normal setting positions step by step by adjusting the optical axes so as to increase the number of lighted display parts among the first - fourth display parts 31-34, and the display modes (light-out, flickering, lighting) are changed in accordance with the added value of an intercepted light signal from the light intercepting element 21 in each group of the light intercepting elements. Thereby, the optical axis can be very easily adjusted in comparison with a conventional one wherein all optical axes must be adjusted at a time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a multi-optical axis photoelectric switch.

[0002]

2. Description of the Related Art As an example of a conventional multi-optical axis photoelectric switch, a switch shown in FIG. A plurality of light receiving elements 4 are provided in a line. Also, the light receiving section 2
Is provided with an operation indicator light 5, and this operation indicator light 5
All of the plurality of light receiving elements 4 are turned off when light from the corresponding light emitting elements 3 is received, and turned on otherwise.
Then, the light emitting and receiving devices 1 and 2 are arranged to face each other, and the light emitting and receiving elements 3 and 4 are set so that an optical signal is transmitted and received.
When an object is located between the light emitting and receiving devices 1 and 2, the object is detected by blocking the light from the light emitting element 2 to the light receiving element 4, and this is recognized when the operation indicator light 5 is turned on. You. Also, to set this multi-optical axis photoelectric switch,
First, by light measurement, the light emitting and receiving elements 3 and 4 are opposed to each other.
The light emitters and receivers 1 and 2 are temporarily arranged to face each other, and then, while confirming with the operation indicator 5, finely adjust the position of the light emitters and receivers 1 and 2 so that the operation indicator 5 is turned off. Adjustments were being made.

[0003]

However, in recent years,
The beam of the multi-optical axis photoelectric switch and the pitch between the optical axes are
Both tend to be narrow. The reason for narrowing the beam of light is that if the beam of light is wide, the light signal from the projector is reflected by an object unrelated to the detected object even though the light signal is blocked by the detected object, and is received by the light receiving element. This is because there is a concern that erroneous detection may occur. The reason why the pitch between the optical axes is narrowed is that if the pitch between the optical axes is wide, a small detected object may pass through the dead zone between the optical axes and become undetectable. is there.

However, when the pitch between the optical axes becomes narrow,
The work of roughly opposing the light emitting and receiving elements is difficult by visual measurement, and it is necessary to adjust the optical axis while checking the operation indicator from the beginning. However, since the beam of light is narrow, the allowable range of the optical axis shift of the light emitting / receiving element is also narrowed, and the position where all the light receiving elements receive the optical signal is limited to an extremely narrow range. In addition, as described above, when the operation indicator 5 is turned off only when the optical axes completely match, it is not known whether the vehicle is approaching the regular set position during the optical axis adjustment. Therefore, it took a very long time to adjust the optical axis.

[0005] On the other hand, there is a configuration dedicated to optical axis adjustment, for example, a configuration provided with a laser pointer in the light emitting and receiving device. However, since a laser light source and the like are separately required, the manufacturing cost is high. In addition, a configuration in which a plurality of indicator lights for adjusting the optical axis are provided for each of the light emitting and receiving elements corresponding to each other can be considered. Becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a multi-optical axis photoelectric switch capable of easily adjusting an optical axis without increasing the cost.

[0007]

In order to achieve the above object, a multi-optical axis photoelectric switch according to the first aspect of the present invention includes a light receiving device arranged to face a light emitting device, and the light receiving device is arranged in a line with the light emitting device. A plurality of light receiving elements forming a pair with each of the plurality of light emitting elements arranged in a row are arranged and provided in a line, and each light receiving element receives and outputs light from a normal counterpart light emitting element. In order to receive only the light receiving signal, in a multi-optical axis photoelectric switch having a receiving means that operates in synchronization with each other light emitting element, a plurality of light receiving elements are divided into at least two or more light receiving element groups, The display means corresponding to each of the light receiving element groups, and in each of the light receiving element groups, light receiving signals from a plurality of light receiving elements constituting the light receiving element group are added, and based on a change in the added light receiving signal, Each corresponding Characterized in place and control means for controlling so as to change the display mode of the shown means.

According to a second aspect of the present invention, in the multi-optical axis photoelectric switch according to the first aspect, the photodetector is a basic unit including at least two display means and a control means, and a desired number of additional units. Each extension unit is provided with a plurality of light receiving elements, and the basic unit is
The present invention is characterized in that the total number of light receiving elements in the entire light receiver is recognized, and the light receiving elements are divided into a plurality of light receiving element groups and correspond to each display means.

[0009]

<Invention of claim 1> A plurality of light receiving elements are divided into two or more light receiving element groups, and display means corresponding to each of the light receiving element groups is provided. The number of display means can be reduced as compared with a conventional one provided with an indicator light for axis adjustment. Further, unlike a conventional device provided with a laser pointer, a laser light source or the like is not separately required, so that the manufacturing cost can be reduced as compared with these conventional devices. Then, by adjusting the optical axis so as to increase the number of display means that have been set to the display position indicating that the display means has been set to the normal position, the display means can be gradually approached to the normal setting position. Thus, the optical axis adjustment can be easily performed as compared with the conventional one in which the optical axis adjustment of all the light receiving elements must be performed at once. Moreover, each display means, in each corresponding light receiving element group,
Since the display mode changes based on the added light-receiving signals from the plurality of light-receiving elements constituting the light-receiving element group, the degree of deviation of the optical axis of each light-receiving element group can be determined, and the light-receiving element of each light-receiving element group can be determined. The optical axis adjustment can be performed more easily than the case where all operate only when light is received.

According to this structure, the basic unit recognizes the total number of light receiving elements of the entire light receiving device,
Since the light receiving element groups are divided into a plurality of light receiving element groups and correspond to the respective display means, the object of the present invention can be achieved even in a case where a desired number of additional units are assembled and the total number of light receiving elements fluctuates. Can be.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> A first embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the multi-optical axis photoelectric switch of the present embodiment includes a light projector 10 and a light receiver 20 which are arranged to face each other.
Each of the light emitting and receiving devices 10 and 20 has, for example, a prism shape extending vertically, and a plurality of light emitting elements 11 are arranged in a line in a vertical direction on a surface of the light emitting device 10 facing the light receiving device 20. Then, on the surface of the light receiver 20 facing the light emitter 10,
A plurality of light receiving elements 21 paired with each of the light emitting elements 11,
Again, they are arranged in a line along the vertical direction.

Each of the light emitting and receiving elements 11 and 21 is provided, for example, by 16 each, and the light emitting and receiving terminals 11 and 21 arranged in the same order in the vertical direction are mutually proper counterparts. . Then, as will be described in detail later, the light receiving signal that is received and output by each light receiving element 21 is received by the light receiving circuit 22 only when light from the normal counterpart light emitting element 11 is received. When the light receiving elements 21 arranged vertically are distinguished from each other, “A” to “P” are added to the end of the reference numerals in order from the light receiving elements 21 on the upper end side.

An operation display section 26 is provided on the upper surface of the light receiver 20. The operation display unit 26 includes, for example, an LED as a display lamp.

On one side surface of the light receiver 20 adjacent to the surface on which the light receiving element 21 is arranged, for example, first to fourth display units 31 are provided.
To 34 (corresponding to the display means of the present invention). More specifically, a total of 16 light receiving elements 21 are divided into four light receiving element groups 41 to 4 each including four light receiving elements 21.
The light receiving elements 21A to 21A to 2
The first light receiving element group 41 composed of 1D corresponds to the first display unit 31, the second light receiving element group 42 composed of light receiving elements 21E to 21H corresponds to the second display unit 32, and the light receiving element 21
A third light receiving element group 43 including I to 21L corresponds to the third display unit 33, and a fourth light receiving element group 44 including light receiving elements 21M to 21P corresponds to the fourth display unit.

Each of the display sections 31 to 34 is composed of, for example, an LED as a display lamp. Although not shown, a system diagram showing the correspondence between the display units 31 to 34 and the light receiving element groups 41 to 44 may be written on the surface of the light receiver 20.

FIG. 2 shows an electrical configuration of the multi-optical axis photoelectric switch according to the present embodiment. As shown in the figure, the light projector 10 is provided with a light emitting circuit 14 to which the light emitting element 11 is connected, and the light emitting circuit 14 operates based on a predetermined clock pulse signal (see FIG. 3). Then, a drive signal is sequentially applied from the light projecting element 11 on the upper end side of the light projector 10 to the light projecting element 11 on the lower end side, and this operation is repeated at a high cycle. Thereby, the light emitting element 1 on the upper end side of the light projector 10
Optical signals are sequentially emitted from 1.

On the other hand, the light receiver 20 includes the light receiving element 21.
Light receiving circuit 22 (corresponding to the receiving means of the present invention)
Is provided. The light receiving circuit 22 is provided with a plurality of switch elements 25. One of the switch elements 25 is connected to the output terminal of each light receiving element 21 and the other is connected to the lead section. Commonly connected to terminals.

A control terminal 25A provided in each switch element 25 is connected to an output terminal of a light receiving control circuit 24 via a shift register 23. Then, each switch element 25 is always in an off state, and a drive signal is sequentially applied to each switch element 25 from the light receiving control circuit 24 via the shift register 23, thereby turning on the switch element 25 which is turned on. Only the light receiving signal of the continuous light receiving element 21 is taken into the light receiving control circuit 24.

Further, the light receiving control circuit 24 includes the light emitting and receiving device 1
The clock pulse signal (see FIG. 3) is fetched from the light projecting circuit 14 via a line L1 connecting 0 and 20, and is synchronized with the clock pulse signal (ie, the light projecting timing of each light projecting element 11). And a predetermined switch element 25
Turn on. Specifically, the control in the first half of the flowchart shown in FIG. 6 is executed. In steps S2 to S4, only the switch elements 25 connected to the light receiving element 21A are turned on at the moment when the light emitting elements 11 corresponding to the light receiving element 21A emit light signals. . These steps are performed in the subsequent light receiving element 21B.
To 21P sequentially (step S5). As a result, only when each light receiving element 21 receives light from the legitimate counterpart light emitting element 11, the light receiving signal output by that light receiving element 21 is taken into the light receiving control circuit 24.

The light receiving control circuit 24 includes a switch element 25
Are sequentially synchronized with the timing of ON / OFF control of the received signals, a magnitude relationship between a predetermined reference voltage VC1 (see FIG. 3) and the received reception signal is checked. When all of the light receiving signals sequentially taken into the light receiving control circuit 24 exceed the reference voltage VC1, the operation display section 26 is turned off, and when any one of the light receiving signals falls below the reference voltage VC1. , The operation display unit 26 is turned on. From the output terminal 27 extending from the light receiving control circuit 24, for example, a detection signal that is inverted depending on whether or not an object to be detected is detected is output.

As described above, the light receiving control circuit 24
Since the magnitude of the received signal and the reference voltage VC1 is determined in synchronization with the timing of the on / off control of each switch element 25, it is possible to identify which of the light receiving elements 21 the light receiving signal exceeds the reference voltage VC1. Then, the light receiving control circuit 24 takes in the light receiving signals output from the respective light receiving elements 21 as binarized digital signals and adds them to each of the light receiving element groups 41 to 44. Here, the control in the latter half of the flowchart shown in FIG. 6 is executed. First, in step S7, all the light receiving elements 2 of the first light receiving element group 41
When 1A to 21D exceed the reference voltage VC1, "YE
S ”, and turns on the first display unit 31 (step S
8). If there is at least one light receiving element 21 that does not exceed the reference voltage VC1, in step S9, if all the light receiving elements 21 do not exceed the reference voltage VC1, "YES"
And the first display unit 31 is turned off (step S1).
0). If any one of the light receiving elements 21 exceeds the reference voltage VC1, "NO" is turned on and off (step S11).
(See FIG. 4B). Similarly, the light receiving control circuit 24
Are the second light receiving element group 42, the third light receiving element group 43, and the fourth
After the above-described steps S7 to S11 are sequentially performed for the light receiving element group 44 (step S12), the second display unit 32, the second display unit 32, and the fourth display unit 31 are turned on, turned off, or blinked (step S13). .

The configuration of the multi-optical axis photoelectric switch of the present embodiment is as described above. The optical axis of this optical axis photoelectric switch is adjusted as follows. That is, first, the projector 10
And the light receiver 20 are separated from each other by a predetermined distance so as to face each other.
Each light receiving element 21 provided in the light receiver 20 is opposed to each other.

Next, a power switch (not shown) of the multi-optical axis photoelectric switch is turned on. At this time, the light emitting / receiving element 11,
If the 21s are not facing each other, the display units 31 to 34 do not light up. In this case, for example, one end of the light receiver 20, specifically, for example, the lower end is slightly and randomly moved. Then, at a predetermined position, FIG.
As shown in the figure, the fourth display unit 34 corresponding to one light receiving element group 44 on the lower end side of the light receiver 20 is turned on, and the third display unit 33 corresponding to the light receiving element group 43 blinks. As a result, the operator can operate the light receiving element 2 on the lower end side of the light receiver 20.
1M to 21P recognize that the light projecting element 11 on the lower end side of the light projector 10 is in the normal opposing state, and the third light receiving element group 43 is almost in the normal opposing state similar to the fourth light receiving element group. Can be recognized.

Therefore, for example, while temporarily holding the lower end of the light projector 10, the upper end side of the light projector 10 is slightly tilted left and right. At this time, when the light projector 10 moves away from the regular setting position, the third display unit 33 and eventually the fourth display unit 34 turn off, but when approaching the regular setting position, FIG.
As shown in (B), in addition to the fourth display unit 34, the third display unit 33 is turned on, and the second display unit 32 is blinked. Then, such fine adjustment is performed, and as shown in FIG. 7 (D), all the display units 31 to 34 are turned on, so that the light emitting and receiving devices 10 and 20 are set to the normal facing state. Can be recognized, whereby the optical axis adjustment is completed.

When the optical axis adjustment is completed as described above, the light receiving signals of all the light receiving elements 21 are taken into the light receiving control circuit 24, and the operation display section 26 is turned off. When the detected object is located between the light emitting and receiving devices 10 and 20, the optical signal is interrupted and any one of the light receiving elements 2
The received signal of No. 1 is not taken into the light receiving control circuit 24, the operation display section 26 is turned on, and the detected object is detected.

As described above, according to the multi-optical axis photoelectric switch according to the present embodiment, all the light receiving elements are divided into four light receiving element groups 41 to 44, and the corresponding display sections 31 to 44 are arranged.
Since the light-receiving element 34 is provided, the number of optical-axis-adjustment display units can be reduced as compared with a conventional light-emission-adjustment display lamp provided for each light receiving element. Further, unlike a device having a laser pointer, a laser light source or the like is not separately required, and the manufacturing cost can be reduced as compared with those of the related art. By adjusting the optical axis so as to increase the number of illuminated display units among the first to fourth display units 31 to 34, it is possible to gradually approach the regular set position. Moreover,
Each display unit changes its display mode (off, blinking, lighting) according to the added value of the light receiving signal from the light receiving element 21 of each light receiving element group. You can also know step by step whether you are approaching. Thereby, the optical axis adjustment can be performed extremely easily as compared with the conventional one in which the optical axis adjustment of all the light receiving elements must be performed at once.

As another example of the control means for controlling the display mode of the display unit, a circuit using a circuit configured as shown in FIG. 5 may be used. For the display unit 31, the reception control circuit 24 is connected to the first light receiving elements 21A to 21A at its negative power supply terminal.
Display unit 3 when any of the received signals of 1D is captured
Transistor Tr for switching current to 1
2 are connected. On the other hand, the emitter of the transistor Tr1 that adjusts the amount of current to the display unit 31 according to the added value of the reception control circuit 24 is connected to the positive power supply terminal. With such a configuration, the first light receiving element group 41
A current corresponding to the added value of the light receiving signals from the light receiving elements 21A to 21D flows through the display section 31, and the brightness of the display section 31 changes in an analog manner as shown in FIG.

<Second Embodiment> The photodetector 50 provided in the multi-optical axis photoelectric switch according to the present embodiment is configured by assembling a desired number of additional units 61 to a basic unit 60 as shown in FIG. More specifically, these basic and extension units 60 and 61 both have a prism shape extending vertically.
An extension unit 61 is joined to the upper end surface of the basic unit 60, and another extension unit 61 is joined to the upper end surface of the extension unit 61, so that a plurality of units are joined in series. .

In each of the basic and extension units 60 and 61, four light receiving elements 62 are arranged in a line in the vertical direction. These light receiving elements 62 are, as shown in FIG. It is connected to a light receiving circuit 63 provided in 60 and 61. Further, when the units 60 and 61 are joined to each other, the light receiving elements 62 of the units 60 and 61 are combined.
Are positioned and held in a straight line, and the light receiving circuits 63 of the units 60, 61 are connected to each other by connection terminals (not shown) provided at the joints between the units 60, 61. Each light receiving circuit 63 includes a circuit (not shown) corresponding to the switch element and the shift register described in the first embodiment, and the light receiving circuits 63 of the units 60 and 61 are connected to each other. Thus, the electric circuit described in the first embodiment with reference to FIG. 2 is formed over the entire light receiver 50. Then, the control circuit 64 provided in the basic unit 60 fetches the light receiving signal of each light receiving element 62 in synchronization with the light emitting timing of the light emitting device 58 described later.

The control circuit 64 includes a light receiving element number discriminating circuit 65 for discriminating the number of light receiving elements 62 in the entire light receiving device 50.
Is provided. The light receiving element number discriminating circuit 65 detects the number of the connected light receiving circuits 63 based on, for example, a difference in resistance value, and detects the number of the light receiving elements 63 in the entire light receiver 50.
The total number of 2 is detected.

An output terminal of the control circuit 64 is connected to, for example, four display units 51 to 54.
５４54 are always off, but turn on or blink in response to a drive signal from the control circuit 64. Here, the control circuit 6
Reference numeral 4 designates the light receiving elements 62 of the entire light receiving device 50 based on the detection result of the light receiving element number discriminating circuit 65, for example, the display units 51 to 5
Divide by four, which is the total number of four, and divide it into four light receiving element groups each consisting of the light receiving elements 62 of the quotient, and identify them. Then, the respective light receiving element groups are made to correspond to the respective display units 51 to 54, and all the light receiving signals related to the light receiving elements 62 of the respective light receiving element groups corresponding to the respective display units 51 to 54 exceed the reference voltage. , The display units 51 to 54 are turned on, and if any of them does not exceed the reference voltage, it blinks, or if all of them do not exceed the reference voltage, they are turned off.

On the other hand, as shown in FIG.
A desired number of additional units 71 are assembled to the basic unit 70, and each of the units 70, 71 has four light emitting elements 72 arranged in a line in the vertical direction.
The light emitting elements 72 are connected to a light emitting circuit 73 provided in each of the units 70 and 71. When the units 70 and 71 are joined to each other, the light emitting elements 72 are arranged in a straight line.
The light emitting circuits 73 of the units 70 and 71 are connected to each other by connection terminals (not shown) provided at the joining portions. And
With a control circuit (not shown) provided in the basic unit 70, the light projecting elements 72 of the entire light projector 58 sequentially output optical signals as in the first embodiment.

Incidentally, the multi-optical axis photoelectric switch of this embodiment is also provided with an operation display section (not shown), as in the first embodiment.

The operation and effect of the multi-optical axis photoelectric switch of the present embodiment will be described below. On the far left of FIG.
The state where one additional unit 61 is assembled to the basic unit 60 is shown. In this case, the light receiving element 62 is
Since the total number is 8, it is divided into four light receiving element groups each including two light receiving elements 62. And these 4
A set of light receiving element groups corresponds to each of the display units 51 to 54, and when both light receiving elements 62 of each light receiving element group receive a light receiving signal from a normal light emitting element, 5
4 is turned on, blinks when any of them is not receiving light, or goes out when all of them are not receiving light.

The second from the left in FIG.
0 shows a state in which two additional units 61 are assembled, which is also shown in FIG. 9, and in this case,
Each of the four light receiving element groups is divided into four light receiving element groups each including three light receiving elements 62.
~ 54. Hereinafter, each time the extension unit 61 increases, the number of light receiving elements constituting each light receiving element group increases.

As described above, according to the present embodiment, the basic unit 60 controls the plurality of light receiving elements 62 of the entire light receiver 50 to
Since it is divided into a plurality of light receiving element groups and corresponds to each of the display sections 51 to 54, a desired number of additional units 61 are assembled,
Even when the total number of the light receiving elements 62 fluctuates, the same operation and effect as in the first embodiment can be obtained.

<Other Embodiments> The present invention is not limited to the above embodiments. For example, the following embodiments are also included in the technical scope of the present invention.
In addition to the following, various changes can be made without departing from the scope of the invention.

(1) The display unit (display means) for adjusting the optical axis in each of the above embodiments is turned on when all the light receiving elements of each light receiving element group receive a light receiving signal from a normal light emitting element.
Flashes when any of them are not receiving light,
The light was turned off when all of the light was not received.However, the light is not limited to this.For example, the light flashes when all of the light receiving elements receive light from the regular light emitting element, and lights when any of the light receiving elements does not receive light. However, various combinations may be employed, such as turning off the light when not all of the light is received.

(2) In the above-described embodiment, the display mode of the display unit is set to three stages of lighting, blinking, and turning off. However, the lighting period is changed according to the added value of the received light signal. In addition, a configuration in which the display mode of the display unit changes in response to finer optical axis adjustment may be employed.

(3) The display mode of the display unit for adjusting the optical axis is as follows.
Although the display mode is based on the change in the light cycle, a display mode in which the color changes according to the added value of the received light signal may be used.

(4) Further, when the display section is made of liquid crystal and all the light receiving elements receive light from the normal light emitting element, "OK" is displayed. When any of them does not receive light, "NG" is displayed. "May be displayed, and" NO "may be displayed when all of them are not received.

(5) In each of the above embodiments,
Although extending in the up-down direction, it may extend in the horizontal direction, or may have a configuration extending in an oblique up-down direction.

(5) In the above embodiments, the number of terminals of the light receiving terminal group corresponding to each display unit is the same, but may be different from each other.

(6) Light Receiver 5 in Second Embodiment
The zero basic unit 60 includes the plurality of display units 51 to 54 and the plurality of light receiving elements 62, but the basic unit includes only the plurality of display units (display means) and does not include the light receiving element. It may be something.

[Brief description of the drawings]

FIG. 1 is a perspective view of a multi-optical axis photoelectric switch according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the multi-optical axis photoelectric switch.

FIG. 3 is a time chart of a clock pulse signal and a reception signal.

FIG. 4 is a flowchart of a light receiving control circuit.

FIG. 5 is a circuit diagram of a display unit of another control means.

FIG. 6 is an explanatory diagram of a display mode change by a control unit.

FIG. 7 is a side view of the light receiver of the multi-optical axis photoelectric switch when the optical axis is adjusted.

FIG. 8 is a perspective view of a multi-optical axis photoelectric switch according to a second embodiment.

FIG. 9 is a block diagram of the multi-optical axis photoelectric switch;

FIG. 10 is a perspective view of a conventional multi-optical axis photoelectric switch.

[Explanation of symbols]

 10, 58 ... Light emitter 11, 72 ... Light emitting element 20, 50 ... Light receiver 21, 62 ... Light receiving element 22, 63 ... Light receiving circuit (receiving means) 24 ... Light receiving control circuit 31-34, 51-54 ... Display unit ( Display means) 41 to 44: Light receiving element group 60: Basic unit 61: Expansion unit 64: Control circuit 65: Light receiving element number discriminating circuit

Claims (2)

[Claims] 1. A light receiving device arranged opposite to a light emitting device, wherein a plurality of light receiving devices forming a pair with each of a plurality of light emitting devices arranged in a line in the light emitting device are arranged in a line. And receiving means operable in synchronization with each of the counterpart light emitting elements so that each of the light receiving elements receives only a light receiving signal output by receiving light from a normal counterpart light emitting element. In a multi-optical axis photoelectric switch comprising: a plurality of light receiving elements, divided into at least two or more light receiving element groups, display means corresponding to each of the light receiving element groups, in each of the light receiving element groups, Control means for adding light-receiving signals from a plurality of light-receiving elements constituting the light-receiving element group, and controlling to change the display mode of each of the corresponding display means based on a change in the added light-receiving signal; Multi-optical axis photoelectric switch, characterized in that it includes. 2. The optical receiver according to claim 1, wherein a desired number of extension units are assembled to a basic unit including two or more of the display units and the control unit, and each of the extension units has a plurality of units. Wherein the basic unit recognizes the total number of light receiving elements of the entire light receiver, divides the light receiving elements into a plurality of light receiving element groups, and corresponds to each of the display means. The multi-optical axis photoelectric switch according to claim 1, wherein: