JPH0625871Y2 - Photoelectric switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a multi-path photoelectric switch,
In particular, the present invention relates to an improvement in increasing the degree of freedom in arranging the optical paths of a multi-optical path photoelectric switch.

[Prior Art] When measuring whether or not there is an object to be detected in a predetermined space plane, a photoelectric switch having multiple optical paths as shown in FIG. 6 is used. The light emitting unit 2 has a plurality of light emitting elements 4 housed in a row. A plurality of light receiving elements (not shown) are housed in the light receiving section 6 so as to face the respective light emitting elements 4.

Therefore, an optical path 10 is formed between each light emitting element 4 and each light receiving element. When the object to be detected interrupts the optical path 10, the light from the light emitting element 4 does not enter the light receiving element, so that the existence of the object to be detected can be detected. That is, in the device shown in FIG. 6, in the detection plane 12 indicated by the two-dot chain line,
It is possible to detect the presence or absence of an object to be detected.

[Problems to be Solved by the Invention] However, the conventional photoelectric switch has the following technical problems.

First, when changing the size of the plane to be detected, it is necessary to separately prepare photoelectric switches (light emitting section 2 and light receiving section 6) having different optical paths. That is, the size of the detection plane 12 could not be easily changed. Furthermore, the detection plane 12
There is also a problem in that photoelectric switches having various numbers of optical paths have to be prepared in accordance with the size of the above, and the manufacturing cost increases.

Secondly, in order to avoid obstacles and the like, it may be desirable to make only a part of the detection plane 12 a non-detection region. In this case, the 7th
As shown in the figure, it is necessary to prepare a photoelectric switch (light emitting portion 2 and light receiving portion 6) having a portion 5 where no photoelectric element is provided. Since the position of the portion 5 where the photoelectric element is not provided changes depending on the case, it is necessary to prepare photoelectric switches (light emitting section 2 and light receiving section 6) having various photoelectric element arrays. Therefore, there is a problem that the types of photoelectric switches increase and the manufacturing cost increases.

An object of the present invention is to solve the conventional problems as described above, and to provide a photoelectric switch that can easily change the size of the detection plane and the photoelectric element arrangement and can be manufactured at low cost. And

[Means for Solving the Problems] In the photoelectric switch according to the first aspect, at least one of the light emitting unit and the light receiving unit is electrically provided with a plurality of units each including a light emitting element or a light receiving element and a processing circuit thereof in a housing. A relay unit that is configured by mechanically connecting in sequence and that does not have the processing circuit and that has a transmission line that transmits a signal necessary for signal processing between a unit at a front stage and a unit at a rear stage. It is characterized in that a region where detection is not performed is formed by connecting the above.

[Operation] The photoelectric switch according to the present invention is configured by connecting a unit including mechanical and electrical connecting means. Therefore, it is easy to form the detection plane in a desired size. Further, the non-detection region can be easily formed by connecting the relay unit.

[Embodiment] FIG. 1 shows a photoelectric switch according to an embodiment of the present invention. The light emitting unit 2 and the light receiving unit 6 are arranged so as to face each other. Both the light-emitting part 2 and the light-receiving part 6 have units 22, 24,
It is configured by connecting 25, 26, 28, 62, 64, 65, 66, 68.
An optical path window covered with the light transmitting body 30 is provided in each unit, and a photoelectric element is stored immediately below the optical path window. A light emitting diode, a laser diode, or the like, which is a light emitting element, is provided in the light emitting section 2 as a photoelectric element, and the light receiving section 6 includes
A photodiode or the like which is a light receiving element is provided as a photoelectric element. The light emitting elements of the light emitting section 2 and the light receiving elements of the light receiving section 6 are provided at positions facing each other.
A plurality of optical paths are formed.

However, no optical path is formed between the relay units 25 and 65. That is, the space 200 shown by the alternate long and short dash line in FIG.
Indicates a non-detection area.

-Mechanical Configuration- Since the configurations of the light emitting unit 2 and the light receiving unit 6 are substantially the same, the structure of the light emitting unit 2 will be described below. Each unit constituting the light emitting unit 2 is removable. FIG. 2 (A to E) is a diagram showing a state in which each unit is removed. Second
FIG. A shows the basic unit 22. 2B, C
Indicates expansion units 24 and 26. FIG. 2D shows the end unit 28. FIG. 2E shows the relay unit 25.

The light emitting part 2 of the photoelectric switch shown in FIG. 1 is a basic unit.
The relay unit 25 is connected to the relay unit 22, the extension unit 26 is connected to the relay unit 25, and then the extension unit 24 and the end unit 28 are connected.

The basic unit 22 is composed of a thick portion 22a and a fine portion 22b. Four optical path windows 32 are formed in the thick portion 22a and the details 22b, and light emitting elements are housed immediately below them. details
The optical path window 32 of 22b is covered with a lens 33 having a filter effect, and the optical path window of the thick portion 22a is further covered and protected by a light transmitting body 30. Guide grooves 38 are provided on both sides of the detail 22b. This guide groove 38
This is to facilitate the connection when connecting the extension units 24 and 26. Also, in the detail 22b, the expansion unit 2
Resilient protrusion 40 to ensure connection of 4,26
Are provided as mechanical connection means. Further, at the tip of the detail 22b, a female connector 4 which is an electrical connection means is provided.
4 are provided.

A cross section of the basic unit 22 taken along line I-I is shown in FIG. 3A. The light emitting element 42 is connected to the circuit board 46. The circuit board 46 has a circuit for causing the light emitting element 42 to emit light,
A circuit for timing and a circuit for calculating the detection output are formed (described later). Of the signals of these circuits, the necessary signals are extracted to the female connector 44. The holes 48 and 49 are for fixing and mounting.

In addition to the above, the basic unit 62 of the light receiving unit 6 is provided with a light emitting diode for displaying a detection output in a thick portion.

Next, the extension unit will be described. In this embodiment, the extension unit 24 shown in FIG. 2B and the extension unit C shown in FIG.
The expansion unit 26 shown in is used. First, the structure of the extension unit 24 shown in FIG. 2B will be described. This expansion unit 24
Is composed of a hollow portion 24a that is thick and hollow, and a thin portion 24b that is thin.

Four optical path windows 32 are formed in the hollow portion 24a and the details 24b. Optical path window 32 of detail 24b is covered by lens 33. The optical path window of the hollow portion 24a is covered and protected by the light transmitting body 30. The light emitting element is an optical path window 32 with details 24b.
It is provided directly below and is not provided on the hollow portion 24a side.

Guide grooves 38 are provided on both side surfaces of the detail 24b.
The guide groove 38 is for facilitating the connection when connecting the other extension units 24, 26. Also details
To ensure the connection of the extension units 24 and 26 to 24b,
The convex portion 40 having elasticity is provided as a mechanical connecting means. Further, a female connector 44, which is an electrical connection means, is provided at the tip of the detail 24.

A cross section of the extension unit 24 taken along the line II-II is shown in FIG. 3B. The light emitting element 42 is connected to the circuit board 46. The circuit board 46 has a circuit for causing the light emitting element 42 to emit light,
A circuit for timing and a circuit for calculating the detection output are formed (described later). Of the signals of these circuits, the necessary signals are extracted to the female connector 44 and the male connector 45. As is clear from this sectional view, the structure of the detail 24b is the same as the detail 22b of the basic unit 22.
Is almost the same as.

A convex portion 50 is formed on the inner side surface of the hollow portion 24a.
The protrusion 50 is provided so as to engage with the guide groove 38 of the basic unit 22. That is, it is for facilitating the connection when the details 22b of the basic unit 22 are connected by covering the hollow portion 24a of the extension unit 24.
The hollow portion 24a is provided with an engagement hole 52 which is a mechanical connecting means. In the engaging hole 52, the convex portion 40 of the basic unit 22
Engage with each other to make a reliable connection.

Further, at this time, the female connector 44 of the basic unit 22 and the male connector 45 inside the hollow portion 24a of the extension unit 24 are joined to each other, and electrical connection is also made.

In the connected state, the light emitting element 42 of the basic unit 22
The light transmitting body 30 of the extension unit 24 is located above the above, and an optical path for sending light toward the light receiving section 6 is formed.

Next, the expansion unit 26 shown in FIG. 2C will be described. This expansion unit 26 is the expansion unit 24 of FIG. 2B.
And the basic configuration is exactly the same. However, as is clear from the figure, the hollow portion 26a and the detail 26b are formed at an angle of approximately 90 degrees. Therefore, by using this extension unit 26, the arrangement direction of the light emitting element 42 can be bent 90 degrees. For example, the detection plane 12 shown in FIG.
Etc. can be easily formed. That is, various types of detection planes can be easily formed. Line III-III in FIG. 2C
A cross section at is shown in FIG. 3C.

In this embodiment, the hollow portion 26a and the small portion 26b are shown to have an angle of about 90 degrees, but if one having an angle of 45 degrees or the like is prepared, the shape of the detection plane can be freely and easily. Can be formed.

Next, the relay unit 25 of FIG. 2E will be described. The appearance of the relay unit 25 is almost the same as that of the extension unit 24 shown in FIG. 2B. Therefore, the expansion unit
Like 24 and 26, they can be interconnected with other units.

A cross section taken along line VV of FIG. 2E is shown in FIG. 3E.
The structure of the hollow portion 25a is exactly the same as that of the extension unit 24. However, the circuit board 46 is not provided inside the detail 25b. The light emitting element 42 may or may not be provided. A cable 47, which is a transmission line, connects between the male connector 45 and the female connector 44 provided at both ends of the detail 25b.

Note that, instead of the cable 47, a circuit board 46 having the same connection state as this may be provided.

Further, in some cases, the relay unit can be configured with the internal structure of the extension unit 26 as shown in FIG. 2C as shown in FIG. 3E.

The relay unit 25 not only forms a region in which detection is not performed, but also has a role of transmitting a necessary signal to the next-stage unit by a cable.

Finally, the end unit 28 shown in FIG. 2D will be described. The end unit 28 is the connected extension unit 24, 26
It is intended to cover details 24b (26b) at the end of the.
The structure is almost the same as the hollow portions 24a and 26a of the extension units 24 and 26 except that the mounting holes 54 are formed. Note that FIG. 3D is a sectional view taken along line IV-IV in FIG. 2D.

-Electrical Configuration- Next, FIG. 4 shows an electrical circuit configuration of the photoelectric switch shown in FIG. The left side is the light emitting unit 2, and the right side is the light receiving unit 6. In the light emitting unit 2, one block surrounded by a dashed line indicates each unit. The white circles between each unit are
It is shown that they are connected by the connectors 44 and 45. The relay unit 26 connects the connector 44 and the same signal line of the connector 44. The above-mentioned configuration is the same for the light receiving unit 6.

An oscillation circuit 70 is provided in the basic unit 22 of the light emitting section 2, and its oscillation output is as shown by S ₁ in FIG. The counter 72 divides this oscillation output S ₁ and outputs it.
S ₂ On the other hand, the oscillation output S ₁ is also given to the inverter 71, becomes the inverted oscillation output S _3, and is input to the AND gate 73. Divide output to the other input of AND gate 73
S ₂ is given. Therefore, the output S ₄ of the AND gate 73 is such that the inverted oscillation output S ₃ appears only when the divided output S ₂ is at the H level. The output S ₄ of the AND gate 73 is called a reference clock.

Further, the timing pulse generator 74 receives the frequency-divided output S ₂ , inverts it, and delays it. Therefore,
Timing pulse generator 74 generates timing pulse S ₅ as shown at S ₅ in FIG.

The timing pulse S ₅ and the reference pulse S ₄ are given to the shift register 76. When the first pulse of the reference clock S ₄ is input when the timing pulse S ₅ is at the H level, the shift register 76 outputs the drive timing signal T ₁ from its output. After that, every time the pulse of the reference clock S ₄ is input, the drive timing signals T ₂ , T ₃ , T ₄ ...
· T ₈ and go to output. Since the reference clock S ₄ has 16 pulses as one group, the reference clock S ₄ is output even after the drive timing signal T ₈ is output. However, in this embodiment, there are eight optical paths, and the drive timing signal T ₉
Since the shift register for outputting the subsequent signals is not provided, the drive timing signal T _{9 and} subsequent signals are not output. In other words, in this embodiment, it is possible to connect additional units to form up to 16 optical paths. Further, the number of optical paths that can be formed can be increased or decreased by changing the length of the frequency-divided output S ₂ .

As described above, the drive timing signals T ₁ , T _2, ..., T ₈ are sequentially output from the outputs of the shift registers 76, 77, 78 (see FIG. 5). As a result, the light emitting circuits DRV ₁ , DRV ₂ , DR
A driving timing signal is sequentially applied to V ₃ ... DRV ₈ and the light emitting diodes LED ₁ , LED ₂ , LED ₃ ... LED ₈ sequentially emit light. Thus, the light emitting diodes are made to sequentially emit light in order to eliminate the influence from the adjacent light emitting diodes.

In order to realize the circuit described above, the reference clock S ₄ and the intermediate output of the shift register between each unit.
TS, power supply, ground, etc. are connected by a connector. Further, the relay unit 25 has a role of transmitting these signals from the unit in the front stage to the unit in the rear stage.

Note that the reference clock S ₄ is not output during the period INT, as is clear from FIG. This is in consideration of the case where there is another photoelectric switch provided adjacently. That is, during this period INT, another adjacent photoelectric switch is caused to emit light to prevent malfunction.

Next, the circuit operation of the light receiving side 6 will be described. For synchronization, the reference clock S ₄ of the light emitting side 2 is transmitted to the light receiving side 6 by the external cable 150. The light receiving side 6 receives light on the basis of the reference clock S ₄ in synchronization with the light emission timing.

The sent reference clock S ₄ is input to the timing pulse generator 84. The timing pulse generator 84 inverts the reference clock S ₄ and integrates it. The pulse of the reference clock S ₄ is blunted by the time constant of the integrating circuit, and the output of the timing pulse generator 84 becomes as shown by S ₆ in FIG. This output S ₆ is given as a timing pulse to the shift register 86 to synchronize with the light emitting side 2. That is, when the timing pulse S ₆ is at the H level, the light reception timing signal T ₁ is output by the first pulse of the reference clock S ₄ . After that, the reference clock S ₄
The light reception timing signals T ₂ , T _3, ..., T ₈ are sequentially output for each pulse.

Receiving the timing signal _{T 1, T 2, T 3} ···· T 8 , respectively, applied to the switch gate _{R 1, R 2, R 3} ···· R 8. Photodiodes PD ₁ , PD ₂ , PD ₃ ... Converted into current by PD ₈ , and received circuit RC
The signals that have passed through V ₁ , RCV ₂ , RCV ₃ ... RCV ₈ are routed through the switch gates R ₁ , R ₂ , R ₃ ... R ₈ to the signal processing circuits P ₁ , P ₂ , P ₃ ...
Given to P ₈ . Therefore, only the signal from the photodiode provided to face the light emitting diode that emits light is given to the signal processing circuit.

The outputs from the signal processing circuits P ₁ , P ₂ , P _3, ... P ₈ are connected by AND gates 92, 93, 94, 95, 96, 97. That is, the output of each unit is sent to the next unit as the intermediate detection output TD. Therefore, if one of the photodiodes does not receive light, the AND gate
The output of 93 becomes L level. In response to this, the output circuit 81 turns on the detection display light emitting diode 152 and outputs a detection output.

In this embodiment, in order to stabilize the detection, a stabilized detection output with a high detection threshold value is also prepared. This circuit configuration is the same as the above detection circuit except that the threshold value for detection by the photodiode is high. In FIG. 4, only the output circuit 82 and the light emitting diode 154 for stability detection display are shown, and the others are omitted.

In order to realize the above functions, the reference clock S ₄ , the detection intermediate output TD (normal detection and stabilization detection), the shift register intermediate output TS, the power supply,
The ground and the like are connected by a connector. Further, the relay unit 55 has a role of transmitting these signals from the unit at the front stage to the unit at the rear stage.

In the above embodiment, only the reference clock S ₄ is sent to the light receiving side 6 and the light receiving side 6 generates the timing pulse S ₆ . In another embodiment, the timing pulse
S ₅ may also be sent to the light receiving side 6.

[Effect of the Invention] In the photoelectric switch according to the present invention, at least one of the light emitting portion and the light receiving portion is electrically and mechanically sequentially connected to a plurality of units each including a light emitting element or a light receiving element and a processing circuit for the light emitting element or the light receiving element. By connecting a relay unit having a transmission line for transmitting a signal necessary for signal processing between a unit at a front stage and a unit at a rear stage without including the processing circuit. The feature is that a region where no detection is performed is formed.

Therefore, the detection plane can be easily formed to have a desired size, and the non-detection region can be easily formed by connecting the relay unit.

That is, the size of the detection plane and the photoelectric element arrangement can be easily changed, and a photoelectric switch that can be manufactured at low cost can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing the appearance of a photoelectric switch according to an embodiment of the present invention, FIG. 2A is a diagram showing a basic unit, FIG. 2B is a diagram showing an extension unit, and FIG. 2C is another extension unit. FIG. 2D is a view showing an end unit, FIG. 2E is a view showing a relay unit, FIG. 3A is a sectional view taken along line I-I of FIG. 2A, and FIG. 2 is a sectional view taken along line II-II in FIG. 2B, FIG. 3C is a sectional view taken along line III-III in FIG. 2C, and FIG. 3D is a sectional view taken along line IV-IV in FIG. FIG. E is a sectional view taken along line VV of FIG. 2E, FIG. 4 is a diagram showing an electric circuit of the photoelectric switch of FIG. 1, and FIG. 5 is a time for explaining the operation of the circuit of FIG. FIG. 6 is a chart showing a conventional photoelectric switch, and FIG. 7 is a diagram showing a conventional photoelectric switch partially provided with a non-detection region. 2 …… Light emitting part 6 …… Light receiving part 22,62 …… Basic unit 24,26,64,66 …… Additional unit 25,65 …… Relay unit 47 …… Cable

Claims (1)

[Scope of utility model registration request] 1. A photoelectric switch including a light emitting section having a plurality of light emitting elements, a light receiving section having a plurality of light receiving elements provided so as to face the light emitting elements of the light emitting section, wherein at least the light emitting section and the light receiving section are provided. One is configured by sequentially electrically and mechanically connecting a plurality of units each having a light emitting element or a light receiving element and a processing circuit thereof in a housing, which does not have the processing circuit A photoelectric switch characterized by forming a non-detection region by connecting a relay unit having a transmission line for transmitting a signal required for processing between a unit at a front stage and a unit at a rear stage.