JP2515903Y2 - Detection switch device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection switch device which judges the presence or absence of an object to be detected by comparing the level of a detection signal output from a detection section with a judgment level and outputs an object detection signal.

[0002]

2. Description of the Related Art In a photoelectric switch, which is an example of a detection switch device of this type, a light projecting element for irradiating light to a detection area and a light receiving element for receiving reflected light from the detection area are provided. The presence or absence of an object is detected by determining whether the level of the detection signal corresponding to the amount of received light exceeds a preset determination level.

In this case, the determination level for detecting the presence / absence of an object can generally be changed according to the detection condition, and recently, it is output from a light receiving element according to the presence / absence of an object. It is considered that the calculation is performed in a predetermined relationship based on the levels of two detection signals and the setting is automatically performed.

For example, a detection signal when an object to be detected exists and a detection signal by light incident from the outside when an object to be detected does not exist are input, and the level of each detection signal is an intermediate level. Is set as the determination level so that the presence / absence of an object to be detected can be surely detected even when there is ambient light or noise to some extent.

In this way, the determination level can be automatically set to a level according to the environment, and the user performs a troublesome work such as operating the sensitivity setting volume and the like to set the detection condition. There is no need, and the object can be easily set only by operating the detection-time setting switch and the non-detection-time setting switch using an object to be detected.

[0006]

By the way, in such a conventional configuration, when the difference between the detection level in the presence of the object to be detected and the detection level in the absence of the object to be detected is small, for example, When the level of the reflected light from the object and the level of the incident light from the background are close to each other, the determination level to be set depends on the slight level difference between the detection signals.

However, if the determination level is set in the state of such a minute level difference, the detection signal may be erroneously output due to the adverse effects of ambient light, noise, etc. even in the absence of the object to be detected. However, due to the hysteresis characteristic of the comparator, there is a possibility that once the detection state is determined, even if the detected object does not exist, the detection state remains unreset.

Therefore, for example, in the case where the product flowing through the line is the detected object of the photoelectric switch, the detection output can be surely obtained only when the detected object is present due to the determination level set as described above. It is necessary to test whether it can be obtained. Then, if a reliable detection operation is not performed as a result of the test, it is necessary to perform the setting work again, and there is a problem that the user has troublesome work and the usability is deteriorated.

Further, at this time, even if the detection operation is performed by resetting the determination level, it is not known whether there is a sufficient margin for the ambient light or noise. It is a situation where it is not possible to determine whether or not there is reliability with respect to noise, and there is still a possibility that erroneous detection may occur depending on the usage environment.

The present invention has been made in view of the above circumstances, and an object thereof is to set a determination level of the presence or absence of an object by a simple operation, and when the determination level is set, It is an object of the present invention to provide a detection switch device capable of simultaneously confirming how much margin can be used to prevent erroneous detection due to ambient light or noise.

[0011]

SUMMARY OF THE INVENTION The present invention is a detection switch device for determining the presence or absence of an object to be detected by comparing the level of a detection signal output from a detection section with a determination level and outputting an object detection signal. It is intended to target, detection error
First operated in a state where the object to be detected is present in the rear
Setting switch, a second setting switch operated in a state where the object to be detected does not exist in the detection area, and a level of a detection signal given from the detection unit when the first setting switch is operated. Is set as a first detection level and the level of the detection signal given from the detection section when the second setting switch is operated is stored as a second detection level, and the first and second detection level values are stored .
And evaluation level setting means for setting the decision level in a substantially middle level, and calculating means for calculating the number of lighting times corresponding to the difference between the detection margin frequency a represents the first and second detection level value, this arithmetic means characterized in was constructed by providing a display means for displaying the point light number Ru good.

[0012]

According to the detection switch device of the present invention, when the first setting switch is operated in the presence of the object to be detected and the second setting switch is operated in the absence of the object to be detected, the judgment level setting is made. The means stores the levels of the first and second detection signals obtained in each state and sets the determination level based on those levels. Then, the calculation means is a lighting circuit that indicates the detection margin frequency according to the stored difference between the first detection level and the second detection level.
The number is calculated and the display means is calculated by this calculating means.
I would like to display the number of times lights point was. Therefore, the user can confirm the detection margin frequency by visually observing the number of times the display means is lit, and whether the set determination level has a sufficient margin, that is, whether the detection margin frequency is large or small. It is possible to confirm whether or not there is a sufficient difference in the detection level depending on the presence or absence of the detected object. This allows
For example, depending on the state of the environment of use, i.e. in accordance with the incident state of degree such as disturbance light and noise at the installation location, or the like is determined in advance an indication of the detection margin frequency required, the table
When the indicated detection margin frequency is less than the standard
In addition, the user may change the detection conditions and installation environment and judge again.
By setting the constant level, the detection margin frequency
It is possible to make it more than the above-mentioned desired standard, and
Then, it becomes possible to set so as to perform a reliable detection operation.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a reflection type photoelectric switch will be described below with reference to the drawings. In FIG. 1 showing the entire electrical configuration, a microcomputer 1 is a so-called one-chip microcomputer in which a CPU, a ROM, a RAM, an A / D conversion circuit and the like are built in, and serves as a judgment level setting means and a calculation means. The object detection program and the setting program, which will be described later, are stored in advance.

The power supply input terminal VD of the microcomputer 1 is connected to the DC power supply line 2, and a predetermined voltage is applied from a DC power supply (not shown) via the power supply terminal V and the constant voltage circuit 3. The ground terminal of the microcomputer 1 is connected to the ground terminal E.

The anode of the light projecting element 4 such as a light emitting diode is connected to the DC power supply line 2 through the drive circuit 5, and the cathode is connected to the ground terminal E. Drive circuit 5
Is connected to the output terminal a of the microcomputer 1,
A light projecting pulse signal is applied, and the light projecting element 4 is caused to perform a light projecting operation in accordance with the light projecting pulse signal.

The cathode of the light receiving element 6 such as a photodiode is connected to the DC power supply line 2, and the anode is connected to the ground terminal E via the bias circuit 7 and the input terminal of the light receiving amplifier 8. The output terminal of the light receiving amplifier 8 is connected to the input terminal b of the microcomputer 1 via the main amplifier 9. The microcomputer 1 is adapted to convert an analog detection signal, which is amplified by the main amplifier 9 and then applied to the input terminal b, into a digital signal by an A / D conversion function.

The detection-time setting switch 10 as the first setting switch and the non-detection-time setting switch 11 as the second setting switch are connected to the input terminals c and d of the microcomputer 1, respectively, and the mode changeover switch 12 is connected.
Is connected to the input terminal e of the microcomputer 1. The anodes of the operation indicator lamp 13 and the stable operation indicator lamp 14 such as light emitting diodes are respectively connected to the DC power supply line 2, and the cathodes thereof are respectively connected to the output terminals f and g of the microcomputer 1. As will be described later, the stable operation indicator lamp 14 also has a function as a display means, and performs a blinking operation to display the detection margin frequency by the number of times of lighting.

The data input / output terminal of the EEPROM (rewritable non-volatile memory) 15 is the microcomputer 1.
Is connected to the input / output terminal h. The microcomputer 1 is adapted to read or write necessary data from the EEPROM 15 at any time as described later. The external output terminal P for object detection is connected to the output terminal i of the microcomputer 1 via the output circuit 16.

Next, the operation of this embodiment will be described with reference to FIG. Here, after briefly explaining (1) the detection operation, (2) the determination level setting operation will be described with reference to the flowchart of the setting program shown in FIG.

(1) Detection Operation When the mode selector switch 12 is set to the detection mode with the power turned on, the microcomputer 1 executes the detection operation as follows according to a detection program (not shown). To do. That is, the microcomputer 1 outputs a light projecting pulse signal to the drive circuit 5 to cause the light projecting element 4 to pulse-light at a predetermined frequency. Detection
When an object to be detected is present in ( a), the pulsed light from the light projecting element 4 is reflected by the object to be detected and enters the light receiving element 6.

As a result, when a light receiving signal corresponding to the amount of light received is output from the light receiving element 6, the light receiving signal amplified via the light receiving amplifier 8 and the main amplifier 9 is applied to the input terminal b of the microcomputer 1. become. The microcomputer 1 converts the analog light receiving signal given to the input terminal b into a digital detection signal by the A / D conversion function and inputs the signal, and the level of the detection signal is set to a determination level set as described later. Compare with K.

When the microcomputer 1 judges that the level of the detection signal is higher than the judgment level K, it counts as the presence of light, and when the count reaches a predetermined number, it outputs the output circuit 16 from the output terminal i. Through this, an object detection signal is output to the external output terminal P and a display signal is output to the output terminal f to turn on the operation indicator lamp 13. Thereby, for example, the external output terminal P
If a load drive circuit or the like is connected to the device, it is driven by the object detection signal, and the user is notified by lighting the operation indicator lamp 13.

When the above-described detection operation is performed, the microcomputer 1 compares the input detection signal with a preset stable detection level which is higher than the above-mentioned determination level K, and detects the detection signal. When it is determined that the level is higher than the stable detection level, it is determined that the stable light input state is reached, and the display signal is output from the output terminal g to turn on the stable operation indicator lamp 14. As a result, it is displayed that the detected state is stable.

(2) Judgment Level Setting Operation When the user switches the mode changeover switch 12 to "SET" in order to set the judgment level K in the detection operation as described above, the microcomputer 1 executes the setting program according to the flowchart shown in FIG.

That is, the microcomputer 1 determines in step S1 and S2 which of the detection setting switch 10 and the non-detection setting switch 11 is turned on, and when neither of the switches 10 and 11 is turned on, the microcomputer 1 determines If "NO" is determined, the process proceeds to step S3. If the mode switch 12 is in the "SET" state, "YES" is determined and the process returns to step S1.

After that, the microcomputer 1 repeats steps S1, S2 and S3 so that the user can detect it.
When the detection setting switch 10 is turned on in order to set the detection level when the detected object is present in the exit area, it is determined to be "YES" in step S1 and step S1 is performed.
It will move to 4.

In step S4, the microcomputer 1 causes the light projecting element 4 to perform the light projecting operation in the same manner as described above, and the reflected light from the object to be detected causes the light receiving element 6 to pass through the light receiving amplifier 8 and the main amplifier 9. A digital detection signal obtained by A / D converting the received light receiving signal is read as the detection level V1, and further written in the EEPROM 15 to be stored.

Next, the microcomputer 1 sets the judgment level K based on the currently detected detection level V1 and the preset non-detection level V2.
In this case, the non-detection level V2 is provisionally set, and as will be described later, the non-detection level V2 corresponding to the use environment installed when the non-detection time setting switch 11 is turned on is set. It is like this. Now, the microcomputer 1 calculates an average value (substantially intermediate level) of the detected level V1 and the non-detected level V2 and stores it as the determination level K (= (V1 + V2) / 2).

Subsequently, when the microcomputer 1 proceeds to step S6, it performs a stable operation indicating the detection margin frequency S.
The number of times the indicator lamp 14 is turned on is calculated. That is, the microcomputer 1 first calculates the difference ΔS (= V1−V2) between the detected level V1 and the non-detected level V2, and at the same time, sets the value of 20% of the value of the determination level K to the margin index N ( =
0.2 × K). Next, the microcomputer 1 determines the detection level difference ΔS with respect to the margin index N.
The number of times of lighting is calculated by setting the ratio of S to the detection margin frequency S. That is, the detection margin frequency S can be obtained as the detection margin frequency S = ΔS / N.

As a result, the processing by turning on the detection time setting switch 10 is completed, and the microcomputer 1 returns to step S1 via step S3, and returns to step S1.
Repeat S2 and S3. And switch 1 when not detected
When 1 is turned on, the microcomputer 1 determines "YES" in step S2 and proceeds to step S7.

The microcomputer 1 operates in step S7.
Then, in the same manner as described above, the detection signal in the state where the object to be detected does not exist in the detection area is input, the level is read as the non-detection level V2, and written in the EEPROM 15 to detect the non-detection level V2 corresponding to the use environment. Memorize

In this way, when the detection and non-detection levels V1 and V2 are obtained, the microcomputer 1 again determines the determination level K in steps S5 and S6.
And the number of times of lighting is calculated and stored. After this, the microcomputer 1 proceeds to step S
In step 3, the steps S1 and S2 are repeated while determining that the mode changeover switch 12 is released from the "SET" state.

When the setting of the detection level V1 and the non-detection level V2 is completed and the mode switch 12 is released from the "SET" state by the user, the microcomputer 1 returns "NO" in step S3. Then, the process proceeds to step S8. In step S8, the microcomputer 1 outputs a display signal of the number of times of lighting corresponding to the stored detection margin frequency S from the output terminal g, blinks the stable operation indicator lamp 14, and returns to the detection program. In this case, the number of times the stable operation indicator lamp 14 is turned on is
For example, it is set from 0 times to a maximum of 5 times.

As a result, the user can recognize whether or not the detection operation based on the currently set detection level V1 and non-detection level V2 has a margin. That is, for example, when the number of lighting of the stable operation indicator lamp 14 is large, the difference between the detection time level V1 and the non-detection time level V2 is large, and the margin for performing the detection operation is also large.

In this case, as described above, the value of the detection margin frequency S is with respect to the margin index N in which the difference ΔS between the detection level V1 and the non-detection level V2 corresponds to 20% of the determination level K. Since the calculation is performed as a value indicating how many times there is, if the detection margin frequency S is less than "1", a reliable detection operation cannot be guaranteed even when there is no ambient light or noise in the usage environment. Yes, if "1" or more, the higher the value, the higher the degree of reliable detection becomes, and the more accurate detection operation can be performed even when there is a lot of ambient light or noise in the usage environment. Is shown.

Therefore, as a guideline for the detection margin frequency S, when the location where the photoelectric switch is disposed is a use environment where there is no ambient light or noise, the value of the detection margin frequency S is "1".
If the value of the detection margin frequency S needs to be “3” in a usage environment in which there is an extremely large amount of ambient light or noise, a stable operation in which the blinking operation is performed after the determination level setting operation is performed. By observing the number of times the indicator lamp 14 has been turned on, it becomes possible to recognize whether or not the detection operation can be accurately performed, depending on the usage environment of the photoelectric switch at that time.

According to this embodiment as described above, in the decision level setting operation, the microcomputer 1
The judgment level K is set and the detection margin frequency S is displayed.
Since the number of lightings is calculated and displayed by the number of lightings of the stable operation indicator lamp 14, the user simply operates the detection time setting switch 10 and the non-detection time setting switch 11 to easily determine the determination level K. Can be set, and in the process of setting the determination level K, it is possible to recognize how much the detection margin frequency S is not erroneously detected due to ambient light, noise, etc., by the number of lightings, and the usage environment It is possible to quickly determine whether or not there is the adapted detection margin frequency S.

Further, according to the present embodiment, since the stable operation indicator lamp 14 displays the number of times of lighting corresponding to the detection margin frequency S, it can be constructed at low cost without separately providing a display means. .

In the above embodiment, the detection margin frequency S is displayed by using the stable operation indicator lamp 14. However, the present invention is not limited to this, and, for example, the operation indicator lamp 13 may be used. Alternatively, a dedicated indicator light may be separately provided.

Further, in the above embodiment, the determination level, the case has been described where to set determination level K, which is calculated as the average value of the detection time of the level V1 and the non-detection time level V2, which, for example, in advance Set a constant comparison reference level and change the amplification level of the light receiving amplifier to set it as the actual judgment level , or change the light projection amount by the light projecting element to make the actual judgment. Including setting as a level
It is a waste.

Furthermore, in the above embodiment, the first and second setting switches are provided with the detection time setting switch 10 and the non-detection time setting switch 11 respectively, but the present invention is not limited to this. A single setting switch may have the functions of the first and second setting switches. That is, for example, the setting program may function as a detection-time setting switch when the setting switch is first operated, and may function as a non-detection-time setting switch when the setting switch is operated next.

In the above embodiment, the mode changeover switch 12 is provided and the judgment level setting operation is executed by operating the mode changeover switch 12. However, the present invention is not limited to this. Alternatively, the determination level setting operation may be performed when the detection setting switch 10 or the non-detection setting switch 11 is operated.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the photoelectric switch has been described, but the present invention is not limited to this and may be applied to other detection switches.

[0044]

As described above, according to the detection switch device of the present invention, the judgment level can be set to the abbreviation of the first and second detection level values by operating the first and second setting switches.
Automatically and sets an intermediate level, the computing means and display means, the <br/> As a display means calculates the number of lighting times representing the detected margin frequency corresponding to the difference between the first and second detection level because be displayed by lit number, together with enabling the determination level setting by a simple operation, since it quickly recognize whether it has detected margin frequency of how much is determined level set, for example, required for the use environment By recognizing whether or not there is the detection margin frequency, it is possible to judge whether or not the accurate detection operation can be performed even if there is an adverse effect due to ambient light or noise.

[Brief description of drawings]

FIG. 1 is a schematic electrical configuration diagram showing an embodiment of the present invention.

[Fig. 2] Flow chart of setting program

[Explanation of symbols]

1 is a microcomputer (judgment level setting means, computing means), 2 is a DC power supply line, 4 is a light projecting element, 6 is a light receiving element, 8 is a light receiving amplifier, 9 is a main amplifier, 10 is a detection time setting switch (first Setting switch), 11 is a non-detection setting switch (second setting switch), 12 is a mode change switch, 13 is an operation indicator lamp, 14 is a stable operation indicator lamp (display means), and 15 is an EEPROM.

Claims (1)

(57) [Scope of utility model registration request] 1. A detection switch device for determining the presence or absence of an object to be detected by comparing the level of a detection signal output from a detection section with a determination level, and outputting an object detection signal, wherein the object is detected within a detection area. A first setting switch operated in the presence of the detected object, a second setting switch operated in the state where the detected object does not exist in the detection area, and the first setting switch operated The level of the detection signal given from the detection section is sometimes stored as a first detection level, and the level of the detection signal given from the detection section when the second setting switch is operated is stored as a second detection level. with these and evaluation level setting means for setting the decision level at substantially middle level of the first and second detection level value represents the detection margin power the first and second detection level Calculating means for calculating the number of lighting times corresponding to the difference value, the detection switch device being characterized in that comprising a display means for displaying the point light number Ru good in the calculation means.