JP2003298401A - Amplifier separated photoelectric sensor, flood apparatus therefor and light receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an amplifier separated photoelectric sensor, a flood apparatus therefor and a light receiving apparatus in which various kinds of abnormality such as disconnection and erroneous connection or the like are distinctively detected. <P>SOLUTION: A first threshold X1 is set between a disconnection voltage level V1b and an erroneous connection voltage level V1c, a second threshold is set between the erroneous connection voltage level V1c and a normal voltage level V1a, and a fifth threshold is set between the normal voltage level V1a and a ground level. Based upon the comparison with a flood voltage level V1, 'disconnection/opening abnormality' on a flood side is detected. A third threshold Y1 is set between a disconnection voltage level V2b and the normal voltage level V1a, a fourth threshold Y2 is set between the normal voltage level V1a and an erroneous connection voltage level V2c, and a sixth threshold Y3 is set between the erroneous connection voltage level V2c and the ground level. Based upon the comparison with a non-flood voltage level V2, 'disconnection/opening abnormality' on a light receiving side is detected and a display pattern corresponding to each abnormal state is displayed on a digital display part 27. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplifier-separated photoelectric sensor and its light-projecting device and light-receiving device, and more particularly to an abnormality detecting means for detecting disconnection / opening or erroneous connection between a detection head portion and an amplifier portion. Regarding what you have.

[0002]

2. Description of the Related Art Conventionally, a light projecting head section having a light projecting element and a light receiving head section having a light receiving element, and respective connection lines derived therefrom are detachably connected. There is an amplifier-separated photoelectric sensor including an amplifier unit. The drive signal is applied from the amplifier to the light emitting element of the light emitting head via the light emitting connection line to emit light, and the light receiving signal output from the light receiving element is detected in the amplifier via the light receiving connection line. Give to the means,
A predetermined detection operation is performed based on the light reception signal received by the detection means.

By the way, in this type of photoelectric sensor, for example, the light emitting connection line or the light receiving connection line is broken, or the light receiving connection line from the light receiving unit is connected to the light emitting head unit connecting unit in the amplifier unit. Or, conversely, an erroneous connection may occur, such as connecting a light projecting connection line from the light projecting section to the connection section for the light receiving head section. In such a case, since the light emitting / receiving operation cannot be normally performed, there is a conventional device having a function of detecting such an abnormal state.

For example, in Japanese Utility Model Publication No. 3-49478, the voltage levels of the light projecting connection section and the light receiving connection section of the amplifier section are compared with threshold values set corresponding to each, and both are compared. It is disclosed that an output signal based on a comparison result is given to an input terminal of an OR circuit and a buzzer or the like is driven based on an output from the OR circuit. Since the voltage level of each connection portion in the abnormal state such as the above-mentioned disconnection or erroneous connection is different from the voltage level in the normal state, the abnormal state can be detected based on this.
However, in this configuration, since it is only necessary to drive the buzzer or the like when detecting various abnormal states, it is not possible to determine whether the abnormality is due to a disconnection or an incorrect connection.

Further, in Japanese Utility Model Publication No. 56-894, a visible light emitting element is connected in series to the cathode side of a light projecting element through a switching transistor, and a visible light emitting element is projected based on a drive signal given to a control terminal of the switching transistor. It is disclosed that the optical element is made to emit light and the visible light emitting element is made to emit light as well. With such a configuration, it is possible to detect disconnection of the light projecting element that emits invisible light and the like by the light emitting operation of the visible light emitting element that emits light in conjunction with it. However, with this configuration, only the disconnection of the light projecting element can be detected.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an amplifier-separated photoelectric sensor capable of distinguishing and detecting various abnormalities such as disconnection and erroneous connection, and a light projecting device and a light receiving device thereof. It is in the area of providing equipment.

[0007]

In order to achieve the above object, an amplifier separation type photoelectric sensor according to the invention of claim 1 is
An anomaly detection operation is performed based on a detection head including a photoelectric element, a connection terminal portion detachably connected to the photoelectric element of the detection head, and a magnitude comparison between a voltage level of the connection terminal portion and a threshold value. In an amplifier-separated photoelectric sensor including an amplifier unit having an abnormality detection unit, the threshold value in the abnormality detection operation of the abnormality detection unit is provided in plurality based on the voltage level of the connection terminal unit in each abnormal state, The amplifier unit includes a digital display unit, a storage unit that stores a plurality of display patterns on the digital display unit in association with each of the various abnormal states detected by the abnormality detection unit, and the abnormality detection unit. During operation, the display pattern associated with the detected abnormal state among the plurality of display patterns stored in the storage means is read out. Characterized in place and a control means for displaying on the digital display.

According to a second aspect of the present invention, there is provided a light emitting device for a head-separated photoelectric sensor, which includes a light emitting head portion provided with a light emitting element for emitting light toward a detection region, and the light emitting head portion. A connection terminal portion for light emission that is detachably connected to the optical element, a drive means for applying a drive signal to the light emission element through the connection terminal portion at a predetermined timing to perform pulse driving, and the connection terminal portion. A head-separated photoelectric sensor light-projecting device comprising a main body portion having an abnormality detection means for performing an abnormality detection operation based on a magnitude comparison of a voltage level and a threshold value at
The abnormality detection means is configured to perform an abnormality detection operation based on a magnitude comparison between the voltage level of the connection terminal portion and the threshold value when the light projecting element projects light, and the threshold value is the threshold value of the light projecting element. At the time of light emission, the circuit connecting the light emitting element and the connection terminal portion is disconnected, or the disconnection / open abnormal voltage level at the connection terminal portion when the light emitting element is open, and the connection The first threshold value between the wrong connection voltage level at the connection terminal section when the light receiving head section including the light receiving element is incorrectly connected to the terminal section, the wrong connection voltage level, and when normal And a second threshold value between normal voltage levels at the connection terminal portion of the main body portion, and a digital display means in the main body portion, and the digital display means corresponding to the abnormality detection based on the first threshold value. 1 display pattern, and A storage unit that stores a second display pattern corresponding to the abnormality detection based on the second threshold value, and the display pattern corresponding to the storage unit is read from the storage unit according to each abnormal state detected by the abnormality detection unit. And a control means for displaying on the digital display means.

According to a third aspect of the present invention, in the light projecting device for the head-separated photoelectric sensor according to the second aspect, the threshold value in the abnormality detecting operation of the abnormality detecting means is in addition to the first and second threshold values. Then, at the time of projecting the projecting element,
A third between the normal voltage level and the element short-circuit voltage level at the connection terminal portion when the light projecting element is short-circuited;
The threshold value is set and the storage means stores the third
It is configured to store a third display pattern corresponding to a threshold-based abnormality detection, and the control unit reads the third display pattern from the storage unit and performs the digital display for abnormality detection based on the third threshold. It is characterized in that it is displayed on the means.

According to a fourth aspect of the present invention, there is provided a light receiving device for an amplifier-separated photoelectric sensor, which comprises a light receiving head portion having a light receiving element for receiving the light projected from the light projecting device, and a light receiving element of the light receiving head portion. A connection terminal portion for detachable connection for light reception, a detection means for performing a predetermined detection operation based on a light reception signal received from the light receiving element via the connection terminal portion, and a voltage level at the connection terminal portion. A light receiving device of an amplifier-separated photoelectric sensor, comprising: an amplifier unit having an abnormality detecting means for performing an abnormality detecting operation based on a magnitude comparison with a threshold value, wherein the abnormality detecting means is a non-emitter of the light projecting device. It is configured to perform the abnormality detection operation based on the magnitude comparison of the voltage level at the connection terminal portion at the time of light emission and the threshold value, and the threshold value is the light receiving element and the light receiving element when the light projecting device is not projecting light. The connection terminal Between the disconnection / open abnormal voltage level at the connection terminal portion when the light receiving element is open, and the normal voltage level at the connection terminal portion when the circuit is continuous. A second threshold value between a threshold voltage, a normal voltage level, and an erroneous connection voltage level at the connection terminal section when the projection head section including a projection element is erroneously connected to the connection terminal section. A threshold value, a digital display unit in the amplifier unit, a first display pattern corresponding to the abnormality detection based on the first threshold value in the digital display unit, and an abnormality detection based on the second threshold value. A storage unit that stores a corresponding second display pattern, and the display pattern corresponding to the storage unit is read out from the storage unit in accordance with each abnormal state detected by the abnormality detection unit. Characterized in place and a control means for displaying on the stage.

According to a fifth aspect of the present invention, in the light receiving device of the amplifier-separated photoelectric sensor according to the fourth aspect, the threshold value in the abnormality detecting operation of the abnormality detecting means is in addition to the first and second threshold values. A third threshold value between the erroneous connection voltage level and the element short circuit voltage level at the connection terminal portion when the light receiving element is short-circuited when the light projecting element is not projecting light; The storage unit is configured to store a third display pattern corresponding to the abnormality detection based on the third threshold, and the control unit sets the third display pattern to the abnormality detection based on the third threshold. It is characterized in that it is read from the storage means and displayed on the digital display means.

According to a sixth aspect of the present invention, there is provided an amplifier-separated photoelectric sensor, which includes a light-projecting head section having a light-projecting element for projecting light toward a detection region, and light projected from the light-projecting element. A light-receiving head portion including a light-receiving element for receiving light, a light-emitting element of the light-emitting head portion, and a light-emitting element of the light-receiving head portion, and a connection terminal portion for light-receiving, which are detachably connected, Based on drive means for applying a drive signal to the light projecting element at a predetermined timing via the light projecting connection terminal portion to drive the light pulse, and a light receiving signal received from the light receiving element via the light receiving connection terminal portion. An amplifier-separated photoelectric sensor including a detection unit that performs a predetermined detection operation and an amplifier unit that includes an abnormality detection unit that performs an abnormality detection operation based on the comparison of the voltage level at each of the connection terminal portions and a threshold value. And the difference The detection means comprises a projection abnormality detection means that operates in synchronization with the projection of the projection element, and a reception abnormality detection means that operates in synchronization with the non-projection, and the abnormality detection operation of the projection abnormality detection means. The threshold value in is for the light projection of the light projecting element when the light projecting element and the light projecting connection terminal are connected to each other by a circuit break or the light projecting element is open. An open / closed abnormal voltage level at the connection terminal portion and an error in the light emitting connection terminal portion when the light receiving head portion having a light receiving element is erroneously connected to the light emitting connection terminal portion. A first threshold value between connection voltage levels, the wrong connection voltage level, and a second voltage value between the normal voltage level at the light emitting connection terminal portion in a normal state.
The threshold value in the abnormality detection operation of the light receiving abnormality detecting means is set to a threshold value, and when the light projecting element is not projecting light, the circuit connecting the light receiving element and the light receiving connection terminal portion is disconnected, or Disconnection / opening abnormal voltage level at the light-receiving connection terminal when the light-receiving element is open,
And a third threshold value between the normal voltage level at the light receiving connection terminal portion in a normal state, a normal voltage level, and a light projecting head portion having a light projecting element at the light receiving connection terminal portion. And a fourth threshold value between erroneous connection voltage levels at the light-receiving connection terminal section when the connection is erroneous, and the amplifier section includes a digital display unit and the digital display unit including the digital display unit. Storage means for storing the first to fourth display patterns corresponding to the abnormality detection based on each of the first to fourth threshold values, and the storage means corresponding to each of the abnormal states detected by the both abnormality detection means. It is characterized in that it is provided with a control means for reading a display pattern from the storage means and displaying it on the digital display means.

According to a seventh aspect of the present invention, there is provided an amplifier-separated photoelectric sensor, which includes a light-projecting head section having a light-projecting element for projecting light toward a detection region, and light projected from the light-projecting element. A light-receiving head portion including a light-receiving element for receiving light, a light-emitting element of the light-emitting head portion, and a light-emitting element of the light-receiving head portion, and a connection terminal portion for light-receiving, which are detachably connected, Based on drive means for applying a drive signal to the light projecting element at a predetermined timing via the light projecting connection terminal portion to drive the light pulse, and a light receiving signal received from the light receiving element via the light receiving connection terminal portion. An amplifier-separated photoelectric sensor including a detection unit that performs a predetermined detection operation and an amplifier unit that includes an abnormality detection unit that performs an abnormality detection operation based on the comparison of the voltage level at each of the connection terminal portions and a threshold value. And the difference The detection means comprises a projection abnormality detection means that operates in synchronization with the projection of the projection element, and a reception abnormality detection means that operates in synchronization with the non-projection, and the abnormality detection operation of the projection abnormality detection means. The threshold value in is for the light projection of the light projecting element when the light projecting element and the light projecting connection terminal are connected to each other by a circuit break or the light projecting element is open. Set to a first threshold value between the disconnection / open abnormal voltage level at the connection terminal portion and the normal voltage level at the light emission connection terminal portion in a normal state,
The threshold value in the abnormality detection operation of the light receiving abnormality detecting means is such that the circuit connecting the light receiving element and the light receiving connection terminal portion is disconnected when the light projecting element is not projecting light, or
Set to a third threshold value between a wire break / open abnormal voltage level at the light receiving connection terminal portion when the light receiving element is open and a normal voltage level at the light receiving connection terminal portion when the light receiving element is normal. The amplifier section includes a digital display unit, and the digital display unit includes the first and third digital display units.
Storage means for storing the first and third display patterns corresponding to the abnormality detection based on each of the thresholds, and the display pattern corresponding thereto according to each abnormal state detected by both the abnormality detection means. It is characterized in that it is provided with control means for reading out from the storage means and displaying it on the digital display means.

According to another aspect of the present invention, there is provided an amplifier-separated photoelectric sensor, which includes a light-projecting head portion having a light-projecting element for projecting light toward a detection region, and light projected from the light-projecting element. A light-receiving head portion including a light-receiving element for receiving light, a light-emitting element of the light-emitting head portion, and a light-emitting element of the light-receiving head portion, and a connection terminal portion for light-receiving, which are detachably connected, Based on drive means for applying a drive signal to the light projecting element at a predetermined timing via the light projecting connection terminal portion to drive the light pulse, and a light receiving signal received from the light receiving element via the light receiving connection terminal portion. An amplifier-separated photoelectric sensor including a detection unit that performs a predetermined detection operation and an amplifier unit that includes an abnormality detection unit that performs an abnormality detection operation based on the comparison of the voltage level at each of the connection terminal portions and a threshold value. And the difference The detection means comprises a projection abnormality detection means that operates in synchronization with the projection of the projection element, and a reception abnormality detection means that operates in synchronization with the non-projection, and the abnormality detection operation of the projection abnormality detection means. The threshold value in the light projecting connection terminal portion when the light receiving head portion including the light receiving element is erroneously connected to the light projecting connection terminal portion at the time of projecting the light projecting element. Wrong connection voltage level, and
A second threshold value between the normal voltage levels at the light projecting connection terminal portion in a normal state, and the threshold value in the abnormality detection operation of the light receiving abnormality detecting means is set when the light projecting element is not projecting light. In the case of (1), the normal voltage level at the light-receiving connection terminal portion in the normal state, and the light-receiving connection portion when the light-emitting head portion including the light-emitting element is erroneously connected to the light-receiving connection terminal portion The fourth threshold value is set between the wrong connection voltage levels at the connection terminal section, and the amplifier section has a digital display unit, and the digital display unit has an abnormality based on each of the second and fourth threshold values. Second corresponding to detection
And storage means for storing a fourth display pattern, and control for reading out the display pattern corresponding to the abnormal state detected by the both abnormality detection means from the storage means and displaying it on the digital display means. It is characterized by having means.

According to a ninth aspect of the present invention, in the amplifier-separated photoelectric sensor according to any one of the sixth to eighth aspects, the threshold value in the abnormality detection operation of the projection abnormality detection means is added to each of the threshold values. Then, at the time of light projection of the light projecting element, a fifth threshold value is set between the normal voltage level and the element short circuit voltage level at the light projecting connection terminal when the light projecting element is short-circuited. When the threshold value in the abnormality detection operation of the light receiving abnormality detection means is in addition to the threshold values, the false connection voltage level when the light projecting element is not projecting light, and when the light receiving element is short-circuited A fifth threshold value is set to a sixth threshold value between the element short-circuit voltage levels at the light-receiving connection terminal portion, and the storage means stores fifth and sixth threshold values corresponding to abnormality detection based on the fifth and sixth threshold values, respectively.
The control means reads out the corresponding display pattern from the storage means and displays it on the digital display means in accordance with each abnormal state detected by the both abnormality detection means. It has a feature in making it.

According to a tenth aspect of the present invention, in the amplifier-separated photoelectric sensor according to any one of the sixth to ninth aspects, when the control means does not detect any abnormal state in the abnormality detecting means. It is characterized in that the level of the light receiving signal output from the light receiving element is displayed on the digital display means.

[0017]

According to the present invention, the circuit connecting the light projecting element and the connecting terminal section is broken or the light projecting is performed based on the voltage level at the connection terminal section (for projecting light) at the time of projecting light. "Open / abnormality" in which the element is open, "wrong connection abnormality" in which the light receiving head unit is erroneously connected, and "element short-circuit abnormality in which the light projecting element is short-circuited" are detected separately. Further, based on the voltage level at the connection terminal portion (for light reception) during non-light emission, the circuit connecting the light receiving element and the connection terminal portion is broken, or the light receiving element is opened "open / open abnormality", The "erroneous connection abnormality" in which the head unit is erroneously connected and the element short-circuit abnormality in which the light receiving element is short-circuited are also detected separately. The display pattern corresponding to each abnormality is read from the storage means and displayed on the digital display means.

With such a configuration, looking at the digital display means of the amplifier section, "disconnection / opening abnormality", "erroneous connection abnormality" and "short circuit abnormality" on the light emitting side, and "disconnection on the light receiving side""Error","wrong connection error" and "short circuit error"
Any of the abnormal states can be immediately known, which allows the operator to quickly deal with each abnormal state.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. The amplifier-separated photoelectric sensor 10 according to the present embodiment includes a light projecting element 12 (for example, a light emitting diode), and a light projecting head unit 11 including a signal line L1 connected to the light projecting element 12, and a light receiving element. 14 (for example, a phototransistor), and its light receiving element 14
Light receiving head unit 13 formed by deriving a signal line L2 connected to
And an amplifier section 20 having two sets of connection terminal sections 21 and 22 for light projection and light reception, to which the signal lines L1 and L2 from both head sections 11 and 13 are respectively connected. The light emitting head unit 11 and the light receiving head unit 13 are
For example, the presence / absence of an object is detected based on the light reception signal D level from the light receiving element 14 which is arranged opposite to each other with a predetermined detection region interposed therebetween and changes depending on the light blocking state of the object existing between both head portions. The amplifier-separated photoelectric sensor 10 according to the present embodiment is, as will be described in detail below, the projection head unit 11.
Further, the light receiving head unit 13 is provided with an abnormality detection function capable of separately detecting "open / open abnormality", "short circuit abnormality" and "erroneous connection abnormality".

The amplifier unit 20 includes a CPU 23 functioning as a detection unit, an abnormality detection unit, a control unit, etc., a memory 28 corresponding to a storage unit, and a digital display unit 27 corresponding to a digital display unit (for example, 7 segments 4 digits). Display liquid crystal display) and. One of the connection terminals 21A for projecting light is a transistor whose one collector terminal is connected to the DC power supply Vcc through a bias resistor and which receives a drive pulse P from the CPU 23 to perform a switching operation. 24 is connected to the emitter side, and the other connection terminal 21B is connected to the ground line. Also, both connection terminals 21A, 21B
Between them, two resistors 25, 25 are connected in series,
For example, the voltage level V of the connection point of these resistors 25, 25
1 is given to the CPU 23.

One of the light-receiving connection terminal portions 22 is connected to the DC power source Vcc via a bias resistor and to the CPU 23 via a DC voltage removing capacitor 26. The other connection terminal 22B is connected to the ground line. Also,
The voltage level V2 of the one connection terminal 22A is the CPU2.
It is given to three.

Further, the CPU 23 uses the transistor 2
A drive signal (light projecting pulse P) is given to 4 at a predetermined timing. As a result, the light projecting element 12 of the light projecting head portion 11 connected to the light projecting connection terminal portion 21 emits light to perform a light projecting operation. Further, the CPU 23 reads the light reception signal D level given via the capacitor 26 from the light receiving element 14 of the light receiving head portion 13 connected to the light receiving connection terminal portion in synchronization with the output timing of the drive signal. Then, an object detection operation that compares the received light signal D level with a predetermined reference value, a measurement operation that measures the received light amount based on the received light signal D level, and the like are performed, and a display pattern corresponding to the result is digitally displayed. It is displayed on the section 27.

The CPU 23 reads the voltage level 1 when the drive signal is output (hereinafter referred to as "light projection"), as will be apparent from the description of the operation described later.
In the projection abnormality detection operation of comparing the magnitude with the first, second, and fifth threshold values X1, X2, and X3 described below, and when the drive signal is not output (hereinafter, “non-projection”) The second voltage level is read, and a light reception abnormality detection operation is performed to compare the magnitude with the third, fourth and sixth threshold values Y1, Y2 and Y3 described below.

Next, the above-mentioned first to fourth threshold values will be described with reference to FIGS. 2 to 4. First, looking at the voltage level V1 at the time of light projection, when the light projection head unit 11 connected to the light projecting connection terminal unit 21 normally performs a light projecting operation (see FIG. 1), The voltage between the connection terminals 21A and 21B becomes the same level as the terminal voltage of the light projecting element 12, and becomes a level obtained by dividing the voltage by the resistors 25 and 25 (hereinafter, "normal voltage level V1a"). on the other hand,
As shown in FIG. 2A, for example, when the signal line L1 connected to the light projecting head unit 11 is broken or the light projecting element 12 is opened, the output current from the transistor 24 is entirely transferred to the resistors 25 and 25. The current flows, and accordingly, the voltage is pulled to the potential side of the DC power supply Vcc and becomes a high level (hereinafter, "voltage level V1b during disconnection"). In addition, as shown in FIG. 3B, the light-receiving head portion 13 is erroneously attached to the light-projecting connection terminal portion 21.
In the case of an erroneous connection in which the signal line L2 connected to is connected, the light-receiving element 14 is turned on, and accordingly the level between the normal voltage level V1a and the disconnection voltage level V1b ( Hereafter, "voltage level V1c at incorrect connection"). Further, as shown in FIG. 3C, when the light projecting element 12 of the light projecting head section 11 connected to the projecting connection terminal section 21 is short-circuited, the level becomes the ground level (0).

Therefore, in the present embodiment, as shown in FIG. 4A, the first threshold value X1 is set to, for example, the voltage level V at the time of disconnection.
Set to an intermediate level between 1b and the voltage level V1c at the time of incorrect connection,
The second threshold value is set to, for example, an intermediate level X2 between the voltage level V1c at the time of incorrect connection and the voltage level V1a at the time of normal operation, and the fifth threshold
The threshold value is set to, for example, an intermediate level X3 between the normal voltage level V1a and the ground level.

Next, the voltage level V2 during non-light projection
When the light receiving head portion 13 connected to the light receiving connection terminal portion 22 normally performs the light receiving operation (see FIG. 1), a minute current flows through the resistor connected to the DC power supply Vcc. That is, the load voltage of the resistor is slightly lower than the potential level of the DC power supply Vcc (hereinafter,
“Normal voltage level V2a”). On the other hand, FIG. 3 (D)
As shown in, for example, when the signal line L2 connected to the light receiving head unit 13 is broken or the light receiving element 14 is opened, no current flows from the DC power supply Vcc, and the voltage level of the DC power supply Vcc is almost the same level ( Hereinafter, it is held at "voltage level V2b during disconnection"). Further, as shown in FIG. 7E, the light-receiving connection terminal portion 22 is erroneously attached to the light-projecting head portion 1.
In the case of an incorrect connection in which the signal line L1 connected to 1 is connected,
The current from the DC power supply Vcc flows into the light projecting element 12, and is held at the terminal voltage level of the light projecting element 12 (hereinafter, "voltage level V2c at the time of short circuit"). Further, as shown in FIG. 6F, when the light receiving element 14 of the light receiving head portion 13 connected to the light receiving connection terminal portion 22 is short-circuited, the level becomes the ground level (0).

Therefore, in the present embodiment, as shown in FIG. 4B, the third threshold value Y1 is set to, for example, the voltage level V at the time of disconnection.
2b is set to an intermediate level between the normal voltage level V1a, the fourth threshold value Y2 is set to, for example, an intermediate level between the normal voltage level V1a and the incorrect connection voltage level V2c, and the sixth threshold value Y3 is set to For example, it is set to an intermediate level between the voltage level V2c and the ground level at the time of incorrect connection.

A plurality of display codes are stored in the memory 28 in association with each abnormal state detected based on the above threshold values, and the CPU 23 (control means) in accordance with the detection operation of each abnormal state. (Corresponding to) and various display codes as shown in FIG. 5 are displayed on the digital display unit 27.

Next, the operation of the CPU 23 will be described with reference to the flow charts shown in FIGS.
As shown in FIG. 6, the drive signal is output at the output timing of the drive signal (“Y” in step S1), and the timing is not the projection abnormality detection timing (step S3).
("N"), the received light signal D is captured, the above-described light receiving operation is performed, and object detection is executed (step S6). On the other hand, if it is the light emission abnormality detection timing (“Y” in step S3), the voltage level V1 is fetched and the light emission abnormality routine is executed (steps S4 and S5).

[Detection of light emission abnormality] In the light emission abnormality routine,
As shown in FIG. 7, first, in step S21, the voltage level V1 is compared with the first threshold value X1, and if the voltage level is higher than this (“Y” in step S21), disconnection /
The display code 1 is read from the memory 28 as an opening abnormality (see FIG. 2 (A)), which means a disconnection / opening abnormality, for example, "* E **" (* indicates a space, and the digital display unit 27 does not light up. The same applies hereinafter) is displayed on the digital display unit 27 (step S22; see FIG. 5A). On the other hand, if it is lower than the first threshold value X1 (step S2
1 is “N”), the second threshold value X2 is compared in step S23, and if the level is higher than this (“Y” in step S23), it is determined as an erroneous connection abnormality (see FIG. 2B). Meaning "*** d" (corresponding to display code 2) is displayed on the digital display unit 27 (step S2).
4. See FIG. 5B).

If it is lower than the second threshold value X2 ("N" in step S23), the third threshold value X3 is obtained in step S25.
If the level is higher than this (step S2
5 "Y"), short circuit abnormality (see FIG. 2C),
This means, for example, “* E * d” (corresponding to the display code 3) is displayed on the digital display unit 27 (step S
26. See FIG. 5C). On the other hand, if it is lower than the fifth threshold value X3 (“N” in step S25), the normal state is set and the above-described light receiving operation is performed in step S6 of FIG.

Next, when it is not the output timing of the drive signal ("N" in step S1), at the light reception abnormality detection timing ("Y" in step S7), the voltage level V2 is fetched and the light reception abnormality routine is executed. (Steps S8, S9).

[Light-Reception Abnormality Detection] In the light-reception abnormality routine,
As shown in FIG. 8, first, in step S31, the voltage level V2 is compared with the third threshold value Y1. If the voltage level is higher than this (“Y” in step S31), disconnection /
This means an opening abnormality (see FIG. 3D),
For example, "-d **" (corresponding to the display code 4) is displayed on the digital display unit 27 (step S32, FIG. 5D).
reference). On the other hand, if it is lower than the third threshold value Y1, (step S
If the level is higher than this ("Y" in step S33), the light reception abnormality detection operation is terminated.

Further, if it is lower than the fourth threshold value Y2 ("N" in step S33), the sixth threshold value Y in step S34.
3 and if the level is higher than this (step S
At 34, "Y"), and an erroneous connection abnormality (see FIG. 3E), which means this, for example, "**-E" (corresponding to the display code 5) is displayed on the digital display unit 27 (step). S35, refer to FIG. On the other hand, if it is lower than the sixth threshold value Y3 (“N” in step S34), a short circuit abnormality (FIG. 3).
(See (F)) means that, for example, “-d-
"E" (corresponding to the display code 6) is displayed on the digital display unit 27 (step S36; see FIG. 5F).

The light emission abnormality detection timing in step S3 and the light reception abnormality detection timing in step S7 in FIG. 6 may be the same time intervals as the output timing of the drive signal, but they are not necessarily on the light emission side. The abnormality detection operation on the light receiving side does not have to be executed for each light projecting / receiving operation for the object detecting operation, and may be set to a time interval longer than the drive signal output timing, for example. Further, when various abnormalities are detected, the control operation may be stopped while displaying the abnormality on the digital display unit 27. Further, at that time, a configuration may be added to notify the operator that an abnormality has been detected by a predetermined notification means such as issuing a warning sound.

With such a configuration, when looking at the digital display section 27 provided in the amplifier section 20, "disconnection / open abnormality", "erroneous connection abnormality" and "short circuit abnormality" on the light emitting side, light reception "Disconnection / opening abnormality", "wrong connection abnormality" and "short circuit abnormality" can be identified and recognized for each side, which enables the operator to quickly deal with each abnormal state. Become.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications within the scope of the invention.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an amplifier-separated photoelectric sensor according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing various abnormal states on the light projecting side.

FIG. 3 is an explanatory diagram showing various abnormal states on the light receiving side.

FIG. 4 is a relationship diagram between voltage levels V1 and V2 and thresholds.

FIG. 5 is a schematic diagram showing a display pattern of a digital display unit 27.

FIG. 6 is a flowchart of CPU23 control.

FIG. 7 is a flowchart showing a projection abnormality routine.

FIG. 8 is a flowchart showing a light reception abnormality routine.

[Explanation of symbols]

10 ... Amplifier separated photoelectric sensor 11 ... Projection head section 12 ... Projecting element 13 ... Light receiving head 14 ... Light receiving element 20 ... Amplifier section 21, 22 ... (for light emission / light reception) connection terminals 23 ... CPU 25 ... resistance 27 ... Digital display 28 ... Memory V1, V2 ... Voltage level

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G065 AA04 AB14 AB28 BA07 BC04                       BC07 BC14 BC22 BC31 BC33                       BC35 BD01 DA03 DA15                 5J050 AA35 AA42 AA46 BB18 BB20                       DD03 EE39 FF04 FF08                 5K035 AA07 CC01 CC10 DD03 EE04                       FF01 GG01 KK04

Claims (10)

[Claims] 1. A detection head including a photoelectric element, a connection terminal portion detachably connected to the photoelectric element of the detection head, and a magnitude comparison between a voltage level of the connection terminal portion and a threshold value. In an amplifier-separated photoelectric sensor including an amplifier unit having an abnormality detection unit that performs an abnormality detection operation, the threshold value in the abnormality detection operation of the abnormality detection unit is:
A plurality of digital display means and a plurality of display patterns on the digital display means are provided on the amplifier section by the abnormality detection means, based on the voltage level of the connection terminal portion in each abnormal state. A storage unit that stores the abnormal states in association with each of the various abnormal states, and a display pattern associated with the detected abnormal state among the plurality of display patterns stored in the storage unit during the abnormality detection operation. An amplifier-separated photoelectric sensor, comprising: a control unit for reading and displaying on the digital display unit. 2. A light projecting head unit including a light projecting element for projecting light toward a detection region, and a connecting terminal unit for light projecting detachably connected to the light projecting element of the light projecting head unit. And a drive means for pulse-driving a drive signal to the light projecting element at a predetermined timing via the connection terminal portion, and an abnormality detection operation based on the magnitude comparison of the voltage level and the threshold value at the connection terminal portion. A head-separated photoelectric sensor light-projecting device comprising: a main body portion having an abnormality detecting means for performing the operation, wherein the abnormality detecting means includes a voltage level of the connection terminal portion when the light-emitting element emits light; It is configured to perform an abnormality detection operation based on a magnitude comparison with the threshold value, and the threshold value is such that when the light projecting element projects light, the circuit connecting the light projecting element and the connection terminal portion is broken, or When the light emitting element is open, A disconnection / open abnormal voltage level at the terminal portion and a erroneous connection voltage level at the connection terminal portion when a light receiving head portion having a light receiving element is erroneously connected to the connection terminal portion 1 threshold value and a second threshold value between the incorrect connection voltage level and the normal voltage level at the connection terminal section in the normal state, and the main body section is provided with a digital display means and its digital display. Storage means for storing a first display pattern corresponding to abnormality detection based on the first threshold value and a second display pattern corresponding to abnormality detection based on the second threshold value; and detection by the abnormality detection means. Head-separated light, comprising: a control unit that reads out the display pattern corresponding to the abnormal state from the storage unit and displays the digital pattern on the digital display unit according to the abnormal state. Projector of electric sensor. 3. The abnormality detection operation of the abnormality detection means, wherein the threshold value is, in addition to the first and second threshold values, the normal voltage level and the projection value when the projection element projects light. A third display pattern corresponding to an abnormality detection based on the third threshold value is set in the storage means while being set to a third threshold value between the element short-circuit voltage levels at the connection terminal portion when the element is short-circuited. The control unit is configured to store the abnormality detection based on the third threshold value.
The light projecting device for a head-separated photoelectric sensor according to claim 2, wherein the third display pattern is read from the storage means and displayed on the digital display means. 4. A light receiving head portion including a light receiving element for receiving light emitted from a light projecting device; a light receiving connection terminal portion detachably connected to the light receiving element of the light receiving head portion; Detection means for performing a predetermined detection operation based on a light reception signal received from the light receiving element via the connection terminal portion, and abnormality detection for performing an abnormality detection operation based on the magnitude comparison of the voltage level and the threshold value at the connection terminal portion. A light receiving device of an amplifier-separated photoelectric sensor including an amplifier unit including means, wherein the abnormality detecting unit includes a voltage level and the threshold value at the connection terminal unit when the light projecting device is not projecting light. Is configured to perform the abnormality detection operation on the basis of the magnitude comparison of the light receiving element and the threshold value, when the light projecting device is not projecting light, the circuit connecting the light receiving element and the connection terminal portion is broken, or the light receiving element is Is open Disconnection at the connection terminal portion when /
A first threshold value between the open abnormal voltage level and the normal voltage level at the connection terminal section in the normal state, the normal voltage level, and the projection head section provided with a projection element at the connection terminal section. Is set to a second threshold value between erroneous connection voltage levels at the connection terminal section when the connection section is erroneously connected, and the amplifier section includes a digital display unit and the digital display unit including the first display unit. Storage means for storing a first display pattern corresponding to abnormality detection based on a threshold value and a second display pattern corresponding to abnormality detection based on the second threshold value; and each abnormality state detected by the abnormality detection means. According to another aspect of the present invention, there is provided a light receiving device for an amplifier-separated photoelectric sensor, comprising: a control unit that reads out the corresponding display pattern from the storage unit and displays the display pattern on the digital display unit. 5. The abnormal connection voltage level of the threshold value in the abnormality detection operation of the abnormality detection means, in addition to the first and second threshold values, when the light projecting element is not projecting light.
And a third threshold value set between the element short circuit voltage levels at the connection terminal portion when the light receiving element is short-circuited, and the storage means stores a third threshold value corresponding to abnormality detection based on the third threshold value. It is configured to store three display patterns, and the control unit is configured to detect an abnormality based on the third threshold,
The light receiving device for an amplifier-separated photoelectric sensor according to claim 4, wherein the third display pattern is read from the storage means and displayed on the digital display means. 6. A light-projecting head unit including a light-projecting element for projecting light toward a detection region, and a light-receiving head unit including a light-receiving element for receiving light projected from the light-projecting element, The light projecting element of the light projecting head section and the light receiving element of the light receiving head section are detachably connected, and a projecting and receiving light receiving connection terminal section and the projecting connection terminal section through the projecting connecting terminal section. Driving means for applying a drive signal to the optical element at a predetermined timing to perform pulse driving, detecting means for performing a predetermined detection operation based on a light receiving signal received from the light receiving element via the light receiving connection terminal portion, and each of the above An amplifier-separated photoelectric sensor including an amplifier unit having an abnormality detection unit that performs an abnormality detection operation based on a comparison of the voltage level at a connection terminal unit and a threshold value, wherein the abnormality detection unit is a light projecting unit. Operates synchronously when the element emits light The projection abnormality detecting unit and the light reception abnormality detecting unit that operates in synchronization with non-projecting, the threshold value in the abnormality detection operation of the projection abnormality detecting unit, when projecting the light emitting element, A circuit connecting the light projecting element and the light projecting connection terminal section is broken, or a wire break / open abnormal voltage level at the projecting connection terminal section when the light projecting element is open, and A first threshold value between the erroneous connection voltage levels at the light emitting connection terminal portion when the light receiving head portion including the light receiving element is erroneously connected to the light emitting connection terminal portion, and the erroneous connection voltage And a second threshold value between the normal voltage level at the light-projection connection terminal portion in the normal state, and the threshold value in the abnormality detection operation of the light-reception abnormality detection means is When not projecting light, the light receiving element and the Circuit disconnection optical connection terminal portion is contiguous, or,
A disconnection / open abnormal voltage level at the light receiving connection terminal portion when the light receiving element is open, and a third threshold value between the normal voltage level at the light receiving connection terminal portion when normal, Fourth between the normal voltage level and the erroneous connection voltage level at the light receiving connection terminal portion when the light emitting head portion including the light emitting element is erroneously connected to the light receiving connection terminal portion. A threshold value, the amplifier section stores digital display means, and the digital display means stores first to fourth display patterns corresponding to abnormality detection based on the first to fourth threshold values, respectively. Storage means, and control means for reading the display pattern corresponding to each of the abnormal states detected by the both abnormality detection means from the storage means and displaying the read display pattern on the digital display means. Amplifier separate type photoelectric sensor, characterized in that. 7. A light projecting head unit including a light projecting element for projecting light toward a detection region, and a light receiving head unit including a light receiving element for receiving light projected from the light projecting element, The light projecting element of the light projecting head section and the light receiving element of the light receiving head section are detachably connected, and a projecting and receiving light receiving connection terminal section and the projecting connection terminal section through the projecting connecting terminal section. Driving means for applying a drive signal to the optical element at a predetermined timing to perform pulse driving, detecting means for performing a predetermined detection operation based on a light receiving signal received from the light receiving element via the light receiving connection terminal portion, and each of the above An amplifier-separated photoelectric sensor including an amplifier unit having an abnormality detection unit that performs an abnormality detection operation based on a comparison of the voltage level at a connection terminal unit and a threshold value, wherein the abnormality detection unit is a light projecting unit. Operates synchronously when the element emits light The projection abnormality detecting unit and the light reception abnormality detecting unit that operates in synchronization with non-projecting, the threshold value in the abnormality detection operation of the projection abnormality detecting unit, when projecting the light emitting element, A circuit connecting the light projecting element and the light projecting connection terminal section is broken, or a wire break / open abnormal voltage level at the light projecting connection terminal section when the light projecting element is open, and a normal state. Is set to a first threshold value between normal voltage levels at the light projecting connection terminal portion, and the threshold value in the abnormality detecting operation of the light receiving abnormality detecting means is when the light projecting element is not projecting, The circuit in which the light receiving element and the light receiving connection terminal portion are connected is broken, or
Set to a third threshold value between a wire break / open abnormal voltage level at the light receiving connection terminal portion when the light receiving element is open and a normal voltage level at the light receiving connection terminal portion when the light receiving element is normal. The amplifier section includes digital display means, and storage means for storing first and third display patterns corresponding to abnormality detection based on the first and third thresholds in the digital display means. An amplifier separation device, comprising: a control unit that reads out the corresponding display pattern from the storage unit and displays the display pattern on the digital display unit according to each abnormal state detected by the both abnormality detection units. Type photoelectric sensor. 8. A light-projecting head unit including a light-projecting element for projecting light toward a detection region, and a light-receiving head unit including a light-receiving element for receiving light projected from the light-projecting element, The light projecting element of the light projecting head section and the light receiving element of the light receiving head section are detachably connected, and a projecting and receiving light receiving connection terminal section and the projecting connection terminal section through the projecting connecting terminal section. Driving means for applying a drive signal to the optical element at a predetermined timing to perform pulse driving, detecting means for performing a predetermined detection operation based on a light receiving signal received from the light receiving element via the light receiving connection terminal portion, and each of the above An amplifier-separated photoelectric sensor including an amplifier unit having an abnormality detection unit that performs an abnormality detection operation based on a comparison of the voltage level at a connection terminal unit and a threshold value, wherein the abnormality detection unit is a light projecting unit. Operates synchronously when the element emits light The projection abnormality detecting unit and the light reception abnormality detecting unit that operates in synchronization with non-projecting, the threshold value in the abnormality detection operation of the projection abnormality detecting unit, when projecting the light emitting element, An erroneous connection voltage level at the light projecting connection terminal section when a light receiving head section having a light receiving element is erroneously connected to the light projecting connection terminal section, and the light projecting connection section when the light emitting head section is normal The second threshold value between normal voltage levels at the connection terminal portion is set to the second threshold value, and the threshold value in the abnormality detection operation of the light reception abnormality detection means is normal when the light projecting element is not projecting light. Voltage level at the light-receiving connection terminal portion and the wrong connection voltage at the light-receiving connection terminal portion when the light-emitting head portion including the light-emitting element is erroneously connected to the light-receiving connection terminal portion And a fourth threshold between levels and And a storage unit for storing, in the digital display unit, second and fourth display patterns corresponding to abnormality detection based on the second and fourth thresholds, respectively. An amplifier-separated photoelectric sensor, comprising: a control unit that reads out the display pattern corresponding to each abnormal state detected by the abnormality detection unit from the storage unit and displays the display pattern on the digital display unit. . 9. The normal voltage level and the light projecting element are short-circuited when the light projecting element projects light, in addition to the threshold values in the abnormality detecting operation of the light projecting abnormality detecting means. Is set to a fifth threshold value between the element short-circuit voltage levels at the light projecting connection terminal section at the time, and the threshold value in the abnormality detecting operation of the light receiving abnormality detecting means is, in addition to the threshold values, The storage unit is set to a sixth threshold value between the erroneous connection voltage level and the element short-circuit voltage level at the light-receiving connection terminal when the light-receiving element is short-circuited when the optical element is not projecting light. Is configured to store fifth and sixth display patterns corresponding to the abnormality detection based on the fifth and sixth thresholds, respectively, and the control unit is configured to store each of the detection patterns detected by the abnormality detection units. Depending on the abnormal condition, 9. The amplifier-separated photoelectric sensor according to claim 6, wherein the corresponding display pattern is read from the storage means and displayed on the digital display means. 10. The control means is configured to display the level of a light reception signal output from the light receiving element on the digital display means when the abnormality detection means detects no abnormality. The amplifier-separated photoelectric sensor according to any one of claims 6 to 9, wherein