JP2000321364A - Foreign substance detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a foreign substance and the size by a simple mechanism by constituting the device so that counter electrodes can move in the direction of enlarging the clearance and return to the original position, when a specimen exceeding the clearance passes through the clearance. SOLUTION: This device is provided with a sensor part having a first sensor 11 and a second sensor 12 which are separated upper and lower and opposite to each other. On the underbase of the first sensor 11, a first electrode plate 31 is provided, and on the upper face of the second sensor 12, an electrode part 21 in the running direction divided into a second electrode plate 32 and a third electrode plate 33, and an electrode part 22 in the width direction divided into a fourth electrode plate 34 and a fifth electrode plate 35 are provided. A mail matter passing between the first and second sensor parts 11, 12 changes the dielectric constant due to the material or the like. When a mail matter of thickness exceeding the clearance between both sensors is carried, the first sensor 11 is pushed by the thickness to move upward, and after passing through, it is returned to the fixed position by a spring. Length and width of the mail matter can be judged by the respective receiving level and the receiving time of the second/third electrode plates 32, 33 of the electrode part 21 in the running direction and the fourth/fifth electrode plates 34, 35 of the electrode part 22 in the width direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foreign object detecting device, and more particularly, to a foreign object detecting device capable of detecting a foreign object in a mail or an abnormal thickness.

[0002]

2. Description of the Related Art In a conventional foreign matter detector of a mail sorting machine, only the thickness, overlap and the like of a mail are detected. Some mail items are enclosed with metal objects of a thickness that cannot be eliminated by the foreign object detector, which has been one of the causes of the failure of the sorting machine. Therefore, in order to add a metal detection function to the sorting machine, a dedicated sensor of a type utilizing a change in an electromagnetic field was attached to detect and eliminate metal objects mixed in mail.

[0003]

However, this prior art has the following problems. First, there is a problem that it is difficult to detect the size and thickness of a metal piece.
Therefore, thin postcards with labels or the like containing metal paint etc. should be classified,
There is a problem that the conventional foreign matter detector has erroneously detected and sent to the foreign matter exclusion box.

Further, in the conventional foreign matter detector, there is a problem that the thickness abnormality detecting device for detecting the thickness of postal matter and the foreign matter detector are separate, and the structure of the device is complicated and the device is relatively large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a foreign object detecting apparatus capable of detecting an abnormal thickness and an abnormal thickness by using a simple mechanism, and detecting the size of the foreign object using a simple mechanism. It is an object of the present invention to provide a foreign object detection device and a foreign object detection device having both of these functions.

[0006]

According to a first aspect of the present invention, there is provided a foreign matter detection device according to the first aspect of the present invention, wherein an object to be inspected is passed between a pair of opposing electrodes and the dielectric constant of the opposing electrode changes. In a foreign matter detection device for detecting foreign matter in an inspection object, the counter electrode can move in a direction in which the separation distance increases when the inspection object passes beyond the separation distance and can return to the original position. Is composed of, and
It is configured to include a movement detection device that detects movement of the counter electrode.

According to the invention having such a configuration, when an inspection object having an abnormal thickness passes beyond the separation distance of the counter electrode, the counter electrode moves so as to increase the separation distance, and the movement of the counter electrode moves. By detecting with the detecting device, the thickness of the inspection object can be detected by the foreign object detector, and both the foreign object detection and the thickness abnormality detection can be performed by one detecting device.

The foreign object detection device according to claim 2, wherein the object to be inspected is passed between a pair of opposed electrodes, and the foreign object of the object to be inspected is detected by a change in the dielectric constant of the opposed electrode. One of the opposing electrodes is composed of a traveling direction electrode portion composed of a plurality of electrodes arranged in the passing direction of the inspection object, and a plurality of electrodes arranged in a direction orthogonal to the passing direction of the inspection object. And a width-directional electrode portion.

According to the invention having such a configuration, the size of the foreign matter in the traveling direction is determined based on the reception level and the reception time of the traveling direction electrode section while the object to be inspected is conveyed through the traveling direction electrode section. Can be. In addition, the size of the foreign matter in the width direction can be determined based on the reception level and the reception time of the width direction electrode portion while the inspection object is conveyed through the width direction electrode portion. Therefore, the size of the foreign matter can be determined by the traveling direction electrode portion and the width direction electrode portion.

The foreign object detection device according to claim 3, wherein the object to be inspected is passed between a pair of opposed electrodes, and the object to be inspected is detected by a change in the dielectric constant of the opposed electrode. The counter electrode is configured to be movable in a direction in which the separation distance increases when the object to be inspected that exceeds the separation distance passes and to be able to return to the original position, and to detect the movement of the counter electrode. A movement detection device, and one of the opposing electrodes has a traveling direction electrode portion composed of a plurality of electrodes arranged in the passing direction of the inspection object, and a direction perpendicular to the passing direction of the inspection object. And a width direction electrode portion composed of a plurality of arranged electrodes.

According to the invention having such a configuration, claim 1 is provided.
Since the foreign matter detection device has the configuration described in claim 2 and the configuration described in claim 2, it is possible to determine the size of the foreign matter with one detection device and to detect the thickness abnormality of the inspection object. it can.

According to a fourth aspect of the present invention, there is provided a foreign matter detection device.
Alternatively, in the foreign matter detection device according to 3, the traveling direction electrode portion and the width direction electrode portion are each configured by a combination of an electrode to which a voltage is applied and an electrode to which a voltage is not applied. According to the invention having such a configuration, when a voltage is applied to the electrode, the dielectric constant is determined between the electrode and the electrode to which the voltage is not applied. Can be detected.

According to a fifth aspect of the present invention, there is provided a foreign matter detection device.
Alternatively, in the foreign object detection device according to Item 3, the movement detection device includes a switch that is turned on / off as the counter electrode moves. According to the invention having such a configuration,
By turning on / off the switch, an abnormality in the thickness of the inspection object can be detected.

According to a sixth aspect of the present invention, there is provided a foreign matter detecting device.
6. The foreign matter detecting device according to any one of the above-described items 5, wherein substantially the entire surface of each of the pair of counter electrodes opposite to the surface facing each other is covered with a grounded ground electrode. According to the invention having such a configuration, since the outer surface side is almost entirely shielded by the grounded electrode, the opposite electrode can be protected from external noise, and the detection accuracy of foreign metal is excellent.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the foreign matter detecting device of the present invention will be described below with reference to the drawings. FIG.
It is a schematic structure figure showing the sensor part of the foreign object detecting device of the present invention. In this figure, a mail, which is an inspection object, is conveyed, and the conveyance direction passing through the sensor unit is defined as an x-axis.
The horizontal direction perpendicular to the axis is the y axis, and the vertical direction perpendicular to the x axis is the z axis.

The sensor section includes a first sensor 11 and a second sensor 12 as a pair of counter electrodes which are spaced apart from each other by a predetermined distance in the z-axis direction and face in parallel. Upper first
On the lower surface of the insulating substrate 110 of the sensor 11, the first sensor 1
A first electrode plate 31 that substantially covers the lower surface of the first electrode plate 1 is provided.
Further, the upper surface of the first sensor is almost covered with a ground electrode plate 111 connected to GND.

On the upper surface (the surface facing the first sensor) of the insulating substrate 120 of the lower second sensor 12, a traveling direction electrode portion 21 and a width direction electrode portion 22 are provided. The traveling direction electrode portion 21 is divided into a second electrode plate 32 and a third electrode plate 33 in the passing direction of the object to be inspected, and the second electrode plate 32 and the third electrode plate 33 are moved in the mail transport direction. , And are arranged in the x-axis direction with a slight gap therebetween. The voltage is applied to the second electrode plate 32.

The width direction electrode portion 22 has a fourth electrode 34 and a fifth electrode 3 in the y-axis direction orthogonal to the passing direction of the inspection object.
The fourth electrode plate 34 and the fifth electrode plate 35 are arranged in the y-axis direction with a slight gap therebetween. The total distance of the fourth electrode plate 34 and the fifth electrode plate 35 in the y-axis direction is substantially equal to the width of the second electrode plate 32 and the third electrode plate 33, and covers the width of mail. Voltage is 4th
The voltage is applied to the electrode plate 34. The lower surface of the insulating substrate 120 of the second sensor 12 is almost covered with a ground electrode plate 121 connected to GND.

The first sensor 11 and the second sensor 12
For example, using a printed board of double-sided copper foil, one copper foil is patterned into the shape of the first electrode plate 31 to the fifth electrode plate 35 on the opposite side, and the copper foil on the opposite side is grounded.
It can be manufactured by setting it to 121.

When a voltage is applied to the second electrode plate 32 and the fourth electrode plate 34, an electric field is generated between the first sensor 11 and the second sensor 12. The generated electric field is applied to the first electrode plate 31,
The dielectric constant is determined by the reception at the electrode plate 33 and the fifth electrode plate 35.

As shown in FIG. 2, the first sensor 11 is pushed by the thickness of the mail when a mail having a thickness exceeding the distance between the first sensor 11 and the second sensor 12 is conveyed. And the distance between the first sensor 11 and the second sensor 12 is increased, and a downward force is always applied by the spring 50.
The second sensor 1 which is fixed when the mail passes through
2 and returns to a fixed position having a predetermined separation distance from the second position.

The first sensor 11 is mechanically connected to a switch 41 for turning on / off between two electrodes of a switching element 40 as a movement detecting device, and when the first sensor 11 is pushed by mail and rises, The switch 41 also rises to turn off the switching element 40, and when the first sensor 11 returns to the original position, the switch 41 also returns to the original position, and the switching element 40 is turned on.

Next, a description will be given of a method of detecting the sensor portion of the foreign object detecting device having the above-described configuration. The conveyed mail passes between the first sensor 11 and the second sensor 12, and there is no mail due to the material of the mail and the substance contained therein by the first electrode plate 31 to the fifth electrode plate 35. The dielectric constant changes as compared with the case. In particular, the dielectric constant greatly changes due to a metal foreign matter.

In the case of a metal foreign object long in the x-axis direction like the metal foreign object 101 in FIG. 1, the length is longer depending on the reception level and the reception time of the second electrode plate 32 and the third electrode plate 33 constituting the traveling direction electrode portion 21. Can be determined. Further, the metal foreign matter 1 shown in FIG.
In the case of a metal foreign substance that is long in the y-axis direction, such as 02, the fourth electrode plate 34 and the fifth electrode plate 35
The width can be determined based on the reception level and the reception time.

As described above, since the size in the running direction can be determined by the running direction electrode portion 21 and the size in the width direction can be determined by the width direction electrode portion 22, the size of the foreign matter can be determined by combining these. The reception signal of the first electrode plate 11 detects a foreign substance whose thickness is within a specified range. As described above, it is determined whether or not the signal input from each electrode plate is a metal object exceeding the specified value.

Also, since the ground electrode plates 111 and 121 connected to GND are provided so as to substantially cover the outside of the first sensor 11 and the second sensor 12, these ground electrode plates 111 and 121 are shielded. The first electrode plate 31 to the fifth electrode plate 35 are protected from the influence of external noise, and the detection accuracy of foreign substances is improved.

Next, a method of detecting the thickness of mail will be described. A mail having a thickness greater than a specified value, that is, a thickness exceeding the separation distance between the first sensor 11 and the second sensor 12 is the first mail item.
When sent to the sensor 11 and the second sensor 12, the first sensor 11 moves in the z-axis direction, and the switch 41 is separated.
When the switch 41 is separated, a thickness exceeding a specified value can be detected.

As described above, the foreign object detecting device having the sensor unit shown in FIGS. 1 and 2 can detect the size of the foreign object and the thickness abnormality of the mail with a single sensor unit.

Next, a foreign substance detecting device provided with the above-mentioned sensor unit will be described with reference to FIG. FIG. 3 is a configuration diagram illustrating a schematic configuration of the foreign object detection device. This foreign object detection device 1
Is provided in front of the mail sorting section, and detects and removes mail having foreign matter of a predetermined size and mail exceeding a predetermined thickness. The foreign object detecting device 1 includes a supply unit 2 for storing mail to be inspected, the first sensor 11 and the second sensor 11.
A sensor unit having a sensor 12, and a branching device 4 for separating mails going to the sorting unit and mails going to the foreign matter exclusion box 3
And a transport belt 5 as transport means for transporting mail from the supply unit 2 and transporting the mail to the sorting unit via the sensor unit and the branching device.

The branching device 4 sets the route of the transport path so that the mail is always transported to the sorting section. The electrode plates 31 to 35 of the first sensor 11 and the second sensor 12 are connected to the foreign object detection control device 6. Foreign object detection control device 6
Determines the size of the foreign matter based on the reception level and the reception time indicating the change in the dielectric constant between the electrode plates, and outputs the result to the main control device 7. The entire foreign matter detection device 1 including the foreign matter detection control device 1 and the branching device 4 is controlled by the main control device 7.

The operation of the foreign object detecting device 1 will be described with reference to FIG.
This will be described with reference to the flowchart of FIG. In step 1,
The mail conveyed by the conveying belt 5 from the supply unit 2 of the mail machine passes through the first sensor 11 and the second sensor 12. In step 2, information on each input signal from the first sensor 11, the second sensor 12, and the switching element 40 is output to the foreign object detection control device 6. In step 3, when the switch 41 is operated, the thickness is determined by the foreign object detection control device 6 to be equal to or greater than the specified thickness. In step 4, the foreign object detection control device 6 outputs an output signal of the rejection operation to the main control device 7, Step 5
Then, the main control device 7 controls the branching device 4 to change the course of the mail conveyance path, and sends the mail to the reject box 3.

Further, even when the switching element 40 does not operate, in step 7, the foreign matter detection control device 6 determines the size of the metallic foreign matter based on the signals from the first sensor 11 and the second sensor 12, and determines whether or not the size of the metallic foreign matter is larger than the specified value. It is determined whether there is a reception level. If the reception level is higher than the specified level, it is determined that a foreign matter having a size exceeding the specified level exists in the postal matter, and an output signal of the rejection operation is output to the main control device in step 4, and in steps 5 and 6, The main controller 7 controls the branching device 4 to send the mail to the foreign matter exclusion box 3.

The postal matter for which no abnormality has been detected is conveyed to the sorting section via the branching device 4. After the transfer to the sorting section or the transfer to the foreign matter exclusion box 3 is completed, the process proceeds to step 8 to detect the next postal matter.

According to such a foreign substance detection device, a special sensor for detecting a special foreign substance is not required, and a printed board made of double-sided copper foil can be used as a sensor for an electrode plate. The first sensor and the second sensor can be easily created. Also, the size of the metal object to some extent can be grasped by the input signal pattern of the electrode plate,
Mail that does not need to be removed (such as a postcard on which a thin label or the like containing metal paint or the like is affixed) can also be detected, so that the sorting efficiency is improved and the detection accuracy is excellent. Further, since a sheet having a thickness exceeding a specified thickness can be detected, it is not necessary to attach both a dedicated sensor for detecting foreign matter and a thickness detector, and the entire apparatus can be simplified and reduced in size.

In the above description, the electrode of the second sensor is divided into four, but the number of electrodes is not limited to this.
Further, the switching element is not limited to the illustrated one, and the spring may be another elastic member. Further, the inspection object is not limited to mail.

[0036]

According to the foreign matter detecting device of the present invention, the movement of the opposing electrode is detected by the movement detecting device. Therefore, the foreign object can be detected and the thickness abnormality of the inspection object can be detected. According to the foreign matter detection device of the present invention, one of the opposed electrodes is divided so that the size of the foreign matter in the traveling direction and the width direction can be detected, so that the size of the foreign matter can be determined. . Further, according to the foreign object detection device of the present invention, the movement of the opposing electrode is detected by the movement detection device, and one of the opposing electrodes is divided to separate the foreign object in the traveling direction and the width direction. Can be detected, the size of the foreign matter and the thickness abnormality of the inspection object can be detected by one sensor.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a sensor unit of a foreign object detection device according to the present invention.

FIG. 2 is a conceptual diagram illustrating an example of a thickness detection method in a sensor unit of the foreign object detection device according to the present invention.

FIG. 3 is a configuration diagram showing an example of a schematic configuration of a foreign object detection device of the present invention.

FIG. 4 is a flowchart showing a detection method of the foreign object detection device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 foreign matter detection device 2 supply unit 3 foreign matter exclusion box 4 branching device 5 transport belt 6 foreign matter detection control device 7 main control device 11 first sensor 110 insulating substrate 111 ground electrode plate 12 second sensor 120 insulating substrate 121 ground electrode plate 21 traveling Direction electrode part 22 Width direction electrode part 31 First electrode plate 32 Second electrode plate 33 Third electrode plate 34 Fourth electrode plate 35 Fifth electrode plate 40 Switching element 41 Switch 50 Spring

Claims (6)

[Claims] 1. A foreign matter detection device for detecting a foreign matter in an object to be inspected by changing an electric permittivity of the opposite electrode by passing the object to be inspected between a pair of opposed electrodes, wherein the opposed electrodes are spaced apart from each other. And a movement detection device configured to be movable in a direction in which the distance between the inspection objects becomes larger and return to an original position when the inspection object passes, and to detect movement of the counter electrode. Characteristic foreign matter detection device. 2. A foreign matter detecting device for detecting a foreign matter in an object to be inspected by changing a dielectric constant of the opposite electrode by passing the object to be inspected between a pair of opposed electrodes, wherein one of the opposed electrodes is connected to the object to be inspected. A traveling direction electrode portion composed of a plurality of electrodes arranged in the passing direction of the inspection object, and a width direction electrode portion composed of a plurality of electrodes arranged in a direction orthogonal to the passing direction of the inspection object. A foreign matter detection device, comprising: 3. A foreign matter detecting device for detecting a foreign matter in the object to be inspected by changing a dielectric constant of the opposed electrode by passing the object to be inspected between a pair of opposed electrodes, wherein the opposed electrodes are spaced apart from each other. A movement detection device configured to be movable in a direction in which the distance between the inspection objects exceeds the distance when the inspection object passes and to be able to return to an original position, and to detect movement of the counter electrode, One of the opposing electrodes is composed of a traveling direction electrode portion composed of a plurality of electrodes arranged in the passing direction of the inspection object, and a plurality of electrodes arranged in a direction orthogonal to the passing direction of the inspection object. And a width direction electrode portion. 4. The foreign matter detection device according to claim 2, wherein the traveling direction electrode portion and the width direction electrode portion are each formed of a combination of an electrode to which a voltage is applied and an electrode to which a voltage is not applied. A foreign matter detection device, characterized in that: 5. The foreign matter detection device according to claim 1, wherein the movement detection device is a switch that is turned on / off in accordance with movement of the counter electrode. 6. The foreign matter detection device according to claim 1, wherein substantially the entire surface of the pair of opposed electrodes opposite to the surface facing each other is covered with a grounded ground electrode. A foreign matter detection device characterized by the above-mentioned.