JPH10290961A - Foreign matter detecting system for paper sheets - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foreign matter detecting system for paper sheets which executes foreign matter detection by using only the detection results of a transporting state detecting means and the foreign matter detector existing in the position superposing on the paper sheets from the position of the paper sheets in the transverse direction of a belt and the set position of the foreign matter detector. SOLUTION: The belt layout of a transporting path for detecting the foreign matter is formed to a shape where four pieces of foreign matter detecting pulleys 10 are symmetrically arranged around the foreign matter detector 9. The length and the position of a letter 3A in the belt transverse direction is detected by a line sensor 8 and the foreign matter detector 9 existing in the position superposing on the letter 3 in the belt transverse direction is selected as the detector for detecting the foreign matter. The output of the selected foreign matter detector 9 and the threshold stored in a threshold memory means are compared by a foreign matter deciding means. If the output is above the threshold, the output may be decided as the foreign matter. If the foreign matter cannot be decided by the foreign matter detecting means 5, the output of a thickness detector 1 is used and is compared with the threshold for deciding the foreign matter from the output of the thickness stored in a thereshold memory means by the foreign matter deciding means and is decided to be the foreign matter if the value is above the threshold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mail letter monitoring apparatus used in a mail sorting machine, and more particularly to a foreign matter detecting apparatus for detecting the foreign matter contained in a letter.

[0002]

2. Description of the Related Art Conventionally, as an example using a sheet conveyance state detecting means, there is a method for detecting the thickness of a sheet described in Japanese Patent Application Laid-Open No. 6-329299. Was not something to do.

[0003] In addition, there are two methods for detecting foreign substances: (1) a method in which a plurality of foreign substance detectors are arranged in the belt width direction and the output of all of them is used; and (2) a belt is sandwiched between two pairs of wide pulleys. In some cases, the pulley is fixed in the belt width direction, one pulley is fixed, and the other pulley is movable, based on the amount of movement of the movable pulley when the paper sheet passes.

[0004]

An example using the above-mentioned prior art conveyance state detecting means is an apparatus for detecting a thickness at the time of conveying a sheet to prevent a double feed or a jam.
It did not relate to foreign object detection.

Further, since the width and length of the conveyed paper sheets are not constant, in the example of the foreign substance detection method (1), a foreign substance detector in a portion through which the paper sheets do not pass is also used for foreign substance detection. Therefore, detection accuracy may be reduced. Furthermore, (2)
In this example, the movable pulley is supported by a spring.
Consideration must be given to preventing vibration of the movable pulley and flapping of the pulley, and it is difficult to select a spring constant.

An object of the present invention is to use only the foreign object detector located at a position overlapping the sheet from the detection result of the conveyance state detecting means, the position of the sheet in the belt width direction, and the installation position of the foreign object detector. It is an object of the present invention to provide a foreign matter detection device for paper sheets that performs foreign matter detection.

[0007]

In order to achieve the above object, a foreign object detecting apparatus for paper sheets according to the present invention comprises a foreign object detecting means comprising a plurality of foreign object detectors arranged in a belt width direction, and a foreign object detecting device. From the transport state detecting means disposed on the upstream side of the sheet, and from the transport state detecting means, the output of only the foreign substance detector at the position overlapping the paper sheet from the position of the paper sheet in the belt width direction and the installation position of the foreign substance detector is selected. Detector control means, threshold value storage means storing in advance a threshold value for determining foreign matter, and foreign matter determination for determining foreign matter by comparing the output from the detector control means with the threshold value from the threshold value storage means Means.

According to the above construction, the foreign object detector located at a position overlapping the paper sheet is detected from the position of the paper sheet in the belt width direction and the installation position of the foreign object detector from the conveyance state detecting means, and the detector control means is provided. , Only the foreign matter detector located at a position overlapping with the paper sheet in the belt width direction is selected and output.
This output is compared with a threshold value for determining foreign matter stored in the storage means by the foreign matter determination means, and when the output is equal to or larger than the threshold value, the foreign matter can be determined. If the determination cannot be made by the output of the foreign matter detecting means, the output from the thickness detector included in the foreign matter detecting means or from the independent thickness detecting means is used for the foreign matter determination, and the threshold value storing means is used. The stored thickness is compared with a threshold value for detecting foreign matter, and if the threshold value is exceeded, it can be determined that the foreign matter is present.

According to this method, the output of the foreign matter detector located at a position that does not overlap the paper sheet in the belt width direction is not used for foreign matter determination, so that erroneous detection can be prevented. In addition, since the output of the thickness detector can also be used for foreign substance detection, foreign substances can be detected with high accuracy by using both the foreign substance detector and the thickness detector, and paper sheets containing foreign substances can be accurately detected. Since detection and rejection can be performed, high-speed sorting can be performed without impairing the transport speed of paper sheets.

[0010]

Embodiments of the present invention will be described below.

FIG. 1 shows an example of a transport path 1 provided with a foreign object detecting device according to the present invention.

As shown in FIG. 1, the conveying path 1 is a belt 2A,
2B, 2C, 2D, and 2E, and paper sheets, for example, letter 3A,
It is sandwiched between 2D and 2E and transported in the direction of the arrow shown in the figure.

The letter 3A separated by a sheet separating device (not shown) is sent to the transport path 1. The transmitted letter 3A passes through the conveyance state detection means 4 provided in the middle of the conveyance path 1, and then passes through the foreign matter detection means 5 and the thickness detection means 6 provided downstream of the conveyance state detection means 4. pass. Here, whichever of the foreign matter detecting means 5 and the thickness detecting means 6 may be provided on the upstream side, the thickness detecting means 6 may be configured to also be used as the foreign matter detecting means 5.

The foreign material referred to in the present invention refers to a material having high rigidity such as a coin, a key, a pencil, a floppy disk and the like put in a letter.

When these foreign substances are conveyed inside a letter or the like, (1) a letter jam occurs during the conveyance.
(2) The letter is broken, and (3) the foreign matter inside breaks the letter and scatters outside. Therefore, it is necessary to accurately detect and reject the letter containing the foreign matter.

Next, the configuration and operation of each means will be described.

The transport state detecting means 4 includes a linear light source 7
And a line sensor 8 as a light receiving element. One is installed on the right side of the conveyance path and the other is installed on the left side of the opposing conveyance path so as to detect a letter-like state of the conveyance path 1 in the belt width direction. Have been. The reason why the linear light source 7 and the line sensor 8 are provided in the belt width direction is to detect the length and position of the letter 3 in the belt width direction and the shape of the letter. For this purpose, the width of the belts 2A and 2B of the transport path 1 in which the transport state detecting means 4 is installed is a width capable of detecting the length and position of the letter 3 in the belt width direction. That is, the width of the belt is shorter than the length of the letter 3 in the belt width direction.

Foreign matter detecting means 5 indicated by a two-dot chain line in FIG.
Has a basic configuration in which a belt 2C suspended on four foreign substance detection pulleys 10 is symmetrically arranged about a foreign substance detector 9 as shown in the figure. In this embodiment, the foreign object detector 9 has a configuration in which a plurality of non-contact displacement gauges or a plurality of contact displacement gauges having extremely small contact resistance are arranged in parallel in the belt width direction at predetermined intervals. Using.

The transport path 1 on which the foreign matter detecting means 5 is installed
The belts 2C and 2D have a width that allows detection of the maximum length of the letter 3 in the belt width direction, and a belt width that allows the maximum length of the letter 3 in the belt width direction to be included.

FIG. 1 shows an example of waveforms when a letter containing foreign matter and a letter containing no foreign matter pass as the output of the foreign matter detector 9. By arranging the belt 2C for foreign matter detection symmetrically with respect to the foreign matter detector 9, the foreign matter detector 9
When there is no foreign matter, the output waveform has one peak, whereas when there is a foreign matter, the output waveform often has two or more peaks. This is for determining foreign matter.

FIG. 2 shows three foreign substance detectors 9A, 9B, 9
C is juxtaposed and shows an example in which the case where the position of one foreign object detector 9C does not overlap the position of letter 3 is shown. The output waveform from the foreign substance detector of FIG.

As shown in FIG. 2, the waveform of the foreign object detector 9C located at a position not overlapping the position of the letter 3 is smaller than the waveforms of the foreign object detectors 9A and 9B located at the position overlapping the position of the letter 3. Since it is output as a waveform and causes erroneous detection when used for foreign matter detection, it is difficult to use it as an output for foreign matter detection. Therefore, the length and position of the letter 3 in the belt width direction are detected by the above-described conveyance state detecting means 4, and based on the detection result, the foreign matter detector 9 located at a position overlapping the position of the letter 3 by the detector control means 11. Is selected as an output for detecting foreign matter. In FIG. 2, a foreign object is detected from the two foreign object detectors 9A and 9B. As a result, foreign matter detection can be performed using only the output of the foreign matter detector 9 located at a position overlapping with the position of the letter 3, so that erroneous detection can be prevented.

As described above, the thickness detecting means 6 can have a structure included in the foreign matter detecting means or an independent structure. Here, the independent case will be described.

As shown in FIG. 1, the thickness detecting means 6 has a rotating shaft in the width direction of the belt, and has a thickness detecting pulley 12 serving as a reference for detecting the thickness. A plurality of thickness detectors 13 are arranged on the tangent line to the belt 2 and the thickness is detected from the amount of displacement of the belt in the direction perpendicular to the belt width direction when passing the paper sheet. A plurality of non-contact or extremely small displacement gauges having a small contact resistance are arranged side by side at predetermined intervals in the belt width direction. Of the belts 2D and 2E of the conveyance path 1 where the thickness detecting means 6 is installed, the belt 2D has a width capable of detecting the maximum length of the letter 3 in the belt width direction, and the maximum length of the letter 3 in the belt width direction. The belt width should be large enough to accommodate the length. Since the thickness detection uses the tangent of the belt 2D and the thickness detection pulley 12 in the belt width direction, the belt 2E is preferably capable of sandwiching the letter 3, so that the belt width is not the same as 2D. The width may be the same as 2A or 2B.

FIG. 2 shows two thickness detectors 13A and 13A.
An example is shown in which B is juxtaposed. The thickness detector 13 also outputs a waveform similar to the foreign matter detector 9. Therefore, if the foreign matter is not determined by the foreign matter detecting means 5, in this embodiment, the thickness detecting means 6 arranged downstream of the foreign matter detecting means 5 is used.
By using the output of the thickness detector 13, the detection of foreign matter can be further detected. Since not only the foreign substance detector 9 but also the thickness detector 13 can be used for foreign substance detection, highly accurate foreign substance detection can be performed. When the thickness detector 13 is used more than the above example, the foreign matter detector 9 is used.
In the same manner as described above, using the detector control means 11 to select the thickness detector 13 overlapping the letter position from the position of the letter in the belt width direction and the installation position of the thickness detector 13 to detect foreign matter. Can be.

Next, using the example of the letter 3 in FIG. 2, FIG. 3 shows the flow of foreign matter detection.

A line sensor 8, three foreign object detectors 9A,
The outputs from 9B, 9C and the two thickness detectors 13A, 13B are sent to an A / D converter 14, where they are converted into digital signals. The length and position information of the letter 3 from the line sensor 8 are sent to the detector control means 11, and the foreign matter detectors 9A, 9B and 9C are selected by the switch 15 for foreign matter detection, and the selected two foreign matter detections are performed. For example, 9A, 9
The output of B is sent to the foreign matter determination means 16. Here, the switch 15 may be included in the detector control means 11. Further, the switching device 15 includes the thickness detectors 13A and 13A.
The selection when using the output of B is also possible. Foreign matter determination means 1
Reference numeral 6 denotes a threshold value of the threshold value storage means 17 which stores a threshold value determined from the difference between the peaks of the waveform as described above, and the threshold values of the foreign matter detectors 9A and 9B selected by the detector control means 11. The output waveforms are compared to determine foreign matter, and the waveform of the foreign matter detector 9A or 9B, or the waveform of 9A and 9B,
For example, if the waveform has two peaks as in the example of FIG.

Further, in the case where foreign matter detection is performed using the output of the thickness detecting means 6, the switching unit 15 controls the foreign matter determining means 1
6, the outputs of the thickness detectors 13A and 13B are input, and the output of the thickness detectors 13A and 13B is compared with the threshold value for judging a foreign substance from the output of the thickness stored in the threshold value storage means 17. To determine foreign matter. This determination method uses the foreign substance detector 9.
The determination can be performed by the same processing as the output from. In the case where foreign matter detection is performed using the thickness detecting means 6,
Only when the output of the thickness detector 13 is used, or when the foreign matter determining means determines that there is a high possibility that there is a foreign matter even when the waveform cannot be clearly read, for example, when there are two peaks in the waveform, the thickness is determined. It is possible to select a processing method of performing foreign object detection using the output of the detector. According to this method, the foreign substance can be detected using not only the output of the foreign substance detector but also the output of the thickness detector, so that the foreign substance can be detected with high accuracy. Although not shown in the present embodiment, paper sheets determined to contain foreign matter are discharged into a reject box provided on the exit side of the transport path in which the foreign matter detection device is arranged because the paper sheets may cause a jam or the like. By performing the transfer control described above, it is possible to prevent a reduction in the speed of the transfer processing.

[0029]

As described above, according to the present invention,
Since the foreign matter is detected using only the output of the foreign matter detector located at a position overlapping the paper sheet from the position of the paper sheet in the width direction of the passing belt and the installation position of the foreign matter detector, erroneous detection can be prevented. . Also, the output of the thickness detector can be used for foreign substance detection, and foreign substances can be detected with high accuracy by using the outputs of both the foreign substance detector and the thickness detector.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a transport path including a paper sheet foreign matter detection device according to the present invention.

FIG. 2 is a diagram illustrating outputs from a plurality of foreign matter detectors and a thickness detector.

FIG. 3 is a view for explaining a detection flow of the foreign object detection device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Conveying path, 2 ... Belt, 3 ... Paper sheet (letter letter), 4 ... Conveyance state detecting means, 5 ... Foreign matter detecting means, 6 ... Thickness detecting means, 7 ... Line light source, 8 ... Line sensor, 9: Foreign matter detector, 10: Foreign matter detection pulley, 11: Detector control means, 12: Thickness detection pulley, 13: Thickness detector, 14
... A / D converter, 15 ... Switcher, 16 ... Foreign matter determination means, 17 ... Threshold storage means.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshihiko Tajiri 1 Ikegami, Haruoka-cho, Owariasahi-shi, Aichi Pref. Information Technology Division of Hitachi, Ltd.

Claims (3)

[Claims] 1. A sheet conveying device for conveying sheets sandwiched between belts, wherein a conveying state detecting means for detecting the conveying state of the sheets is disposed downstream of the separating device. A foreign matter detecting means disposed downstream of the transport state detecting means, and when the foreign matter detecting means detects a foreign matter in the sheet, the foreign matter detecting means rejects the paper sheet containing the foreign matter. A foreign matter detection device for paper sheets, wherein the foreign matter detection device transmits the foreign matter to a control unit so as to control the conveyance to the stacking unit. 2. The apparatus according to claim 1, wherein said foreign matter detecting means comprises:
A foreign object detector that detects a plurality of displacement amounts arranged in the width direction of the belt, and a sheet sheet based on a position of the sheet in the belt width direction detected by the conveyance state detecting unit and an installation position of the foreign object detector. And a detector control means for selecting only a foreign object detector located at a position overlapping with and detecting the output of foreign object detection. 3. The apparatus according to claim 2, wherein said foreign matter detecting means comprises:
A foreign matter detection device for paper sheets, which is installed downstream of the paper sheet separation device and upstream of a character reading device, a double feed detection device, or the like.