JP3704415B2 - Foreign matter detection device for paper sheets - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a postal letter monitoring apparatus used for a postal sorting machine, and more particularly to a foreign matter detection apparatus for paper sheets that detects foreign matter contained in a letter.
[0002]
[Prior art]
Conventionally, as an example of using a paper sheet conveyance state detection means, there is a method for detecting the thickness of a paper sheet described in JP-A-6-329299, but it does not detect foreign matter. .
[0003]
In addition, the foreign matter detection methods include (1) a plurality of foreign matter detectors arranged in the belt width direction and performing from all outputs, or (2) a belt sandwiched between two wide pulleys. There is one that is attached in the belt width direction, one pulley is fixed, and the other pulley is movable, and the amount of movement of the movable pulley when the paper sheet passes is determined.
[0004]
[Problems to be solved by the invention]
The above-described example using the transport state detection means of the prior art is an apparatus for detecting a thickness during transport of paper sheets to prevent double feed, jam, etc., and is not related to foreign object detection.
[0005]
In addition, since the width and length of the conveyed paper sheets are not constant, in the example of the foreign object detection method (1), the foreign object detector in the part where the paper sheets do not pass is also used for the foreign object detection. Accuracy may be reduced. Further, in the example of (2), since the movable pulley is supported by the spring, it is necessary to consider the vibration prevention of the movable pulley and the flutter of the pulley, and there is a problem that it is difficult to select the spring constant.
[0006]
The object of the present invention is to detect foreign matter using only the detection result of the conveyance state detection means and the position of the paper sheet in the belt width direction and the foreign object detector located at the position overlapping the paper sheet from the installation position of the foreign object detector. An object of the present invention is to provide a foreign matter detection apparatus for paper sheets.
[0007]
[Means for Solving the Problems]
An object of the present invention is a paper sheet foreign matter detection device provided in a paper sheet transporting device that transports paper sheets with a belt sandwiched between them, and is disposed downstream of a separation device to determine the transport state of the paper sheets. A conveyance state detection unit for detecting, and a foreign matter detection unit disposed downstream of the conveyance state detection unit. When the foreign matter detection unit detects a foreign matter in the paper sheet, the foreign matter detection unit In the foreign matter detection apparatus for paper sheets, the foreign matter detection means transmits a plurality of displacements arranged in the width direction of the belt to transmit to the control means so as to control the conveyance of the paper sheets containing the foreign matter to the reject stacking means. Select only the foreign object detector that detects the amount, the position of the paper sheet in the belt width direction detected by the conveyance state detection means, and the foreign object detector that is in a position overlapping the paper sheet from the installation position of the foreign object detector. Foreign object detection It is accomplished by comprising a detector control unit to.
[0008]
Further, the above object is achieved by the foreign object detection means being installed downstream of the separation device and upstream of a character reading device, a double feed detection device or the like .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0011]
FIG. 1 shows an example of a conveyance path 1 provided with the foreign object detection device of the present invention.
[0012]
As shown in the drawing, the conveyance path 1 is composed of belts 2A, 2B, 2C, 2D, and 2E, and a paper sheet such as a letter 3A is sandwiched between the belts 2A, 2B, 2C, 2D, and 2E. Then, it is conveyed in the direction of the arrow shown in the figure.
[0013]
The letter 3A separated by a paper sheet separating apparatus (not shown) is sent out to the conveyance path 1. The sent letter 3A passes through the conveyance state detection means 4 installed 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 on the downstream side of the conveyance state detection means 4. pass. Here, either the foreign matter detection means 5 or the thickness detection means 6 may be provided on the upstream side, and the thickness detection means 6 may be used as the foreign matter detection means 5.
[0014]
The foreign matter referred to in the present invention refers to a highly rigid material such as a coin, key, pencil, floppy disk or the like placed in a letter.
[0015]
When these foreign substances are conveyed in a letter, etc., (1) a letter jam occurs in the middle of the conveyance, (2) the letter is broken, and (3) the foreign substances break the letter and scatter outside. Therefore, it is necessary to accurately detect and reject a letter that contains foreign matter.
[0016]
Next, the configuration and operation of each means will be described.
[0017]
The conveyance state detection means 4 is composed of a line-shaped light source 7 and a line sensor 8 which is a light receiving element, and one is placed on the right side of the conveyance path so as to detect the state of the letter in the belt width direction of the conveyance path 1. The other is installed on the left side of the opposite conveying path. Thus, the reason why the linear light source 7 and the line sensor 8 are installed in the belt width direction is to detect the length and position of the letter 3 in the belt width direction and the letter shape. For this purpose, the widths of the belts 2A and 2B of the conveyance path 1 in which the conveyance state detection unit 4 is installed are set to be widths 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.
[0018]
As shown in the figure, the foreign matter detection means 5 shown by a two-dot chain line in FIG. 1 has a basic configuration in which a belt 2C suspended on four foreign matter detection pulleys 10 is symmetrically arranged around the foreign matter detector 9. Yes. In this embodiment, the foreign object detector 9 has a configuration in which a plurality of non-contact displacement meters or contact displacement meters having a very small contact resistance are arranged in parallel in the belt width direction with a predetermined interval. Using.
[0019]
The belts 2C and 2D of the conveyance path 1 in which the foreign matter detection means 5 is installed have a width that enables detection of 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 is included. The belt width.
[0020]
FIG. 1 shows an example of a waveform when a letter containing foreign matter and a letter not containing foreign matter pass as the output of the foreign matter detector 9. By arranging the foreign matter detection belt 2C symmetrically with respect to the foreign matter detector 9, when there is no foreign matter, the output waveform has one peak when there is no foreign matter. The output waveform in the case of being present often has two or more peaks, and foreign matter is determined using the difference between the peaks of the waveform.
[0021]
FIG. 2 shows an example in which three foreign object detectors 9A, 9B and 9C are arranged in parallel, and the position of one foreign object detector 9C does not overlap with the position of the letter 3. The output waveforms from the three foreign object detectors when the letter 3 passes are shown on the right side of the figure.
[0022]
As shown in FIG. 2, the waveform of the foreign object detector 9C at a position not overlapping with the position of the letter 3 is output as a smaller waveform than the waveforms of the foreign object detectors 9A and 9B at the position overlapping with the position of the letter 3. Therefore, it is difficult to use as an output for detecting foreign matter because it causes false detection when used for detecting foreign matter. 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 substance detector 9 at a position overlapping with the position of the letter 3 is detected by the detector control means 11. Is selected as the output for foreign object detection. In FIG. 2, the 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 the position overlapping the position of the letter 3, so that erroneous detection can be prevented.
[0023]
As described above, the thickness detection unit 6 can be included in the foreign matter detection unit or can be configured independently, but here, an independent case will be described.
[0024]
As shown in FIG. 1, the thickness detecting means 6 has a rotation axis in the belt width direction, and includes a thickness detecting pulley 12 serving as a reference for thickness detection, the thickness detecting pulley 12 and the belt 2. A plurality of thickness detectors 13 are arranged on the tangent line, and the thickness is detected from the amount of belt displacement perpendicular to the belt width direction when passing through the paper sheet. A plurality of displacement meters having a very small contact resistance are used, and a plurality of them are arranged in parallel in the belt width direction with a predetermined interval. 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 that allows detection of the maximum length of the letter 3 in the belt width direction, and the maximum of the letter 3 in the belt width direction. The belt width is such that the length can be entered. The belt width is not the same as 2D because the belt 2E can hold the letter 3 because the belt 2D and the thickness detection pulley 12 are tangent to the belt width direction for the thickness detection. Of course, it may be the same width as 2A or 2B.
[0025]
FIG. 2 shows an example in which two thickness detectors 13A and 13B are arranged in parallel. This thickness detector 13 also outputs the same waveform as the foreign object detector 9. For this reason, when the foreign matter detection means 5 does not determine that the foreign matter is present, in this embodiment, the output of the thickness detector 13 of the thickness detection means 6 disposed downstream of the foreign matter detection means 5 is used to further increase the foreign matter. It is possible to detect contamination. Since not only the foreign object detector 9 but also the thickness detector 13 can be used for foreign object detection, highly accurate foreign object detection can be performed. Further, when using the thickness detector 13 larger than the above-described example, the position of the letter in the belt width direction and the installation of the thickness detector 13 using the detector control means 11 in the same manner as the foreign object detector 9. The thickness detector 13 that overlaps from the position to the position of the letter can be selected to detect foreign matter.
[0026]
Next, using the example of letter 3 in FIG. 2, the flow of foreign object detection is shown in FIG.
[0027]
The outputs from the line sensor 8, the three foreign matter detectors 9A, 9B, 9C and the two thickness detectors 13A, 13B are sent to the 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 is sent to the detector control means 11, the foreign matter detectors 9A, 9B, and 9C are selected by the switch 15 to detect the foreign matter, and the two selected foreign matter detections are performed. The outputs of the containers, for example, 9A and 9B are sent to the foreign matter determination means 16. Here, the switch 15 may be included in the detector control means 11. The switch 15 can also be selected when the outputs of the thickness detectors 13A and 13B are used. As described above, the foreign matter determination means 16 includes the threshold value of the threshold value storage means 17 that stores the threshold value determined from the difference in the peak of the waveform and the foreign matter detector 9A selected by the detector control means 11. The output waveform from 9B is compared to determine the foreign matter, and the foreign matter detector 9A or 9B waveform, or the waveforms of 9A and 9B, become a waveform with two peaks as in the example of FIG. In this case, it is determined as a foreign object.
[0028]
Further, when foreign matter detection is performed using the output of the thickness detection means 6, the output of the thickness detectors 13 </ b> A and 13 </ b> B is input to the foreign matter determination means 16 by the switch 15 and stored in the threshold storage means 17. The threshold value for determining foreign matter from the output of the thickness is compared with the outputs of the thickness detectors 13A and 13B to determine the foreign matter. This determination method can be determined by the same processing as the output from the foreign object detector 9. Further, when the foreign matter detection is performed using the thickness detection means 6, the output of the thickness detector 13 is always used, or the foreign matter determination means cannot clearly read, for example, two waveform peaks. However, only when it is determined that there is a high possibility that there is a foreign object, the processing method of performing the foreign object detection using the output of the thickness detector can be selected. According to this method, foreign matter can be detected using not only the output of the foreign matter detector but also the output of the thickness detector, so that the foreign matter can be detected with high accuracy. Although not shown in the present embodiment, paper sheets determined to have foreign matters cause jams and the like, and therefore are discharged into a reject box provided on the exit side of the conveyance path in which the foreign matter detection device is disposed. By performing this transport control, it is possible to prevent a decrease in the speed of the transport process.
[0029]
【The invention's effect】
As described above, according to the present invention, foreign matter can be removed using only the output of the foreign object detector located at the position overlapping the paper sheet from the position of the passing paper sheet in the belt width direction and the installation position of the foreign object detector. Since it detects, a misdetection can be prevented. The output of the thickness detector can also be used for foreign object detection, and the foreign object can be detected with high accuracy by using the outputs of both the foreign object detector and the thickness detector.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a conveyance path provided with a paper sheet foreign object detection device of the present invention.
FIG. 2 is a diagram for explaining outputs from a plurality of foreign matter detectors and thickness detectors.
FIG. 3 is a diagram illustrating a detection flow of the foreign object detection device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Conveyance path, 2 ... Belt, 3 ... Paper sheet (letter letter), 4 ... Conveyance state detection means, 5 ... Foreign matter detection means, 6 ... Thickness detection means, 7 ... Line-shaped light source, 8 ... Line sensor, DESCRIPTION OF SYMBOLS 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 ... Switch, 16 ... Foreign matter determination means, 17... Threshold value storage means.

Claims (2)

A paper sheet foreign matter detection device provided in a paper sheet transport device that transports paper sheets while being sandwiched between belts,
A conveyance state detection unit disposed on the downstream side of the separation device for detecting the conveyance state of the paper sheet; and a foreign matter detection unit disposed on the downstream side of the conveyance state detection unit. In the foreign matter detection device for paper sheets, when the foreign matter in the leaves is detected, the foreign matter detection means transmits to the control means so as to control the conveyance of the paper sheets containing the foreign matter to the reject stacking means.
The foreign matter detection means includes a foreign matter detector for detecting a plurality of displacement amounts arranged in the belt width direction, a position of the paper sheet in the belt width direction detected by the transport state detection means, and the foreign matter detector. A paper sheet foreign matter detection apparatus comprising detector control means for selecting only a foreign matter detector located at a position overlapping with a paper sheet from an installation position and outputting the foreign matter detection output. In claim 1,
The foreign matter detection device for paper sheets, wherein the foreign matter detection means is installed downstream of the separation device and upstream of a character reading device, a double feed detection device, or the like.

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