JPS5912579B2 - Paper sheet detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention can be used, for example, in an optical character reading device, when an object to be read with a thickness different from the standard is conveyed, or when two or more objects to be read with the same thickness as the standard overlap. The present invention relates to a paper sheet detection device that detects when paper sheets are being conveyed.

In recent years, as a means to efficiently process increasing amounts of information,
For example, various optical character reading devices have been developed and put into practical use.

In this type of character reading device, in order to process information at high speed, means are generally used to mechanically transport objects to be read, such as paper sheets, such as forms, sequentially. In this case, it is required to accurately convey the objects to be read one by one, but since the objects to be read are conveyed mechanically, it is actually difficult to convey them as required. Therefore, in order to compensate for such defects in mechanical conveyance, it is necessary to electrically convey objects to be read of a specified thickness, or even if two or more objects to be read of a specified thickness are overlapped. It is necessary to determine whether or not it is being transported. Therefore, conventionally, a paper sheet detection device as shown in FIG. 1, for example, has been used. this is,
The light source 3 in the detector 2
The transmitted light is converted into an electrical signal by the photoelectric conversion element 4 in the detector 2, and this electrical signal is temporally integrated by the integrating circuit 5, and the integrated value is sent to the quantizing circuit 6.
By comparing it with the transport time of the object to be read 1 in the determination circuit 7, it is determined whether the object to be read has a specified thickness or whether a plurality of objects are overlapped. However, in such conventional detection devices, the integrated value in the integrating circuit may vary due to changes in illuminance over time of the light source that makes up the detector, dust adhering to the light source or photoelectric conversion element, or even noise. , there was a risk of detection errors. Furthermore, since an integrating circuit or the like is used, there is a problem in that adjustment thereof is extremely troublesome. This invention was made in view of the above-mentioned circumstances, and its purpose is to ensure that paper sheets that are sequentially conveyed have a specified thickness, regardless of changes in the illuminance of the light source in the detector over time or attached dust. It is an object of the present invention to provide a paper sheet detection device that can accurately detect whether paper sheets are inverted or not, or whether a plurality of sheets are superposed.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 10 denotes an object to be read, such as a paper sheet, such as a form, which is supplied from a supply/take-out section (not shown), and is conveyed by a conveyance roller 11 in the direction of the unmarked mark in the figure. It's getting old.

A detector 12 is provided near the conveyance roller 11. This detector 12 detects an object to be read 10 that is being conveyed.
For example, it optically detects the thickness of the object to be read, and is composed of a light source 13 that irradiates light onto the object 10 to be read, and a photoelectric conversion element 14 that receives the transmitted light and converts it into an electrical signal. There is. Therefore, the output of the detector 12, that is, the output signal of the photoelectric conversion element 14, is transmitted to the analog processing circuit 15.
via an analog-to-digital converter (hereinafter referred to as A-
(referred to as a D converter) 16. This A-D converter 16 is the output of the analog processing circuit 15, that is, the detector 12
A signal corresponding to the amount of light transmitted through the object 10 outputted from the detector 10 is sampled multiple times and each is converted into a digital signal, and the sampling point is set when the object 10 passes the detector 12. It is assumed that sampling is performed multiple times (for example, about 10 times). Therefore, by this means, the object to be read 10 being conveyed can be moved at multiple locations S, , S2 along the conveyance direction as shown in FIG.
, S3, . . . , the thickness is sequentially detected. The output of the A-D converter 16 is supplied to a gate circuit 17, and this gate circuit 17 is also supplied with a signal from a switch (external setting means 18). When the object 10 to be read is conveyed, it is turned on while it passes through the detector 12, and the gate of the gate circuit 17 is opened by the on signal, and the output of the A-D converter 16 at that time is A storage circuit 19 stores a plurality of thickness detection signals for the first object 10 to be read.
It is intended to supply

The storage circuit 19 is a circuit that stores a plurality of thickness detection signals for the first object 10 to be read. That is, in this embodiment, for example, the average value of the plurality of thickness detection signals is stored. The memory circuit 19
The contents of are supplied to the comparator circuit 20, which
is also supplied with the output of the A-D converter 16. The comparison circuit 20 compares the memory contents of the memory circuit 19 (the average value of the thickness detection signal of the first object 10) and the A-D converter 16.
This is a circuit that compares the outputs of , that is, a plurality of thickness detection signals for the second and subsequent objects 10 to be read, to see if they match, and the comparison results are supplied to the determination circuit 21 . The determination circuit 21 is a circuit that determines, based on the comparison result of the comparison circuit 20, whether or not the conveyed object 10 to be read has a specified thickness or whether a plurality of objects 10 are overlapped. That is, in this embodiment, in the comparator circuit 20, one object to be read 10 output from the A-D converter 16
If a predetermined number of consecutive thickness detection signals differ from the contents of the storage circuit 19, it is determined that the object 10 to be read does not have a specified thickness, or that two or more sheets of the object 10 overlap even if they have a specified thickness. I'm starting to do that. Next, the operation in such a configuration will be explained.

First, before the objects 10 to be read to be subjected to the reading process are automatically sequentially supplied by the supply/take-out section, only the first object 10 to be read is manually fed and transported. Then, the switch 18 is set to the ON state only while this first object 10 is passing through the detector 12.
In this case, if the first object 10 to be read is always supplied with only one sheet (two sheets are not taken), the first object 10 is
It is also possible to automatically supply the objects one after another starting from the first one, and turn on the switch 18 automatically only while the first object 10 is passing through the detector 12. When the first object 10 to be read is conveyed by the conveyance roller 11, the detector 12 outputs an electric signal corresponding to the amount of transmitted light. That is, the detector 12 detects the object to be read 1 being conveyed.
It optically detects the thickness of 0 and converts it into an electrical signal. This electrical signal is supplied to an A-D converter 16 via an analog processing circuit 15. A-D converter 1
6 is the object 1 to be read outputted from the analog processing circuit 15.
A signal corresponding to the amount of transmitted light of 0 is sampled multiple times, each of which is converted into a digital signal, and the digital signal is supplied to the gate circuit 17. Consequently, at this time, the A-D converter 16 sequentially outputs a plurality of thickness detection signals for the first object 10 to be read. Since the switch 18 is set to the on state at this time, the gate circuit 17 sequentially supplies each signal from the A-D converter 16 to the memory circuit 19. As a result, the memory circuit 19
stores the average value of a plurality of thickness detection signals for the first object 10 to be read. Therefore, when the first object 10 to be read is fed manually or automatically, the second object 10 is fed.
By automatically sequentially supplying the objects 10 to be read after the first one, each of the objects 10 to be read is sequentially conveyed.
The thickness of the object to be read 10 is sequentially detected by the detector 12 in the same way as for the second object to be read 10, and a plurality of thickness detection signals for the second and subsequent objects 10 are sent from the A-D converter 16 to each object to be read. Output every 10.

At this time, the switch 18 is in the OFF state and the gate circuit 17 is closed, so that the output of the A/D converter 16 is supplied to the comparator circuit 20. Therefore,
The comparison circuit 20 compares the contents of the storage circuit 19, that is, the thickness detection signal of the first object 10 to be read and the plurality of thickness detection signals of the objects 10 actually conveyed after the second one. A comparison is made to see if they match, and the comparison result is supplied to the determination circuit 21. As a result, the determination circuit 21 determines that the object to be read 10
It is determined whether or not it has a specified thickness or whether two or more sheets are superposed, and the determination result is output. That is,
In the comparison circuit 20, among the plurality of thickness detection signals for one object to be read 10 output from the A-D converter 16,
If a predetermined number of signals are consecutively different from the stored contents of the memory circuit 19, the object to be read 10 being conveyed at that time may not have the specified thickness, or even if it has the specified thickness, two or more sheets overlap. It is determined that the In this way, the thickness of the first object to be read 10 conveyed is stored in the memory circuit 19 at the initial time, and from the second onward, the stored contents and the thickness of each object to be read 10 actually conveyed are stored in the memory circuit 19. The comparison circuit 20
Based on the comparison result, a determination circuit 21 determines whether the object 10 to be read has a specified thickness or whether the object 10 to be read is a plurality of overlapping objects 10 having a specified thickness.

In the above embodiment, in the comparator circuit 20, if a predetermined number of signals out of a plurality of thickness detection signals for one object to be read 10 successively differ from the contents of the storage circuit 19, the The reading material 10 does not have the specified thickness or 2
Although the case where it is determined that more than one sheet has been superimposed has been described, the present invention is not limited to this. For example, if a predetermined number of signals among the above-mentioned detection signals discontinuously differ from the contents of the storage circuit 19,
The determination may be made in the same manner as described above, or alternatively, the determination may be made by comparing the average value of each of the detection signals with the contents of the memory path 19.

Furthermore, although a case has been described in which a detector that uses transmitted light is used as a detector for detecting the thickness of the object to be read, the present invention is not limited thereto, and the present invention can be similarly implemented using a detector that uses reflected light, for example.

Furthermore, although we have explained the case where the paper sheets that are sequentially conveyed are objects to be read such as forms in an optical character reading device,
The present invention is not limited to this, and the same method can be applied to mail items such as letters, bank notes, etc. In addition, the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the invention.

As described in detail above, according to the present invention, the thickness of the first sheet to be conveyed is stored in response to switching of a switch, and the thickness of the first sheet to be conveyed is stored, and the thickness of the second and subsequent sheets is The paper sheets are compared with each other, and based on the results of the comparison, it is determined whether the paper sheets are of a specified thickness or not, or whether multiple sheets are stacked together. Regardless of dust etc., it is possible to accurately detect whether or not the paper sheets being conveyed in sequence are of the specified thickness or whether multiple sheets are stacked together, and it is also possible to simplify adjustments, making it economical. It is possible to provide an excellent paper sheet detection device.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a conventional paper sheet detection device, FIG. 2 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 3 is a diagram for explaining the thickness detection means. . 10... Paper sheets, 12... Detector, 1
6...Analog-digital converter, 18...
...Switch (external setting means), 19...
Memory circuit, 20... Comparison circuit, 21...
・Judgment circuit.

Claims (1)

[Claims] 1 Paper sheets that are sequentially conveyed, a detection means that detects the thickness of the paper sheets at multiple locations, and a memory circuit that stores the thickness of the first sheet obtained by this means. a storage means for storing data in the storage means; an external setting means for updating the stored contents of the storage means; and a plurality of thickness detections for the second and subsequent paper sheets obtained by the stored contents of the storage means and the detection means. a comparison circuit that compares the signal multiple times; and a determination circuit that determines whether the paper sheet has a specified thickness or whether a plurality of sheets are overlapped based on the comparison results of the comparison circuit multiple times. A paper sheet detection device characterized by comprising: