JPH0823899B2 - Checking device for paper sheets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] Regarding a paper sheet checking device, a paper sheet having predetermined print information and a constant image size obtained by a sensor for the purpose of improving the efficiency of check processing. In a check device for converting an image signal of a class into a digital pixel signal and executing a predetermined image processing on the digital pixel signal to judge the paper sheet, the digital pixel signal corresponds to the constant image size. The pre-processing for comparing the addition value obtained by the addition processing in the range and the predetermined reference value is executed, and the predetermined image processing is performed for the sufficient digital pixel signal according to the execution result of the pre-processing. It has a configuration having a function of executing only the obtained paper sheets.

[Industrial applications]

INDUSTRIAL APPLICABILITY The present invention relates to a paper sheet checking device, particularly a bill, a stock certificate,
The present invention relates to a check device for determining the authenticity of bonds, checks, lottery tickets, identification cards, etc.

[Conventional technology]

Generally, for paper sheets such as banknotes, stock certificates, bonds, checks, lottery tickets, identification cards, etc., due to their value and importance, various items are checked and the carrier is forged or altered. It is determined whether or not it has been done, and the mode is as shown in FIG. 3, for example.

That is, the paper sheets 18 to be determined stored in the hopper 10
The sheets are sent one by one to the driving roller 12 by the feeding device 11, and are conveyed to the stackers 15 and 16 on the conveying path 13. In the middle of this transport path 13, the paper sheets 18 that have been transported
Various sensors 17 such as an optical sensor for detecting the grayscale image signal of are provided. Then, the output signal of the sensor 17 is amplified and then converted into a digital pixel signal such as a binary signal or a gradation signal and stored in the memory. Next, various check programs A, B, C, ... N involving image processing are executed on the stored data, and it is determined whether or not the results of all the check processing are “OK”. are doing. Here, when the check processing of all the items is determined to be “OK”, that is, when the conveyed paper sheet 18 is normal, an output signal to that effect is output and the paper The conveyance path switching unit 14 is controlled so that the leaves are stored in the first stacker 15. In addition, when the check processing of all items is not “OK”, that is, the paper sheets that have been conveyed 18
If the sheet is not normal, an output signal to that effect is output, and the conveyance path switching unit 14 is controlled so that the paper sheet is stored in the second stacker 16.

[Problems to be Solved by the Invention]

As described above, in the conventional method of checking sheets having predetermined print information (such as a pattern having a predetermined pattern) and a predetermined image size, the conveyance path 13
The grayscale image signal detected by the sensor 17 provided in the middle of the
The converted digital pixel signal after A / D conversion is subjected to predetermined image processing to determine whether the paper sheet is altered or forged. Here, this determination is intended for paper sheets that originally have no defects such as tears,
It is also assumed that the transport mechanism and the sensor are operating normally. However, in the conventional check method, not only in such a case (which makes sense when judged), but also because the predetermined image processing is uniformly executed for all the conveyed paper sheets, There is a problem that the check processing is not efficient because the processing time as a whole becomes long.

Therefore, in the present invention, before the predetermined image processing is performed on each digital pixel signal, the digital pixel signals are added to obtain an added value for the entire paper sheet, and then the added value and the predetermined value are determined. An object of the present invention is to improve the efficiency of the check process by executing a preprocess for comparing with a reference value and selecting whether to execute the next check process based on the result of the preprocess.

[Means for solving the problem]

FIG. 1 is a flow explanatory diagram showing the principle of the check system for paper sheets such as banknotes, stock certificates, bonds, checks, lottery tickets, identification cards, etc. in the present invention.

That is, the position adjusting mechanism 1 adjusts the rotation and skew of the paper sheet with to set the paper sheet at a predetermined position on the conveying path, and proceeds to the next step.

Various sensors 2, such as an optical sensor and a capacitance sensor, determine the grayscale image signal of the set paper sheet, and proceed to the next step.

The A / D converter 3 A / D-converts the grayscale image signal to obtain a digital pixel signal that distinguishes the background portion from the paper sheet portion, and proceeds to the next step.

The adder 4 simply adds, for example, the paper sheet portion of this digital pixel signal, and proceeds to the next step.

This added value is compared with the reference value stored in the memory 5, and the process proceeds to the next step. Here, this reference value is set to a predetermined range obtained when the paper sheet to be checked does not have a defect such as a tear and the position adjusting mechanism 1 and the sensor 2 are operating normally. .

Based on the result of this comparison process, it is determined whether the grayscale image signal output from the sensor 2 is normal. If "YES", the process proceeds to step, and if "NO", the process proceeds to step.

The CPU 6 executes various kinds of image processing on the digital pixel signal, and determines whether the paper sheet to be checked is true or false, that is, whether the paper sheet has undergone processing such as alteration or forgery. Go to the next step.

 The paper sheets to be checked are discharged to a stacker.

The check process for authenticity of the paper sheet is executed by the procedure.

[Action]

In the present invention, as described above, the steps from
By performing the procedure of 1., it may not be a paper sheet that has a defect such as a tear originally, and the grayscale image signal output from the sensor may not be in a state where the position adjustment mechanism and the sensor are not operating normally. It is checked whether or not there is such a thing, and the image processing, which is the original check processing (subsequent), is not executed for such paper sheets.

In other words, among the conveyed paper sheets, only the paper sheets for which sufficient digital pixel data has been obtained to execute the original check processing are executed, and subsequent image processing is executed to check for alterations and forgery. Judging.

〔Example〕

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

FIG. 2 relates to the pre-processing at the time of checking the authenticity of a bill, and when an optical transmission sensor is used as a sensor and digital pixel data is added, this pixel data is pre-selected by a predetermined number of bits to the right. The method of adding after shifting to. This method is used to determine whether or not to perform the subsequent image processing in the addition processing, and it is sufficient to use the rough value (upper bit) of the addition value. That's it.

That is, ′ The light receiving amount of the light receiving sensor group when the bill passes through the light transmitting sensor portion is obtained, and the digital data X for each pixel is extracted from this light receiving amount and the process proceeds to the next step.

Note that X takes a value of 0 to FFH (H is a hexadecimal number display).

Here, the received light amount is slightly different depending on the watermark part, the dark pattern part, the braille part, etc. even in the banknote part, but between the banknote part and the background part, the light reception amount in the banknote part = 40H to 60H in the background part. The amount of received light = E0H or more, which is clearly different.

′ It is determined whether or not the digital data X <80H is established. If “YES”, the process proceeds to step ′, and if “NO”, the process proceeds to step ′.

That is, in consideration of measurement error and the like, when the value of X is 80H or more, it is determined that the pixel is not the pixel of the banknote.

'The process of shifting the digital data X to the right by 4 bits is executed, and the process proceeds to step'.

'No new processing for the digital data X is executed and the process proceeds to step'.

A process of cumulatively adding the digital data X to the '16 -bit register is executed to obtain the added value S, and the process proceeds to the next step.

′ Determine whether or not the above processing has been completed for all pixels, and if “YES”, proceed to step ′,
If “NO”, the process returns to step ′.

It is determined whether or not '2000H <S <5000H is satisfied. If "YES", the process proceeds to step', and if "NO", the process proceeds to step '.

′ No further image processing is executed.

The process proceeds to the image processing after ′, and the check processing for the authenticity of the bill is performed.

In such a procedure, it is selected whether or not to execute the authenticity check process on the conveyed bill.

Here, the resolution of the light transmission sensor is 4.06 mm ² (1.4 × 2.9 m
In m), when a 1,000-yen bill (149 x 76 mm) is inserted, 2789 (149 x 76 ÷ 4.06) pixels of this sensor are the paper sheet portion, and the other pixels are the background portion. Then, the theoretical value when the X value of the pixels of the bill part is regarded as 50H uniformly and cumulatively added for all the pixels of the bill part is 36790H (50H × 2789)
However, in order to handle this theoretical value, an 18-bit addition register is required, and there is a problem that an ordinary maximum 16-bit addition register overflows.

On the other hand, the processing result of this cumulative addition is merely used for determining whether or not it is worthy of checking whether it is true or false, and in this determination, the value of the processing result is substantially centered on the theoretical value. Rough predetermined range, for example
It is enough to check whether it is in 20000H to 50000H.

Therefore, in the above-described embodiment, the method of adding the digital data X after performing the process of shifting the digital data X to the right by, for example, 4 bits is adopted. As a result, the predetermined range is also
It is 2000H to 5000H, and in the process of cumulative addition, the 16-bit addition register does not overflow.

In addition, each numerical value in the above embodiment is merely an example,
Other values may be used.

〔The invention's effect〕

According to the present invention, when performing a check process for authenticity of a paper sheet, prior to this check process, a pre-process for adding digital image data is executed to obtain an added value of all the paper sheets. If the added value is within the predetermined range, that is, if it is worth performing the check process for the paper sheet to be checked, for example, there is no abnormal shape of the paper sheet, there is no defect or fold, and the transport mechanism or sensor is normal. Only when sufficient digital pixel signals for the print information of the paper sheet are obtained, the subsequent image processing is executed to determine the authenticity of the paper sheet. Since the meaningless image processing is not executed, the efficiency of the check processing can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention, FIG. 2 is an explanatory view showing an embodiment of the present invention, and FIG. 3 is an explanatory view showing a conventional paper sheet checking method. In FIG. 1, 1 ... Position adjustment mechanism 2 ... Sensor 3 ... A / D conversion unit 4 ... Addition unit 5 ... Memory 6 ... CPU

Claims (3)

[Claims] 1. An image signal of a paper sheet having predetermined print information and a fixed image size obtained by a sensor is converted into a digital pixel signal, and a predetermined image processing is executed on the digital pixel signal. Then, in the checking device for determining the paper sheet, a pre-processing for comparing the added value obtained by adding the digital pixel signal in a range corresponding to the fixed image size with a predetermined reference value is executed. However, according to the execution result of the pre-processing, the predetermined image processing is provided only for the paper sheet for which sufficient digital pixel signals are obtained, and Checking device. 2. A process for shifting the digital pixel signal to a lower position by a predetermined bit before the addition process of the digital pixel signal so that a register used in the addition process does not overflow. Checking device for the paper sheets described. 3. The paper sheet checking apparatus according to claim 1, wherein the paper sheets are banknotes.