JPH0464118B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a banknote discriminating device that determines the type and authenticity of banknotes.

``Prior art'' As one of this type of banknote discriminating device, JP-A-61
−The device described in Publication No. 18087 (name of the invention;
A pattern reading device for paper sheets is known. This device is characterized by detecting a line-shaped optical pattern on the diagonal of a paper sheet and comparing it with a reference pattern to determine authenticity.

``Problems to be Solved by the Invention'' By the way, the above-mentioned banknote discriminating device detects the optical pattern on the diagonal of the paper sheet in a line shape, so the detection is uneven, which makes it difficult to accurately identify the banknote. There was a problem that it was not possible to determine authenticity.

An object of the present invention is to provide a banknote discriminating device that can accurately determine the authenticity of banknotes by applying a novel determination method that is different from conventional methods of determining authenticity.

"Means for Solving the Problems" In order to achieve the above object, the present invention, as shown in FIG. a storage means 2 into which pattern data PD is written;
A detection means 3 divides the pattern data PD in the storage means 2 into a plurality of dots within the plane of the banknote, and further detects a plurality of extreme values of the pattern data PD in units of dots by comparing these dots with each other. By comparing the relationship between at least one of the minimum value and maximum value among the extreme values detected by this detection means 3 and other extreme values with pre-stored data by denomination, The detecting means 4 is equipped with a determining means 4 for determining the authenticity of a dot, and the detecting means 4 detects a dot by comparing the size of a predetermined reference dot with pattern data PD of each dot surrounding the reference dot. , is characterized in that an extreme value of the pattern data PD is detected.

"Operation" According to the present invention, the pattern data outputted from the pattern reading means 1 is not compared with the reference pattern as it is, but is once written into the storage means 2, and based on this written data, an extreme value (maximum value or local minimum value), and determine whether it is true or false based on this local minimum value.

In this case, it is possible to extract the maximum and minimum values, which are shown as extreme values, from a predetermined area of the banknote. Extreme values can be detected evenly. For example, since it is possible to detect extreme values on the entire surface of a banknote, it is possible to obtain extremely reliable extreme values and perform highly accurate banknote discrimination.

"Embodiment" Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 and FIG. 3 are both diagrams showing the configuration of a banknote discriminating device according to an embodiment of the present invention. In FIG. 2, reference numeral 11 is a CCD image sensor, and 12 is a conveyance path for conveying banknotes K. When the banknote K conveyed by the conveyance path 12 passes below the image sensor 11, the light from the lamp provided below the image sensor 11 reaches the image sensor 11 through the banknote K. A pattern of shading is read by the image sensor 11. The output of this image sensor 11 is amplified by an amplifier 13 shown in FIG. A/
The D converter 14 sequentially converts the output of the amplifier 13 into digital data and outputs it to the data input terminal of the primary memory 16 as pattern data PD. The banknote detection unit 15 detects the time point when the banknote K reaches the image sensor 11 and the time point when the banknote K has finished passing below the image sensor 11 based on the output of the amplifier 13, and in the former case, starts the start pulse SP. In the latter case, the end pulse EP is output to the controller 17, respectively. Controller 17
After the start pulse SP is output from the banknote detection unit 15, the address data is sequentially outputted to the primary memory 16, pattern data PD is sequentially written in the primary memory 16, and the banknote detection unit 15
At the time when the end pulse EP is output from
It outputs an interrupt signal to the bus line 19 of the CPU 18, and further outputs a basic clock pulse BCK to the driver 20. The driver 20 generates a transfer pulse and a shift pulse based on the basic clock pulse BCK, and outputs them to the image sensor 11.

The CPU 18 determines the type and authenticity of the banknotes K, and is connected to various parts via a bus line 19. 22 is a ROM in which the program of the CPU 18 is stored; 23 is a RAM for data storage;
4 is an I/O interface, and this I/O
It is connected to a processing circuit, etc. via an interface 24.

Next, the operation of the apparatus with the above configuration will be explained with reference to the flowchart shown in FIG. First, the driver 20 always outputs a transfer pulse and a shift pulse to the image sensor 11.
Then, when the front end of the banknote K reaches the position of the image sensor 11, the output of the amplifier 13 decreases as shown in FIG. At this falling time t1, the banknote detection unit 15 outputs a start pulse SP to the controller 17 (step 1 in FIG. 4).
(see SP1). After receiving this start pulse SP, the controller 17 outputs the address data to the primary memory 16 and stores the pattern data PD output from the A/D converter 14 in the same memory 16.
to be memorized. As a result, the banknote K shown in FIG.
Pattern data PD indicating each shading state of the dot positions P1 to Pn is written into the primary memory 16 (step SP2).

When this writing is completed, the end pulse EP is sent from the banknote detection unit 15 to the controller 17.
(Step SP3). Controller 1
7 receives this end pulse EP and outputs an interrupt signal to the CPU 18 via the bus line 19. The CPU 18 receives this interrupt signal and performs the following processing.

First, find the local maximum points, and then 5
Obtain two local maximum value data (step SP4).

Here, the following process is used to obtain local maximum value data. First, a reference dot is determined, and pattern data PD of the reference dot is read out from the primary memory 16. Next, the pattern data PD of each dot surrounding the reference dot is read out and compared in size with the pattern data PD of the reference dot.
Then, find a dot whose pattern data PD is larger than the pattern data PD of the reference dot (if there are multiple dots, find the largest one among them), use that dot as the next reference dot, and repeat the same process as above. Then, the pattern data PD of the reference dot is the pattern data of all surrounding dots.
If it is larger than PD, that reference dot is detected as a maximum point.

Next, find the minimum points, and 5
Obtain two minimum value data (step SP5). Note that the method for finding the minimum point is the same as the method for finding the maximum point.

Note that the multiple minimum points and maximum points obtained in the above and above are referred to as "extreme values" in the claims.
It is defined as

Next, using the maximum point of the local maximum points as a reference, the relative distance and the difference in pattern data PD between the reference point and other local maximum points (local maximum points and minimum points) are calculated (step SP6).

Note that the maximum point among the local maximum points obtained in this process is defined as the "maximum value among local maximum points" shown in the claims.

In addition, the relative distance and the difference in pattern data PD between the reference point, which is the maximum point of the maximum points, and the other extreme points (maximum point and minimum point) detected in this process are shown in the claims. It is defined as "the relationship between the maximum value among extreme values and other extreme values."

Next, the bill K is determined by comparing the denomination-specific data preset in the ROM 22 with the data obtained through the processing in step SP6.
The authenticity and denomination of the item are determined, and the determination results are outputted via the I/O interface 24 (step SP7).

Note that in step SP6 above, the maximum point among the maximum points is used as the reference, but the minimum point among the minimum points may be used as the reference, or a completely different point (such as the corner point of the banknote K) may be used as the reference. may be used as a standard.

Furthermore, here, the smallest point among the minimum points is defined as "minimum value among the minimum points" shown in the claims.

Further, in the above embodiment, the authenticity/type of the banknote K is determined based on the positional relationship and size relationship of the poles, but in addition to this, other conventionally known determinations, namely If discrimination based on , reflection and transmission patterns, magnetic discrimination, color discrimination, etc. are performed together, the determination accuracy can be further improved.

Further, in the above embodiment, the CCD image sensor 11 is used, but a phototransistor array may be used instead. In the case of an image sensor, the detection accuracy is too high, so there is a possibility that there will be many extreme points, but in the case of a phototransistor array, the accuracy is somewhat low and the image will appear blurry, making it easier to detect characteristic extreme points.

"Effects of the Invention" As explained above, according to the present invention, there is provided a reading means for optically reading the pattern of a banknote, a storage means in which pattern data outputted from the reading means is written, and a storage means in the storage means. Since a detection means for reading pattern data and detecting an extreme value and a discrimination means for determining the authenticity of the banknote based on the extreme value detected by the detection means are provided, the maximum value indicated as an extreme value is provided. Values and minimum values can be extracted from predetermined areas of banknotes, and extreme values can be detected evenly. In other words, compared to conventional devices that detect and compare lines, it is possible to detect extreme values on the entire surface of a banknote, so it is possible to obtain extremely reliable extreme values and improve accuracy. It becomes possible to perform high banknote discrimination.

Therefore, the present invention can provide a completely new discrimination method that has not existed before, and by combining it with conventional discrimination devices, it is possible to perform even more accurate discrimination. .

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIGS. 2 and 3 are diagrams each showing the configuration of an embodiment of the present invention, and FIG. 2 shows an image sensor 1.
1 and banknote K, FIG. 3 is a block diagram showing the overall configuration of the embodiment, FIG. 4 is a flowchart for explaining the operation of the embodiment, and FIG. 5 shows the output waveform of the amplifier 13. 6A and 6B are diagrams showing dot positions at which pattern data of a banknote K is recorded. 1...Reading means, 2...Storage means, 3...Detection means, 4...Discrimination means, K...Banknotes.

Claims (1)

[Scope of Claims] 1. A reading means for reading the shading pattern of a banknote in a plane; a storage means into which pattern data outputted from the reading means is written; and a plurality of pattern data in the storage means are read in a plane of the banknote. a detection means for detecting a plurality of extreme values of the pattern data in units of dots by dividing the pattern data into dots and comparing these dots with each other; and a determining means for determining the authenticity of a banknote by comparing the relationship between at least one of the maximum values and other extreme values with pre-stored data for each denomination, the detecting means The bill discriminating device detects an extreme value of pattern data by comparing a predetermined reference dot with pattern data of dots surrounding the reference dot.