JPH01233592A - Mobile origin selection system and sheet paper discrimination system using the same - Google Patents

Abstract

PURPOSE:To reduce memory capacity for the storage of true security data by comparing storage data in the storage area of coordinate transformed data with that in the storage area of the true security data at a comparison part, and discriminating the truth/forgery of a security via a discrimination part. CONSTITUTION:A CPU 210 extracts the contour data of the security from measuring data in a measuring data storage area 221, and detects the apex of the data. Next, the change of increment of the coordinate of the contour data in the neighborhood of a detected apex is checked, and when sides sandwiching the apex are intersected orthogonally, the apex is designated as a mobile origin. Also, the CPU 210 designates the mobile origin by finding a point corresponding to the center of the security when all of the apexes are checked. And coordinate transformation is performed so that each apex of the security of the measuring data can be set at position relation which becomes reference setting a selected mobile origin as reference, and the data is stored in a transform data storage area 222. In such a way, since the discrimination part 230 can discriminate the true security data in a true security data storage area 231 from the transform data in the area 222 via the comparison part 232, the memory capacity of the area 231 can be reduced.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial application field Means for solving the problem to be solved by the invention (i) First invention (ii) Second invention action (i) First invention (ii) Second invention embodiment! , Correspondence between the embodiment and FIG. 1■, Premise of the embodiment (i) Principle of coordinate transformation (ii) Selection of movement origin■, Configuration of the embodiment (i) Configuration of the entire securities identification system (ii) Measurement section (iii) Configuration of the storage unit (iv) Configuration of the determination unit ■, Operation of the embodiment (i) Operation of selecting the movement origin (ii) Overall operation ■, Summary of the embodiment ■3 Modifications of the invention Invention Effects [Summary] Regarding the paper sheet identification system, the purpose is to reduce the storage area for genuine bill data, and to detect candidate points that can be the origin of movement, and to make the detected candidate points meet the conditions for the origin of movement. consider whether it meets the
The system is configured to select an appropriate candidate point based on the result of the examination and select the movement origin.

[Industrial application field]

The present invention relates to a paper sheet M discrimination system, and particularly to a paper sheet discrimination system that selects a movement origin.

[Prior Art] In a system for identifying paper sheets such as banknotes and securities, the entire paper sheet M (for example, securities) to be inspected is divided into minute regions, and each of the minute regions is detected by an optical sensor, a thickness sensor, etc. The shading, color, and external shape of the pattern are measured, and the measured values are converted into gradation signals and stored. The securities are stratified based on the result of comparing this measured value with genuine bill data that has been measured and stored in advance.

FIG. 5 is a block diagram of a conventional securities identification system.

Hereinafter, the securities subject to identification will be simply referred to as securities.

The conveyance unit 503 of the measurement unit 500 carries the image sensor 501
The security is conveyed to the sensing range of the image sensor 501 so that the gradation of the entire security can be measured.

The image sensor 501 senses the gray scale of each minute area on the surface of the security to which each element corresponds, and converts it into an electrical signal. The electrical signal is analog-digital (A/
D) The converter 502 converts it into a digital value representing the gradation, and stores it in the measurement data storage area 521 of the storage unit 520.

Here, the coordinates of each minute area of the security are expressed with the direction in which the two-dimensional elements of the image sensor 501 are arranged as the X direction and the Y direction, respectively, and the measurement data is divided into elements of the array corresponding to the coordinates of the minute area. shall be stored.

The transport unit 503 transports the securities so that the long sides are generally in the Y direction. However, due to misalignment during transport, the long sides of the securities
It is also conceivable that the image sensor 501 performs measurement while being tilted with respect to the axis. The measurement data measured in such a tilted state will be referred to as skew data hereinafter.

The genuine bill data storage area 531 stores the results of measuring a genuine bill using the same image sensor 501 (genuine bill data) in order to compare the measured data to identify the securities. Since the inclinations of the skew data vary, in order to compare this, genuine bill data at all inclination angles are required.

A central processing unit (CPU) 510 determines the tilt angle θ of the security from the measurement data, retrieves the data of the genuine note measured at the tilt angle θ from the genuine note data storage area 531, and uses this as a genuine note for comparison. The determination unit 530 is instructed to use it as data.

The discriminating unit 530 compares the measured data of the securities stored in the measured data storage area 521 with specified genuine bill data, identifies the securities based on the result, and displays the data from the input/output device 540 such as a display or printer. Output and report the identification results.

[Problem to be solved by the invention]

By the way, in the above-mentioned conventional securities identification system, in order to directly compare the oblique data with the genuine note data, it is necessary to store the genuine note data measured at all tilt angles in the genuine note data storage area 531. . Therefore, there was a problem in that a huge amount of capacity was required to store genuine bill data.

The present invention was created in view of these points, and an object of the present invention is to provide a paper sheet discrimination system that reduces the amount of genuine bill data.

[Means to solve the problem]

Figure 1 (A) is a block diagram of the principle of the moving origin selection method of the present invention.

Detect a candidate point that can be the movement origin.

It is examined whether the detected candidate point satisfies the conditions as a moving origin.

Appropriate candidate points are selected based on the results of the examination.

Therefore, as a whole, the movement origin is selected from several candidate points.

(ii) Second invention FIG. 1(B) is a block diagram of the principle of the paper sheet discrimination system of the present invention.

In the figure, a measuring means 104 measures a desired physical quantity in each minute area of the paper sheet.

The storage means 105 stores the measured values of physical quantities of paper sheets measured by the measuring means 104.

The central processing unit 106 selects a movement origin from the measured values stored in the storage means 105, rearranges the measurement values stored in the storage means 105 using the movement origin as a reference, and performs coordinate transformation.

The discriminating unit 107 includes a genuine bill data recording means 171. It has a comparing means 172 that compares the genuine note data recorded in the genuine note data recording means 171 and the transformation data obtained by coordinate transformation by the central processing unit 106, and identifies paper sheets.

Therefore, overall, a moving origin is selected, and the measured values are coordinate-transformed to a reference position using the selected moving origin as a reference.
The paper sheet is configured to be compared with genuine bill data at a reference position to discriminate the paper sheet.

[For production]

(i) 1st U Hereinafter, reference will be made to FIG. 1(A).

A candidate point having the characteristics of a moving origin is detected from the data to be subjected to coordinate transformation, and it is examined whether the candidate point satisfies the conditions for becoming a moving origin. Based on the results of the examination, a moving origin is selected from candidate points that satisfy the conditions.

(ii) Second inhalation Hereinafter, reference is made to FIG. 1 CB).

The measurement values in each minute region of the paper sheet measured by the measuring means 104 are stored in the storage means 105.

The central processing unit 106 selects a moving origin from the measurement data stored in the storage unit 105 using the moving origin selection method, and uses the moving origin as a reference to convert data equivalent to the case where the paper sheet is measured at the reference position. Perform coordinate transformation so that

The discrimination unit 107 compares the genuine note data recorded in the genuine note data recording means 171 with the converted data after the coordinate transformation by the comparing means 172, and discriminates the paper sheet based on the result.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows the configuration of a securities identification system according to an embodiment of the present invention.

(2) Correspondence between the embodiment and FIG. 1 Here, the correspondence between the embodiment of the present invention and FIG. 1 will be shown.

The measuring means 104 corresponds to the measuring section 200.

The storage means 105 corresponds to the storage section 220.

The central processing unit 106 is a central processing unit (CPU) 210
corresponds to

The determining unit 107 corresponds to the determining unit 230.

Genuine bill data recording means 171 stores genuine bill data storage area 23
Corresponds to 1.

The comparison means 172 corresponds to the comparison section 232.

Examples of the present invention will be described below assuming that the correspondence relationship as described above exists.

FIG. 6 is an explanatory diagram of the principle of coordinate transformation.

In Figure (a), the rectangle representing the security is tilted by θ with respect to the XY coordinate axes, and is in an oblique state.

At this time, the coordinate axes and origin can be re-determined to conveniently represent the coordinates of each vertex of the rectangle, and the coordinates of each point of the rectangle can be transformed.

For example, by performing coordinate transformation such that vertex A is the origin and sides AB and AC are the coordinate axes, (
The positional relationship in which the measurement data is tilted by an angle θ with respect to the XY coordinate axes as shown in a) is changed to
It is possible to convert to a reference position that is not tilted with respect to the Y coordinate axis.

When measuring a security by dividing it into minute areas, the positional relationship of the elements of the array that stores the measured values in each minute area of the security,
The measurement value is configured to be stored in the storage area so that the positional relationship of each minute area corresponds. In this case, by rearranging the elements of the array, the coordinate transformation described above can be performed, and measurement data (transformed data) equivalent to that when the security is measured at the reference position can be obtained. As a rearrangement method for performing such coordinate transformation, Bresenham's method is known.

(ii) Selection of movement origin In order to perform the coordinate transformation as described above, it is necessary to determine an origin that serves as a reference representing the positional relationship of each measurement point in the measurement data. The origin of this coordinate transformation is called a movement origin. As the origin of movement, a point that facilitates expression of the positional relationship of each measurement point is appropriate, so for rectangular paper sheets such as securities, the apexes or the center of the four corners are appropriate.

However, the security is not always measured in perfect condition; for example, because one end is bent or torn, the vertex that should serve as the movement origin (for example, vertex A) may not be found. be.

Even in such a case, it is possible to detect other point candidates that should be the movement origin, and select a point from among them that meets appropriate conditions as the movement origin, and use it as the movement origin.

In FIG. 2, the securities identification system includes a measurement section 200 that measures the density gradation of each minute region of a security, a storage section 220 that stores measurement data, etc., and a storage section 220 that processes the measurement data. A central processing unit (CPU) 210 that converts into converted data, a determination unit 230 that determines whether the securities are genuine or not,
It is formed by an input/output device 240 that outputs the inspection results of securities by the discrimination section 230.

Hereinafter, the securities subject to identification will be simply referred to as securities.

(ii) Structure of Measuring Unit The measuring unit 200 includes a two-dimensional image sensor 201. Analog-digital (A/D) that converts the output of the image sensor 201 into digital data
Converter 202. It is comprised of a conveyance unit 203 that conveys the securities within the sensing range of the image sensor 201.

Here, the directions in which the elements of the two-dimensional image sensor 201 are arranged are defined as the X direction and the Y direction, respectively.

The coordinates of a minute area with a security within the sensing range of the image sensor 201 correspond to the order in which the elements of the image sensor 201 that sense the density of the minute area are arranged in the X and Y directions, and the positional relationship between the minute areas is Saved.

(iii) Configuration of storage unit The storage unit 220 has a measurement data storage area 221. It is formed by a transformed data storage area 222 that stores transformed data that is the result of coordinate transformation of measurement data.

The measurement data is stored such that the positional relationship of the storage location of the output of each element of the image sensor 201 corresponds to the positional relationship of the elements of the image sensor 201. Therefore, the positional relationship between minute areas is also preserved in the positional relationship of storage locations within the measurement data storage area 221.

(iv) Configuration of Discriminating Unit The discriminating unit 230 stores a genuine bill data storage area 231 that stores the results of measurement by the image sensor 201 (hereinafter referred to as genuine bill data) of genuine bills at a reference position, and converts It is formed by including a comparison section 232 that compares the data and genuine bill data.

For example, it is assumed that the genuine note data is measured at a reference position where the long side of the genuine note is parallel to the Y direction.

FIG. 3 is a flow chart showing the operation of selecting the movement origin in the embodiment shown in FIG.

FIG. 4 is an explanatory diagram of measurement data when a security is torn or damaged.

Hereinafter, reference will be made to FIGS. 2 to 4.

In FIG. 4, each eye on the base corresponds to one element (pixel) of the image sensor 201, and each eye on the base corresponds to the entire sensing range of the image sensor 201 (the eye on the base in the center is omitted). . Further, the directions of thick arrows in the figure are assumed to be the X and Y directions.

CPU21. O extracts the outline data of the security from the measurement data stored in the measurement data storage area 221. For example, a series of filled areas in FIG. 4 corresponds to the outline of a security (step 301).

The CPU 210 determines a point (vertex) that takes the maximum and minimum of each X and Y coordinate from the contour data extracted in step 301.
Detect. For example, the point P has the minimum value of the Y coordinate,
The point that takes the maximum value is point P2. Similarly, regarding the X coordinate, point P3. P4 is detected (step 302).

The CPU 210 examines how the increment in the Y coordinate (ΔY) of the contour data coordinates in the vicinity of the vertex detected in step 302 changes with respect to the increment in the X coordinate (ΔX). Check how they intersect (step 303).

If the sides that sandwich the vertex are orthogonal, that vertex is one of the four corners of the security, so that vertex is set as the movement origin. For example, in region C near point P1 in FIG. 4, the ratio of ΔX and ΔY is 1 knee 5, and in region A, ΔX and
The ratio is 5:1.

From this, it can be seen that the sides corresponding to area A and area C are orthogonal, so point P is set as the movement origin (step 3
05).

On the other hand, in FIG. 4, when examining the vicinity of point P4, the ratio of ΔX and ΔY in area B changes irregularly, and in area D
(!: 'It can be seen that the edges corresponding to pM region B are not orthogonal. In this way, if the edges on both sides of the vertex are not orthogonal, if there are other vertices that have not gone through the procedure of step 303 yet, Return to step 303 (step 306
).

In step 306, if all the vertices have been examined in step 303, a point corresponding to the center of the security (for example, point C in FIG. 4) is found and set as the movement origin (step 307).

(ii) The density gradation of each minute region of the security measured by the overall motion measurement section 200 is stored in the measurement data storage area 221 of the storage section 220.

The CPU 210 stores the measurement data in the measurement data storage area 22.
1 and select the movement origin as described above.

The CPU 210 performs coordinate transformation using the selected movement origin as a reference so that each vertex of the security in the measurement data has a reference positional relationship, and stores the resulting transformation data in the transformation data storage area 222. .

The determining unit 230 compares the genuine note data read from the genuine note data storage area 231 and the converted data read from the converted data storage area 222 using the comparing unit 232, and determines whether the security is a genuine note based on the result. The input/output device 240 reports the result of the discrimination.

■Summary of the example As mentioned above, we detect vertices from the contour data, examine how the contours (edges) that sandwich each vertex intersect, and find one of the four corners of the security or the center of the security. can be selected as the movement origin representing the positional relationship of each minute area of the security.

As a result, even if the security is torn or the edges are bent, the measurement data can be rearranged based on the selected movement origin, and coordinate transformation can be performed so that the positional relationship of the four corners of the security corresponds to the reference position. Therefore, it is possible to compare the measured data of the genuine note at the reference position.

■0 Modifications of the Invention In the above-described embodiments of the present invention, a case was considered in which the vertices or the center point of the four corners of the security were selected as the movement origin, but the positional relationship of each minute area of the paper sheet was considered. It can be applied as long as it selects convenient points to represent. Also, 2
It is possible to process values measured by various types of sensors, not just dimensional image sensors.

Also, in "■, Correspondence between Examples and Figure 1",
Although the correspondence between the present invention and the embodiments has been described, those skilled in the art can easily imagine that the present invention is not limited to this and that there are various modifications.

〔Effect of the invention〕

As described above, according to the present invention, the measurement data is rearranged by selecting the movement origin from the measurement data and performing coordinate transformation, and data equivalent to that obtained when paper sheets are measured at the reference position can be obtained. It will be done.

This makes it possible to always compare the genuine bill data at the reference position, and therefore the storage capacity for storing the genuine bill data can be made extremely small, which is extremely useful in practice.

[Brief explanation of the drawing]

Fig. 1 (A) is a principle block diagram of the moving origin selection method of the present invention, Fig. 1 (B) is a principle block diagram of the paper sheet discrimination system of the present invention, and Fig. 2 is according to an embodiment of the present invention. FIG. 3 is a flowchart showing the movement origin selection operation according to the embodiment shown in FIG. 2; FIG. 4 is an explanatory diagram of measurement data when a security has a tear; FIG. FIG. 6, a block diagram of a conventional securities identification system, is an explanatory diagram of the principle of coordinate transformation. 104 is a measuring means, 105 is a storage means, 106 is a central processing unit, 107 is a discrimination section, 171 is a genuine bill data recording means, 172 is a comparison means, 200.500 is a measurement section, 201.501 is an image sensor , 202.502 is an analog-to-digital converter (A/D converter), 203.503 is a transport section, 210.510 is a central processing unit (CPU), 220.5
20 is a storage unit, 221,521 is a measurement data storage area, 222 is a converted data storage area, 230.530 is a discrimination unit, 231.531 is a genuine bill data storage area, 232.532
is a comparison unit, and 240.540 is an input/output device. 1st picture (A) % 21tt Mouth door processing professional 77th picture 1 (B Nゝ real? way and if J, z 1st ^ 8 fish) Fig. 2 Fig. 3 Fig. 4 14 Toke Zobetsu system b, talent Xa Fig. 5 Fig. 6

Claims (2)

[Claims] (1) Detect a candidate point that can be a moving origin, consider whether the detected candidate point satisfies the conditions for a moving origin, select an appropriate candidate point based on the results of the examination, and set the moving origin. A moving origin selection method that selects. (2) Measuring means (104) for measuring desired physical quantities in each minute region of paper sheets; and storage means (105) for storing the measured values of the physical quantities of paper sheets measured by the measuring means (104). and a central processing unit that selects a movement origin from the measured values stored in the storage means (105), rearranges the measurement values stored in the storage means (105), and performs coordinate transformation using the movement origin as a reference. (106); genuine bill data recording means (171) for recording genuine bill data that is the result of measuring a genuine bill of the same type as the paper sheet at a certain reference position by the measuring means (104); Comparison means (172) for comparing genuine note data recorded in the note data recording means (171) and transformation data coordinate-transformed by the central processing unit (106), and a discrimination device for distinguishing paper sheets. A paper sheet discrimination system comprising: a part (107); and a paper sheet discrimination system configured to select a movement origin.