JPH0792854B2 - Paper discriminating device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a paper sheet discriminating apparatus for discriminating paper sheets such as banknotes, and particularly in a direction in which the front edge of the paper sheet is orthogonal to the conveying direction. The present invention relates to a paper sheet discriminating apparatus capable of accurately discriminating a widthwise dimension of a paper sheet even when conveyed in an oblique state.

“Prior Art” Hereinafter, a paper sheet bill will be described.

As one of the methods for discriminating the denomination of a bill, conventionally, the outer dimension of the bill (the dimension in the moving direction of the bill is called the length dimension, and the dimension in the direction orthogonal to the moving direction of the bill is the width dimension). (To be called) is measured, and the measurement result is compared with a reference value.

For example, Japanese Laid-Open Patent Publication No. Sho 54-121761 discloses that two photoelectric detectors are arranged along the width direction of a banknote, and the distance between the two photoelectric detectors and the distance based on the deviation of the banknote detection time. From the diagonal angle obtained from the diagonal angle obtained from the other, on the other hand, the dimension in the length direction of the bill in the photoelectric detector (the dimension based on the detection time of the bill) and the obtained diagonal angle, using the trigonometric function, the true length dimension is obtained. It was calculated.

Applying this technology, a linear sensor that can detect the position of the banknote in the width direction is used to detect the distance based on the deviation of the detection time of the banknote at two specific positions in the width direction, and the diagonal It has been considered that the true width dimension is calculated using the same trigonometric function from the widthwise dimension of the banknote detected by the line-shaped sensor and the obtained slant angle, after obtaining the angle.

[Problems to be Solved by the Invention] However, when performing a subtraction process using a trigonometric function, it is necessary to perform multiplication / division of a large number of digits including a decimal point in order to obtain a predetermined accuracy. Since a certain amount of calculation time is required, a bill discriminating apparatus that is usually combined with pattern discrimination or the like has been an obstacle in improving the discriminating processing speed.

It is also possible to prepare and refer to a table of correction data in advance and make a simple correction with a correction value based on the oblique angle, but it is necessary to store a large number of correction data for each banknote size, and the width size There is a problem in that it is inefficient to secure the area of the data storage unit only for calculating

The present invention has been made in view of the above circumstances, and does not require a particularly large area of the data storage unit, does not require a long time for calculation processing, and is a determination device capable of obtaining an accurate width dimension by a simple process. It is intended to provide.

[Means for Solving the Problems] In order to achieve the above object, the inventions described in the claims of the present application have the following configurations.

The invention according to claim 1 is provided along a direction orthogonal to the conveying direction of the paper sheets, and is obtained from the width direction detecting means for detecting the width direction of the conveyed paper sheets, and the width direction detecting means. Based on the detection signal, the detection data relating to the first corner portion located on the front side in the transport direction of the front edge of the transported sheet, and the second corner located on the rear side in the transport direction at the front edge. The detection data related to the first corner is stored, and the first data is detected during the time corresponding to the time difference between the detection data related to the first corner and the detection data related to the second corner. Storage means for storing detection data relating to a side edge portion of the paper sheet extending rearward in the transport direction from a corner portion or the second corner portion, and detection relating to the first corner portion stored in the storage means. Data, detection data relating to the second corner, and Based on the detection data relating to the side edge, those formed by composed of a calculating means for calculating the true width direction dimension of the sheet being conveyed.

According to a second aspect of the invention, in the first aspect of the invention, the first dimension data is calculated from the detection data relating to the first and second corners, and the first dimension data is obtained from the detection data relating to the side edge. The second dimension data is added to the first dimension data.

According to a third aspect of the invention, in the second aspect of the invention, one half of the displacement amount of the side edge portion in the width direction caused by the time difference is used as the second dimension data.

According to a fourth aspect of the present invention, in the first aspect of the present invention, firstly, the detection data relating to the second corner portion and the detection data relating to the side edge portion are used.
Is calculated, and the second dimension data obtained from the detection data relating to the side edge portion is subtracted from the first dimension data.

According to a fifth aspect of the invention, in the fourth aspect of the invention, one half of the data regarding the displacement amount of the side edge portion in the width direction is used as the second dimension data.

"Operation" According to the configuration of the invention described in claim 1, based on the detection signal obtained from the width direction detecting means a, the detection data relating to the leading first corner of the front edge of the conveyed paper sheet. Then, the detection data relating to the second corner subsequent to the front edge of the paper sheet is obtained, and both detection data are stored in the storage means b.

On the other hand, during the time corresponding to the time difference between the time when the detection data relating to the first corner portion is obtained and the detection data relating to the second corner portion is obtained, from the first corner portion or the second corner portion. The detection data relating to the side edge portion of the paper sheet extending rearward from the corner of the sheet is obtained by the width direction detection means a and is also stored in the storage means b.

Then, based on the detection data relating to the first corner portion stored in the storage unit b, the calculation unit c calculates the true widthwise dimension of the conveyed paper sheet.

Further, in the invention according to claims 2 to 5, the second dimension data itself relating to the side edge portion, or a half thereof, having the characteristic of increasing and decreasing depending on the time difference in which the first and second corner portions are detected. By adding and subtracting from the first size data, the true width size can be calculated by correcting the first size data.

[Examples] Examples of the present invention will be described below with reference to the drawings.

First, the first embodiment shown in FIGS. 2 to 5 will be described.

Reference numerals 1L and 1R are width sensors, and these width sensors 1L
1R is a large number of sheets arranged in the width direction of the paper sheet P (direction orthogonal to the conveying direction toward the arrow in FIG. 3 and usually along the long side of the paper sheet P). Photoelectric conversion element S ₁
…… It consists of S _n .

The width sensors 1L and 1R are sensor control circuits 2L and 2R, respectively.
It is controlled by this control circuit 2L
2R is a system in which each of the optical conversion elements S ₁ ... S _m has a predetermined period (sufficient than the transport speed, based on the pulse output from the clock generator 3 such as a rotary encoder synchronized with the drive mechanism of the transport system. The sheet P is scanned in the width direction to obtain data as to whether each light conversion element S ₁ ... S _m is covered (shielded) by the sheet P, Furthermore, time-series data supplied from the left and right width sensors 1L and 1R, wL ₁ , wL ₂ , ... wL _n wR ₁ , wR ₂ , ... wR _n [same subscript can be regarded as simultaneous ( Data), and each data is a set of data about ON or OFF of each photoelectric conversion element S _m obtained by the scanning at that time] is supplied to the counters 4L and 4R. It is supposed to do.

Further, the counters 4L and 4R count the number of the light conversion elements S _m that have detected the passage of the paper sheet P at a certain time, and supply this count value to the CPU 5 as data of the width dimension of the paper sheet P. There is. Further, the CPU 5 operates according to the program written in the ROM 6, and temporarily writes the width data in the RAM 7 and sequentially reads the width data to perform predetermined arithmetic processing.

If the width data measured at time x is W'x, this W'x is W'x = wLx + wRx + a (1) [where a is the interval between the left and right width sensors 1L and 1R] Constant of]. (See FIG. 4) Further, as shown in FIG. 3, when the paper sheet P intrudes onto the width sensor 1L with the left end leading, the data wL obtained from the width sensor 1L monotonically increases. Further, when the paper P advances to some extent, the data wR of the right width sensor 1R also monotonically increases, and when the right end (right corner) of the paper P enters the width sensor 1R at the timing i, the maximum value wR _max ( = WR _i ) and then decreases monotonically. Therefore, the amount of skew of the paper sheet P can be determined based on the changes in these data strings.

Next, the principle of skew correction based on the measurement of the above data string will be described with reference to FIG.

The width data at time j after time i when wR becomes maximum can be expressed as W′j = wL _j + wR _j + a from the above equation (1), and in the section after time i, as time progresses, wR simply decreases.

Here, if the correction width data W ″ j is defined as W ″ j = wL _j + wR _{j + i} + a, the corrected width data Wj is Wj = (Wj ′ from W′j and W ″ j. + Wj ") / 2 = wLj + ( can be calculated based on _{wR j + wR j + i)} / 2 + a ...... (2) becomes equation.

That is, when the amount of skew is large, the difference between the timings at which the left and right sensors detect the presence of banknotes becomes large, so the above i also becomes large, and by increasing this _i , the value of wR _{j + i} becomes Since a simpler reduced value will be used, as the calculation result of the above equation (2),
A smaller value is obtained for Wj, and as a result, qualitatively, the larger the amount of tilt, the larger the correction of the measured data.

Then, Wj calculated based on the above equation (2) can approximate the true width value W calculated using the trigonometric function from the oblique angle θ with an accuracy that does not pose a practical problem. It becomes a value. The basis will be described below with reference to FIG.

That is, W ′ and W ″ can be expressed as W ′ = W / cos θ (3) W ″ = W × cos θ (4), respectively. From these equations (3) and (4), W ″ = W ′ × cos ² θ (6) is obtained, that is, W is calculated by the equation (5) using W ′ and W ″ as variables without using the trigonometric function of the tilt angle θ. be able to.

Further, for the purpose of simplifying the arithmetic processing, if an approximate expression (W ′ + W ″) / 2 (expression before modification of the above two expressions) is used instead of the above expression (5), the error Diff in this case is , Can be expressed as, when applying the above equation (6) into this equation, the Diff = W '× (1- cosθ) 2/2.

Therefore, for example, the error Diff that occurs when θ = 10 ° and W ′ = 200 mm is Diff≈0.023 mm, and sufficient accuracy can be obtained for practical use.

That is, in the present invention, the width data is obtained by the formula W = (W'-W ") / 2 (7).

Then, the width data Wj obtained by the above calculation is used as a reference width data (for example, width data for each banknote of each denomination) and CP.
By comparing U, the denomination, authenticity, etc. of the paper sheet can be discriminated.

Needless to say, the specific configuration of the hardware necessary for implementing the present application is not limited to the above-mentioned embodiment. For example, as the width sensor, instead of the one using a large number of photoelectric conversion element groups as in the embodiment, photoelectric conversion means over a predetermined inspection width is used, and the output of this photoelectric conversion means is used as a light reception amount (light reception width). It is also possible to use the width data of the paper sheet by utilizing the fact that it changes in accordance with it.

Further, by repeating the calculation processing of the width dimension based on the data sequentially detected after the time i when the right edge of the paper sheet is detected and arithmetically averaging the same, the disturbance of the edge portion of the paper sheet is caused. Of course, it is possible to eliminate the influence of the error.

Furthermore, in the first embodiment, the left and right width sensors
Time-series data supplied from 1L and 1R wLn ・ w
Rn is a set of data regarding ON or OFF of each photoelectric conversion element Sm, that is, it is described as a count value, but it is not necessarily a count value, and after storing as coordinate data, the above calculation as width data is performed. It is also possible to do.

Next, a second embodiment will be described with reference to FIG.

The second embodiment differs from the first embodiment in that the left and right width sensors 1L and 1R are composed of one width sensor 10.

Therefore, in the second embodiment, the width data of the paper sheet P can be obtained based on the coordinate data of the light shielding position supplied from the width sensor 10, and for example, the left edge position data ZL and the right edge of the paper sheet P can be obtained. Based on the position data ZR, the width data W '
And W ″ are obtained and the true width data is calculated.

Therefore, in the second embodiment, the object of the present invention can be achieved with a circuit configuration which is more simplified than the circuit configuration shown in FIG. 2 of the first embodiment.

Next, a third embodiment will be described with reference to FIG.

The third embodiment can be achieved by any of the circuit configurations of the first embodiment and the second embodiment, and any of them can be implemented by further simplified control.

That is, in the first or second embodiment, it is necessary to obtain the width data W'after obtaining the width data W ', obtain the width data W ", and perform the arithmetic processing represented by the equation (7). However, in the third and the above, the width data corresponding to the width data W ″ can be obtained at the timing when the width data W ′ can be obtained, and the true width data can be obtained at an early timing. There is something.

That is, attention is paid to the above formula (7) in this third embodiment.

First, the above equation (7) is modified as follows.

W = (W ′ + W ″) / 2 = (2W′−W ′ + W ″) / 2 = W ′ − (W′−W ″) / 2 (8) Alternatively, W = (W ′ + W ″) / 2 = (2W ″ −W ′ + W ″) / 2 = W ″ + (W′−W ″) / 2 (9) Further, from the above equations (3) and (4), FIG. As shown, when the width data W ′ and W ″ are rewritten, the following becomes clear.

The width data W'corresponds to the width data when the preceding first corner of the front edge of the conveyed paper sheet P is detected and the following second corner of the front edge is detected. The width data W '
Corresponds to the sum of the width data M and N shown in FIG.

The width data W ″ corresponds to the width data from the first corner of the front edge of the paper sheet P being conveyed to the second corner subsequent to the front edge, which is selected. Similarly, W ″ corresponds to the width data M shown in FIG.

Further, the width data N shown in FIG. 7 is the same as the time difference from the time when the detection data relating to the first corner is obtained until the detection data relating to the second corner is obtained. The detection data is related to the side edge portion of the paper sheet P extending from the first corner portion or the second corner portion toward the rear side of the conveyance, that is, the amount of displacement of the side edge portion of the paper sheet P in the width direction. Clearly it is width data.

The above formula (8) is based on the maximum width data detected from the paper sheet P conveyed in an oblique state, that is, the width data M + N between the coordinates ZLi and ZRi, and the lateral displacement of the side edge portion of the paper sheet P. Half the quantity N, that is, the width data N between the coordinates ZLo and ZLi
It is clear that this corresponds to the subtraction processing of half of the.

Further, the above expression (9) is applied from the first corner portion of the front end portion detected from the sheet P conveyed in an oblique state to the second corner portion of the front end portion.
To the corners of the sheet, that is, the width data M between the coordinate ZLo and the coordinate ZLi, to half the displacement amount N in the width direction of the side edge of the paper sheet P, that is, the width data N between the coordinate ZLo and the coordinate ZLi. It is clear that this corresponds to the addition processing of half of the.

From these facts, at least the detection data concerning the preceding first corner of the front edge of the conveyed paper sheet P, the detection data concerning the following second corner of the front edge, and the first Transport from the first corner or from the second corner during the time corresponding to the time difference between the detection data related to the corner and the detection data related to the second corner. It becomes apparent that the true width data can be calculated by storing the detection data related to the side edge portion of the paper sheet P extending in the direction.

From the above description, it will be understood that each of these detection data becomes simpler by using coordinate data.

"Effects of the Invention" As is clear from the above description, the present invention uses the width direction detecting means for detecting at least the left and right ends of the paper sheet, and therefore the width data calculated from the measurement result is used. Since the true width data can be obtained by performing the addition and subtraction processing, the trigonometric function operation that causes a large load on the arithmetic element and the storage of the correction data table that causes a large load in the storage unit are performed. It is possible to easily obtain the true width data without the need.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIGS. 2 to 5 show the first embodiment of the present invention, FIG. 2 is a block diagram of the entire discriminating apparatus, and FIG. FIG. 4 is a plan view showing the arrangement of width sensors in the conveyance direction of leaves, FIG. 4 is an explanatory view of sampling timing of width data, FIG. 5 is an explanatory view of the principle of non-oblique correction, and FIG. FIG. 7 is a plan view showing the arrangement of the width sensors according to the embodiment, and FIG. 7 is a diagram showing the third embodiment of the present invention, which is an explanatory view showing a simpler principle of non-oblique correction. a ... Width direction detection means, b ... storage means, c ... calculation means.

Claims (5)

[Claims] 1. A width direction detecting unit arranged along a direction orthogonal to a sheet conveying direction and detecting the width direction of the conveyed sheet, and a detection signal obtained from the width direction detecting unit. Based on the above, the detection data relating to the first corner portion located on the front side in the transport direction of the front edge of the transported paper sheet, and the detection data relating to the second corner portion located on the rear side in the transport direction at the front edge. While storing the detection data, during the time corresponding to the time difference between the detection data concerning the first corner and the detection data concerning the second corner, the first corner or Storage means for storing detection data relating to a side edge portion of the paper sheet extending rearward in the transport direction from the second corner portion; detection data relating to the first corner portion stored in the storage means; Detection data relating to the second corner and the side edge Based on the detection data related to, the paper sheet determination apparatus characterized by being composed of a calculating means for calculating the true width direction dimension of the sheet being conveyed. 2. The first dimension data obtained by the detection data relating to the first corner portion and the detection data relating to the second corner portion, and the calculating means including the detection data relating to the side edge portion. 2. The sheet discriminating apparatus according to claim 1, wherein the true widthwise dimension of the conveyed sheet is calculated by adding the second dimension data obtained from the above. 3. The second dimension data added to the first dimension data is dimension data corresponding to half the displacement amount of the side edge portion in the width direction.
The paper sheet discrimination device described. 4. The calculating means obtains from the first dimension data obtained from the detection data relating to the second corner portion and the detection data relating to the side edge portion, and from the detection data relating to the side edge portion. 2. The paper sheet discriminating apparatus according to claim 1, wherein the true widthwise dimension of the conveyed paper sheet is calculated by subtracting the generated second size data. 5. The second dimension data subtracted from the first dimension data is dimension data corresponding to half the displacement amount of the side edge portion in the width direction. The paper sheet discrimination device described.