JPH02193289A - Method for correcting paper currency data - Google Patents

Abstract

PURPOSE:To obtain data with high accuracy as output data based upon an optical detecting means by normalizing detection output data (gathered data) on paper currency to be decided in real time for the output variation, etc., of the light source and photodetection sensor of an optical detecting means. CONSTITUTION:The maximum output level Va of detection output data on paper currency to be decided from an optical sensor is detected, the magnification between this maximum output level Va and a preset sensor output criterion V0 is calculated, and the detection output data d1(t) on the paper currency to be decided is multiplied by the magnification to correct the detection output data g1(t) on the paper currency to be decided. Therefore, the gathered data g1(t) on the paper currency to be decided can be normalized in real time for the output variation of the light source and photodetection sensor 1. Consequently, the data with high accuracy is obtained as the output data of the optical sensor.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for correcting banknote data in a banknote discrimination device for determining the denomination, authenticity, etc. of banknotes in cash processing machines, automatic teller machines, etc. It is.

(Prior Art) In a conventional banknote discrimination device, a light source emits light onto a banknote being transported, and data such as reflected light or transmitted light from an optical sensor is collected and used as discrimination data. Further, the discrimination performance of the apparatus is influenced by whether the discrimination data is collected under the same conditions as when standard data is collected, or by normalizing the collected data so that it becomes the same as when collected under the same conditions. However, since identification data is subject to output fluctuations due to disturbances such as fluctuations in the light intensity of the light source and external temperature, these fluctuation factors are eliminated and the optical sensor output (received light) is collected under conditions equivalent to standard data. There is a banknote data correction method that corrects the sensor output).

An example of a bill data correction method for such a conventional bill validating device will be described below.

Conventional banknote validation devices determine whether the banknotes being conveyed are genuine or counterfeit, and only when the banknotes are determined to be genuine,
Data within a certain predetermined range, that is, the optical sensor output value A, of the collected data regarding the valid banknotes is stored in a non-volatile RAM, and the average value of a plurality of valid banknotes (8 sheets) is calculated,
Understand the current optical sensor output status. Furthermore, for the average value W, calculate the magnification E of the sensor standard output value ■ collected in the same manner as described above at the time of standard data collection, and make the magnification of the amplification part of the optical sensor output of this device the current value E times. It was to do so.

(Problem to be Solved by the Invention) However, in the conventional banknote data correction method of a banknote validating device, the light receiving sensor output or the light source output cannot follow sudden changes in disturbance, and the optical sensor output Since the data that requires correction is data from banknotes, if there is a change in the optical sensor over time and the banknote does not pass, correction data corresponding to the change over time will not be generated. Therefore, the correction data has the disadvantage that it cannot follow sudden fluctuations in external disturbances or changes over time in the optical sensor.

Furthermore, in consideration of the amount of variation in collected data such as tracking of correction data and the number of passed banknotes, it becomes necessary to increase the allowable value of standard data to be compared and determined with the collected data. The above-mentioned tolerance value is an element that greatly influences the discrimination performance,
Therefore, if the allowable value of the standard data had to be increased, there was a risk that performance would deteriorate.

Therefore, an object of the present invention is to provide a banknote data correction method that allows desired collected data to be obtained with high accuracy without causing a decline in the performance of a banknote validating device even when there are sudden fluctuations in disturbances or changes over time. It is about providing.

(Means for Solving the Problem) The banknote data correction method of the present invention detects the optical pattern of the banknote by an optical detection means, and based on the detection output data, determines the denomination of the banknote, the insertion direction, and the denomination of the banknote. In a banknote discrimination device that determines the authenticity of a type, etc., the maximum output level of the detection output data of the banknote to be determined by the optical detection means is detected, the magnification of the maximum output level and a reference setting value is calculated, and the By multiplying the detection output data of the banknotes to be determined by a magnification, the detection output data of the banknotes to be determined by the same optical detection means is corrected.

(Function) Therefore, the maximum output level of the detection output data of the banknote to be discriminated by the optical detection means is detected, the magnification of the maximum output level and the reference setting value is calculated, and the magnification is calculated as the detection output of the banknote to be discriminated. Since the detection output data (collected data) of the same optical detection means of the banknote to be discriminated is corrected by multiplying the data, it is possible to compensate for fluctuations in the output of the light source and light receiving sensor in the optical detection means. , it becomes possible to correct the detection output data (collected data) of the banknotes to be discriminated in real time. Therefore, even if there is a fluctuation in the output of the optical detection means due to a disturbance in the banknote validating device or a change over time in the optical detection means, the system is not dependent on these.
Highly accurate output data can be obtained based on the optical detection means. Furthermore, it becomes possible to reduce the tolerance value of the standard pattern used for determining the authenticity of the denomination of a banknote in the banknote validating apparatus, thereby improving the performance of the banknote validating apparatus.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the banknote data correction method according to the present invention.

The banknote data correction method of the present invention detects the optical pattern of the banknote by an optical detection means, and based on this detection output data, determines the denomination of the banknote, the insertion direction, the authenticity of the banknote denomination, etc. This is for normalizing the detection output data of the bill to be discriminated in the discrimination device.

In FIG. 1, numeral 1 is a light receiving sensor that irradiates light onto a bill (not shown) being conveyed in a bill validating device and detects the reflected light or transmitted light; 2 is a photoelectric sensor that detects the voltage photoelectrically converted by the light receiving sensor An amplifier section 3 amplifies the analog voltage to an optimum value, and an analog/digital conversion section (hereinafter referred to as A/D conversion) converts the analog voltage amplified by the amplifier section 2 into a digital value at each sample timing synchronized with the speed of the conveyed bill. ), 4 is a register for temporarily storing the data converted into a digital value by this A/D converter 3, and 5 is a register for storing the data in the RAM 6 or reading standard pattern data stored in the ROM 7. This is a central processing unit (hereinafter referred to as CPU) that generates correction data through arithmetic processing.

Next, the operation of this embodiment will be explained with reference to FIGS. 1 to 4. In addition, FIG. 2 is a diagram showing the sensor output waveform of the light receiving sensor 1 of FIG. 1, FIG. 3 is a normalization process flowchart of the CPU 5 in one optical sensor as an optical detection means, and FIG. 3 is a flowchart showing the calculation processing of the CPU 5.

First, in the banknote discrimination device, light is irradiated onto the banknotes to be discriminated being conveyed, and the reflected light or transmitted light (hereinafter, only the reflected light will be explained) is photoelectrically converted by the light receiving sensor 1, and the photoelectrically converted analog The output is amplified by the amplifier 2 to an optimum value. This amplified analog signal is A/D
The converting unit 3 converts the data into a digital signal at a sampling timing synchronized with the conveyance speed of the banknote, and the converted digital data is temporarily stored in the register 4 and sent to the CP.
U5 stores the digital data at a predetermined address in RAM6.

Here, in FIG. 2, g s (t) is a pattern expressed as a continuous function of uncorrected digital data of the bill to be discriminated when the light receiving sensor 1 is scanned in a certain denomination direction i stored in the RAM 6. It is. Here i=1.2
．． ..., j, where i represents the type number in the direction of the machine type, and if the banknotes to be discriminated are in three denominations of Japanese yen (10,000, 5,000, 5,000,
1,000 tickets), 4 directions (1 front, 1 front, reverse, reverse),
j=12. Furthermore, gt(t) is data when the amount of light from the light source of the optical sensor that irradiates the bill to be discriminated decreases.

Further, f+(t) in the figure is a standard pattern when the light receiving sensor 1 is scanned in the same denomination direction i, as in the case of g I(t). gt(t) is a state in which the output is reduced compared to the standard pattern fi,(t) due to data collected under different conditions such as a reduction in the light intensity of the light source of the optical sensor.

Next, signal processing by the CPU 5 in the method of correcting the banknote data to be discriminated gr (t) will be explained using FIG. 3.

First, in advance, t=C)-n(t
: sample timing value, n: maximum value of sample timing value) is detected, and this maximum output level ■ is detected. is stored in the ROM 7 as a sensor output reference value. Next, collected data gt(t) of banknotes to be determined
, the maximum output level 8 of the collected data g+(t) at t=O−n is detected (step SL in FIG. 3).

S2), V is 1=1. is the value of gt(t) at . Here, when calculating the magnification C of the standard pattern f+(t) and the banknote data to be discriminated gt(t) using the maximum output level of each pattern as a standard, C=V. /V, ...(1)
A relational expression like this holds true. Therefore, the optical sensor output data g s (t) of the banknote to be discriminated is corrected using the following relational expression (2).

g'mu(t) = C-g +(t)
...(2) Therefore, in step S3 of FIG.
Sensor output standard value ■. and the maximum output level ■ of the collected data of the banknotes to be determined, which ratio, that is, the magnification C, is calculated, and in step S4 of the figure, the collected data gt(t) is multiplied by the magnification C to obtain the normalized data g' s (t ).

On the other hand, regarding the above-mentioned detection of the maximum output level ■ of the banknote data to be discriminated g1(t), calculation of the magnification C, and calculation of the banknote data to be discriminated (normalized data) g's(t) after correction. A flowchart of the arithmetic processing by the CPU 5 is shown in FIG. That is, as can be seen from steps Sl and S2, the time point at which the banknote validating device starts operating is set to 1==0.
Then, the maximum output level ■1 also starts from ■8=0. Then, the device starts operating, and in step S3, collected data gt(
It is determined whether or not t) is larger than the previous sample timing that has already been obtained, and if g+(t) is larger than ■8, the process moves to step S4, and g+(t)
If is larger than va, then in step S5 V is set and g+(t) at the current sample timing t is used instead of the previous value, that is, V −= g 1(t), and the process moves to step S4.

Then, in step S4, the sample timing value t
If n is not the maximum value, in step S6, the sample timing value is added by +1, that is, the operations after step S3 are repeated with the next sample timing value.

Then, in step S4, when the sample timing value t reaches the maximum value n, the process moves to step S7.

The above is the detection of the maximum output level of the collected data of banknotes to be discriminated. Next, in step S7, the final value of V used before proceeding to step S7 (this value is the largest) is used, and this value of vl is used. Find the magnification C by dividing (Calculation of magnification C).

Next, in step S8, the collected data g+(t) is multiplied by the magnification C to calculate correction data g'□(1) (calculation of normalized data g'+(t)).

In addition, in the present invention, the maximum output level ■ . ■Detect this maximum output level.

By setting the reference level necessary for normalization of the banknote to be discriminated by the optical sensor, in the case of the conventional method in which the standard level detection for normalization is set at a fixed reading position, the standard level reading position of the banknote may be accidentally detected. It is possible to eliminate the problem that when there is dirt or the like on the image, the reference level does not reach the desired level and normalization cannot be performed accurately. Therefore, in the present invention, even if the white part of the base of a part of the banknote on the scanning line is dirty when scanning with the optical sensor, the white part of the other base can be used, so that the optical sensor output standard level can be accurately determined. can be detected and stable normalization is possible.

As can be seen from the above description, the present invention provides the maximum output level v8 of the detection output data of the bill to be discriminated by the optical sensor.
is detected, and the magnification c (c = v o /
v −) is calculated, and the detection output data g 1 (t) of the banknotes to be discriminated is multiplied by this magnification to correct the detection output data g I (t) of the banknotes to be discriminated. Such processing is performed for each banknote being conveyed and for each optical sensor. By doing this, it is possible to normalize the detected output data (collected data) g+(t) of the banknotes to be discriminated in real time with respect to output fluctuations of the light source in the optical sensor and the light receiving sensor 1, etc. Therefore, even if there are fluctuations in the output of the optical sensor due to disturbances (including sudden disturbances) in the banknote validating device or changes in the optical sensor over time, the output data of the optical sensor can be highly accurate without depending on these factors. You can get something. Furthermore, the permissible value of the standard pattern data used for determining the authenticity of the denomination of banknotes in the banknote validating apparatus can also be reduced, and the performance of the banknote validating apparatus can be improved.

In this embodiment, a case has been described in which a reflected light sensor is used as an optical sensor and applied to reflected light. However, the present invention is not limited to this, and a transmission type sensor is used as an optical sensor to detect transmitted light Of course, the same can be applied to .

(Effects of the Invention) As described above, by using the present invention, the detection output data (collected data) of banknotes to be discriminated can be normalized in real time against fluctuations in the output of the light source and light receiving sensor in the optical detection means. Therefore, even if there are fluctuations in the output of the optical detection means due to disturbances in the banknote validating device or changes over time in the optical detection means, the output data based on the optical detection means can be highly processed without depending on these factors. Accuracy can be obtained.

Further, according to the present invention, it is possible to reduce the tolerance value of a standard pattern used for determining the authenticity of the denomination of a banknote in a banknote validating device, thereby improving the performance of the banknote validating device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the banknote data correction method according to the present invention, FIG. 2 is an output waveform diagram of the light receiving sensor 1 shown in FIG. 1, and FIG. Flowchart FIG. 4 is a flowchart showing the arithmetic processing of the CPU 5 in FIG. 1... Light receiving sensor, 3... A/D conversion section, 5. CP
U, 6・RAM, 7・ROM. Patent Applicant: Oki Electric Industry Co., Ltd. Flowchart 4 showing the arithmetic processing of the CPU 5 shown in FIG. 1

Claims (1)

[Claims] Detecting the optical pattern of the banknote by an optical detection means,
In a banknote discrimination device that determines the denomination of a banknote, the insertion direction, the authenticity of the banknote denomination, etc. based on the detection output data, the maximum output level of the detection output data of the banknote to be determined by the optical detection means is detected. Then, by calculating a magnification between the maximum output level and the reference setting value, and multiplying the detection output data of the banknote to be discriminated by the magnification, the detection output data of the banknote to be discriminated by the same optical detection means is calculated. A banknote data correction method, characterized in that the banknote data is corrected.