JPH11106094A - Thickness detector for paper sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly accurate device not affected by eccentricity or the like by subtracting an integrated value one base unit before an optional base unit stored in a first storing means from an integrated value in an optional base unit, adding a value equivalent to the thickness of a paper sheet in a base unit before an optical base unit stored in a second storing means by rotation of a reference roller integral multiple and calculating a value equivalent to the thickness of the paper sheet in an optional base unit. SOLUTION: A control unit stores the displacement of roller eccentricity in the reference rotational angle range of a reference roller by rotating the reference roller by a specified number of times while no bill is fed, and then stores an integrated value thereof in a memory. Then, in correction of a bill thickness after the feeding start of the bill, a circuit subtracts correction integration data MS as integration data one correction unit before an optional correction timing from S (C) as integration data of reference roller one cycle in an optional correction timing. Then, memory data T (C) as a value equivalent to paper thickness before one cycle of the reference roller is added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet thickness detecting device for detecting the thickness of sheets such as banknotes, and more particularly to a plurality of types of foreign banknotes having different thicknesses in an automatic teller machine. The present invention relates to a sheet thickness detecting device suitable for detecting the thickness of a sheet.

[0002]

2. Description of the Related Art A sheet thickness detecting device according to the prior art rotates at a fixed period, and its outer peripheral surface is brought into contact with a reference roller serving as a thickness reference, facing the reference roller, and is displaceable. A detection roller provided; an entry detection unit for detecting that a sheet has entered between the reference roller and the detection roller; a conveyance unit for feeding the sheet between the reference roller and the detection roller; and a detection roller. Conversion means for converting the displacement (angle) of the sheet into an electric signal, and correction means for integrating and correcting the output signal from the conversion means, wherein the output from the conversion means when the paper sheet passes through the thickness detecting unit is provided. By subtracting the integrated value of the output from the conversion means over the integral multiple of the rotation period of the reference roller, which was previously collected when the sheet was not transported, from the value obtained by integrating the integral multiple of the reference roller rotation period, Compensate for eccentricity The average thickness of the sheet to an integer multiple of the reference roller outer peripheral length as the unit length has been detected.

As a document describing a technique relating to a sheet thickness detecting device according to the prior art, there is, for example, Japanese Patent Application Laid-Open No. 5-278901.

[0004]

However, in the conventional sheet thickness detecting apparatus, the basic unit (minimum length) of the thickness measurement must be an integral multiple of the outer peripheral length of the reference roller. In order to measure the thickness of each medium strictly, it is allowed that only one sheet exists within an arbitrary media feed amount (length) corresponding to an integral multiple of the reference roller outer peripheral length. It was not done.

The reason for this is that, for example, when the length of a sheet is L and the interval between the sheet and the next sheet is i, the sum (= L
When + 2i) is shorter than the outer peripheral length of the reference roller, two or more sheets are always present in the medium feed amount corresponding to the basic unit length of measurement, and the thickness of each sheet is detected. Because it becomes impossible.

For this reason, in the prior art, in an apparatus for simultaneously handling sheets having various sizes such as foreign bills, the outer diameter of the reference roller and the number of sheets to be processed per unit time are greatly restricted. However, there is a problem that the configuration becomes impossible in some cases.

Further, in the prior art, since the integrated value of the displacement of the detection roller is simply used, only the average thickness of the paper sheet can be detected. There was also a problem that the thickness could not be detected.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, and to provide a sheet thickness detecting device capable of accurately detecting the thickness of sheets having various sizes. It is to be. It is a further object of the present invention to provide a sheet thickness detecting device capable of accurately detecting the thickness of a sheet even when foreign matter is stuck to the sheet.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a sheet thickness detecting device for measuring the thickness of a sheet to be conveyed. A reference roller serving as a reference surface of the reference roller, a pressure contact member which comes into contact with the outer peripheral surface of the reference roller while applying pressure, and is displaceably provided with respect to the outer peripheral surface; A conversion circuit that converts the signal into a signal, an integration circuit that reads the output signal of the conversion means at each predetermined rotation angle of the reference roller, and integrates the signal over an integral multiple rotation of the reference roller, and stores an integration value obtained by the integration circuit. A first storage unit for storing the sheet thickness equivalent value obtained from the integrated value, and a calculation process using the data of the first and second storage units. Calculation means, and read by the reference roller. The basic unit of the thickness correction is set to an integral multiple of the take-out cycle, and the basic unit of the read cycle and the thickness correction is set so that the integral multiple of the basic unit of the thickness correction becomes an integral multiple of the reference roller. By rotating the reference roller in a state in which only the pressure contact member is in contact with the roller, the integrated value in all basic units, and rotating the reference roller in a state in which the pressure contact member is in contact with the reference roller via a sheet. And the integral values in all basic units by the first
And the second storage means stores a value corresponding to the thickness of the sheet in each basic unit from the two integrated values stored in the first storage means, and stores the integrated value in an arbitrary basic unit. Subtracts the integral value one basic unit before the arbitrary basic unit stored in the first storage means, and further subtracts the integral number of the reference roller from the arbitrary basic unit stored in the second storage means. A first feature is that a value equivalent to the thickness of the sheet in the arbitrary basic unit is obtained by adding a value equivalent to the thickness of the sheet in the basic unit just before the rotation.

Further, the present invention provides a sheet thickness detecting apparatus according to the above-mentioned feature, wherein the sheet thickness detecting means for detecting the presence or absence of a sheet is provided, and the paper thickness is included in a basic unit of arbitrary thickness correction. When the leaf does not exist between the reference roller and the pressing member, the second storage means stores the value corresponding to the thickness of the paper in the basic unit of the arbitrary thickness correction as "0" in the second storage means.
In the paper sheet thickness detecting device according to the first characteristic, it is preferable that the paper sheet is not fed between the reference roller and the pressing member while at least the reference roller rotates an integral multiple. 3.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a sheet thickness detecting apparatus according to an embodiment of the present invention. FIG. 1 is a diagram illustrating a schematic configuration of a mechanism of a bill thickness detecting device according to the present embodiment, and FIG. 2 is a diagram illustrating a schematic circuit configuration of the device.

The sheet thickness detecting device shown in FIG. 1 is driven to rotate at a constant period by a motor (not shown), and a reference roller 1 whose outer peripheral surface is a reference position of the thickness in measuring the thickness of the banknote; The detection roller 2, which is a pressure contact member that swings about the fulcrum of the link 3 while being pressurized by the pressure spring 4 and contacts the outer peripheral portion of the reference roller 1, is attached to the fulcrum of the link 3. An angle sensor 5 for converting the displacement of the detection roller 2 appearing as an angular displacement of the link 3 into an electric signal; a bill presence / absence sensor 11 for detecting the presence / absence of a bill between the reference roller 1 and the detection roller 2; And a transport belt 7 for transporting between the rollers 1 and 2.

As shown in FIG. 2, the circuit configuration of the present apparatus includes an amplifier 8 for amplifying an electric signal from the angle sensor 5 and an analog signal A for converting an analog signal amplified by the amplifier 8 into a digital signal (digitization). A / D converter 9 and a control unit 10 for detecting the thickness of a sheet based on the digitized digital signal are provided. The control unit 10 has a function of integrating the read displacement data (digitization) and a function of correcting the paper thickness equivalent value, and integration progress data to which the displacement data of the angle sensor is added / reference roller used in the correction calculation. 1
Integral data for correction, which is the integral value of displacement data for rotation /
Similarly, a memory for storing a paper thickness equivalent value used in the correction calculation is provided. Although not shown, the control unit 10 also controls a motor for driving the reference roller 1 and a motor for driving the transport belt 7 and other controls.

The detecting apparatus according to the present embodiment is for obtaining the paper thickness equivalent value of each of the N0 basic units existing during one rotation of the reference roller, and the paper thickness equivalent values are M0 constituting the basic unit. This is a value obtained by extracting the paper thickness equivalent from the integral value of the pieces of displacement data. In other words, one revolution of the reference roller is divided into N0 basic units, and each basic unit is divided into M basic units.
The value corresponding to the paper thickness is obtained by extracting from the integral value of zero displacement data.

For example, if a unit obtained by dividing one rotation of the reference roller for every 20 ° is defined as one basic unit, the number of basic units N0
Is 18 (= 360/20) and the number of data M0 to be scanned in the basic unit is 20, the read cycle TR
Becomes (1/360 °). That is, the present mechanism detects the rotation angle of the angle sensor 5 20 times per 1 °, thereby
The eccentricity of the reference roller according to the rotation angle of the reference roller is obtained by obtaining the accumulated paper thickness equivalent value of the basic unit and obtaining the accumulated paper thickness equivalent value of the basic unit 18 times.

The reading period of the displacement data is TR, the number of data constituting one basic unit is MO, the number NO of basic units existing during one rotation of the reference roller, and the reference roller rotation period T
C is set so that the following relationship is established.

[0017]

## EQU1 ## TR × M0 × N0 = TC (1) The data stored in the memory is each N shown in FIG.
Integration progress data S (0) to zero array data
S (N0-1) and paper thickness equivalent values T (0) to T (N0-1)
And correction integrated value data MS.

The detecting device thus configured rotates the reference roller in a state where the paper is not conveyed, and detects the output of the angle sensor 5 due to the rotation of the detection roller 2 including the eccentricity of the reference roller. An angle sensor in a case where the eccentricity of the reference roller detected from the integrated value of the M0 displacement data in each of the basic units obtained by dividing the reference roller into N0 is grasped in the basic unit, and the bill is actually conveyed. By correcting the eccentricity of the reference roller in the basic unit from the output of No. 5, the thickness of the bill in consideration of the eccentricity of the reference roller is detected.

Next, the concept of this correction will be described.
FIG. 5 is a conceptual diagram of the above-mentioned correction, and shows a state in which the bill continuously enters the detection unit.

First, FIG. 5A shows a sensor signal at the time of conveying a bill when it is assumed that the eccentricity of the reference roller is 0.
When there is no eccentricity at all, the sensor output is a signal that changes linearly and unevenly depending on the presence or absence of a bill as shown in the figure. That is,
This indicates that the sensor output in a state where there is no bill and a state where there is a bill logically change in parallel with a step.

However, since the actual reference roller has eccentricity, the sensor output signal has a signal waveform including the eccentricity of the reference roller and having a waveform step with respect to the time axis as shown in FIG. 5B. .

Here, when the number of times of reading N ≧ M0 × N0, the integrated value S (C) of the displacement data and the correction integrated data MS are indicated by oblique lines including a waveform having a step as shown in FIG. 5 (c). Area, and part of the data is in an overlapping form. That is, the difference between the integral value S (C) of the displacement data and the integral data for correction MS is the same as the difference between the two hatched data shown in FIG. 5D.

On the other hand, the data at these two locations is data at a position shifted in phase by exactly one cycle of the reference roller.
The value of the hatched portion, which is the surface height of the reference roller, is equal. That is, the difference between the paper thickness T and T (C) is the sum of the integrated value S (C) and MS
By performing the following calculation, the thickness of the bill for an arbitrary unit width is obtained.

[0024]

[Mathematical formula-see original document] T = T (C) + (S (C) -MS) = S (C) -MS + T (C) As described above, according to the present embodiment, the influence of the eccentricity and the surface shape of the reference roller can be reduced. It is understood that a bill thickness detecting device that can obtain a bill thickness equivalent value for each correction unit without receiving it is obtained.

Next, an outline of the operation of the sheet thickness detecting apparatus according to the present embodiment to which the above principle is applied will be described with reference to the drawings. First, when the bill 6 is transported sandwiched between the transport belts 7 and sent to the contact portion between the reference roller 1 and the detection roller 2, the detection roller 2 is moved to the reference surface by a distance corresponding to the thickness of the bill 6. By moving further, the link 3 is rotated. The rotation angle of the link 3 is measured by the angle sensor 5 and converted into a voltage corresponding to the rotation angle. The voltage signal of the angle sensor 5 is amplified by an amplifier 8 and then A / D
Reads the digitized data digitized by the converter 9 and sets the read cycle TR
Each time, it is taken into the control unit 10 and sequentially added to the integration progress data in the memory.

Next, the control unit 10 subtracts the correction integration value data MS stored in the memory from the displacement data integration value at an arbitrary timing, and subtracts the correction timing data MS also stored in the memory. , The correction operation of adding the previous paper thickness equivalent value only during the period corresponding to the reference roller rotation cycle is performed sequentially, so that each basic unit (TR × M
0) Find the thickness of each bill.

Next, the detailed operation of the detection device according to the present embodiment will be described with reference to the flowchart of FIG. In the data described below, N is the number of readings, S is the integration progress data, T is the paper thickness equivalent value data, MS is the integrated data for the supplementary (step), TMR is the timer count value, and TR is the timer cycle. The prescribed values to be determined, A to C and I are the values described later,
N0 will be described as a value representing the number of roller cycles.

First, in a state where the bill 6 is not conveyed, the control section 10 clears the value of the internal memory (step 40).
1), it is determined whether or not the reference roller 1 has a predetermined number of revolutions (step 402). When the reference roller 1 has a predetermined number of revolutions, each data (N = 0, A = 0, B = 0, C = 0) , TMR =
0, S = 0) (steps 403 to 40)
6).

Next, at step 407, the control unit 10 monitors whether or not the timer count value TMR exceeds the timer specified value TR and waits for a read timing. When the timing is reached, the control unit 10 reads the converted data D (N). (Step 408), the timer for measuring the reading cycle of the displacement data D (N) is initialized (TMR = 0, I = 0, Steps 409 to 410), and the integration progress data S
The displacement data D (N) is added to (0) to S (N0-1). That is, the transition of the displacement of the roller 1 according to the rotation of the reference roller 1 is added as the displacement data D (N). After this addition, 1 is added to the value I, and the value I becomes a predetermined number of cycles N0
(Steps 413 to 4)
14). When the value I reaches the predetermined cycle number N0, the number of times of reading N is counted up next (step 415), and the remainder A of the number of times of data reading N and M0 / the number of times of reading data N and M
The quotient B of 0 / the value B and the remainder C of N0 are calculated (steps 146 to 418).

The control unit according to the present embodiment repeatedly executes these flows until the value A becomes 0 (step 41).
9) Next, the process is executed until the number N becomes larger than the predetermined data read number N0 (step 420), and the process is executed until the value C becomes 0 (until the roller rotates one cycle), and the eccentricity of the reference roller 1 is reduced. Stores the integral value. That is, the control unit according to the present embodiment rotates the reference roller 1 a predetermined number of times in a state where the banknote is not conveyed, and stores the displacement of the roller eccentricity within the reference rotation angle range of the reference roller 1 so that the banknote is not conveyed. In this state, the displacement data for at least the time corresponding to the reference roller rotation period is read, and the integrated value is stored in the memory.

Next, the circuit according to the present embodiment starts the thickness correction processing after starting the conveyance of the bill. The bill thickness correction is performed by subtracting correction integrated data MS, which is integrated data one correction unit before the arbitrary correction timing, from S (C), which is integrated data for one cycle of the reference roller at an arbitrary correction timing. This is done by adding the memory data T (C) which is the value equivalent to the paper thickness just one cycle before the reference roller. The details of the method of the above-described paper thickness correction processing will be described below.

First, after the banknote conveyance is started (step 422), the integrated data S (C) is taken into the integrated data for correction MS (step 423), S (C) is initialized (step 424), and the presence of paper / paper Initialization of the absence flag F (step 425), check of the bill sensor (step 42)
6) are sequentially performed, the flag F is initialized when there is no paper (step 427), and the timing of reading the displacement data D (N) is waited (step 428).
(N) is read (step 429), and the timer TMR is initialized (step 430). That is,
In these steps, initialization of the accumulated data S and the like is performed when the bill is conveyed.

Next, in this procedure, the integration progress data S (0) to
The displacement data D (N) is added to S (N0-1) (step 432), and the number of readings N is updated (N = N +
1) is performed (step 435), and the number of data readings N
And the remainder of M0 (step 436), the value B of the quotient of the number of data readings N and M0 (step 437), and the value C of the remainder of B and N0 (step 438). The value C is an array number for storing the integrated data and the paper thickness data.

Next, in this procedure, it is determined whether or not the calculated other value A is 0 (step 439), and the above steps 426 to 439 are repeated until this value A reaches 0, and the value of the F (flag) is set. Is confirmed, and a correction calculation of the paper thickness equivalent value is executed (step 440). This correction calculation is based on the following equation.

[0035]

(F = 0): When paper is present Paper thickness T = S (C) −MS + T (C) (F ≠ 0): When paper is not present Paper thickness T = 0 In the above equation, S ( C) indicates the current integration progress data, MS indicates the correction integration data, and T (C) indicates the previously detected paper thickness (the value in the first case is "0"). Next, the control unit stores the paper thickness T in the array T (C) in the memory (step 443), waits for the end of the processing in step 444, and waits for the end of the processing until the end of the processing.
Repeat 444. Thus, the detection device can sequentially obtain the paper thickness equivalent value T for each correction unit.

A means for detecting the rotation phase of the reference roller 1, for example, a rotary encoder, is provided so that every time the reference roller 1 rotates by a predetermined angle, five data of the angle sensor are read, so that the reference roller 1 is rotated. It is also possible to obtain a bill thickness detecting device similar to the above, which does not need to keep the rotation speed of the bill constant.

[0037]

As described above, according to the present invention, the integral multiple of the reading period by the reference roller is used as the basic unit of the thickness correction, and the integral multiple of the basic unit of the thickness correction is the integral multiple of the rotation of the reference roller. The reading cycle and the basic unit of thickness correction are set so that the reference roller is rotated while only the pressing member is in contact with the reference roller. By rotating the reference roller in a state of being in contact with the paper sheet, the integral values in all the basic units are stored in the first storage means, and both integral values stored in the first storage means are stored. The value corresponding to the thickness of the sheet in each basic unit is stored in the second storage means, and the integral value in the arbitrary basic unit is shifted by one basic unit from the arbitrary basic unit stored in the first storage means. of By subtracting the minute value from the arbitrary basic unit stored in the second storage means and adding a value corresponding to the thickness of a sheet in the basic unit immediately before the reference roller by integral multiple rotation, By obtaining the value corresponding to the thickness of the sheet in the basic unit, a highly accurate sheet thickness detecting device which is not affected by the processing accuracy such as the eccentricity of the reference roller can be obtained. That is, according to the present invention, it is possible to obtain a highly accurate sheet thickness detecting device which is not affected by the eccentricity of the roller by comparing the integral value obtained one cycle before in the basic unit obtained by dividing the reference roller.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a mechanism of a bill thickness detecting device according to an embodiment.

FIG. 2 is a diagram schematically illustrating a circuit configuration of the device illustrated in FIG. 1;

FIG. 3 is a diagram showing a data configuration stored in a memory shown in FIG. 2;

FIG. 4 is a flowchart for explaining the operation of the apparatus according to the embodiment;

FIG. 5 is a diagram for explaining roller eccentricity correction according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reference roller, 2 ... Detection roller, 3 ... Link, 4 ... Pressurizing spring, 5 ... Angle sensor, 6 ... Banknote, 7 ... Conveying belt,
8 amplifier, 9 A / D converter, 10 controller, 11
Paper sheet sensor.

Claims (3)

[Claims] 1. A sheet thickness detecting device for measuring the thickness of a sheet to be conveyed, comprising: a reference roller having an outer peripheral surface serving as a reference surface of the thickness of the sheet to be measured; A pressure contact member which comes into contact with the outer peripheral surface of the roller while applying a pressure and is displaceable with respect to the outer peripheral surface; a conversion circuit for converting the displacement of the pressure contact member into an electric signal; An integration circuit that reads an output signal at each predetermined rotation angle of the reference roller and integrates the output signal over an integral multiple of the reference roller; a first storage unit that stores an integration value obtained by the integration circuit; A second storage unit for storing a value corresponding to the thickness of the sheet to be obtained; and a calculation unit for performing a calculation process using data of the first and second storage units. Integer multiple is the basic unit of thickness correction, and The reading period and the basic unit of thickness correction are set so that the integral multiple of the basic unit of the correction is the integral multiple of the rotation of the reference roller, and the reference roller is rotated in a state where only the pressing member is in contact with the reference roller. Thus, the integral values in all the basic units and the integral values in all the basic units by rotating the reference roller in a state where the pressing member is in contact with the reference roller via the paper sheet are stored in the first storage means. In addition to the storage, the value corresponding to the thickness of the sheet in each basic unit is stored in the second storage unit from both integral values stored in the first storage unit, and The integral value one basic unit before the arbitrary basic unit stored in the first storage unit is subtracted, and the integral value before the arbitrary basic unit stored in the second storage unit by the reference roller integer multiple rotation is further subtracted. Base Thickness detecting device of a paper sheet, characterized by determining the thickness equivalent value of the sheet in the arbitrary basic unit by adding the thickness value equivalent sheet in the unit. 2. The apparatus according to claim 1, further comprising a sheet presence / absence detecting means for detecting the presence / absence of the sheet, wherein the sheet is not present between the reference roller and the pressing member in a basic unit of any thickness correction. The value equivalent to the thickness of the paper sheet in the basic unit of arbitrary thickness correction is "0"
2. The sheet thickness detecting apparatus according to claim 1, wherein the information is stored in a second storage unit. 3. The sheet thickness detection according to claim 1, wherein the sheet is prevented from being fed between the reference roller and the pressing member while at least the reference roller is rotated by an integral multiple. apparatus.