JPS63208710A - Thickness detector for sheet paper or the like - Google Patents

Abstract

PURPOSE:To eliminate errors due to the wear of a roller and dust sticking on the roller by using thickness data which is the difference between the mean value of thickness detection levels when paper money passes and the mean value of detection levels in a specific period in the absence of paper money. CONSTITUTION:A gate sensor 10 detects the front end of paper money P from an A/D converter 20 in response to a signal from the sensor 10, and holds the value obtained by adding data until the paper P moves into between rollers 25 (until the sampling data increases abruptly to a large value) in a RAM 22 as initial integral value A. Further, the sum value of the sampling data from the entry of the a paper money P into between the rollers 2 and 5 to the point of time when the sampling data indicates small value suddenly is held as a thickness data integral value B in the RAM 22. Then B-A is calculated and then divided by the time zone of the data addition to find the real thickness.

Description

Detailed Description of the Invention Summary of the Invention A roller-type paper sheet thickness detection device calculates the difference between the thickness detection level when one paper sheet passes and the detection level when no paper sheet passes. As a result, the thickness can be detected with high accuracy even if there is dust attached to the roller, roller wear, or eccentricity.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the thickness of paper sheets including two banknotes.

Conventional technology and its problems Thickness detection devices, especially banknote thickness detection devices.

It is installed in a banknote dispensing machine built into a banknote handling device such as an automatic teller machine (ATV) or an automatic teller machine (CD). A thickness detection device is used to detect whether two or more bills dispensed from a bill storage box of a bill dispensing machine overlap (two-bill detection). Nine banknotes are correctly fed out one by one by determining whether the thickness of the passing banknote detected by the thickness detection device corresponds to the thickness of one banknote or the thickness of two banknotes. You can tell if it is.

The thickness detection device includes a detection roller disposed opposite to a conveyance roller provided on a conveyance path of one banknote, and this detection roller is provided on a lever whose base end is pivotally mounted.

The lever is biased by a spring in a direction in which the detection roller comes into pressure contact with the conveyance roller. When a bill passes between these two rollers, the detection roller is displaced by the thickness of the bill passing through. This amount of displacement is expanded as the amount of displacement of the tip of the lever. The amount of displacement of the tip of the lever is detected by a displacement sensor.

The displacement sensor is composed of, for example, a light projector and a light receiver that are arranged opposite to each other with the tip of the lever in between. When the tip of the lever disposed in the optical path of the light projector is displaced, the amount of light received by the light receiver changes in accordance with the amount of displacement. Therefore, the output signal of the optical receiver will represent the thickness of the banknote.

The output signal of a photoelectric sensor changes when dust adheres to its emitter or receiver. Furthermore, there is a problem in that the output signal fluctuates due to wear of the detection roller and the conveyance roller, resulting in an increase in detection errors.

Summary of the Invention Purpose of the Invention This invention reduces errors and improves thickness detection accuracy even if the output of a displacement sensor changes due to dust adhesion, dust adhesion to the roller, roller wear, eccentricity, etc. It is an object of the present invention to provide a paper sheet thickness detection device that can maintain a high thickness.

Structure of the Invention 2 Functions and Effects The paper sheet thickness detecting device according to the present invention includes: (1) a conveyance roller that constitutes a part of the paper sheet conveyance path and is driven to rotate; a detection roller that has been moved, a displacement sensor that detects the amount of displacement of the detection roller, and a means for detecting the average value of the output signal of the displacement sensor while the paper sheet passes between both of the rollers. means for detecting the average value of the output signal of the displacement sensor over a predetermined period when there is no space between the rollers and the conveyance roller is rotationally driven, and means for calculating the difference between the two average values to determine the distance between the two rollers The present invention is characterized by comprising means for obtaining data representing the thickness of the paper sheets that have passed through the paper sheet.

According to this invention, the average value of the output of the displacement sensor is calculated when there is no sheet between the conveyance roller and the detection roller. In addition, calculate the average value of the output of the displacement sensor when one sheet passes between the two rollers, and calculate the average value when there is one sheet to the average when there is no sheet of 1- The value is being subtracted. Therefore, the true component that the thickness of one sheet affects the change in the output of the displacement sensor can be obtained. As a result, the influence of output deterioration due to dust adhesion to the displacement sensor, dust adhesion to the roller, roller abrasion, etc. can be minimized, so that the detection accuracy of the thickness of paper sheets can be maintained at a high level.

As will become clear from what will be described later, by making an integral multiple of the length of the outer periphery of the detection roller and the conveyance roller equal to the length in the conveyance direction of paper sheets, the influence of eccentricity of these rollers is also reduced. be able to.

DESCRIPTION OF EMBODIMENTS An embodiment in which the present invention is applied to an apparatus for detecting the thickness of banknotes will be described below with reference to one drawing.

FIG. 1 is a schematic diagram of the mechanical configuration of a paper sheet thickness detection device.

In this figure, a conveyance path 1 for banknotes P is constituted by upper and lower conveyor belts 9 which are overlapped, and two banknotes P are conveyed while being sandwiched between these belts 9. A conveyance roller 2 is provided on the conveyance path 1 . This conveying roller 2 has a groove formed thereon, into which the belt 9 is hung, and the circumferential surface of the conveying roller 2 is flush with or protrudes from the clamping surface of the belt 9. The conveyance roller 2 and the conveyance belt 9 are driven by a drive device (not shown). The conveyance roller 2 may be a driven roller.

Above the conveyance roller 2, a detection lever 4 is provided on a shaft 3 so as to be swingable about the shaft 3.

The detection lever 4 is L-shaped and has two ends 4a,
4b. The end 4b direction of the detection lever 4 extends long, and a detection roller 5 is rotatably provided in the middle thereof. - A tension spring 6 is provided between the end 4a of the force detection lever 4 and the spring receiver 8. As a result, the detection lever 4 is biased by the spring 6 so that the detection roller 5 comes into pressure contact with the conveyance roller 2 . The detection roller 5 is in contact with the peripheral surface of the conveyance roller 2 other than the belt 9.

Axis 3. The spring receiver 8 and a mounting member 11 of the displacement sensor 7, which will be described later, are fixed to a frame (path shown).

A gate sensor 10 is provided in the middle of the conveyance path 1 at a distance tml from the contact point between the detection roller 5 and the conveyance roller 2 in a direction opposite to the conveyance direction of the banknote P. This gate sensor 10 detects the transported banknotes P, and is composed of, for example, a light projector and a light receiver arranged so as to sandwich the transport path 1 therebetween. The distance is equal to the length of the banknote P, which is called the length of the banknote P in the transport direction.

Letting the diameter of the conveying roller 2 be d and the diameter of the detection roller 5 be d, these diameters are set so that the following relational expression holds for the length of one banknote.

p-nπD-mπd (n, m: positive integers) That is, during the period from when the bill P passes the gate sensor 10 until it comes to the contact point between both rollers 2 and 5, and when the bill P While passing between 2.5 and 2.5, the conveyance roller 2 rotates n times, and the detection roller 5 rotates m times.

When the bill P enters between the conveyance roller 2 and the detection roller 5 while being sandwiched between the belts 9, the detection roller 5 moves in a direction away from the conveyance roller 2 by the thickness thereof. As a result, the detection lever 4 also swings as shown by the chain line. Since the detection roller 5 is provided between the end portion 4b and the shaft 3,
The amount of displacement of the end portion 4b is larger than the amount of displacement of the detection roller 5. The amount of displacement is expanded by the detection lever 4.

The amount of displacement of the end portion 4b of the detection lever 4 is detected by the displacement sensor 7. The displacement sensor 7 includes a light projector provided at opposing positions across the end 4b of the detection lever 4, and a light receiver that receives light from the light projector. When there is no bill between the conveyance roller 2 and the detection roller 5, the optical path of the light emitted from the projector is directed to the end 4b of the lever 4.
Most of the light is received by the light receiver. When one bill enters between the rollers 2 and 5 and the detection lever 4 swings, a portion of the optical path is blocked by the displacement of the end 4b. Two bills are on both rollers 2
, 5, the amount of displacement of the end 4b is doubled, so most of the optical path is blocked by the end 4b,
The amount of light received by the light receiver becomes small.

FIG. 2 is a block diagram showing an outline of the electrical configuration of the paper sheet thickness detection device.

In this figure, the thickness detection signal S output from the displacement sensor 7 is converted into a digital signal by the A/D converter 20 at every short sampling period and is taken into the CPU 21. The CPU 21 includes a RAM 22 that stores various data. A banknote detection signal from the gate sensor 10 is also input to the CPU 21 .

FIG. 3 shows the output signal of the displacement sensor 7 and the signal processing time period.

When the tip of the banknote P conveyed through the conveyance path 1 is detected by the gate sensor 10 and a detection signal from the gate sensor IO is given to the CPU 21, the A/D converter 2
Sampling data acquisition starts from 0.

As mentioned above, the conversion sensor 7
The output S (sampling data) is taken into the CPU 21, and the CPU 21 adds this sampling data. When the sampling data suddenly shows a large value, it is determined that the banknote P has entered between the rollers 2 and 5. The time period from when the gate sensor 10 outputs the detection signal to when the banknote P enters between the rollers 2 and 5 (
The value captured and added during the initial value data capture time period (Ta) is stored in the RAM 22 as the initial integral value A.

From the moment the banknote P enters between the rollers 2 and 5, sampling data is captured and added again, and this process continues until the captured sampling data suddenly shows a small value. (referred to as the thickness data acquisition time period Tb). Sampling in this time period Tb
The added value of the data is RAM as the thickness data integral value B.
22.

The difference between these integral values, ie, B-A, is calculated. The true thickness of the banknote P is determined by dividing this difference by the time period Ta or Tb.

As described later, when determining whether the banknote is a genuine banknote or detecting two banknotes based on the thickness of the banknote obtained, the reference value for these determinations is also based on the integral, not the thickness. If the value corresponds to the value, the above-mentioned division process is not necessarily necessary.

In the above embodiment, from the gate sensor 10 to both rollers 2
, 5 is set equal to the length of the banknote, and the initial value data is taken in during this time. It may also be the time period during which the item is being transported. In addition, since the two banknotes may be conveyed in a skewed state, the gate sensor 1
It is preferable to keep the position of 0 from the rollers 2 and 5 at an appropriate distance (no more than this). Since the conveyance speed of the conveyance path is constant, the time period Ta is a constant time from the time of detection by the gate sensor 10. (if you don't take skinny into account).

There are various types of integration means other than the above-mentioned addition process. For example, the output S of the displacement sensor 7 may be integrated by an integrating circuit over the above time periods Ta and Tb, and the integrated signals may be A/D converted and input into the CPU II. In addition, the thickness detection signal S of the displacement sensor 7
V to convert it into a pulse signal with a frequency corresponding to that voltage.
A /F conversion circuit and a counter for counting output pulses of the V/F conversion circuit may be provided, the counters may be operated over the time periods Ta and Tb, and the counted values may be respectively input to the CPULI. The integration time of the integration circuit and the counting time of the counter can be determined by detecting the rise (or fall) of the output signal of the gate sensor 1O, the rise or fall of the output signal of the displacement sensor 7, etc.

As described above, by calculating the difference between the integral values A and B, the projection of the displacement sensor 7, the adhesion of dust, etc. to the light receiver, and the
Dust attached to rollers 2 and 5.

The influence of wear on the rollers 2.5 and the like can be eliminated.

In this embodiment, an integral multiple of the length of the circumferential surfaces of the rollers 2 and 5 is set to be equal to the length of the banknote P. This also eliminates errors caused by eccentricity of the rollers 2 or 5, as shown in the second diagram. That is, the roller 2 is moved during the time periods Ta and T.
b each rotates n times. The level of the detection signal S repeats fluctuations due to the eccentricity of the roller 2, but since this occurs exactly n times, it is almost canceled out in each time period Ta and Tb, and even if there is a part that is not canceled out, it can be canceled out by the above-mentioned subtraction process. completely canceled out. Roller 5 is in time zone T
Since the rollers rotate m times at a and Tb, the influence of eccentricity of the roller 5 is also almost eliminated.

When discharging banknotes in the transaction processing device or the like described above, a predetermined number of banknotes must be correctly counted. For example, if two overlapping banknotes are fed out of the banknote storage box and transported, the correct number of banknotes cannot be ejected. This banknote thickness detection device is used to determine whether a single banknote with a predetermined thickness is being conveyed. The detected thickness may be compared with a predetermined reference value indicating the thickness of one sheet or a predetermined range centered on this reference value.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the mechanism of the banknote thickness detection device;
The figure is a block diagram showing its electrical configuration. FIG. 3 is a waveform diagram showing the output signal of the displacement sensor. 1... Conveyance path. 2... Conveyance roller. 4...Detection lever. 4b... End of the detection lever. 5...Detection roller. 7...Displacement sensor. IO...Gate sensor. 21...CPU. 22...RAM. P...Banknotes. Patent applicant Tateishi Electric Co., Ltd. Representative Patent attorney Kenji Ushiku (1 other person)

Claims (6)

[Claims] (1) A conveyance roller that forms part of the sheet conveyance path and is driven to rotate; a detection roller that is urged to come into contact with the circumferential surface of the conveyance roller; and a displacement sensor that detects the displacement position of the detection roller. , means for detecting the average value of the output signal of the displacement sensor while the paper sheet passes between the two rollers, when there is no paper sheet between the two rollers and the conveyance roller is rotationally driven; means for detecting the average value of the output signal of the displacement sensor over a predetermined period; and means for calculating the difference between the two average values to obtain data representing the thickness of the paper sheet passed between the two rollers. Equipped with paper sheet thickness detection device. (2) Claim No. 1, wherein the predetermined period is the time required for one sheet of paper to pass through one point on the conveyance path.
) The paper sheet thickness detection device described in item ). (3) Paper sheets according to claim (1), wherein an integral multiple of the length of the outer periphery of the transport roller and the detection roller is set to be equal to the length in the transport direction of the paper sheets. thickness detection device. (4) A patent in which a sensor for detecting the leading edge of the paper sheet being conveyed is provided at a distance equal to the length of the paper sheet from the contact point of both rollers in the direction opposite to the conveyance direction of the conveyance path. A paper sheet thickness detection device according to claim (1). (5) The means for calculating the average value samples the output of the displacement sensor at a predetermined period, stores it in a memory, and adds the stored sampling data. ) The paper sheet thickness detection device described in item ). (6) The thickness of paper sheets according to claim (1), wherein the means for calculating the average value samples and adds the output of the displacement sensor at a predetermined period. Detection device.