JP2000357254A - Paper thickness detector - Google Patents

Abstract

(57) [Problem] To detect the thickness of a paper sheet by an inexpensive method, to easily adjust the mounting, and to obtain the thickness of an inexpensive paper sheet which is not affected by the color of the paper sheet. A detection device is provided. A fixed roller (2) having a fixed shaft and a movable roller (6) having a support structure capable of moving up and down are disposed so as to be opposed to a transport path (1) for transporting sheets (P). , 6
In a sheet thickness detecting device that detects the amount of displacement of the movable roller 6 when the sheet P passes between the sheets as the thickness of the sheet P, the movable amount generated according to the thickness of the sheet P The thickness of the sheet P is detected by transmitting the displacement of the roller 6 to the cantilever 9 and detecting the amount of distortion generated in the cantilever 9 by the strain gauges 17a and 17b fixed to the cantilever 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper sheet thickness detecting apparatus for detecting the thickness of a paper sheet such as a conveyed securities, for example, in a paper sheet processing apparatus such as a securities sheet.

[0002]

2. Description of the Related Art Conventionally, for example, in a thickness detecting device for detecting the thickness of paper sheets such as securities conveyed while being held between belts, a fixing roller having a fixed shaft and a supporting structure capable of moving vertically. And the movable roller is disposed so as to face each other, and the amount of displacement of the movable roller when a sheet passes between the two rollers is detected as the thickness.

When detecting the thickness distribution in the direction perpendicular to the direction in which the sheet is transported, a plurality of thickness detecting devices having the above-described configuration are arranged in parallel in the direction perpendicular to the direction in which the sheet is transported.

Also, an optical distance meter is disposed above and below the conveyed paper sheet so as to face each other, each distance to the paper sheet is measured, and the difference between the two measurement results is detected as the thickness. There are also things.

[0005]

In the conventional method for detecting the thickness by the displacement of the movable roller, a first method for detecting the displacement of the movable roller as the rotation angle of the roller support, the displacement of the roller support is determined by the roller. There is a second method in which a nearby support member is formed of a conductor such as a metal and a sensor that detects non-contact as a change in overcurrent or inductance is used.

However, in the first method, since the thickness of a sheet as an object to be measured is as small as about 0.1 mm, the rotation angle of the roller support is also small, and it is necessary to accurately detect the small rotation angle. Reduces the bearings and shaft play of the rotation support,
Precise processing is required, and the rotation detection sensor is expensive because it needs to have good stability and sensitivity.

[0007] In the second method, the sensor is several hundred KH.
Since an alternating current of several MHz from z is used, the sensor circuit becomes complicated. In addition, since the signal displacement and the output signal of the sensor are non-linear, it is necessary to perform signal processing for linearization, and when installing the sensor, it is necessary to set the gap between the roller support and the initial setting to a predetermined value. There is a problem that both the circuit and the mounting are expensive.

Further, in the method of detecting thickness using an optical distance meter, since the amount of reflected light differs depending on the color of the paper sheet as an object to be measured, an error occurs in the measurement result, resulting in an error in thickness detection. become. In addition, an optical distance meter that is not affected by color is expensive and has large external dimensions, and thus has a problem that the installation place is limited.

Therefore, the present invention detects the thickness of a paper sheet by an inexpensive method, makes it easy to adjust the installation, and is not affected by the color of the paper sheet. It is an object of the present invention to provide a detection device.

[0010]

According to the present invention, there is provided a sheet thickness detecting apparatus provided in a conveying path for conveying sheets, in which the conveyed sheets contact and pass over. A freely movable fixed roller, a displaceable movable roller provided in contact with the fixed roller, a cantilever having the movable roller rotatably attached to a front end and a rear end fixed. When the conveyed paper sheet passes between the fixed roller and the movable roller and is fixed to the cantilever, the cantilever of the cantilever accompanying the displacement of the movable roller generated according to the thickness of the paper sheet A distortion detecting element for detecting an amount of distortion, signal processing means for converting an output signal of the distortion detecting element into a thickness signal corresponding to the thickness of the paper sheet, and a paper sheet based on an output of the signal processing means; Thickness detecting means for detecting the thickness of It is provided.

[0011] The paper sheet thickness detecting device of the present invention comprises:
A rotatably supported fixed roller that is provided on a conveyance path that conveys the paper sheet and through which the conveyed paper sheet contacts and passes, and a displacement that is provided in a contact state on the fixed roller. A freely movable roller, a cantilever having the movable roller rotatably attached to a leading end thereof, and a rear end fixed thereto; and a paper sheet fixed to the cantilever and conveyed between the fixed roller and the movable roller. A strain detecting element for detecting the amount of distortion of the cantilever caused by the displacement of the movable roller, which occurs according to the thickness of the paper sheet when the paper passes, and an output signal of the distortion detecting element, Signal processing means for converting the signal into a thickness signal corresponding to the thickness of the sheet, detection means provided upstream of the fixed roller in the conveyance path to detect the conveyed sheets, and detection means Is conveyed When a leaf is detected, holding means for holding the output signal of the signal processing means immediately before the detection while the detecting means detects the paper sheet, and a signal held by the holding means and the signal processing means The apparatus includes a differential amplifier for amplifying a difference from an output signal, and a thickness detector for detecting a thickness of a sheet based on an output of the differential amplifier.

Further, the paper sheet thickness detecting device of the present invention comprises:
A rotatably supported fixed roller provided on a conveyance path for conveying the paper sheets, through which the conveyed paper sheets contact and pass, and a displacement provided in contact with the fixed rollers. A freely movable roller, a support member rotatably supported by the movable roller, a cantilever having a free end provided at the vicinity of the support member, a free end at the front end, and a fixed rear end, and a fixed at the support member. A contact that transmits the displacement of the movable roller to the tip of the cantilever; and a sheet that is fixed to the cantilever and is conveyed between the fixed roller and the movable roller when the sheet is conveyed. And a distortion detecting element for detecting an amount of distortion of the cantilever caused by the displacement of the movable roller caused according to the thickness of the sheet, and converting an output signal of the distortion detecting element into a thickness signal corresponding to the thickness of the sheet. Signal processing And means, and a thickness detecting means for detecting the thickness of the sheet based on the output of the signal processing means.

[0013] The paper sheet thickness detecting device of the present invention comprises:
A rotatably supported fixed roller provided on a conveyance path for conveying the paper sheets, through which the conveyed paper sheets contact and pass, and a displacement provided in contact with the fixed rollers. A freely movable roller, a support member rotatably supported by the movable roller, a cantilever having a free end provided at the vicinity of the support member, a free end at the front end, and a fixed rear end, and a fixed at the support member. A contact that transmits the displacement of the movable roller to the tip of the cantilever; and a sheet that is fixed to the cantilever and is conveyed between the fixed roller and the movable roller when the sheet is conveyed. Detecting the amount of distortion of the cantilever due to the displacement of the movable roller caused by the thickness of the movable roller, and converting an output signal of the distortion detecting element into a thickness signal corresponding to the thickness of the sheet. Signal processing Means, provided at the upstream side of the fixed roller of the transport path, detecting means for detecting the conveyed paper, and when the detecting means detects the conveyed paper, Holding means for holding the output signal of the signal processing means immediately before the detection means detects a sheet, and amplifying the difference between the signal held by the holding means and the output signal of the signal processing means. And a thickness detecting means for detecting the thickness of a sheet based on the output of the differential amplifying means.

[0014] Further, the sheet thickness detecting device of the present invention comprises:
A rotatably supported fixed roller provided on a conveyance path for conveying the paper sheets, through which the conveyed paper sheets contact and pass, and a displacement provided in contact with the fixed rollers. A free contact, a cantilever having this contact attached to the front end and a rear end fixed, and the paper sheet being conveyed between the fixed roller and the contact fixed to the cantilever, A distortion detecting element for detecting the amount of distortion of the cantilever caused by the displacement of the contact caused according to the thickness of the paper sheet, and an output signal of the distortion detecting element is used as the thickness of the paper sheet. And a thickness detecting means for detecting the thickness of the sheet based on the output of the signal processing means.

Further, the sheet thickness detecting device of the present invention comprises:
A rotatably supported fixed roller provided on a conveyance path for conveying the paper sheets, through which the conveyed paper sheets contact and pass, and a displacement provided in contact with the fixed rollers. A free contact, a cantilever having this contact attached to the front end and a rear end fixed, and the paper sheet being conveyed between the fixed roller and the contact fixed to the cantilever, A distortion detecting element for detecting the amount of distortion of the cantilever caused by the displacement of the contact caused according to the thickness of the paper sheet, and an output signal of the distortion detecting element is used as the thickness of the paper sheet. Signal processing means for converting the sheet into a thickness signal corresponding to the transport path, detection means provided upstream of the fixed roller in the transport path, for detecting the conveyed sheets, and When a detected paper sheet is detected, Holding means for holding the output signal of the signal processing means while the detecting means detects a sheet, and amplifying the difference between the signal held by the holding means and the output signal of the signal processing means. The apparatus includes a differential amplifying means and a thickness detecting means for detecting a thickness of a sheet based on an output of the differential amplifying means.

Further, the sheet thickness detecting device of the present invention is provided on a conveying path for conveying the paper sheets, and is rotatably supported so that the conveyed paper sheets pass over the conveying path. Fixed roller, displaceable contact means provided in a contact state on the fixed roller, one end is fixed, and the other end is when a paper sheet passes between the fixed roller and the contact means. The cantilever to be deflected, and the contact means which is fixed to the cantilever and is generated according to the thickness of the conveyed paper sheet when the conveyed paper sheet passes between the fixed roller and the contact means. A distortion detecting element for detecting an amount of distortion of the cantilever due to the displacement of, a signal processing means for converting an output signal of the distortion detecting element into a thickness signal corresponding to the thickness of the sheet, and Provided to detect the conveyed paper sheets Based on the output of the detection means, and holds the output signal of the signal processing means immediately before the paper sheet passes through the contact means while the detection means detects the paper sheet. Holding means; differential amplifying means for amplifying a difference between a signal held by the holding means and an output signal of the signal processing means; and detecting a thickness of a sheet based on an output of the differential amplifying means. Thickness detecting means.

According to the present invention, the displacement of the movable roller (or contact) generated according to the thickness of the paper sheet is transmitted to the cantilever, and the amount of distortion generated in the cantilever is fixed to the cantilever. By detecting the thickness of the paper sheet by detecting the thickness of the paper sheet, the thickness of the paper sheet can be detected by an inexpensive method, installation and adjustment are easy, and the color of the paper sheet is affected. It is possible to realize an inexpensive paper sheet thickness detecting device which is not affected.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment will be described.

FIGS. 1 and 2 show the configuration of the thickness detecting apparatus according to the first embodiment. In FIGS. 1 and 2, reference numeral 1 denotes a transport path formed of a belt or the like, which transports a sheet P as an object to be measured in a direction indicated by an arrow B with both ends in a direction orthogonal to the transport direction. A fixed roller 2 is provided so that a sheet P to be conveyed passes over the conveyance path 1 while being in contact therewith. The fixed roller 2 is rotatably supported by a support member 4 via a shaft 3, and the support member 4 is fixed to a base 5.

A movable roller 6 is provided on the fixed roller 2 so as to be vertically displaceable in a contact state. The movable roller 6 is rotatably supported by a support member 8 via a shaft 7, and the support member 8 is attached to the tip of a resilient plate-shaped cantilever 9. The rear end of the cantilever 9 is fixed to the holder 10 via a not-shown bolt screw or the like. Note that the support member 8 may be formed integrally with the cantilever 9.

The holder 10 holds the support member 1 via a shaft 11.
The support member 12 is rotatably supported by the base 2, and the support member 12 is fixed to a base 13 formed integrally with the base 5. A stopper 14 is formed integrally with the holder 10.
The tip of an adjustment screw 16 held by a stopper base 15 fixed to the end is in contact. With such a configuration, a desired pressing force is applied to the movable roller 6 depending on the position of the adjustment screw 16.

Plate-shaped strain gauges 17a and 17b as strain detecting elements are attached and fixed to the front and rear surfaces of the cantilever 9 on the holder 10 side, respectively. The strain gauges 17a and 17b detect the amount of strain generated in the cantilever 9 due to the displacement of the movable roller 6, and convert it into a change in resistance value.

An optical detector 18 is provided upstream of the fixed roller 2 in the conveying path 1 as detecting means for detecting the conveyed sheets P. Detector 18
Is composed of a light emitting device 18a and a light receiving device 18b which are arranged opposite to each other with the transport path 1 interposed therebetween.
A detection signal is output when the light from a is cut off.

FIG. 3 shows a configuration of a signal processing circuit for processing output signals of the strain gauges 17a and 17b.
In FIG. 3, a bridge circuit 20 is formed by the strain gauges 17a and 17b and the resistors 21 and 22, and a variable resistor 23 for adjustment is connected to the bridge circuit 20. Each output terminal of the bridge circuit 20 is connected to each input terminal of the differential amplifier 24. Slider 23a of variable resistor 23 and bridge circuit 20
A predetermined DC voltage is applied from the DC power supply 26 to the power supply terminal of the power supply. After the output signal of the differential amplifier 24 is amplified by the DC amplifier 25, it is output as a thickness signal as a DC signal.

FIG. 4 shows a zero point compensating circuit for performing zero point compensation on the thickness signal output from the signal processing circuit. 4, a thickness signal (output of the DC amplifier 25) output from the signal processing circuit of FIG. 3 is input to an input terminal 27, and a paper sheet detection signal from the detector 18 is input to an input terminal 28. Is entered. The thickness signal input to the input terminal 27 is transmitted to a differential amplifier 29 as a differential amplifier.
Is supplied to one of the input terminals, and is also supplied to a sample-and-hold circuit 30 as holding means. The output of the sample-and-hold circuit 30 is supplied to the other input terminal of the differential amplifier 29.

The sample-and-hold circuit 30 includes an analog switch 31, a capacitor 32, and an operational amplifier 3.
3. That is, one end of the analog switch 31 is connected to the input terminal 27, and the other end of the analog switch 31 is connected to the input terminal of the operational amplifier 33.
Is connected to a predetermined potential via a capacitor 32. The output terminal of the operational amplifier 33 is connected to the differential amplifier 2
9 is connected to the other input terminal.

The sheet detection signal from the detector 18 input to the input terminal 27 is supplied to a delay circuit 34 as delay means. The delay circuit 34 delays the paper sheet detection signal from the detector 18 by a predetermined time corresponding to the distance between the detector 18 and the thickness detection ports 2 and 6.

The output signal of the delay circuit 34 is supplied to the analog switch 31 of the sample-and-hold circuit 30.
Thus, the analog switch 31 is turned on by the output signal of the delay circuit 34 (delayed sheet detection signal),
It is designed to be turned off.

Next, the operation of the above configuration will be described.

First, in FIG. 1, in order to bring the fixed roller 2 and the movable roller 6 into contact with each other, the portion of the stopper 14 of the holder 10 is pushed by the adjusting screw 16 and the holder 10 is pressed.
Is rotated about the axis 11 so that the cantilever 9 is rotated.
Is adjusted so that a desired pressing force is applied to the movable roller 6 via the support member 8 and the shaft 7 by utilizing the elasticity of the movable roller 6. Note that this pressing force can be known from the amount of distortion of the strain gauges 17a and 17b, as described later.

The paper sheet P is nipped by the transport path 1 and transported in the direction of arrow B in the figure. When the conveyed paper sheet P enters between the fixed roller 2 and the movable roller 6, the fixed roller 2 and the movable roller 6 rotate on their respective axes 3 and 7, and the movable roller 6 Is lifted upward by the thickness of. When the movable roller 6 is lifted, the cantilever 9 is bent to change the amount of distortion. By detecting the amount of distortion by the strain gauges 17a and 17b, the thickness of the paper sheet P can be known. Hereinafter, this will be specifically described.

Now, let the length of the cantilever 9 (the distance between the center of the movable roller 6 and the fixed end of the holder 10) be l,
The width of the cantilever 9 is d, the thickness of the cantilever 9 is h,
Assuming that the length from the center of the movable roller 6 to the center of the strain gauges 17a and 17b is a and the thickness of the paper sheet P is t, the strain amount e at the strain gauges 17a and 17b is simply expressed by the following equation. It can be obtained in (1).

E = 3ath / (a ³ −3l ² a + 2l ³ ) (1) The pressing force w of the movable roller 6 is roughly calculated by the following equation (2), ignoring the weight of the movable roller 6. be able to.

[0035] ^{w = (6yEdh 2/12)} / (a 3 -3l 2 a + 2l 3) ...... (2) where, y is the cantilever 9 is bent by the movable roller 6
H is the thickness of the cantilever 9, d is
Is the width of the cantilever 9, and E is the Young's modulus of the cantilever 9.

From the above equation (1), since the amount of distortion of the cantilever 9 changes depending on the thickness t of the sheet P, if this distortion is detected by the strain gauges 17a and 17b,
The thickness of the paper sheet P can be known.

From the above equation (2), the pressing force of the movable roller 6 can be adjusted by the adjusting screw 16.

Now, from the above equation (1), l = 25 mm,
Assuming that a = 15 mm, h = 0.5 mm, and t = 0.1 mm, the amount of change in strain of the strain gauges 17a and 17b is 3.
46 × 10 ^-4 .

However, compressive strain is generated on the strain gauge 17a side, and tensile strain is generated on the strain gauge 17b side. Therefore, the resistance values of the strain gauges 17a and 17b increase and decrease, respectively.

Now, in the signal processing circuit of FIG. 3, the resistors 21 and 22 of the bridge circuit 20 are set to R1 = R2 = 120.
Ω. Each resistance value of the strain gauges 17a and 17b is set to 12
Assuming that 0Ω and the gauge factor are “2”, when the strain is 3.46 × 10 ⁻⁴ , each resistance value of the strain gauges 17a and 17b is 2
× 0.041Ω.

The resistance value of the variable resistor 23 of the bridge circuit 20 is set to 10Ω, and 5 V is applied to the slider 23a of the variable resistor 23.
When a DC voltage of (V) is applied, the voltage between the input terminals of the differential amplifier 24 is 0.0033V. Differential amplifier 2
4 is “10” and the DC amplifier 25 is “1”.
00, the amount of voltage change at the output terminal of the DC amplifier 25 is 3.32V.

Next, the operation of the zero point compensation circuit of FIG. 4 will be described with reference to the timing chart shown in FIG.

Conventionally, the strain gauge has not been applied to the detection of the thickness of the conveyed paper sheets. One of the reasons for not being applied to the detection of the thickness of paper sheets is that an operational amplifier for amplifying the output of a strain gauge is expensive. However, recently, with the improvement of the performance of the operational amplifier IC, a simple circuit configuration can be sufficiently applied, and the drift of the zero point can be reduced by the zero point clamp circuit or the like if the paper sheet is running for a short time. Sufficient correction is possible. This zero point compensation method will be described.

As described above, the detector 18 detects the paper P
And outputs a detection signal when the light from the light emitter 18a is blocked. In the sample-and-hold circuit 30, the analog switch 31 is normally in the ON state, and when in the ON state, the output of the operational amplifier 33 is the same as the signal of the input terminal 27 (the output of the DC amplifier 25).

In this state, when the detector 18 detects the sheet P, the analog switch 31 is turned off, and when it is turned off, the voltage of the input terminal 27 immediately before the switch is turned off is turned off. During the state, the voltage is held by the capacitor 32 and the output voltage of the operational amplifier 33 is also held.

As described above, the delay circuit 34 converts the sheet detection signal from the detector 18 into a predetermined time corresponding to the distance between the detector 18 and the thickness detecting ports 2 and 6. Delay. Therefore, as shown in FIG. 5A, the output of the signal processing circuit shown in FIG.
When the thickness of the sheet P is detected (between a and b) in a state where the zero point deviation value is present, the sheet detection signal shown in FIG. During this time, the zero point shift value c is subtracted by the differential amplifier 29 and the differential amplifier 2
The output of No. 9 is zero-point compensated and becomes as shown in FIG. That is, the thickness signal having a zero point shift shown in FIG. 5A is subjected to zero point compensation, and becomes a thickness signal having no zero point shift as shown in FIG. 5D.

In the first embodiment, when the moving speed of the sheet P is high and the movable roller 6 is rapidly displaced, the cantilever 9 may vibrate. In order to prevent this vibration, the cantilever 9 is formed by bonding and laminating a plurality of thin structural materials (for example, a thin stainless steel plate), so that the viscosity characteristics of the adhesive layer can be used for damping the vibration. . As the adhesive layer, for example, a highly adhesive double-sided tape or the like may be used.

Next, a second embodiment will be described.

FIG. 6 shows the configuration of the thickness detecting device according to the second embodiment. The same parts as those in the first embodiment (FIG. 1) are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described.

In the second embodiment, the movable roller 6 is fixed to a rigid support arm 41, and the cantilever 9 is provided independently of the movable roller 6. That is, the support member 8 of the movable roller 6 is attached to the tip of a plate-shaped support arm 41 having a rigid structure, and the rear end of the support arm 41 is attached to the holder 10 via a bolt screw (not shown). Fixed. Note that the support member 8 may be formed integrally with the support arm 41.

The adjusting screw 1 shown in FIG. 1 is provided between a stopper 14 formed on the holder 10 and the stopper base 15.
In place of 6, an anti-vibration spring 42 is interposed. With such a configuration, the vibration-proof spring 42 applies a desired pressing force to the movable roller 6 and suppresses the vibration of the movable roller 6.

On the support member 8 of the movable roller 6, for example, a conical contact 43 as a contact means is fixed. The tip of the contact 43 is in contact with the tip of the cantilever 9 installed substantially parallel to the support arm 41. The rear end of the cantilever 9 is fixed to a support base 44 fixed to the base 13. With such a configuration,
The displacement of the movable roller 6 is transmitted to the cantilever 9 via the contact 43.

Next, a third embodiment will be described.

FIG. 7 shows the configuration of a thickness detecting device according to the third embodiment. The same parts as those in the first embodiment (FIG. 1) are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described.

In the third embodiment, instead of the movable roller 6, a contact 45 is directly pressed on the fixed roller 2, and the contact 45 is fixed to the tip of the cantilever 9. . The contact 45 is formed of a wear-resistant material, and the cantilever 9 has a vibration-proof structure as described above.

With the configuration as described above, since the strain gauge operates by the direct current, the signal processing circuit can be simplified. In addition, since the cantilever, which is the support member for the movable roller (or contact) that detects the thickness, is fixed, precise bearings are not required.
The structure becomes very simple. Furthermore, since the displacement of the movable roller and the amount of distortion of the cantilever are substantially linear,
The conventional linearization processing is not required, and a relatively inexpensive operational amplifier can be used for the signal processing circuit of the strain gage. Thus, a thickness detecting device having a simple structure and an inexpensive thickness can be obtained.

[0057]

As described above in detail, according to the present invention, the thickness of a sheet is detected by an inexpensive method, the mounting and adjustment are easy, and the sheet is affected by the color of the sheet. It is possible to provide an inexpensive paper sheet thickness detecting device.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a configuration of a thickness detecting device according to a first embodiment of the present invention.

FIG. 2 is a plan view seen from the direction of arrow A in FIG.

FIG. 3 is a configuration diagram illustrating a configuration of a signal processing circuit.

FIG. 4 is a configuration diagram showing a configuration of a zero point compensation circuit.

FIG. 5 is a timing chart for explaining the operation of the zero point compensation circuit.

FIG. 6 is a side view schematically showing a configuration of a thickness detecting device according to a second embodiment of the present invention.

FIG. 7 is a side view schematically showing a configuration of a thickness detecting device according to a third embodiment of the present invention.

[Explanation of symbols]

 P: paper sheet (measurement object) 1: transport path 2: fixed roller 4: supporting member 6: movable roller 8: supporting member 9: cantilever 10: holder 17a, 17b: distortion Gauge (strain detection element) 18 Detector (detection means) 20 Bridge circuit 24 Differential amplifier 25 DC amplifier 29 Differential amplifier (differential amplification means) 30 Sample-hold circuit (Holding means) 34 delay circuit (delay means) 41 support arm 42 anti-vibration spring 43 contact (contact means) 44 support base 45 contact (contact means)

Claims (9)

[Claims] 1. A rotatably supported fixed roller provided on a transport path for transporting paper sheets, through which the transported paper sheets contact and pass, and a contact state on the fixed rollers. A movable roller provided with a movable roller, a cantilever having this movable roller rotatably attached to a front end thereof, and a rear end fixed thereto; and a fixed cantilever fixed to the cantilever. A distortion detecting element for detecting a distortion amount of the cantilever caused by displacement of the movable roller according to a thickness of the conveyed paper sheet when passing the paper sheet; and an output signal of the distortion detection element. And a thickness detecting means for detecting the thickness of the paper sheet based on the output of the signal processing means. Paper thickness detection characterized by apparatus. 2. A rotatably supported fixed roller provided on a transport path for transporting paper sheets, through which the transported paper sheets contact and pass, and a contact state on the fixed rollers. A movable roller provided with a movable roller, a cantilever having this movable roller rotatably attached to a front end thereof, and a rear end fixed thereto; and a fixed cantilever fixed to the cantilever. A distortion detecting element for detecting a distortion amount of the cantilever caused by displacement of the movable roller according to a thickness of the conveyed paper sheet when passing the paper sheet; and an output signal of the distortion detection element. A signal processing means for converting a signal into a thickness signal according to the thickness of the paper sheet, provided upstream of the fixed roller of the transport path,
Detecting means for detecting the conveyed paper sheet; and when the detecting means detects the conveyed paper sheet, the output means of the signal processing means immediately before the detecting means detects the paper sheet. Holding means for holding while detecting; differential amplifying means for amplifying a difference between a signal held by the holding means and an output signal of the signal processing means; and paper based on an output of the differential amplifying means. A thickness detecting device for paper sheets, comprising: a thickness detecting means for detecting the thickness of leaves. 3. A rotatably supported fixed roller which is provided in a transport path for transporting the paper sheets and through which the transported paper sheets come into contact with and passes therethrough; A displaceable movable roller provided with: a support member rotatably supported by the movable roller; a cantilever provided near the support member and having a free end at a front end and a fixed rear end; A contactor fixed to a support member and transmitting the displacement of the movable roller to the tip of the cantilever; and when the conveyed paper passes between the fixed roller and the movable roller, fixed to the cantilever, A distortion detecting element for detecting an amount of distortion of the cantilever caused by the displacement of the movable roller that occurs according to the thickness of the sheet, and an output signal of the distortion detecting element according to the thickness of the sheet. Thickness signal And a thickness detecting means for detecting a thickness of the paper sheet based on an output of the signal processing means. 4. A rotatably supported fixed roller provided in a transport path for transporting the paper sheet, through which the transported paper sheet contacts and passes, and is in contact with the fixed roller. A displaceable movable roller provided with: a support member rotatably supported by the movable roller; a cantilever provided near the support member and having a free end at a front end and a fixed rear end; A contactor fixed to a support member and transmitting the displacement of the movable roller to the tip of the cantilever; and when the conveyed paper passes between the fixed roller and the movable roller, fixed to the cantilever, A distortion detecting element for detecting an amount of distortion of the cantilever caused by the displacement of the movable roller that occurs according to the thickness of the sheet, and an output signal of the distortion detecting element according to the thickness of the sheet. Thickness signal A signal processing means for converting into a, provided on the upstream side of the fixed roller of the transport path,
Detecting means for detecting the conveyed paper sheet; and when the detecting means detects the conveyed paper sheet, the output means of the signal processing means immediately before the detecting means detects the paper sheet. Holding means for holding while detecting; differential amplifying means for amplifying a difference between a signal held by the holding means and an output signal of the signal processing means; and paper based on an output of the differential amplifying means. A thickness detecting device for detecting the thickness of a leaf, comprising: a thickness detecting device for detecting the thickness of the leaf; 5. A rotatably supported fixed roller provided on a transport path for transporting the paper sheet, through which the transported paper sheet contacts and passes, and is in contact with the fixed roller. And a cantilever having a rear end fixed thereto, fixed to the cantilever, and conveyed between the fixed roller and the contact. When a paper sheet passes, a distortion detecting element for detecting an amount of distortion of the cantilever due to displacement of the contact caused according to a thickness of the paper sheet, and an output signal of the distortion detecting element is used as the paper. Signal processing means for converting the signal into a thickness signal corresponding to the thickness of the leaves, and thickness detecting means for detecting the thickness of the paper sheet based on the output of the signal processing means. Paper thickness detector. 6. A rotatably supported fixed roller provided in a transport path for transporting the paper sheet, through which the transported paper sheet contacts and passes, and is in contact with the fixed roller. And a cantilever having a rear end fixed thereto, fixed to the cantilever, and conveyed between the fixed roller and the contact. When a paper sheet passes, a distortion detecting element for detecting an amount of distortion of the cantilever due to displacement of the contact caused according to a thickness of the paper sheet, and an output signal of the distortion detecting element is used as the paper. Signal processing means for converting into a thickness signal according to the thickness of the leaves, provided upstream of the fixed roller of the transport path,
Detecting means for detecting the conveyed paper sheet; and when the detecting means detects the conveyed paper sheet, the output means of the signal processing means immediately before the detecting means detects the paper sheet. Holding means for holding while detecting; differential amplifying means for amplifying a difference between a signal held by the holding means and an output signal of the signal processing means; and paper based on an output of the differential amplifying means. A thickness detecting device for detecting the thickness of a leaf, comprising: a thickness detecting device for detecting the thickness of the leaf. 7. The paper sheet according to claim 1, wherein the cantilever has a laminated structure in which a plurality of thin structural members are laminated. Thickness detector. 8. The apparatus according to claim 2, further comprising delay means for delaying an output signal of said detection means for a predetermined time, wherein said holding means responds to an output of said delay means.
6. The sheet thickness detecting device according to any one of 6. 9. A rotatably supported fixed roller provided on a transport path for transporting paper sheets, through which the transported paper sheets contact and pass, and a contact state on the fixed rollers. A cantilever, one end of which is fixed, and the other end of which is deflected when paper sheets pass between the fixed roller and the contact means, and which is fixed to the cantilever; When the conveyed paper sheet passes between the fixed roller and the contact means, a distortion for detecting a distortion amount of the cantilever due to a displacement of the contact means, which is generated according to a thickness of the paper sheet. A sensing element; signal processing means for converting an output signal of the distortion sensing element into a thickness signal corresponding to the thickness of the paper sheet; provided in the transport path, for detecting the transported paper sheet And the output of this detection means A holding unit that holds an output signal of the signal processing unit immediately before the sheet passes through the contact unit while the detecting unit detects the sheet; and A differential amplifying means for amplifying a difference between a signal and an output signal of the signal processing means; and a thickness detecting means for detecting a thickness of a sheet based on an output of the differential amplifying means. A sheet thickness detecting device, characterized in that: