JPH10231030A - Paper sheet delivery mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make stable repetition possible by constituting a force detecting means for detecting pressing force applied to a pickup roller, in such a way as to detect pressing force acting upon the pickup roller while holding the position of the pickup roller in a constant position. SOLUTION: A detection signal of pressing force W directly detected by a load cell 51 is inputted to a controller part 49. The controller part 49 compares the optimum value of pressing force with pressing force W applied to a pickup roller 31. A pressing motor 45 is driven so that the pressing force W becomes equal to the optimum value. In order to prevent the position of the pickup roller 31 from being changed in large degree by the change of the pressing force W, the rigidity of the load cell 51 itself is set as large as possible within a range of being able to detect the pressing force with accuracy of about ±10% or less. Since the displacement of a connecting member 37 is detected by the load cell 51 in an optional position between the pickup roller 31 and a feed roller 33, the layout position of the load cell 51 can be provided with freedom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper-sheet feeding mechanism, and more particularly to a paper-sheet feeding mechanism incorporated in a cash dispenser (CD), a cash dispenser (ATM), a printing apparatus, or the like. It relates to a feeding mechanism. For example, an automatic teller machine (CD), an automatic teller machine (ATM), etc.
A feeding mechanism is provided for separating stacked sheets such as banknotes one by one and sending the separated sheets to a sheet transport unit.

[0002] High reliability is required for such automatic teller machines handling bills, and therefore, it is desired that a pay-out mechanism provided in the automatic teller machine also has high reliability. I have.

[0003]

2. Description of the Related Art An example of a conventional paper sheet feeding mechanism will be described with reference to FIGS. The paper sheet feeding mechanism shown in the figure has a function of separating and feeding paper sheets (banknotes) one by one in, for example, a cash dispenser. FIG. 18 is a front view of a conventional sheet feeding mechanism, and FIG. 19 is a plan view of the sheet feeding mechanism with the sheet removed.

In each of the drawings, reference numeral 1 denotes a pick roller which is in contact with the lower surface of the stacked sheets 2. Reference numeral 3 denotes a feed roller, which is connected to the pick roller 1 by a gear mechanism (not shown). The feed roller 3 rotates at the same peripheral speed as the pick roller 1 to feed the paper sheets 2 to the left in the drawing. . Reference numeral 4 denotes a separator, which is 1 from the bundle of paper sheets 2.
It has the function of separating only the sheets. A pick roller shaft 5 for bearing the pick roller 1 and a feed roller shaft 6 for bearing the feed roller 3
Are connected by a connecting member 7. Both ends of the feed roller 6 are supported by support members 8, and the connecting member 7 and the pick roller 1 are configured to swing about the feed roller shaft 6.

On the other hand, one arm 12A of the lever 9 having an L shape is in contact with the pick roller side end of the connecting member 7. The lever 9 is configured to be rotatable around a lever shaft 10, and the lever 9 is
1 gives a clockwise rotational force to the pick roller 1
Is lifted upwards. Other arm 12B of lever 9
Are provided near the switch 13A and 13B, and when the arm 12B rotates, the photoelectric switch 13A and 13B are disposed.
It is structured to block the light beam of A or 13B.

A pressing mechanism 14 presses the paper sheet 2 against the pick roller 1 with a certain pressing force (W). Specifically, the pressing mechanism 14 includes a pressing motor 15
The rack arm and pinion 16 connected to the pressing motor 15 drives the pressing arm 17 in the up and down direction, thereby pressing the pressing plate 18 against the paper sheet 2 and pressing it, thereby reducing the pressing force W. It is configured to obtain. Also,
Reference numeral 19 denotes a controller unit, which is the photoelectric switch 1 described above.
The rotation of the pressing motor 15 is controlled by ON / OFF of 3A and 13B.

Next, the force acting on the paper sheet 2 will be described with reference to FIG. Here, the pressing force W is the appropriate pressing force W
₀ When than decreases (the decrease since the pressing force and WL), feed force f ₁ of the first sheet (paper sheet at the bottom of the figure) of the paper sheet 2 _-1 is also reduced. That is, the coefficient of friction between the pick roller 1 and the sheet 2 _-1 mu _1, a sheet 2 _-1 lowermost 2
_Assuming that the friction coefficient between the second sheet 2-2 is μ ₂ , the feed force f ₁ can be expressed as f ₁ = (μ ₁ −μ ₂ ) · W (1) The pressing force is the appropriate pressing force W ₀
The feed force f _1L for a smaller WL can be expressed as f _1L = (μ ₁ −μ ₂ ) · WL (2)

Further, the feed force f at the time of the appropriate pressing force W _0
10 can be expressed as f ₁₀ = (μ ₁ −μ ₂ ) · W ₀ (3) Accordingly, as described above, when the pressing force is WL smaller than the appropriate pressing force W ₀ (WL <W ₀ ), the friction coefficient difference (μ ₁ −μ ₂ ) is constant, so that f _1L
<A f _10.

As described above, the pressing force W is adjusted to the proper pressing force W.
₀If it becomes smaller, the first sheet 2_-1Feed force f₁
Becomes smaller, the first sheet 2_-1Is separator 4
May not be able to pass through
is there. Conversely, when the pressing force W increases (the increased pressing force W).
Pressure is WH), and the above-mentioned pressing force W is small.
The opposite phenomenon occurs, and the second and third sheets 2_-2,2 _-3
 Feed force f_TwoAnd f_ThreeBecomes larger,
The second and subsequent sheets 2_-2,2_-3 Etc. are also separated at the same time
May cause an obstacle (double feed) to pass through
is there. Therefore, the first 2_-1Just make sure the separator 4
In order to separate by pressing, the pressing force W is set to WL <W₀<WH
You need to control the range.

Now, the pressing arm 17 stops at a certain position,
It is assumed that the sheet 2 is pressed with the pressing force W. Here, the pick roller 1 and the feed roller 3 are driven so that the sheets 2
When the sheet is fed one by one, the weight of the fed sheet is reduced by its own weight and the pressing force W is reduced, so that the lever 9 and the connecting member 7 rotate in the L direction by the force of the spring 11, and the arm 12B Reaches the photoelectric switch 13A and turns on the photoelectric switch 13A.

When the photoelectric switch 13A is turned on, the controller 19 determines that the pressing force W has decreased, and drives the pressing motor 15 in a direction to increase the pressing force W. As a result, the pressing arm 17 descends, and the pressing force W increases. When the pressing force W increases, the lever 9 and the connecting member 7 rotate in the direction indicated by the arrow H in FIG.
B escapes from the photoelectric switch 13A and exits from the photoelectric switch 13A.
Becomes OFF. When the photoelectric switch 13A is turned off, the controller 19 determines that the pressing force W has increased and stops the pressing motor 15.

On the other hand, when the pressing force W increases, the lever 9 and the connecting member 7 rotate in the H direction, and the arm 12B reaches the photoelectric switch 13B to turn on the photoelectric switch 13B. In this case, the controller 19 is
5 is rotated in a direction in which the pressing force W decreases. The controller 19 controls the pressing motor 15 so that the photoelectric switches 13A and 13B are always turned off, so that the pressing force W is maintained at an optimum value (W ₀ ).

[0013]

However, the above-described conventional feeding mechanism has the following problems. As one of them, in the conventional feeding mechanism, the pick roller shaft 5 is supported by the lever 9 to which the clockwise rotational force is given by the spring 11, so that the pressing force 2 and the spring force of the spring 11 are balanced. In the position, the lever 9 stops. Therefore, even if the pressing force W is within the set range (the range in which the photoelectric switches 13A and 13B are not turned on), the lever 9 rotates due to the increase and decrease of the pressing force W, and as a result, the position of the pick roller shaft 5 moves up and down.

As described above, the optimum value of the pressing force W is₀age
The current pressing force W1 is W1 <W ₀If so, FIG. 2
As shown in FIG. 1, the pick roller shaft 5 is in the optimum position.
The position is higher than the position. Conversely, the current pressing force W2
Is W₀If <W2, as shown in FIG.
In addition, the pick roller shaft 5 has dropped below the optimal position.
Position.

On the other hand, since the position of the feed roller 3 is constant, when the position of the pick roller 1 moves up and down, the inclination of the paper sheet 2 changes. As a result, the leading end of the paper sheet 2 is separated from the feed roller 3 and the separator. The angle of entry into the gap 4 changes. Therefore, in the state shown in FIG. 21, since the leading end of the paper sheet 2 is lowered, the paper sheet 2 easily enters the gap between the feed roller 3 and the separator 4, and the first paper sheet 2 easily comes out. On the other hand, in the state shown in FIG. 22, since the leading end of the paper sheet 2 is raised, it is difficult to enter the gap between the feed roller 3 and the separator 4, and the first paper sheet 2 is hard to come out.

As described with reference to FIG. 20, the pressing force W
There is feed force f ₁ when change with changes in attitude of the paper sheet 2 changes, even will be added further inclination of the influence of the paper sheet 2 in addition to the conventional feeding mechanism, the paper sheet However, there is a problem that the way of feeding 2 changes greatly and stable feeding cannot be performed. Another problem is that
The following items are mentioned. That is, when the kind of the paper sheet 2 to be handled changes and the friction coefficient of the paper sheet 2 changes, the pressing force W also needs to be changed. In the conventional example, the lever 9 is moved at a position where the pressing force W and the spring force are balanced. When the pressing force W is changed, it is necessary to replace the spring 11 with one having a large or small spring constant according to the set value of the pressing force. For this reason, every time the kind of the paper sheet 2 to be handled changes, it is necessary to replace the spring 11, and there is a problem that it is difficult to easily change the set value of the pressing force W.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a paper sheet feeding mechanism which can perform stable feeding and can easily change a set value of pressing force. I do.

[0018]

The above objects can be attained by taking the following means. According to the first aspect of the present invention, the plurality of stacked sheets pressed by the pressing force (W) come into contact with each other from the side opposite to the pressing side, and the sheets are driven by friction. And a feed roller disposed forward of the pick roller in the feeding direction of the paper sheet, and a feed roller arranged to feed the paper sheet, and a paper sheet arranged in close proximity to the feed roller to separate the paper sheet one by one. A separator for separating, force detecting means for detecting a pressing force W applied to the pick roller, and a pressing force (W) applied to the sheet by an output from the force detecting means.
And a control unit for controlling the force, wherein the force detecting means is configured to detect the pressing force W acting on the pick roller while holding the position of the pick roller at a fixed position. It is assumed that.

According to a second aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means is a load cell. According to the third aspect of the present invention, the first aspect is provided.
In the paper sheet feeding mechanism described above, the force detecting means is a piezoelectric element.

According to a fourth aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means includes a high-rigidity member that supports a support portion of the pick roller; A structure comprising: displacement detection means for detecting displacement of the high-rigidity member due to pressure; and displacement / force conversion means for calculating a pressing force from a rigidity value of the high-rigidity member and a displacement amount from the displacement detection means. It is characterized by having done.

According to a fifth aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means includes a connecting member that holds a shaft that supports the pick roller; A column for fixedly supporting one end of the connecting member, a displacement detecting means for detecting a displacement of the connecting member due to the pressing force, and a pressing force is calculated from a rigidity value of the connecting member and a displacement amount from the displacement detecting means. And a displacement / force conversion means.

According to a sixth aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means includes a connecting member that holds a shaft that supports the pick roller; A column for fixedly supporting one end of the connecting member, a strain gauge for detecting the bending of the connecting member due to the pressing force, a strain for calculating the pressing force from the rigidity value of the connecting member and the amount of strain from the strain gauge. And a force conversion means.

According to a seventh aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means is arranged to connect the pick roller and the feed roller. A connecting member that holds a shaft that supports the pick roller; a high-rigidity member that supports the connecting member; and the pressing force at an arbitrary position between the pick roller and the feed roller of the connecting member. A displacement detecting means for detecting a displacement of the connecting member; and a displacement / force converting means for calculating a pressing force from a rigidity value of the connecting member and a displacement amount from the displacement detecting means. Is what you do.

According to an eighth aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means is arranged to connect the pick roller and the feed roller. A connecting member that holds a shaft that supports the pick roller and that has an extended portion that extends from the pick roller in a direction opposite to the direction in which the feed roller is disposed; A contact member having high rigidity for supporting the connecting member by being in contact therewith; displacement detecting means for detecting displacement of the connecting member due to the pressing force; and a rigidity value of the connecting member and displacement from the displacement detecting means. And a displacement / force converting means for calculating the pressing force from the amount.

According to a ninth aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means is arranged to connect the pick roller and the feed roller. A connecting member that holds a shaft that supports the pick roller and that has an extended portion that extends from the pick roller in a direction opposite to the direction in which the feed roller is disposed; A contact member having a high rigidity for supporting the connecting member by contacting, a strain gauge for detecting the bending of the connecting member due to the pressing force, and a rigidity value of the connecting member and a distortion amount from the strain gauge. And a distortion / force conversion means for calculating the pressing force from the pressure.

Further, according to the tenth aspect of the present invention, in the paper sheet feeding mechanism according to the first aspect, the force detecting means is arranged to connect the pick roller and the feed roller. A connecting member holding a shaft that supports the pick roller, and a lever member extending in a direction different from a line segment connecting the center of the pick roller and the center of the feed roller; and a lever member. By measuring the displacement of, the displacement detecting means for detecting the displacement of the connecting member due to the pressing force, a high-rigidity member supporting the connecting member or the lever portion,
It is characterized by comprising a displacement / force converting means for calculating a pressing force from a rigidity value of the connecting member and a displacement amount from the displacement detecting means.

Each of the means described above operates as follows.
1A and 1B are principle diagrams of a paper sheet feeding mechanism according to the present invention. FIG. 1A is a front view of a paper sheet feeding mechanism, and FIG. 1B is a right side view of the paper sheet feeding mechanism. According to the first aspect of the present invention, as shown in the figure, the pick roller 20 is pressed from the side opposite to the pressing side of the plurality of stacked sheets 24 pressed by the pressing force (W). The sheets 24 come into contact with each other and are driven by friction driving. The feed roller 21 is disposed in front of the pick roller 20 in the feeding direction of the paper sheet 24, and has a function of feeding the paper sheet 24.

The separator 22 is disposed close to the feed roller 21 to separate the sheets 24 one by one. Further, the force detecting means 23 detects the pressing force W applied to the pick roller. Further, the control unit 25 includes the force detection unit 23
The pressing force (W) applied to the paper sheet 24 is controlled by the output from. In the above configuration, in the present invention, the force detecting means 23 is configured to abut against the support portion 26 of the pick roller 20 to directly detect the pressing force W acting on the pick roller 20 and to keep the position of the pick roller 20 constant. It has a high rigidity in order to hold it.

With this configuration, the pressing force W acting on the pick roller 20 is transmitted to the pick roller 20, the supporting portion 26, and the force detecting means 23, so that the pressing force W can be directly detected by the force detecting means 23. Becomes possible. Further, since the force detecting means 23 has high rigidity, the position of the pick roller 20 does not greatly change even if the pressing force W changes, so that the sheet 24 is always directed toward the separator 22 in a stable state. Can be paid out.

Further, a load cell or a piezoelectric element may be used as the force detecting means 23 as in the second or third aspect of the present invention. When a load cell or a piezoelectric element is used as the force detecting means, the pressing force can be directly detected, and the rigidity of the load cell or the piezoelectric element itself is high, so that the position of the pick roller 20 can be kept constant. it can.

According to the fourth aspect of the present invention, the high-rigidity member is constituted by a high-rigidity member, a displacement detecting unit, and a displacement-force converting unit. Pick roller 2 to support
The movement of 0 is suppressed. Thereby, the sheets can be sent to the separator 22 in a stable state.

The displacement detecting means detects the displacement of the high-rigidity member due to the pressing force, and the displacement / force converting means calculates the pressing force from the rigidity value of the high-rigidity member and the displacement from the displacement detecting means. The pressing force can be directly detected by the displacement detecting means and the displacement / force converting means. Also,
According to the fifth aspect of the present invention, the force detecting means 23 is a support,
By using the displacement detecting means and the displacement / force converting means, the support fixedly supports one end of a connecting member that holds a shaft that supports the pick roller 20, so that the movement of the pick roller 20 is suppressed. Thereby, the sheets can be sent to the separator 22 in a stable state.

The displacement detecting means detects the displacement of the connecting member due to the pressing force, and the displacement / force converting means calculates the pressing force from the rigidity value of the connecting member and the amount of displacement from the detecting means. The pressing force can be directly detected by the means and the displacement / force conversion means. According to the sixth aspect of the present invention, since the force detecting means 23 is constituted by a support, a strain gauge, and a strain / force conversion means, the support is one end of a connecting member that holds a shaft that supports the pick roller 20. , The movement of the pick roller 20 is suppressed. Thereby, the sheets can be sent to the separator 22 in a stable state.

The strain gauge detects the bending of the connecting member due to the pressing force, and the strain / force converting means calculates the pressing force from the rigidity value of the connecting member and the amount of strain from the strain gauge. The pressing force can be directly detected by the distortion / force conversion means. According to the seventh aspect of the present invention, a connecting member 37 is provided to connect the pick roller 20 and the feed roller 21 and holds a shaft that supports the pick roller 20. Since the displacement detecting means detects the displacement of the connecting member 37 at an arbitrary position between the pick roller 20 and the feed roller 21, the arrangement position of the displacement detecting means can be given a degree of freedom. .

Accordingly, the peripheral portion of the connecting member 37 on which a number of components are disposed can be made compact, and the paper sheet feeding mechanism can be reduced in size. In addition, since the connecting member 37 that holds the shaft that supports the pick roller 20 is supported by a high-rigidity member, the displacement of the pick roller 20 can be suppressed. Can be sent.

According to the eighth and ninth aspects of the present invention, the connecting member is provided with an extending portion extending from the pick roller in a direction opposite to a direction in which the feed roller is disposed,
By providing a high-rigidity contact member that supports the connecting member by contacting the extended portion, the minimum displacement required for detecting the pressing force is allowed, and the extra displacement of the connecting member is provided. Can be regulated. For this reason, it is possible to more reliably suppress the displacement of the pick roller 20 while performing the reliable displacement detection, so that the sheets can be sent to the separator 22 in a more stable state.

According to the tenth aspect of the present invention, the connecting member has a lever portion extending in a direction different from a line segment connecting the center of the pick roller and the center of the feed roller, and the displacement detecting means. By measuring the displacement of the lever portion and detecting the displacement of the connecting member, the position of the displacement detecting means can be set at a position apart from the position between the pick roller and the feed roller.
Therefore, the peripheral portion of the connecting member 37 on which a large number of components are disposed can be made compact, and the paper sheet feeding mechanism can be reduced in size.

[0038]

Next, embodiments of the present invention will be described with reference to the drawings. 2 and 3 show a paper sheet feeding mechanism (hereinafter simply referred to as a feeding mechanism) according to a first embodiment of the present invention. The paper sheet feeding mechanism shown in the figure has a function of separating and feeding paper sheets (banknotes) one by one in, for example, a cash dispenser. FIG. 2 is a front view of the feeding mechanism according to the first embodiment, and FIG. 3 is a right side view of the feeding mechanism (only essential parts are shown).

In each figure, a pick roller 31 is in contact with the lower surface of the stacked sheets 32. Reference numeral 33 denotes a feed roller, which is a gear mechanism (not shown).
, And is rotated at the same peripheral speed as the pick roller 31, so that the paper sheet 32 is sent to the left in the drawing. Reference numeral 34 denotes a separator, which has a function of separating only one sheet from the bundle of the sheets 32. The pick roller shaft 35 that supports the pick roller 31 and the feed roller shaft 36 that supports the feed roller 33 are connected by a connecting member 37. The feed roller shaft 36 has support members 38 at both ends.
And the connecting member 37 and the pick roller 31 are configured to be swingable about the feed roller shaft 36.

Reference numeral 44 denotes a pressing mechanism, which
Is pressed against the pick roller 31 with a certain pressing force (W). Specifically, the pressing mechanism 44 includes a pressing motor 45, and the pressing arm 47 is moved in the vertical direction I by a rack and pinion 46 connected to the pressing motor 45.
The pressing plate 48 is driven so that the pressing plate 48 is brought into contact with the paper sheet 32 and pressed to obtain a pressing force W.
Reference numeral 49 denotes a controller, which is the controller described above.
It functions as displacement / force conversion means or strain / force conversion means.

Next, a description will be given of the force detecting means which is an essential part of the present invention. The force detecting means according to the present embodiment includes a support table 50 fixed to a base (not shown) holding the entire feeding mechanism, and a load cell 51 serving as force detecting means disposed on the support table 50. It is configured. The connecting member 37 described above is disposed so as to be placed on the upper part of the load cell 51, and thus the connecting member 37 is configured to be supported by the support base 50 via the load cell 51. Therefore, the pressing force W acting on the pick roller 31 is transmitted to the load cell 51 via the pick roller 31, the pick roller shaft 35, and the connecting member 37, so that the pressing force W can be directly detected by the load cell 51.

In general, since the load cell 51 has high rigidity, even if the pressing force W changes greatly, the deformation amount is small enough to be ignored. There is no rotation about the roller shaft 36, so that the position of the pick roller 31 does not change. Thus, the paper sheets 24 are always kept in a stable state while the rollers 31 and 3
3 can be fed toward the separator 34, so that the occurrence of non-feeding and double feeding, which occur conventionally, can be suppressed, so that the reliability of the feeding mechanism can be improved.

Here, the specific operation of the feeding mechanism according to the first embodiment shown in FIG. 2 will be described. The detection signal (= force signal) of the pressing force W directly detected by the load cell 51 as described above is input to the controller 49. The controller 49 compares the optimum value Wo of the pressing force with the detected pressing force Ws from the load cell 51, and Ws = Wo
The pressing motor 45 is driven so that

The pick roller 31 is changed by the change of the pressing force W.
The rigidity of the load cell 51 itself is set as large as possible within a range in which the pressing force can be detected with an accuracy of about ± 10% or less so that the position of the load cell 51 does not greatly change. Assuming that the displacement amount (= compression amount) of the load cell 51 due to the pressing force W is Δl and the spring constant of the load cell 51 is k, there is a relation of W = k · Δl (4). As a specific example, when W = 0.5 kgf,
In order to make Δl <0.1 mm, a load cell 51 with k> 5 kgf / mm is used. In order to set Δl <0.01 mm, the load cell 51 with k> 50 kgf / mm is used.

Next, a second embodiment of the present invention will be described. FIG. 4 shows a side view (only the main parts are shown) of the feeding mechanism according to the second embodiment. In FIG. 4, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted. The present embodiment is characterized in that the piezoelectric conversion element 52 is used as the force detecting means. When an external force is applied to a piezoelectric crystal such as crystal or Rochelle salt to distort the crystal, the center of both positive and negative ions in the crystal is shifted, and a positive charge appears at one end of the crystal and a negative charge appears at the other end, and a voltage is applied to both ends. Occurs. If this voltage is detected, an external force, that is, a pressing force W is obtained. In addition, as the force detecting means, the load cell 5 described above is used.
1. In addition to the piezoelectric conversion element 52, a magnetostrictive element, a pressure-sensitive conductive rubber, or the like can be used.

Next, a third embodiment of the present invention will be described. FIG. 5 is a side view (only the main parts are shown) of the feeding mechanism according to the third embodiment. In FIG. 5, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, a highly rigid high rigid member 53 functioning as a spacer is mounted on the support base 50, and the upper end of the high rigid member 53 is brought into contact with the connecting member 37 to support the connecting member 37. In addition, a displacement detection sensor 54 serving as a displacement detecting means is provided above the support table 50 together with the high rigidity member 53. This displacement detection sensor 54 is a non-contact type sensor,
7 can be directly detected.

When the pressing force W is applied, the pressing force is applied to the pick roller 31, the pick roller shaft 35, and the support portion 3.
7 to the high-rigidity member 53. Accordingly, the high-rigidity member 53 is deformed by a small amount (Δα) due to the transmitted pressing force, and the deformation of the high-rigidity member 53 also causes the connecting member 37 to be displaced by a small amount Δα. It is detected by the displacement detection sensor 54.

The spring constant of the high rigidity member 53 is set to a value equal to that of the load cell 51 described above. The displacement detection sensor 5
As a specific example of 4, an eddy current displacement sensor, a laser beam displacement sensor, a contact displacement sensor, or the like can be considered. Also,
The displacement detection sensor 54 is connected to a displacement / force conversion device 55, and the minute displacement amount Δα detected by the displacement detection sensor 54 in the displacement / force conversion device 55 is a force (ie, a pressing force value) corresponding thereto. ) Is converted. Now, the spring constant of the highly rigid member 53 when the k _1, it is possible to obtain a pressing force W by the calculation of _{W = k 1 · Δα ... (} 5).

Next, a fourth embodiment of the present invention will be described. FIG. 6 shows a side view (only the main part is shown) of the feeding mechanism according to the fourth embodiment. In FIG. 6, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted. The feeding mechanism shown in FIG. 6 detects the pressing force W using the rigidity of the connecting member 37. A portion of the connection member 37 close to the support member 38 is supported by the support 56. When the pressing force W acts on the pick roller 31, the connecting member 37 bends by a minimum amount and the end on the pick roller 31 side is slightly displaced by Δβ. The rigidity of the connecting member 37 is determined by the minute displacement Δ
β is set so as to be 0.1 mm or less, preferably 0.01 mm or less.

The displacement .DELTA..beta. Of the connecting member 37 is shown in FIG.
Is detected by the displacement detection sensor 54 similar to that used in the above.
The displacement detection sensor 54 is connected to a displacement / force conversion device 55, and the minute displacement amount Δβ detected by the displacement detection sensor 54 in the displacement / force conversion device 55 is a force (ie, a pressing force value) corresponding thereto. ) Is converted. Now, the spring constant of the connecting member 37 viewed from the displacement detection sensor 54 is k ₂
Then, the pressing force W can be obtained by the calculation of W = k ₂ · Δβ (6).

Next, a fifth embodiment of the present invention will be described. FIG. 7 shows a feeding mechanism according to the fifth embodiment. In FIG. 7, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted. The feeding mechanism shown in FIG. 7 detects the pressing force W using the rigidity of the connecting member 37, similarly to the feeding mechanism shown in FIG. The portion of the connecting member 37 close to the support member 38 is
Support with. When the pressing force W acts on the pick roller 31, the connecting member 37 bends by a very small amount.
Is detected by the strain gauge 57 stuck on the side face of.

The strain gauge 57 is connected to a strain / force conversion device 58, and the amount of deflection detected by the strain gauge 57 in the strain / force conversion device 58 is determined by the corresponding force (ie,
(Pressing force value), whereby the pressing force W can be obtained. Next, a sixth embodiment of the present invention will be described. FIG. 8 shows a feeding mechanism according to the sixth embodiment. In FIG. 8, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted.

The feeding mechanism shown in FIG. 8 detects the pressing force W by utilizing the rigidity of the connecting member 37 as in the fourth embodiment shown in FIG. Connecting member 3 according to the present embodiment
Reference numeral 7 denotes a configuration in which an extension 60 is formed to extend from the pick roller 31 in a direction opposite to the direction in which the feed roller 33 is disposed (to the right in the drawing). This extension 6
Numeral 0 is in contact with a contact member 61 having high rigidity, whereby the connecting member 37 is configured to be supported at both ends by the contact member 61 and the support member 38.

In the above configuration, when the pressing force W acts on the pick roller 31, the connecting member 37 bends by the minimum amount and the end on the pick roller 31 side is slightly displaced by Δβ. The rigidity of the connecting member 37 is set so that the minute displacement amount Δβ is 0.1 mm or less, preferably 0.01 mm or less. At this time, as described above, the connecting member 37 is connected to the contact member 61 and the support member 38.
Since both ends are supported, the amount of deflection is small, and this setting can be easily performed. The method of calculating the pressing force W is the same as the method described in the fourth embodiment, and the description thereof will be omitted.

As described above, in this embodiment, the connecting member 3
7 is provided with a contact member 61 having high rigidity for supporting the connecting member 37 by contacting the extension portion 60, thereby providing the minimum necessary for detecting the pressing force W. Can be allowed to the connecting member 37 and the excessive displacement of the connecting member 37 can be restricted. Accordingly, it is possible to more reliably suppress the displacement of the pick roller 20 while performing the reliable displacement detection, and thus it is possible to send the sheets to the separator 22 in a more stable state.

Next, a seventh embodiment of the present invention will be described. FIG. 9 shows a feeding mechanism according to the seventh embodiment. In FIG. 9, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof will be omitted. The feeding mechanism shown in FIG. 9 also detects the pressing force W using the rigidity of the connecting member 37, similarly to the feeding mechanism shown in FIG. Further, an extension 60 is formed in a direction (rightward direction) opposite to the arrangement direction of the feed roller 33 from the pick roller 31 of the connecting member 37, and the extension 60 is
1.

In the above configuration, when the pressing force W acts on the pick roller 31, the connecting member 37 bends by a minute amount, and the amount of this bending is detected by the strain gauge 57 attached to the side surface of the connecting member 37. The strain gauge 57 is connected to a strain / force conversion device 58, and the amount of deflection detected by the strain gauge 57 in the strain / force conversion device 58 is a force corresponding to the strain (ie,
(Pressing force value), whereby the pressing force W can be obtained.

In this embodiment, as in the sixth embodiment, an extension 60 is formed in the connecting member 37, and a contact member 61 which contacts the extension 60 and supports the connecting member 37.
Is provided, the minimum displacement required for detection of the pressing force W can be allowed to the connecting member 37 and the excessive displacement of the connecting member 37 can be regulated. Can be sent to the separator 22 in a more stable state.

Next, an eighth embodiment of the present invention will be described. FIGS. 10 and 11 show a feeding mechanism according to an eighth embodiment. FIG. 10 is a side view (only the main part is shown) of the feeding mechanism according to the eighth embodiment, and FIG. 11 is a cross-sectional view taken along line AA in FIG. 10 and FIG.
In FIG. 1, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted.

The force detecting means according to the present embodiment includes a support table 50 fixed to a base (not shown) holding the entire feeding mechanism, and a load cell 51 provided on the support table 50 as the force detecting means. , And the connecting member 37 and the like. In the first embodiment, as shown in FIG. 1, the support table 50 and the load cell 51 are disposed immediately below the pick roller shaft 35, and the pressing force W acting on the pick roller 31 is directly detected by the load cell 51. Had to be configured. On the other hand, in the present embodiment, the connecting member 37 provided to connect the pick roller 20 and the feed roller 21 includes the pick roller 20 and the feed roller 2.
The support table 50 and the load cell 51 are arranged at arbitrary positions between them. Specifically, in this embodiment, the distance L ₂ from the center position of the feed roller 33 is
The configuration is such that the support base 50 and the load cell 51 are arranged at separated positions.

In the structure of this embodiment, the connecting member 37
Is mounted on the upper portion of the load cell 51, so that the connecting member 37 is connected to the support base 5 via the load cell 51.
0. Therefore, the pressing force W acting on the pick roller 31 is transmitted to the load cell 51 via the pick roller 31, the pick roller shaft 35, and the connecting member 37, so that the pressing force W can be directly detected by the load cell 51.

Further, since the load cell 51 has high rigidity as described above, the connecting member 37 does not rotate around the feed roller shaft 36.
Therefore, the position of the pick roller 31 does not change. Thus, the paper sheet 24 can be always fed out from each of the rollers 31 and 33 toward the separator 34 in a stable state.

Here, the specific operation of the feeding mechanism according to this embodiment will be described. Load cell 5 as described above
The detection signal (= force signal) of the pressing force W directly detected by 1 is input to the controller 49. The controller 49 compares the optimum value Wo of the pressing force with the pressing force W applied to the pick roller 31. Now, load cell 51
The pressing force detection value Ws, also when the distance between the centers of the feed roller shaft 36 of the pick roller shaft 35 and L ₁ from the pressing force W _{is, W = (L 2 / L} 1) × Ws ... (7) can be expressed. Therefore, the controller unit 49
The pressing force W obtained in (7) is compared with the optimum value Wo, and W
= Wo, specifically, the pressing motor 45 is driven so as to satisfy the following equation (8).

Wo = (L ₂ / L ₁ ) × Ws (8) In order that the position of the pick roller 31 does not greatly change due to the change in the pressing force W, the rigidity of the load cell 51 itself should be less than ± 10%. It is set as large as possible within the range that can be detected with accuracy. If the displacement amount of the pick roller shaft 35 due to the pressing force W is ΔL ₁ , the displacement amount (= compression amount) of the load cell 51 is ΔL ₂ , the spring constant of the load cell 51 is k, and the load acting on the load cell 51 is w, w = k · ΔL ₂ (9) (ΔL ₁ / L ₁ ) = (ΔL ₂ / L ₂ ) (10) W · L ₁ = w · L ₂ (11) From the above equation (9), From equation (11), there is the following relationship: W = k · (L ₂ / L ₁ ) ² · ΔL ₁ (12) As a specific example, L ₂ / L ₁ = 0.5, W
= 0.5 kgf, ΔL ₁ <0.1 mm
A load cell 51 where k> 20 kgf / mm is used. Also,
In order to make ΔL ₁ <0.01 mm, a load cell 51 with k> 200 kgf / mm is used.

According to the paper sheet feeding mechanism having the structure according to the present embodiment, the pick roller 31 of the connecting member 37 is used.
A configuration in which the displacement of the connecting member 37 is detected by the load cell 51 at an arbitrary position between the load cell 51 and the feed roller 33 allows the arrangement position of the load cell 51 to have flexibility. Therefore, the peripheral portion of the connecting member 37 on which a large number of components are disposed can be made compact, and the paper sheet feeding mechanism can be reduced in size.

Further, since the connecting member 37 holding the pick roller shaft 35 bearing the pick roller 31 is supported by the highly rigid support base 50 and the load cell 51, the displacement of the pick roller 31 can be suppressed. Thus, the sheets can be sent to the separator 34 in a stable state. Next, a ninth embodiment of the present invention will be described. FIG. 12 shows a feeding mechanism according to the ninth embodiment. The present embodiment is characterized in that, in the feeding mechanism according to the eighth embodiment described with reference to FIGS. 10 and 11, the piezoelectric conversion element 52 is used as force detecting means. As the force detecting means, a magnetostrictive element, a pressure-sensitive conductive rubber, or the like can be used in addition to the load cell 51 and the piezoelectric conversion element 52 described above.

Next, a tenth embodiment of the present invention will be described. FIG. 13 shows a feeding mechanism according to the tenth embodiment. In FIG. 13, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, in the feeding mechanism according to the eighth embodiment described with reference to FIGS. 10 and 11, a high rigid member 53 having high rigidity functioning as a spacer is mounted on the support base 50. The upper end of the connecting member 37 is brought into contact with an arbitrary position between the pick roller 20 and the feed roller 21 to support the connecting member 37. In addition, a displacement detection sensor 54 serving as a displacement detecting means is provided above the support table 50 together with the high rigidity member 53. The displacement detection sensor 54 is a non-contact type sensor, and is configured to directly detect the displacement of the connecting member 37.

When the pressing force W is applied, the pressing force is transmitted to the high rigidity member 53 via the pick roller 31, the pick roller shaft 35, and the connecting member 37. Accordingly, the high-rigidity member 53 is deformed by a small amount (Δα) due to the transmitted pressing force, and the deformation of the high-rigidity member 53 also causes the connecting member 37 to be displaced by a small amount Δα. It is detected by the displacement detection sensor 54. Now, if the spring constant of the rigid member 53 and k _1, the pressing force W can represent a _{L 1, L 2, k 1} Δα described above as a parameter, in particular W = k ₁ · (L ₂ / L ₁ ) · Δα (13) The pressing force W can be obtained.

Next, an eleventh embodiment of the present invention will be described. FIGS. 14 and 15 show the feeding mechanism according to the eleventh embodiment. FIG. 14 is a side view of the feeding mechanism according to the eleventh embodiment, and FIG. 15 is a bottom view near the feed roller 33 of the feeding mechanism according to the eleventh embodiment.
In FIG. 14, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted.

The feeding mechanism according to the present embodiment extends to the connecting member 37 in a direction different from a line segment connecting the center of the pick roller 31 and the center of the feed roller 33 (a dashed line indicated by an arrow W in the drawing). While forming the lever part 62,
The load cell 51 serving as a displacement detecting means is provided with the lever portion 62.
, And the displacement of the connecting member 37 is detected.

More specifically, the lever portion 62 is configured to extend substantially vertically below a center position of the feed roller 33 with respect to a line W connecting the center of the pick roller 31 and the center of the feed roller 33. . The load cell 51 is configured to be in contact with a predetermined position of the lever portion 62 from the side while being mounted on the support base 50. In the above configuration, when the pressing force W acts on the pick roller 31, the connecting portion 37 and the lever portion 62 slightly rotate clockwise in FIG.
Press. Now, the feed roller shaft 36 and the pick roller shaft 35 a distance of L ₃ of _the feed roller shaft 36 and the distance L ₄ to the contact position of the load cell 51, and the output of the load cell 51 and w, the pressing force W
Is obtained by the following equation.

W = (L ₄ / L ₃ ) · w (14) As described above, the dispensing mechanism according to the present embodiment uses the pick roller 31 and the feed roller 33 can be set at a position apart from the position between the first and third positions. Therefore, the peripheral portion of the connecting member 37 on which a large number of components are disposed can be made compact, and the paper sheet feeding mechanism can be reduced in size.

Next, a twelfth embodiment of the present invention will be described. FIG. 16 shows a feeding mechanism according to the twelfth embodiment. The present embodiment is characterized in that, in the feeding mechanism according to the eleventh embodiment described with reference to FIGS. 14 and 15, the piezoelectric conversion element 52 is used as force detecting means. As the force detecting means, a magnetostrictive element, a pressure-sensitive conductive rubber, or the like can be used in addition to the load cell 51 and the piezoelectric conversion element 52 described above.

Next, a thirteenth embodiment of the present invention will be described. FIG. 17 shows a feeding mechanism according to the thirteenth embodiment. In FIG. 17, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, in the feeding mechanism according to the eleventh embodiment described with reference to FIGS. 14 and 15, the high rigid member 53 having high rigidity functioning as a spacer is mounted on the support base 50,
The upper end of the high-rigidity member 53 is in contact with an arbitrary position of the lever portion 62. In addition, a displacement detection sensor 54 serving as a displacement detecting means is provided above the support table 50 together with the high rigidity member 53. The displacement detection sensor 54 is a non-contact type sensor, and is configured to directly detect the displacement of the connecting member 37.

In the structure according to this embodiment, when the pressing force W is applied to the pick roller 31, the pressing force is applied to the high rigid member via the pick roller 31, the pick roller shaft 35, the connecting member 37, and the lever portion 62. It reaches 53. Therefore,
The high-rigidity member 53 has a small amount (Δ
α), the lever 62 is displaced by a small amount Δα due to the deformation of the high-rigidity member 53. Therefore, the displacement detecting sensor 54 detects the minute displacement Δα of the lever 62. Now, if the spring constant of the rigid member 53 and k _1, the pressing force W may represent _{L 3, L 4, k 1} Δα described above as a parameter, in particular W = k ₁ · (L ₄ / L ₃ ) · Δα (13) The pressing force W can be obtained.

[0076]

According to the present invention as described above, the following various effects can be realized. According to the first aspect of the present invention, it is possible to directly detect the pressing force W by the force detecting means, and since the force detecting means has high rigidity, even if the pressing force W changes in magnitude, the picking force can be detected. Since the position of the roller does not change significantly, the paper sheet can be always fed out to the separator in a stable state.

According to the second or third aspect of the present invention, by using a load cell or a piezoelectric element as the force detecting means, the pressing force can be directly detected. In addition, since the rigidity of the load cell or the piezoelectric element itself is high, the position of the pick roller can be kept constant, so that the paper sheet can always be fed out to the separator in a stable state.

According to the fourth aspect of the present invention, since the high-rigidity member supports the support portion of the pick roller, the movement of the pick roller is suppressed. Thereby, paper sheets can be sent to the separator in a stable state. According to the fifth and sixth aspects of the present invention, since the supporting column fixedly supports one end of the connecting member that holds the shaft that supports the pick roller, the movement of the pick roller is suppressed, thereby stabilizing the paper sheets. It can be sent to the separator in the state where it was done.

According to the seventh aspect of the present invention, since the position of the displacement detecting means can be provided with a degree of freedom, the peripheral portion of the connecting member on which a large number of components are disposed can be made compact. This makes it possible to reduce the size of the paper sheet feeding mechanism. In addition, since the connecting member that holds the shaft that supports the pick roller is supported by the high-rigidity member, the displacement of the pick roller can be suppressed, so that the sheets can be sent to the separator in a stable state.

According to the eighth and ninth aspects of the present invention, the minimum displacement required for detecting the pressing force on the connecting member is allowed, and the excessive displacement of the connecting member is restricted. Can be. For this reason, it is possible to more reliably suppress the displacement of the pick roller while performing the reliable displacement detection, so that the sheets can be sent to the separator in a more stable state.

Further, according to the tenth aspect of the present invention, since the disposition position of the displacement detecting means can be set at a position apart from the position between the pick roller and the feed roller, a large number of components can be disposed. The peripheral portion of the provided connecting member can be made compact, and the paper sheet feeding mechanism can be downsized.

[Brief description of the drawings]

FIG. 1 is a principle view of the present invention, in which (A) is a front view and (B) is a right side view.

FIG. 2 is a front view of a paper sheet feeding mechanism according to the first embodiment of the present invention.

FIG. 3 is a right side view of the paper sheet feeding mechanism according to the first embodiment of the present invention.

FIG. 4 is a side view of a paper sheet feeding mechanism according to a second embodiment of the present invention.

FIG. 5 is a side view of a paper sheet feeding mechanism according to a third embodiment of the present invention.

FIG. 6 is a front view of a paper sheet feeding mechanism according to a fourth embodiment of the present invention.

FIG. 7 is a front view of a paper sheet feeding mechanism according to a fifth embodiment of the present invention.

FIG. 8 is a front view of a paper sheet feeding mechanism according to a sixth embodiment of the present invention.

FIG. 9 is a front view of a paper sheet feeding mechanism according to a seventh embodiment of the present invention.

FIG. 10 is a front view of a paper sheet feeding mechanism according to an eighth embodiment of the present invention.

FIG. 11 is a sectional view taken along the line AA in FIG. 10;

FIG. 12 is a partially cutaway view of a paper sheet feeding mechanism according to a ninth embodiment of the present invention.

FIG. 13 is a partial cutaway view of a paper sheet feeding mechanism according to a tenth embodiment of the present invention.

FIG. 14 is a front view of a paper sheet feeding mechanism according to an eleventh embodiment of the present invention.

FIG. 15 is a bottom view of a paper sheet feeding mechanism according to a twelfth embodiment of the present invention.

FIG. 16 is a bottom view of a paper sheet feeding mechanism according to a thirteenth embodiment of the present invention.

FIG. 17 is a bottom view of a paper sheet feeding mechanism according to a fourteenth embodiment of the present invention.

FIG. 18 is a front view of a conventional paper sheet feeding mechanism.

FIG. 19 is a plan view of a conventional paper sheet feeding mechanism.

FIG. 20 is a diagram for explaining a force relationship generated when a plurality of sheets are stacked.

FIG. 21 is a diagram for explaining a problem that occurs in a conventional paper sheet feeding mechanism.

FIG. 22 is a diagram for explaining a problem that occurs in a conventional paper sheet feeding mechanism.

[Explanation of symbols]

 REFERENCE SIGNS LIST 31 pick roller 32 paper sheet 33 feed roller 34 separator 35 pick roller shaft 36 feed roller shaft 37 connecting member 38 support member 44 pressing mechanism 45 pressing motor 46 rack and pinion 47 pressing arm 49 controller 50 support table 51 load cell 52 piezoelectric element 53 High-rigidity member 54 Displacement detection sensor 55 Displacement / force conversion device 56 Prop 57 Strain gauge 58 Strain / force conversion device 60 Extension part 61 Contact part 62 Lever part

Claims (10)

[Claims] A pick roller which abuts from a side opposite to the pressing side of a plurality of stacked sheets pressed by a pressing force (W) and which feeds the sheets by friction drive; A feed roller that is disposed in front of the pick roller in the feeding direction of the paper sheet and feeds the paper sheet; and a separator that is disposed close to the feed roller and separates the paper sheet one by one; A force detecting unit that detects a pressing force W applied to the pick roller; and a control unit that controls a pressing force (W) applied to the paper sheet based on an output from the force detecting unit. And a sheet feeding mechanism, wherein the pressing force W acting on the pick roller can be detected while holding the position of the pick roller at a fixed position. 2. The paper sheet feeding mechanism according to claim 1, wherein said force detecting means is a load cell. 3. The paper sheet feeding mechanism according to claim 1, wherein said force detecting means is a piezoelectric element. 4. The paper sheet feeding mechanism according to claim 1, wherein said force detecting means detects a high-rigidity member supporting a support portion of said pick roller and a displacement of said high-rigidity member due to a pressing force. A dispensing means for displacing paper sheets, comprising: a displacement detecting means; and a displacement / force converting means for calculating a pressing force from a rigidity value of the high-rigidity member and a displacement amount from the displacement detecting means. mechanism. 5. The paper sheet feeding mechanism according to claim 1, wherein the force detecting means includes: a connecting member that holds a shaft that supports the pick roller; and a support that fixedly supports one end of the connecting member. A configuration comprising: displacement detection means for detecting displacement of the connecting member due to the pressing force; and displacement / force conversion means for calculating a pressing force from a rigidity value of the connecting member and a displacement amount from the displacement detecting means. A paper sheet feeding mechanism characterized by the following. 6. The paper sheet feeding mechanism according to claim 1, wherein the force detecting means includes: a connecting member that holds a shaft that supports the pick roller; and a support that fixes and supports one end of the connecting member. A strain gauge for detecting the bending of the connecting member due to the pressing force, and a strain / force converting means for calculating a pressing force from a rigidity value of the connecting member and a strain amount from the strain gauge. A paper sheet feeding mechanism characterized by the following. 7. The paper sheet feeding mechanism according to claim 1, wherein said force detecting means is arranged to connect said pick roller and said feed roller, and holds a shaft for bearing said pick roller. A connection member, a high-rigidity member that supports the connection member, and a displacement detection unit that detects a displacement of the connection member due to the pressing force at an arbitrary position between the pick roller and the feed roller of the connection member. And a displacement / force converting means for calculating a pressing force from a rigidity value of the connecting member and a displacement amount from the displacement detecting means. 8. The paper sheet feeding mechanism according to claim 1, wherein the force detecting means is arranged to connect the pick roller and the feed roller, and holds a shaft for bearing the pick roller. A connecting member having an extending portion extending from the pick roller in a direction opposite to a direction in which the feed roller is disposed; and a high rigidity supporting the connecting member by contacting the extending portion. A contact member having: a displacement detecting means for detecting a displacement of the connecting member; and a displacement / force converting means for calculating a pressing force from a rigidity value of the connecting member and a displacement amount from the displacement detecting means. A paper sheet feeding mechanism characterized in that the paper sheet feeding mechanism is provided. 9. The paper sheet feeding mechanism according to claim 1, wherein said force detecting means is arranged to connect said pick roller and said feed roller, and holds a shaft for bearing said pick roller. A connecting member having an extending portion extending from the pick roller in a direction opposite to a direction in which the feed roller is disposed; and a high rigidity supporting the connecting member by contacting the extending portion. A contact member having: a strain gauge for detecting bending of the connecting member due to the pressing force; and a strain / force converting means for calculating a pressing force from a rigidity value of the connecting member and a strain amount from the strain gauge. And a feeding mechanism for paper sheets. 10. The paper sheet feeding mechanism according to claim 1, wherein said force detecting means is arranged to connect said pick roller and said feed roller, and holds a shaft for bearing said pick roller. A connecting member having a lever portion extending in a different direction with respect to a line segment connecting the center of the pick roller and the center of the feed roller; and measuring the displacement of the lever portion to obtain the pressing force. Displacement detecting means for detecting the displacement of the connecting member, a high-rigidity member supporting the connecting member or the lever portion, and a pressing force calculated from a rigidity value of the connecting member and a displacement amount from the displacement detecting means. And a displacement / force conversion unit that performs the operation.