US20070090592A1

US20070090592A1 - Paper sheet break detection apparatus

Info

Publication number: US20070090592A1
Application number: US11/580,852
Authority: US
Inventors: Masashi Nakada
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2005-10-21
Filing date: 2006-10-16
Publication date: 2007-04-26
Also published as: JP2007115095A; EP1785950A1; CN1952983A

Abstract

A paper sheet break detection unit having a light source which emits light to a card deformed by the pressure of flanges of front- and back-side lower rollers, a control unit which judges that a card includes a break, based on the reception of light by a light-receiving sensor, and a moving mechanism which moves the flanges of upper and lower rollers along a conveying surface in a direction orthogonal to a direction of conveying a card K, by moving the upper and lower rollers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-306980, filed Oct. 21, 2005, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a paper sheet break detection unit, which detects a break in a paper sheet, for example, paper currency.
2. Description of the Related Art
A unit shown in FIG. 20 is well known as such a detection unit.
Namely, a reference numeral 111 denotes a conveying path. Upper- side conveying rollers 112 a and 112 b are provided at a predetermined interval on the upper side of the conveying path 111, and lower- side conveying rollers 113 a and 113 b are provided on the lower side at a predetermined interval. An upper conveying belt 114 a is extended over the upper- side conveying rollers 112 a and 112 b, and a lower-side conveying belt 114 b is extended over the lower- side conveying rollers 113 a and 113 b. These upper and lower conveying belts 114 a and 114 b hold and convey a paper sheet.
Between the upper- side conveying rollers 112 a and 112 b, a roller 115 having a flange 115 f and a projection plate 116 are provided. The roller 115 is placed with the lower end side of the flange 115 projected downward the conveying path 111, and the projection plate 116 is placed with the upper-end side projected upward the conveying path 111. A light source 118 is provided under the projection plate 116. A light-receiving sensor 119, which receives the light emitted from the light source 118, is provided between the roller 115 and upper-side conveying roller 112 b.
When a paper sheet is conveyed along the direction of the arrow and reaches the projection plate 16, the paper sheet is pressed upward by the projection plate 16, and pressed downward by the flange 115 f when reaching the roller 15. Therefore, if there is a break in a paper sheet, the break is pressed and opened, and the light emitted from the light source 118 is received by the light-receiving sensor 119, passing through the break. When the light is received, it is judged that the paper sheet has a break. If the light is not received, it is judged that the paper sheet does not have a break. (Refer to Jpn. Pat. Appln. KOKAI Publication No. 2000-268225, for example.)
However, conventionally, as the projection plate 116 is fixedly provided, there is a drawback that when a paper sheet is conveyed at high speed to the projection plate 116, the projection plate 116 is worn, and a break of an easy-to-tear paper sheet is not opened.
Further, as the roller 115 and projection plate 116 are provided at fixed positions, when a different size paper sheet is conveyed, the flange 115 f of roller 115 and the projection plate 16 may come off the break of the paper sheet, and the break cannot be detected.
Further, when detecting a break in the same size paper sheet, it is impossible to adjust so that only a break longer than a predetermined length is detected. Therefore, there is a problem that even a negligible break is detected.

BRIEF SUMMARY OF THE INVENTION

The present invention has been made in the above-mentioned circumstances. Accordingly, it is an object of the invention to provide a paper sheet break detection unit, which reliably detects a break even in a different size paper sheet.
According to an aspect of the invention, there is provided a paper sheet break detection unit comprising a conveying unit which conveys a paper sheet along a conveying surface; a first pressing unit which presses one side of the paper sheet conveyed by the conveying unit in a first direction orthogonal to the conveying surface; a second pressing unit which is provided in proximity to the first pressing unit, and presses the other side of the paper sheet conveyed by the conveying unit in a second direction reverse to the first direction; a light-emitting unit which emits light to the paper sheet deformed by the pressure of the first and second pressing units; a light-receiving unit which receives the light illuminated from the light-emitting unit; a judgment unit which judges whether the paper sheet includes a break based on the reception of the light by the light-receiving unit; and a moving mechanism which moves the first and second pressing units along the conveying surface in a direction orthogonal to a direction of conveying the paper sheet.
According to another aspect of the invention, a paper sheet break detection unit is capable of detecting securely a break in a different size paper sheet or in an easy-to-tear paper sheet, and capable of detecting only a break of desired length when detecting a break in the same size paper sheet.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a schematic block diagram showing the configuration of a paper sheet processing system according to a first embodiment of the invention;
FIG. 2 is a front view of a paper sheet break detection unit incorporated in the paper sheet processing system of FIG. 1;
FIG. 3 is a top plane view of the paper sheet break detection unit of FIG. 2;
FIG. 4 is a longitudinal sectional view of the paper sheet break detection unit of FIG. 2;
FIG. 5 is a block diagram showing a control system of the paper sheet processing system of FIG. 1;
FIG. 6 is a front view showing the state that a card having no break is sent to the paper sheet break detection unit of FIG. 2;
FIG. 7 is a longitudinal sectional view showing the state that a card having no break is sent to the paper sheet break detection unit of FIG. 2;
FIG. 8 is a perspective view of a card having no break sent to the paper sheet break detection unit of FIG. 2;
FIG. 9 is a perspective view of a card having a break sent to the paper sheet break detection unit of FIG. 2;
FIG. 10 is a front view showing the state that the card of FIG. 9 is sent to the paper sheet break detection unit of FIG. 2;
FIG. 11 is a longitudinal section view showing the state that the card of FIG. 9 is sent to the paper sheet break detection unit of FIG. 2;
FIG. 12 is a view showing a sensor signal when the paper sheet break detection unit of FIG. 2 does not detect a break in a card;
FIG. 13 is a view showing a sensor signal when the paper sheet break detection unit of FIG. 2 detects a break in a card;
FIG. 14 is a view showing the state that a pair of upper-side rollers of the paper sheet break detection unit of FIG. 2 are moved in the direction of coming close to each other, and the state that a pair of lower-side rollers are moved in the direction of coming close to each other;
FIG. 15 is a view showing the state that a pair of upper-side rollers of the paper sheet break detection unit of FIG. 2 are moved in the direction of separating from each other, and the state that a pair of lower-side rollers are moved in the direction of separating from each other;
FIG. 16 is a view showing the state that when the paper sheet break detection unit of FIG. 2 detects a break in the same size card, pairs of upper-side and lower-side rollers are moved to the position to open a break;
FIG. 17 is a view showing the state that when the paper sheet break detection unit of FIG. 2 detects a break in the same size card, pairs of upper-side and lower-side rollers are moved to the position not to open a break shorter than a predetermined length;
FIG. 18 shows a paper sheet break detection unit according to a second embodiment of the invention, and is a view showing the state that a pair of upper-side air nozzles are moved in the direction of coming close to each other, and a pair of lower-side air nozzles are moved in the direction of coming close to each other;
FIG. 19 is a view showing that a pair of upper-side air nozzles are moved in the direction of separating from each other, and a pair of lower-side air nozzles are moved in the direction of separating from each other; and
FIG. 20 is a front view of a conventional card break detection unit.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention will be explained hereinafter with reference to the accompanying drawings.

Embodiment 1

FIG. 1 is a block diagram showing the configuration of a paper sheet processing system according to a first embodiment of the invention.
In FIG. 1, a reference numeral 1 denotes a take-out unit to take out stacked cards as paper sheets one by one. A card taken out by the take-out unit 1 is conveyed along a conveying path. In the conveying path, a detection unit 2 is provided to detect a break formed in a card. In the downstream side of the card conveying direction of the detection unit 2, a branch gate 3 is provided to guide a card with no break detected to a first direction and a card having a break detected to a second direction. A first stack 4 to stack a card with no break detected is provided in the first direction, a second stack 5 to stack a card having a break detected is provided in the second direction.
FIG. 2 is a front view of the detection unit 2. FIG. 3 is a top plane view of the detection unit. FIG. 4 is a longitudinal sectional view of the detection unit.
In FIG. 2, a reference numeral 11 denotes a conveying path. In the upper side of the conveying path 11, front- and back-side upper conveying rollers 12 a and 12 a′ are provided with a predetermined space taken therebetween in the direction orthogonal to the card conveying direction. In the lower side of the conveying path 11, front- and back-side lower conveying rollers 13 a and 13 a′ are provided with a predetermined space taken therebetween in the direction orthogonal to the card conveying direction.
In the downstream side of the card conveying direction of the front- and back-side upper conveying rollers 12 a and 12 a′, and front- and back-side upper conveying rollers 12 b and 12 b′ are provided. In the downstream side of the card conveying direction of the front- and back-side lower conveying rollers 13 a and 13 a′, and front- and back-side lower conveying rollers 13 b and 13 b′ are provided.
An upper conveying belt 14 a is extended over the front-side upper conveying rollers 12 a and 12 b, and an upper conveying belt 14 c is extended over the back-side upper conveying rollers 12 a′ and 12 b′. A lower conveying belt 14 b is extended over the front-side lower conveying rollers 13 a and 13 b, and a lower conveying belt 14 d is extended over the back-side lower conveying rollers 13 a′ and 13 b′. The conveying unit is composed of the upper conveying belt 14 a/14 c and lower conveying belt 14 b/14 d. In the card take-in side of the detection unit 2, a trigger sensor 8 is provided to detect a card taken in.
Different size cards K1, K2 and K3 are conveyed with one side held by the front-side upper conveying belt 14 a and lower conveying belt 14 b, and conveyed with the other side held by the back-side upper conveying belt 14 c and lower conveying belt 14 d. In this time, the cards are conveyed with the center aligned with the center between the front-side conveying belt 14 a/14 c and back-side conveying belt 14 b/14 d.
A front-side upper roller (a first roller) 15 a is provided between the front-side upper conveying rollers 12 a and 12 b, and a back-side upper roller (a second roller) 15 a′ is provided between the back-side upper conveying rollers 12 a′ and 12 b′. A flange 15 f is provided in the front-side upper roller 15 a, and a flange 15 f′ is provided in the back-side upper roller 15 a′. The flanges 15 f and 15 f′ of the upper rollers 15 a and 15 a′ constitute a first pressing unit.
A front-side lower roller (a third roller) 16 a is provided between the front-side lower conveying rollers 13 a and 13 b, and a back-side lower roller (a fourth roller) 16 a′ is provided between the back-side lower conveying rollers 13 a′ and 13 b′. A flange 16 f is provided in the front-side lower roller 16 a, and a flange 16 f′ is provided in the back-side lower roller 16 a′. The flanges 16 f and 16 f′ of the lower rollers 16 a and 16 a′ constitute a second pressing unit.
The lower side of the flange 15 f/15 f′ of the upper roller 15 a/15 a′ is projected downward the conveying path 11 by a predetermined amount, and the upper side of the flange 16 f/16 f′ of the lower roller 16 a/16 a′ is projected upward the conveying path 11 by a predetermined amount.
The upper rollers 15 a and 15 a′ contact the upper side of the upper conveying belts 14 a and 14 c, and the lower rollers 16 a and 16 a′ contacts the lower side of the lower conveying belts 14 c and 14 d. The upper roller 15 a/15 a′ and lower roller 16 a/16 a′ are rotated following the conveying belts 14 a -14 d.
A linear light source 18 is provided as a light-emitting unit between the lower conveying rollers 13 a/13 a′ and lower roller 16 a/16 a′ along the direction orthogonal to the card conveying direction. A linear light-receiving sensor 19 is provided as a light receiver between the upper conveying roller 12 b/12 b′ and upper roller 15 a/15 a′ along the direction orthogonal to the card conveying direction. The light emitted from the linear light source 18 is received by the light-receiving sensor 19.
The above-mentioned upper roller 15 a/15 a′ and lower roller 16 a/16 a′ are moved by a moving mechanism 26 as shown in FIG. 3.
The upper rollers 15 a and 15 a′ are freely rotated taking the sleeves 21 a and 21 a′ as a rotation axis. The lower rollers 16 a and 16 a′ are freely rotated taking the sleeves 21 b and 21 b′ as a rotation axis.
The sleeves 21 a and 21 a′ are screwed into a shaft 17 a as a first drive shaft, and the sleeves 21 b and 21 b′ are screwed into a shaft 17 b as a second drive shaft. The outer surfaces of the shaft 17 a and 17 b are formed with a male screw inversely and symmetrically with respect to the centerline of the conveying path 11. The inner surfaces of the sleeves 21 a, 21 a′ and 21 b, 21 b′ are formed with a female screw to engage with the male screw of the shafts 17 a and 17 b.
The above-mentioned shafts 17 a and 17 b are provided along the card conveying surface and in the direction orthogonal to the card conveying direction, and are arranged to move the upper roller 15 a/15 a′ and lower roller 16 a/16 a′ along the card conveying surface and in the direction orthogonal to the card conveying direction.
When the above-mentioned shaft 17 a is rotated forward, the upper rollers 15 a and 15 a′ are moved together with the sleeves 21 a and 21 a′ in the direction of coming close to each other, and the distance between the flanges 15 f and 15 f′ is narrowed.
When the shaft 17 b is rotated forward, the lower rollers 16 a and 16 a′ are moved together with the sleeves 21 b and 21 b′ in the direction of coming close to each other, and the distance between the flanges 16 f and 16 f′ is narrowed.
When the shaft 17 a is rotated backward, the upper rollers 15 a and 15 a′ are moved together with the sleeves 21 a and 21 a′ in the direction of separating from each other, and the distance between the flanges 15 f and 15 f′ is widened.
When the shaft 17 b is rotated backward, the lower rollers 16 a and 16 a′ are moved together with the sleeves 21 b and 21 b′ in the direction of separating from each other, and the distance between the flanges 16 f and 16 f′ is widened.
Ends of the shaft 17 a and 17 b penetrate through a base 7, and are connected through a toothed pulley 22 a, a toothed belt 23 and a toothed pulley 22 b constituting an interlock mechanism. One end of the shaft 17 a is directly connected to a drive motor 24, which rotates forward and backward. The shafts 17 a and 17 b are simultaneously rotated in the forward and backward directions by the forward/backward rotation of the drive motor 24.
FIG. 5 is a block diagram of the control system of the paper sheet processing system.
In FIG. 5, a reference numeral 20 denotes a control unit. The control unit 20 is connected with a trigger sensor 8 and a light-receiving sensor 19 through a transmission circuit. The control unit 20 controls the operation of the branch gate 3, based on detection signals sent from the trigger sensor 8 and light-receiving sensor 19.
Namely, the control unit 20 judges that a card has no break as shown in FIG. 8, based on the detection signal shown in FIG. 12 from the light-receiving sensor 19. The control unit 20 judges that a card has a break a as shown in FIG. 9, based on the detection signal shown in FIG. 13 from the light-receiving sensor 19.
The control unit 20 operates the branch gate 3 to send a card K having no break to the first stack 4, and send a card K having a break a to the second stack 5. A break in a card also includes defects in addition to a simple break.
Next, a description will be given on a method of detecting a break in a card.
A card K is conveyed with one side held by the front-side upper conveying belt 14 a and lower conveying belt 14 b, and conveyed with the other side held by the back-side upper conveying belt 14 c and lower conveying belt 14 d, as shown in FIG. 6/FIG. 7 or FIG. 10/FIG. 11. The card K is detected by the trigger sensor 8, and one side is fed to between the front-side upper roller 15 a and lower roller 16 a, and the other side is fed to between the back-side upper roller 15 a′ and lower roller 16′. In this time, one side of the card K is pushed upward by the flange 16 f of the front-side lower roller 16 a, the other side is pushed upward by the flange 16 f′ of the back-side lower roller 16 a′, one side of the card K is pushed downward by the flange 15 f of the front-side upper roller 15 a, and the other side is pushed downward by the flange 15 f′ of the back-side upper roller 15 a.
Therefore, the card K is deformed like a step viewed from the conveying direction, and passes through the light from the light source 18, just like interrupting the light. In this time, when a predetermined dark signal as shown in FIG. 12 is output from the light-receiving sensor 19, the control unit 20 judges that the card K has no break. FIG. 6 and FIG. 7 show the state that a card K. having no break is conveyed. After judging that the card K has no break, the control unit 20 operates the branch gate 3 to send the card K to the first stack 4. FIG. 12 shows a signal output when two cards having no break are continued.
On the other hand, when the light-receiving sensor 19 outputs a detection signal to output a light signal during a dark signal, as shown in FIG. 13, the control unit 20 judges that the card K has a break a. FIG. 10 and FIG. 11 show the state that the card K having a break is conveyed, and the break a is opened. After judging that the card K has a break, the control unit 20 operates the branch gate 3 to send the card K to the second stack 5. FIG. 13 shows a signal output when a card having a break is conveyed subsequent to a card having no break.
As shown in FIG. 5, the control unit 20 is connected with an input unit 25 through a transmission circuit, and is connected with a drive motor 24, which rotates forward and backward through a control circuit. When handling different size cards, the input unit 25 specifies the sizes of the cards. Based on the specified size information, the control unit 20 controls the operation of the drive motor 24.
For example, when a small size is specified, the control unit 20 rotates the drive motor 24 forward and rotates the shaft 17 a forward. Therefore, the front-side upper roller 15 a and back-side upper roller 15 a′ are moved in the direction of coming close to each other as shown in FIG. 14, and the distance between the flanges 15 f and 15 f′ is narrowed.
In this time, the shaft 17 b is rotated forward through the toothed pulley 22 a, toothed belt 23 and toothed pulley 22 b. Therefore, the front-side lower roller 16 a and back-side lower roller 16 a′ are moved in the direction of coming close to each other, and the distance between the flanges 16 f and 16 f′ is narrowed.
Contrarily, when a large size is specified, the control unit 20 rotates the drive motor backward and rotates the shaft 17 a backward. Therefore, the front-side upper roller 15 a and back-side upper roller 15 a′ are moved in the direction of separating from each other as shown in FIG. 15, and the distance between the flanges 15 f and 15 f′ is widened.
In this time, the shaft 17 b is rotated backward through the toothed pulley 22 a, toothed belt 23 and toothed pulley 22 b. Therefore, the front-side lower roller 16 a and back-side lower roller 16 a′ are moved in the direction of separating from each other, and the distance between the flanges 16 f and 16 f′ is widened.
The light source 18 and light-receiving sensor 19 have a light-emitting width and a light-receiving width capable of covering the amount of movement of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′.
As described hereinbefore, the upper roller 15 a/15 a′ and lower roller 16 a/16 a′ are moved in the direction of separating from each other based on the card size, and the flanges 15 f/15 f′ and 16 f/16 f′ can be set at the positions suitable for the card size, and a break in a card can be securely opened and detected.
When handling the same size card, the position to open a break in a card can be changed by changing the distance of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′ from the end-face of a card.
In this case, an operator inputs a desired amount of movement from the input unit 25. Then, the control unit 20 controls the operation of the drive motor 24, and the distance of flanges 15 f/15 f′ and 16 f/16 f′ of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′ from the end-face of a card can be variably controlled.
For example, FIG. 16 shows the case that the break a in a card is opened by moving the flanges 15 f/15 f′ and 16 f/16 f′ of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′ from the end-face of a card to the inside by about 5 mm, and placing the flanges to the break. FIG. 17 shows the case that the break a in a card is not opened by moving the flanges 15 f/15 f′ and 16 f/16 f′ of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′ from the end-face of a card to the inside by about 10 mm, and not placing the flanges to the break.
By adjusting the positions of the flanges 15 f/15 f′ and 16 f/16 f′ of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′, it is possible to detect only a break longer than a predetermined length without wastefully detecting a short break.
Further, in the embodiment described above, a card is conveyed along the longish side. The conveying direction is not limited to this. A card may be conveyed along the shorter side.

Embodiment 2

FIG. 18 and FIG. 19 show a detection unit according to a second embodiment of the invention.
In the second embodiment, upper air nozzles 31 a/31 a′ and lower air nozzle 32 a/32 a′ are provided as first and second air nozzles and as third and fourth air nozzles, instead of the flanges 15 f/15 f′ and 16 f/16 f′ of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′. The upper air nozzles 31 a and 31 a′ are moved in the direction of coming close to each other along the direction orthogonal to the card conveying direction, for example, according to the size of a card, as shown in FIG. 18. The lower air nozzles 32 a and 32 a′ are also moved in the direction of coming close to each other, like the upper air nozzles 31 a and 31 a′.
The upper air nozzles 31 a and 31 a′ are moved in the direction of separating from each other along the direction orthogonal to the card conveying direction, for example, according to the size of a card, as shown in FIG. 9. The lower air nozzles 32 a and 32 a′ are also moved in the direction of separating from each other, like the upper air nozzles 31 a and 31 a′.
Air ejected from the upper air nozzle 31 a/31 a′ and lower air nozzle 32 a/32 a′ is blown to both sides of a card from the up/down direction, opens a break if any, and enables detection of a break.
The same effect as the first embodiment can be obtained from the second embodiment.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Claims

1. A paper sheet break detection unit comprising:

a conveying unit which conveys a paper sheet along a conveying surface;

a first pressing unit which presses one side of the paper sheet conveyed by the conveying unit in a first direction orthogonal to the conveying surface;

a second pressing unit which is provided in proximity to the first pressing unit, and presses the other side of the paper sheet conveyed by the conveying unit in a second direction reverse to the first direction;

a light-emitting unit which emits light to the paper sheet deformed by the pressure of the first and second pressing units;

a light-receiving unit which receives the light illuminated from the light-emitting unit;

a judgment unit which judges whether the paper sheet includes a break, based on the reception of the light by the light-receiving unit; and

a moving mechanism which moves the first and second pressing units along the conveying surface in a direction orthogonal to a direction of conveying the paper sheet.

2. The paper sheet break detection unit according to claim 1, wherein the conveying unit has a pair of first conveying belts which holds and conveys one side of the paper sheet, and a pair of second conveying belts which is provided parallel to the first conveying belt with a predetermined interval, and holds and conveys the other end of the paper sheet;

the first pressing unit is composed of a flange of a first roller to contact the surface of one of the pair of first conveying belts and rotate following the belts, and a flange of a second roller to contact the surface of one of the pair of second conveying belts and rotate following the belts; and

the second pressing unit is composed of a flange of a third roller to contact the surface of the other of the pair of first conveying belts and rotate following the belts, and a flange of a fourth roller to contact the surface of the other of the pair of second conveying belts and rotate following the belts.

3. The paper sheet break detection unit according to claim 2, wherein the moving mechanism has first and second drive shafts which rotate forward and backward, and moves the flanges of the first and second rollers in a direction of coming close to each other by the forward rotation of the first drive shaft, moves the flanges of the third and fourth rollers in a direction of coming close to each other by the forward rotation of the second drive shaft, moves the flanges of the first and second rollers in a direction of separating from each other by the backward rotation of the first drive shaft, and moves the flanges of the third and fourth rollers in a direction of separating from each other by the backward rotation of the second drive shaft.

4. The paper sheet break detection unit according to claim 3, wherein the first and second drive shafts are interlocked through an interlock mechanism.

5. The paper sheet break detection unit according to claim 2, wherein the amount of movement of the flanges of the first and second rollers and the flanges of the third and fourth rollers is controlled according to the size of the paper sheet or the length of a break to be detected.

6. The paper sheet break detection unit according to claim 1, wherein the first pressing unit is composed of a first air nozzle to blow air to one side of the paper sheet, and a second air nozzle to blow air to the other side of the paper sheet; and

the second pressing unit is composed of a third air nozzle to blow air to one side of the paper sheet from a direction reverse to the first air nozzle, and a fourth air nozzle to blow air to the other side of the paper sheet from a direction reverse to the second air nozzle.

7. The paper sheet break detection unit according to claim 6, wherein the first and second air nozzles are moved in a direction of coming close to or separating from each other, and the third and fourth air nozzles are moved in a direction of coming close to or separating from each other.

8. The paper sheet break detection unit according to claim 6, wherein the amount of movement of the first and second air nozzle and third and four air nozzles is controlled according to the size of the paper sheet or the length of a break to be detected.

9. The paper sheet break detection unit according to claim 1, wherein the paper sheet is rectangular, and conveyed along the longish side or shorter side.