Patent Publication Number: US-2021179374-A1

Title: Image reading device and staple determination method

Description:
TECHNICAL FIELD 
     This disclosure relates to an image reading device and a staple determination method 
     BACKGROUND ART 
     An image reading device, in which a document loaded on a document loading platform (paper feeding tray) is transported one by one to a document transport path, an image formed on the document is read by an image reader disposed in the document transport path, and then the document is discharged to a document discharging unit (paper discharging tray), is known. 
     A binding process (stapling process) of a staple or the like is executed in the document loaded on the document loading platform of the image reading device. In a case where a bound bundle (document bundle) of documents is transported by a document transport path, the document is torn, or a transport roller and the image reader disposed on the document transport path are damaged. 
     Therefore, in response to the problem, a technique, in which staple detecting means (for example, a magnetic sensor) for detecting a staple applied to the document loaded on the document loading platform is provided to determine whether or not the stapling process is applied to the document, is proposed (for example, see PTL 1). 
     However, in the document, there are various places to which the stapling process is applied and it is not necessarily always stapled at a disposition position of the staple detecting means. That is, even in the document to which the stapling process is applied, if the staple detecting means is not disposed at a position at which stapling can be detected, presence or absence of the stapling process with respect to the document cannot be determined. 
     A main object of this disclosure is to determine presence or absence of a stapling process with high accuracy. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Patent Unexamined Publication No. 10-239920 
     SUMMARY OF THE INVENTION 
     An image reading device of the disclosure transports a document loaded on a document loading platform to a document transport path and reads an image formed on the document. The image reading device of this disclosure includes: a document delivery unit for delivering the document loaded on the document loading platform to the document transport path; a flip-up detector for detecting flip-up of the document when the document is delivered by the document delivery unit; an abnormal sound detector for detecting occurrence of abnormal sound when the document is delivered by the document delivery unit; a double feeding detector for detecting double-feeding of the document when the document is delivered by the document delivery unit; and a staple determination unit for determining whether or not a stapling process is applied to the document based on detection results of the flip-up detector, the abnormal sound detector, and the double feeding detector. 
     A staple determination method of this disclosure includes: acquiring a detection result of a flip-up detector that detects flip-up of a document when the document loaded on a document loading platform is delivered to a document transport path; acquiring a detection result of an abnormal sound detector that detects occurrence of abnormal sound when the document is delivered; acquiring a detection result of a double feeding detector that detects double-feeding of the document when the document is delivered; and determining whether or not a stapling process is applied to the document based on detection results of the flip-up detector, the abnormal sound detector, and the double feeding detector. 
     According to this disclosure, presence or absence of the stapling process can be determined with high accuracy. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of an entirety of an image reading device in an embodiment. 
         FIG. 2  is a block diagram illustrating a function configuration of the image reading device in the embodiment. 
         FIG. 3  is a side sectional view of the image reading device in the embodiment. 
         FIG. 4  is an upper sectional view of the image reading device in the embodiment. 
         FIG. 5  is a view for explaining a position at which a stapling process is applied to a document. 
         FIG. 6  is a view illustrating a manner of detecting flip-up of the document. 
         FIG. 7  is a view illustrating a manner of detecting occurrence of abnormal sound. 
         FIG. 8  is a view illustrating a manner of detecting double-feeding of the document. 
         FIG. 9  is a view illustrating a manner of detecting metal attached to the document. 
         FIG. 10  is a view illustrating whether or not each detector detects a position to which the stapling process is applied. 
         FIG. 11  is a view illustrating whether or not each detector detects a position to which the stapling process is applied. 
         FIG. 12  is a flowchart illustrating a staple determining operation of the image reading device in the embodiment. 
         FIG. 13  is a view illustrating whether or not each detector detects a position to which the stapling process is applied. 
         FIG. 14  is a view illustrating whether or not each detector detects a position to which the stapling process is applied. 
         FIG. 15  is a flowchart illustrating a staple determining operation of the image reading device in the embodiment. 
         FIG. 16  is a view illustrating whether or not each detector detects a position to which the stapling process is applied. 
         FIG. 17  is a flowchart illustrating a staple determining operation of the image reading device in the embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment will be described with reference to the drawings.  FIG. 1  is a perspective view of an entirety of image reading device  1  in the embodiment as viewed from front and above the device.  FIG. 2  is a block diagram illustrating a function configuration of image reading device  1 .  FIG. 3  is a side sectional view of image reading device  1 .  FIG. 4  is an upper sectional view of image reading device  1 . 
     Image reading device  1  is a document scanner and transports (feeds) a document loaded on document loading platform  120  one by one to document transport path  68 , reads an image formed on the document in image reader  30  disposed on document transport path  68 , and then discharges (ejects) the document to document discharging unit  130 . Moreover, image reading device  1  may be applied to an electrophotographic image forming apparatus. 
     As illustrated in  FIG. 2 , image reading device  1  includes control unit  10 , operation display unit  20 , image reader  30 , auxiliary storage unit  40 , network connection unit  50 , transport unit  60 , flip-up detector  70 , abnormal sound detector  80 , metal detector  90 , double feeding detector  100 , and inclination detector  110 . 
     Control unit  10  includes Central Processing Unit (CPU)  12  and operation memories such as Read Only Memory (ROM)  14  for storing a control program (corresponding to a “staple determining program” of this disclosure) and Random Access Memory (RAM)  16 . CPU  12  reads a control program from ROM  14 , develops the control program in RAM  16 , and centrally controls an operation of each block or the like of image reading device  1  in cooperation with the developed control program. In this case, various data stored in auxiliary storage unit  40  are referred. Auxiliary storage unit  40  is configured of, for example, nonvolatile semiconductor memory (so-called flash memory) or a hard disk drive. Control unit  10  functions as a “staple determination unit” and a “transport controller” of this disclosure. 
     Control unit  10  transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication network such as a Local Area Network (LAN) or a Wide Area Network (WAN) via network connection unit  50 . Control unit  10  transmits an image read by image reader  30  to the external device (for example, the personal computer). Network connection unit  50  is configured of, for example, a communication control card such as a LAN card. 
     Image reader  30  optically reads an image formed on the document transported in document transport path  68 , photoelectrically converts the image, and outputs the image to control unit  10  as image data. Specifically, image reader  30  irradiates light from an exposure lamp onto the document, receives reflected light on a receiving surface of a solid-state imaging device such as a Charge Coupled Device (CCD) via an imaging lens to perform photoelectric conversion. In the embodiment, image reader  30  can collectively read images formed on both surfaces (front surface and back surface) of the document. 
     Operation display unit  20  functions as operation information input unit  22  and information display unit  24 . Operation information input unit  22  includes various operation keys such as ten keys and a start key, accepts various input operations by a user, and outputs an operation signal to control unit  10 . Information display unit  24  displays various operation screens, an operation status of each function, and the like according to a display control signal input from control unit  10 . 
     Transport unit  60  includes document transport path  68 , document loading platform  120 , document discharging unit  130 , and the like. Transport unit  60  has a plurality of transport rollers for transporting the document on document transport path  68 . Document loading platform  120  and document discharging unit  130  are configured to be capable of moving up and down according to the number of loaded documents. 
     As illustrated in  FIGS. 3 and 4 , paper feeding roller  61 , metal detector  90 , separation and retard rollers  62  and  63 , abnormal sound detector  80 , inclination detector  110 , double feeding detector  100 , first transport roller pair  64 , second transport roller pair  65 , image reader  30 , and third transport roller pair  66  are disposed on document transport path  68  from an upstream side in a document transporting direction. 
     The document loaded on document loading platform  120  is drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61 . The documents drawn in between separation roller  62  and retard roller  63  are separated one by one and sent, and are transported to first transport roller pair  64 . Furthermore, the document is transported to image reader  30  at a constant speed by first and second transport roller pairs  64  and  65 . Images formed on the front surface and the back surface of the document are read in image reader  30 . Thereafter, the document is discharged to document discharging unit  130  by third transport roller pair  66 , a paper discharge roller pair, and the like. Moreover, separation roller  62  and retard roller  63  function as a “document delivery unit” of this disclosure. 
     Meanwhile, a stapling process is applied to the document loaded on document loading platform  120  of image reading device  1 . In general, the stapling process is a process of stitching a plurality of documents of binding objects using a binding needle (staple needle) made of metal or nonmetal to bind the plurality of the documents with the staple needle itself. In the embodiment, the stapling process also includes a process of crimping and binding the plurality of the documents without stitching the plurality of the documents as the binding targets using the staple needle. In a case where a bundle (document bundle) of the documents which are bound as described above is transported by document transport path  68 , there is a problem that the document itself is torn, or transport roller pairs  64 ,  65 , and  66 , and image reader  30  disposed on document transport path  68  are damaged. 
     Therefore, in the embodiment, as stapling process detecting means for detecting the stapling process applied to the document loaded on document loading platform  120 , image reading device  1  includes flip-up detector  70 , abnormal sound detector  80 , metal detector  90 , double feeding detector  100 , and inclination detector  110 . Control unit  10  determines whether or not the stapling process is applied to the document based on detection results of flip-up detector  70 , abnormal sound detector  80 , metal detector  90 , double feeding detector  100 , and inclination detector  110 . In a case where control unit  10  determines that the stapling process is applied to the document, control unit  10  controls transport unit  60  so as to stop a transport operation of the document. 
       FIG. 5  is a view for explaining an example of a position at which the stapling process is applied to document P. As illustrated in  FIG. 5 , positions at which the stapling process is applied to document P include S 1  to S 3  of a leading end portion, S 4  to S 6  of a center portion, and S 7  to S 9  of a trailing end portion of document P in the document transporting direction. 
     Next, a configuration of flip-up detector  70  will be described. As illustrated in  FIG. 3 , flip-up detector  70  is an ultrasonic sensor provided above paper feeding roller  61  and detects flip-up of document P when document P is delivered by separation roller  62  and retard roller  63 . 
       FIG. 6  is a view illustrating a manner of detecting flip-up of the document. In  FIG. 6 , (a) illustrates a manner before the plurality of documents P loaded on document loading platform  120  are drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61 . In the example illustrated in (a), the stapling process is applied to position S 8  of the trailing end portion of document P in the document transporting direction. 
     In  FIG. 6 , (b) illustrates a manner when documents P drawn into between separation roller  62  and retard roller  63  are separated and delivered one by one. In this case, first document P is fed by separation roller  62  and second and subsequent documents P are blocked to be fed by retard roller  63 . As a result, first document P flips up (rises). Flip-up detector  70  normally transmits an ultrasonic pulse in a direction opposite to the document transporting direction and in a case where first document P flips up, for example, equal to a predetermined height or more, receives a reflected wave reflected by document P, detects flip-up of document P from the received reflected wave, and outputs the fact to control unit  10 . That is, flip-up detector  70  directly detects that the stapling process is applied to document P. 
     If the stapling process is applied to positions S 4  to S 6  of the center portion and positions S 7  to S 9  of the trailing end portion of document P in the document transporting direction, first document P flips up, so that the flip-up can be detected by flip-up detector  70 . Moreover, flip-up detector  70  is not limited to the ultrasonic sensor, but may be an infrared photosensor, or a touch sensor provided at a position capable of coming into contact with document P in a case where document P flips up. 
     Next, a configuration of abnormal sound detector  80  will be described. Abnormal sound detector  80  detects occurrence of abnormal sound when document P is delivered by separation roller  62  and retard roller  63 . Specifically, abnormal sound detector  80  constantly inputs sound generated around abnormal sound detector  80 , calculates a time-series variation in a specific frequency region of a sound signal, and compares the calculated time-series variation with a time-series variation (profile) in the specific frequency region of an abnormal sound signal which is created in advance, thereby detecting whether or not there is the abnormal sound. 
       FIG. 7  is a view illustrating a manner of detecting occurrence of the abnormal sound. In  FIG. 7 , (a) illustrates a manner in which the plurality of documents P loaded on document loading platform  120  are drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61 . In the example illustrated in (a), the stapling process is applied to position S 1  of the tip portion of document P in the document transporting direction. 
     In  FIG. 7 , (b) illustrates a manner when documents P drawn into between separation roller  62  and retard roller  63  are separated and delivered one by one. In this case, only first document P rotates in the counterclockwise direction around position S 1  of the tip portion of document P as a rotation fulcrum in (b). As a result, paper breakage or tearing occurring in first document P, or the abnormal sound due to rubbing between first document P and second document P occurs. Abnormal sound detector  80  detects the generated abnormal sound and outputs the fact to control unit  10 . In a case where the stapling process is applied to position S 3  of the tip portion of document P, only first document P rotates in the clockwise direction around position S 3  as the rotation fulcrum in (b). As a result, paper breakage or tearing occurring in first document P, or the abnormal sound due to rubbing between first document P and second document P occurs. That is, if the stapling process is applied to position S 1  or S 3  of the tip portion of document P, the abnormal sound occurs and the abnormal sound can be detected by abnormal sound detector  80 . As described above abnormal sound detector  80  directly detects that the stapling process is applied to document P. 
     It may detect more accurately that the stapling process is applied to position S 1  or S 3  of the tip portion of document P by using inclination detector  110  together with abnormal sound detector  80 . Inclination detector  110  detects an inclination (for example, an inclination equal to a predetermined angle or more) in the document transporting direction of document P when document P is delivered by separation roller  62  and retard roller  63 . Inclination detector  110  is configured to include a plurality of sensors which are disposed, for example, in a document width direction orthogonal to in the document transporting direction and detect a passage of document P. Inclination detector  110  detects the inclination of document P based on a timing detected by each sensor through which transported document P passes. In a case where the stapling process is applied to position S 1  or S 3  of the tip portion of document P, inclination detector  110  directly detects that document P drawn into between separation roller  62  and retard roller  63  rotates rather than through the occurrence of the abnormal sound. 
     Next, a configuration of double feeding detector  100  will be described. Double feeding detector  100  is, for example, an ultrasonic sensor disposed on the downstream side of separation roller  62  and retard roller  63  in the document transporting direction, and detects double-feeding (state where plurality of documents P are stacked and transported) of document P when document P is delivered by separation roller  62  and retard roller  63 . Double feeding detector  100  may be a laser reader. 
       FIG. 8  is a view illustrating a manner of detecting double-feeding of the document. In  FIG. 8 . (a) illustrates a manner in which the plurality of documents P loaded on document loading platform  120  are drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61 . In the example illustrated in (a), the stapling process is applied to position S 2  of the tip portion of document P in the document transporting direction. The stapling process may be applied to positions S 1  and S 3  of the tip portion of document P. 
     In  FIG. 8 , (b) illustrates a manner that the plurality of documents P drawn into between separation roller  62  and retard roller  63  are delivered without separation. Double feeding detector  100  includes a transmission portion and a reception portion facing each other via document transport path  68 , and detects whether or not documents P are double-fed according to a reception intensity of the reception portion with respect to an ultrasonic pulse normally transmitted from the transmission portion. In a case where document P does not exist between the transmission portion and the reception portion, the ultrasonic pulse hardly attenuates and reaches the reception portion (reception intensity is the maximum). In a case where one document P exists, the ultrasonic pulse is absorbed by document P and an attenuated reception intensity is obtained. As illustrated in (b), in a case where the plurality of documents P to which the stapling process is applied exist (that is, the plurality of documents P are stacked and transported), the ultrasonic pulse transmitted from the transmission portion is absorbed more greatly and a plurality of times of reflection occur between the documents, so that vibration energy is greatly canceled and the reception intensity is remarkably attenuated. As described above, when the ultrasonic pulse transmitted from the transmission portion is received by the reception portion, in a case where a signal intensity of the ultrasonic pulse is greatly attenuated, double feeding detector  100  directly detects that the stapling process is applied to document P. A threshold of the reception intensity for detecting whether or not documents P are double-fed may be arbitrary set by the user. 
     In a case where the stapling process is applied to position S 1  or S 3  of document P, only the uppermost one of the plurality of documents P passes through separation roller  62  and retard roller  63  and second and subsequent documents P are held by retard roller  63 , so that breakage of document P (first) occurs due to rotational misalignment. In this case, double feeding detector  100  cannot detect that the stapling process is applied to document P. In a case where the stapling process is applied to position S 4 , S 6 , S 7 , or S 9  of document P, only the uppermost one of the plurality of documents P passes through separation roller  62  and retard roller  63  and second and subsequent documents P are held by retard roller  63 , so that breakage of document P (first) occurs due to flip-up and turning from a side portion. Also in this case, double feeding detector  100  cannot detect that the stapling process is applied to document P. In a case where the stapling process is applied to position S 5  or S 8  of document P, only the uppermost one of the plurality of documents P passes through separation roller  62  and retard roller  63  and second and subsequent documents P are held by retard roller  63 , so that breakage of document P (first) occurs due to flip-up and turning from a center portion. Also in this case, double feeding detector  100  cannot detect that the stapling process is applied to document P. 
     That is, in a case where the stapling process is applied to position S 2  or both positions S 1  and S 3  of document P, double feeding detector  100  can detect that the stapling process is applied to document P. 
     Next, a configuration of metal detector  90  will be described. As illustrated in  FIG. 3 , metal detector  90  is disposed on the upstream side of separation roller  62  and retard roller  63  in the document transporting direction, and when document P is delivered by separation roller  62  and retard roller  63 , metal detector  90  detects metal (for example, the staple needle) attached to document P. Metal detector  90  uses, for example, electromagnetic induction and detects the metal by detecting a magnetic field associated with an eddy current generated when the metal passes through a detection coil. Metal detector  90  may detect the metal without using electromagnetic induction. 
       FIG. 9  is a view illustrating a manner of detecting metal attached to the document. In  FIG. 9 , (a) illustrates a manner before the plurality of documents P loaded on document loading platform  120  are drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61 . In the example illustrated in (a), the stapling process is applied to positions S 1  and S 3  of the tip portion of document P in the document transporting direction, and the staple needle (metal) is attached to document P. 
     In  FIG. 9 , (b) illustrates a manner that before document P is drawn into between separation roller  62  and retard roller  63 , the staple needles attached to positions S 1  and S 3  of the tip portion of document P are detected by metal detector  90 . In this case, before the plurality of documents P are drawn into between separation roller  62  and retard roller  63 , it is possible to early and directly detect that the metal is attached to document P and the stapling process is applied to document P compared to a case where the staple needles are attached to the center portion and the trailing end portion of document P in the document transporting direction. 
       FIGS. 10 and 11  are views illustrating a relationship between each of positions S 1  to S 9  to which the stapling process is applied in document P, and whether or not the stapling process is detected by each of the detectors (flip-up detector  70 , metal detector  90 , abnormal sound detector  80 , and double feeding detector  100 ).  FIG. 10  illustrates a case where as the stapling process, a process of stitching the plurality of documents P of binding objects is applied using the staple needle made of metal to bind the plurality of documents P with the staple needle itself.  FIG. 11  illustrates a case where as the stapling process, a process of stitching the plurality of documents P of binding objects is applied using the staple needle made of nonmetal to bind the plurality of documents P with the staple needle itself, or a process of crimping and binding the plurality of documents P without stitching the plurality of documents P as the binding targets is applied using the staple needle. 
     In  FIGS. 10 and 11 , “A” indicates that the stapling process can be detected before the position to which the stapling process is applied passes through separation roller  62  and retard roller  63 , that is, the stapling process is early detected. In addition, “B” indicates that the stapling process can be detected before the position to which the stapling process is applied reaches image reader  30  after the position to which the stapling process is applied passes through separation roller  62  and retard roller  63 . In addition, “C” indicates that document P itself is torn or transport roller pairs  64  to  66  and image reader  30  disposed on document transport path  68  are broken regardless of whether or not the stapling process is detected by each detector, in a case where only each of the detectors (flip-up detector  70 , metal detector  90 , abnormal sound detector  80 , and double feeding detector  100 ) is provided. 
     For example, as illustrated in  FIGS. 10 and 11 , when the positions to which the stapling process is applied are S 1  to S 3 , the stapling process cannot be detected by flip-up detector  70 , but the stapling process can be detected by at least one of metal detector  90 , abnormal sound detector  80 , and double feeding detector  100  without causing tearing of document P and breakage of transport roller pairs  64  to  66  and image reader  30 . Therefore, even if the position to which the stapling process is applied varies in document P, it is possible to accurately determine presence or absence of the stapling process with respect to document P. 
       FIG. 12  is a flowchart illustrating a staple determining operation of image reading device  1  in the embodiment. A process of step S 100  in  FIG. 12  is started when power supply of image reading device  1  is turned on and document P is loaded on document loading platform  120 . 
     First, control unit  10  controls transport unit  60  (paper feeding roller  61 ) and starts a feeding operation of document P loaded on document loading platform  120  (step S 100 ). Next, control unit  10  acquires a detection result of metal detector  90  and determines whether or not metal is attached to document P and whether or not the stapling process is applied to document P (step S 120 ). As a result of the determination, in a case where the metal is attached (step S 120 , YES), control unit  10  controls transport unit  60  so as to stop the transport of document P (step S 260 ). 
     Next, control unit  10  causes information display unit  24  to display abnormal information, more specifically, information indicating the fact that the stapling process is applied to document. P (step S 280 ). Upon completion of the process of step S 280 , image reading device  1  completes the process in FIG.  12 . 
     Returning to the determination of step S 120 , in a case where metal is not attached (step S 120 , NO), control unit  10  controls transport unit  60  (separation roller  62  and retard roller  63 ) and starts a separation operation of documents P drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61  (step S 140 ). 
     Next, control unit  10  acquires a detection result of metal detector  90  and determines whether or not metal is attached to document P and whether or not the stapling process is applied to document P (step S 160 ). As a result of the determination, in a case where the metal is attached (step S 160 , YES), the process proceeds to step S 260 . 
     On the other hand, in a case where metal is not attached (step S 160 , NO), control unit  10  acquires the detection result of flip-up detector  70  and determines whether or not document P flips up and whether or not the stapling process is applied to document P (step S 180 ). As a result of the determination, in a case where document P flips up (step S 180 , YES), the process proceeds to step S 260 . 
     On the other hand, in a case where document P does not flip up (step S 180 , NO), control unit  10  acquires the detection result of abnormal sound detector  80  and determines whether or not the abnormal sound occurs and whether or not the stapling process is applied (step S 200 ). As a result of the determination, in a case where the abnormal sound occurs (step S 200 , YES), the process proceeds to step S 260 . 
     On the other hand, in a case where the abnormal sound does not occur (step S 200 , NO), control unit  10  acquires the detection result of double feeding detector  100  and determines whether or not double-feeding of documents P generates and whether or not the stapling process is applied (step S 220 ). As a result of the determination, in a case where the double-feeding of document P generates (step S 220 , YES), the process proceeds to step S 260 . 
     On the other hand, in a case where the double-feeding of document P does not generate (step S 220 , NO), control unit  10  determines whether or not an image reading operation of image reader  30  with respect to all documents P loaded on document loading platform  120  is completed (step S 240 ). As a result of the determination, in a case where the image reading operation is not completed (step S 240 , NO), the process proceeds to step S 160 . On the other hand, in a case where the image reading operation is completed (step S 240 , YES), image reading device  1  completes the process in  FIG. 12 . 
     As described above in detail, in the embodiment, image reading device  1  includes the document delivery unit (separation and retard rollers  62  and  63 ) that delivers document P loaded on document loading platform  120  to document transport path  68 ; flip-up detector  70  that detects the flip-up of document P when document P is delivered by the document delivery unit; metal detector  90  that detects the metal attached to document P when document P is delivered by the document delivery unit; abnormal sound detector  80  that detects occurrence of the abnormal sound when document P is delivered by the document delivery unit; double feeding detector  100  that detects the double-feeding of documents P when document P is delivered by the document delivery unit; and the staple determination unit (CPU  12 ) that determines whether or not the stapling process is applied to document P based on the detection results of flip-up detector  70 , metal detector  90 , abnormal sound detector  80 , and double feeding detector  100 . 
     According to the embodiment having such a configuration, even if the position to which the stapling process is applied varies in document P, it is possible to detect that the stapling process is applied to document P by at least one of flip-up detector  70 , metal detector  90 , abnormal sound detector  80 , and double feeding detector  100 . As a result, it is possible to accurately determine presence or absence of the stapling process and in a case where it is determined that the stapling process is applied to document P, the transport operation of document P can be early stopped. Therefore, it is possible to prevent occurrence of a problem which is generated in a case where document P to which the stapling process is applied is transported through document transport path  68 , more specifically, a problem that document P itself is torn or transport roller pairs  64  to  66  and image reader  30  disposed on document transport path  68  are broken. 
     In the embodiment, an example, in which it is determined whether or not the stapling process is applied to document P based on the detection results of flip-up detector  70 , metal detector  90 , abnormal sound detector  80 , and double feeding detector  100 , is described, but the example is not limited to the embodiment. For example, it may be determined whether or not the stapling process is applied to document P based on the detection results of flip-up detector  70  and metal detector  90 . 
       FIGS. 13 and 14  are views illustrating a relationship between each of positions S 1  to S 9  to which the stapling process is applied in document P, and whether or not the stapling process is detected by each of the detectors (flip-up detector  70  and metal detector  90 ).  FIG. 13  illustrates a case where as the stapling process, a process of stitching the plurality of documents P of binding objects is applied using the staple needle made of metal to bind the plurality of documents P with the staple needle itself.  FIG. 14  illustrates a case where as the stapling process, a process of stitching one document P is applied using the staple needle made of metal. 
     In  FIGS. 13 and 14 , “A” indicates that the stapling process can be detected before the position to which the stapling process is applied passes through separation roller  62  and retard roller  63 , that is, the stapling process is early detected. In addition, “C” indicates that document P itself is torn or transport roller pairs  64  to  66  and image reader  30  disposed on document transport path  68  are broken regardless of whether or not the stapling process is detected by each of the detectors (flip-up detector  70  and metal detector  90 ) is provided. 
     As illustrated in  FIGS. 13 and 14 , even if the position to which the stapling process is applied varies in document P, it is possible to accurately determine presence or absence of the stapling process with respect to document P by fewer detectors. 
       FIG. 15  is a flowchart illustrating a staple determining operation of image reading device  1  in a case where flip-up detector  70  and metal detector  90  are used. A process of step S 300  in  FIG. 15  is started when power supply of image reading device  1  is turned on and document P is loaded on document loading platform  120 . 
     First, control unit  10  controls transport unit  60  (paper feeding roller  61 ) and starts a feeding operation of document P loaded on document loading platform  120  (step S 300 ). Next, control unit  10  acquires a detection result of metal detector  90  and determines whether or not metal is attached to document P and whether or not the stapling process is applied to document P (step S 320 ). As a result of the determination, in a case where the metal is attached (step S 320 , YES), control unit  10  controls transport unit  60  so as to stop the transport of document P (step S 420 ). 
     Next, control unit  10  causes information display unit  24  to display abnormal information, more specifically, information indicating the fact that the stapling process is applied to document P (step S 440 ). Upon completion of the process of step S 440 , image reading device  1  completes the process in  FIG. 15 . 
     Returning to the determination of step S 320 , in a case where metal is not attached (step S 320 , NO), control unit  10  controls transport unit  60  (separation roller  62  and retard roller  63 ) and starts a separation operation of documents P drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61  (step S 340 ). 
     Next, control unit  10  acquires a detection result of metal detector  90  and determines whether or not metal is attached to document P and whether or not the stapling process is applied to document P (step S 360 ). As a result of the determination, in a case where the metal is attached (step S 360 , YES), the process proceeds to step S 420 . 
     On the other hand, in a case where metal is not attached (step S 360 , NO), control unit  10  acquires the detection result of flip-up detector  70  and determines whether or not document P flips up and whether or not the stapling process is applied to document P (step S 380 ). As a result of the determination, in a case where document P flips up (step S 380 , YES), the process proceeds to step S 420 . 
     On the other hand, in a case where document P does not flip up (step S 380 , NO), control unit  10  determines whether or not the image reading operation of image reader  30  is completed with respect to all documents P loaded on document loading platform  120  (step S 400 ). As a result of the determination, in a case where the image reading operation is not completed (step S 400 , NO), the process proceeds to step S 360 . On the other hand, in a case where the image reading operation is completed (step S 400 , YES), image reading device  1  completes the process in  FIG. 15 . 
     It is not determined whether or not the stapling process is applied to document P based on the detection results of flip-up detector  70 , metal detector  90 , abnormal sound detector  80 , and double feeding detector  100 , and it may be determined whether or not the stapling process is applied to document P based on the detection results of flip-up detector  70 , abnormal sound detector  80 , and double feeding detector  100 . 
       FIG. 16  is a view illustrating a relationship between each of positions S 1  to S 9  to which the stapling process is applied in document P, and whether or not the stapling process is detected by each of the detectors (flip-up detector  70 , abnormal sound detector  80 , and double feeding detector  100 ).  FIG. 16  illustrates a case where as the stapling process, a process of stitching the plurality of documents P of binding objects is applied using the staple needle to bind the plurality of documents P by the staple needle itself, or a process of crimping and binding the plurality of documents P without stitching the plurality of documents P as the binding targets is applied using the staple needle. 
     In  FIG. 16 , “A” indicates that the stapling process can be detected before the position to which the stapling process is applied passes through first transport roller pair  64 . In addition, “C” indicates that document P itself is torn or transport roller pairs  64  to  66  and image reader  30  disposed on document transport path  68  are broken regardless of whether or not the stapling process is detected by each of detectors (flip-up detector  70 , abnormal sound detector  80 , and double feeding detector  100 ). 
     As illustrated in  FIG. 16 , even if the position to which the stapling process is applied varies in document P, it is possible to accurately determine presence or absence of the stapling process with respect to document P. However, from the viewpoint of more reliably preventing breakage of document P, transport roller pairs  64  to  66 , and image reader  30 , it is preferable that the stapling process is detected before the position to which the stapling process is applied passes through separation roller  62  and retard roller  63 , that is, the stapling process is early detected, and it is preferable that it is determined whether or not the stapling process is applied to document P based on the detection results of flip-up detector  70 , metal detector  90 , abnormal sound detector  80 , and double feeding detector  100 . 
       FIG. 17  is a flowchart illustrating a staple determining operation of image reading device  1  using flip-up detector  70 , abnormal sound detector  80 , and double feeding detector  100 . A process of step S 500  in  FIG. 17  is started when power supply of image reading device  1  is turned on and document P is loaded on document loading platform  120 . 
     First, control unit  10  controls transport unit  60  (paper feeding roller  61 ) and starts a feeding operation of document P loaded on document loading platform  120  (step S 500 ). Next, control unit  10  controls transport unit  60  (separation roller  62  and retard roller  63 ) and starts a separation operation of documents P drawn into between separation roller  62  and retard roller  63  by paper feeding roller  61  (step S 520 ). 
     Next, control unit  10  acquires the detection result of flip-up detector  70  and determines whether or not document P flips up and whether or not the stapling process is applied to document P (step S 540 ). As a result of the determination, in a case where document P flips up (step S 540 , YES), control unit  10  controls transport unit  60  so as to stop the transport of document P (step S 620 ). 
     Next, control unit  10  causes information display unit  24  to display abnormal information, more specifically, information indicating the fact that the stapling process is applied to document P (step S 640 ). The process of step S 640  is completed, so that image reading device  1  completes the process in  FIG. 17 . 
     Returning to the determination of step S 540 , in a case where document P does not flip up (step S 540 , NO), control unit  10  acquires the detection result of abnormal sound detector  80  and determines whether or not the abnormal sound occurs and whether or not the stapling process is applied (step S 560 ). As a result of the determination, in a case where the abnormal sound occurs (step S 560 , YES), the process proceeds to step S 620 . 
     On the other hand, in a case where the abnormal sound does not occur (step S 560 , NO), control unit  10  acquires the detection result of double feeding detector  100  and determines whether or not double-feeding of documents P generates and whether or not the stapling process is applied (step S 580 ). As a result of the determination, in a case where the double-feeding of document P generates (step S 580 , YES), the process proceeds to step S 620 . 
     On the other hand, in a case where the double-feeding of document P does not generate (step S 580 , NO), control unit  10  determines whether or not an image reading operation of image reader  30  with respect to all documents P loaded on document loading platform  120  is completed (step S 600 ). As a result of the determination, in a case where the image reading operation is not completed (step S 600 , NO), the process proceeds to step S 540 . On the other hand, in a case where the image reading operation is completed (step S 600 , YES), image reading device  1  completes the process in  FIG. 17 . 
     In addition, all of the above-described embodiments merely illustrate an example of a concrete implementation in implementing this disclosure, and the technical scope of this disclosure should not be interpreted restrictively by them. That is, this disclosure can be implemented in various forms without departing from the gist or the main features thereof. 
     INDUSTRIAL APPLICABILITY 
     This disclosure is useful as an image reading device and a staple determination method capable of accurately determining the presence or absence of a stapling process. 
     REFERENCE MARKS IN THE DRAWINGS 
       1  IMAGE READING DEVICE 
       10  CONTROL UNIT 
       12  CPU 
       14  ROM 
       16  RAM 
       20  OPERATION DISPLAY UNIT 
       22  OPERATION INFORMATION INPUT UNIT 
       24  INFORMATION DISPLAY UNIT 
       30  IMAGE READER 
       40  AUXILIARY STORAGE UNIT 
       50  NETWORK CONNECTION UNIT 
       60  TRANSPORT UNIT 
       61  PAPER FEEDING ROLLER 
       62  SEPARATION ROLLER 
       63  RETARD ROLLER 
       64  FIRST TRANSPORT ROLLER PAIR 
       65  SECOND TRANSPORT ROLLER PAIR 
       66  THIRD TRANSPORT ROLLER PAIR 
       68  DOCUMENT TRANSPORT PATH 
       70  FLIP-UP DETECTOR 
       80  ABNORMAL SOUND DETECTOR 
       90  METAL DETECTOR 
       100  DOUBLE FEEDING DETECTOR 
       110  INCLINATION DETECTOR 
       120  DOCUMENT LOADING PLATFORM 
       130  DOCUMENT DISCHARGING UNIT 
     P DOCUMENT