JP2014043349A - Original conveying device, jam determination method and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original conveying device capable of suppressing an error of sound-dependent determination of the occurrence of jam, the error being attributable to a sound generated caused by conveyance of an original.SOLUTION: An original conveying device 100 includes: separation parts 111a, 111b, 112a and 112b; a first sound signal generation part 141a, at least a part of which is provided in a vicinity of the separation parts, and generates a first sound signal corresponding to a sound generated by the original during conveyance; second sound signal generation parts 141b and 141c, at least a part of which are provided at least at one end, in a direction perpendicular to a conveyance direction of the original, of a conveying path of the original, and generates second sound signals corresponding to the sound generated by the original during conveyance; and a sound jam determination part 153 to determine whether or not a jam has occurred based on the second sound signals. The sound jam determination part changes a determination method for the jam based on the first sound signal.

Description

  The present invention relates to an original conveying apparatus, a jam determination method, and a computer program, and more particularly, to an original conveying apparatus, a jam determination method, and a computer program for determining whether or not a jam has occurred based on a sound generated while an original is being conveyed. .

  In an original conveying apparatus such as an image reading apparatus or an image copying apparatus, a jam (paper jam) may occur when the original moves on the conveying path. In general, the document feeder determines whether or not a jam has occurred depending on whether or not the document has been transported to a predetermined position in the transport path within a predetermined time after the start of document transport. A function for stopping the operation of the apparatus is provided.

  On the other hand, when a jam occurs, a loud sound is generated in the conveyance path. Therefore, the document conveyance device does not wait for a predetermined time by determining whether or not a jam has occurred based on the sound generated in the conveyance path. It may be possible to detect the occurrence of jam.

  A jam detection device for a copying machine that converts a sound generated in a conveyance path into an electric signal and determines that a jam has occurred when a time exceeding a reference level exceeds a reference value is disclosed (Patent Document 1). See).

JP 57-169767 A

  For example, when a loud sound is generated on the conveyance path as the document is conveyed, such as when a document having wrinkles is conveyed, it may be erroneously determined that a jam has occurred.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a document conveying device, a jam determining method, and such a jam determining method capable of suppressing erroneous determination of the occurrence of jam due to sound due to sound generated along with document conveyance. It is to provide a computer program to be executed.

  A document conveying apparatus according to one aspect of the present invention is provided with a separation unit and a first sound signal that is provided at least partially near the separation unit and outputs a first sound signal corresponding to a sound generated while the document is conveyed. A second sound signal output that is provided at least at one end of the output unit and at least a part of the document transport path in a direction orthogonal to the document transport direction and outputs a second sound signal corresponding to a sound generated while the document is transported. And a sound jam determination unit that determines whether or not a jam has occurred based on the second sound signal, and the sound jam determination unit changes a jam determination method based on the first sound signal To do.

  The jam determination method according to one aspect of the present invention includes a first sound signal output unit that outputs a first sound signal corresponding to a sound generated while a document is being conveyed, at least a part of which is provided in the vicinity of the separation unit. A first sound signal acquisition step for acquiring a first sound signal from at least one of the first sound signal acquisition step and at least one end in a direction orthogonal to the document transport direction of the document transport path according to the sound generated during document transport A second sound signal acquisition step of acquiring a second sound signal from a second sound signal output unit that outputs the second sound signal; a determination step of determining whether or not a jam has occurred based on the second sound signal; In the determination step, the jam determination method is changed based on the first sound signal.

  According to another aspect of the present invention, there is provided a computer program including a first sound signal output unit that is provided at least partially in the vicinity of the separation unit and outputs a first sound signal corresponding to a sound generated while a document is being conveyed. A first sound signal obtaining step for obtaining a first sound signal; and at least a part of the first sound signal obtaining step corresponding to a sound generated during conveyance of the document, provided at least at one end in a direction orthogonal to the document conveyance direction of the document conveyance path. A second sound signal acquisition step of acquiring a second sound signal from a second sound signal output unit that outputs a two sound signal; a determination step of determining whether or not a jam has occurred based on the second sound signal; Is executed by the computer, and the determination method of the jam is changed based on the first sound signal in the determination step.

  According to the present invention, it is possible to reduce the sound generated along with the conveyance of the document based on the sound signal generated by the sound signal output unit provided in the vicinity of the separation unit of the document. It has become possible to suppress erroneous determination of the occurrence of jam due to sound.

2 is a perspective view showing a document conveying device 100. FIG. 4 is a diagram for explaining a conveyance path inside document conveying apparatus 100. FIG. FIG. 2 is a view of the document feeder 100 as viewed from above with the upper housing 102 removed. It is the figure seen from the lower side in the state which removed the upper housing | casing 102. FIG. 2 is a block diagram illustrating a schematic configuration of a document conveying apparatus 100. FIG. 4 is a flowchart showing an example of the operation of the entire process of the document feeder 100. It is a flowchart which shows the example of operation | movement of an abnormality determination process. It is a flowchart which shows the example of operation | movement of a sound jam determination process. It is a figure for demonstrating skew jam. It is a figure for demonstrating a staple jam. FIG. 10 is a diagram for describing a case where a document having wrinkles is conveyed. It is a graph which shows the 1st main outline signal about the manuscript which has a wrinkle. It is a graph which shows the sub external shape signal about the manuscript which has a wrinkle. It is a graph which shows the 1st difference signal about the manuscript which has a wrinkle. It is a graph which shows the 1st counter value about the original which has a wrinkle. It is a graph which shows the counter value about the signal of FIG. 12A. It is a graph which shows the example of the 1st main outline signal at the time of skew jam occurrence. It is a graph which shows the example of the sub external shape signal at the time of skew jam generation. It is a graph which shows the example of the 1st difference signal at the time of skew jam occurrence. It is a graph which shows the example of the 1st counter value at the time of skew jam occurrence. It is a graph which shows the 1st main outline signal at the time of staple jam generation. It is a graph which shows the sub external shape signal at the time of staple jam generation. It is a graph which shows the 1st difference signal at the time of staple jam generation. It is a graph which shows the 1st counter value at the time of staple jam generation. It is a graph which shows the 1st main external shape signal at the time of skew jam occurrence. It is a graph which shows the sub external shape signal at the time of skew jam generation. It is a graph which shows the 1st difference signal at the time of skew jam generation. It is a graph which shows the 1st counter value at the time of skew jam occurrence. It is a graph which shows the 1st main outline signal at the time of staple jam generation. It is a graph which shows the sub external shape signal at the time of staple jam generation. It is a graph which shows the 1st difference signal at the time of staple jam generation. It is a graph which shows the 1st counter value at the time of staple jam generation. It is a flowchart which shows the example of operation | movement of a position jam determination process. It is a flowchart which shows the example of operation | movement of a double feed determination process. It is a figure for demonstrating the characteristic of an ultrasonic signal. It is a flowchart which shows the other example of operation | movement of a sound jam determination process. It is a graph which shows the sub external shape signal of the original document which has a wrinkle. It is a graph which shows the 3rd counter value of the original which has a wrinkle. It is a graph which shows the 1st main outline signal of a manuscript which has a wrinkle. It is a graph which shows the 4th counter value of the manuscript which has a wrinkle. It is a graph which shows the sub external shape signal at the time of skew jam generation. It is a graph which shows the 3rd counter value at the time of skew jam occurrence. It is a graph which shows the 1st main external shape signal at the time of skew jam occurrence. It is a graph which shows the 4th counter value at the time of skew jam occurrence. It is a graph which shows the sub external shape signal at the time of staple jam generation. It is a graph which shows the 3rd counter value at the time of staple jam generation. It is a graph which shows the 1st main outline signal at the time of staple jam generation. It is a graph which shows the 4th counter value at the time of staple jam generation. It is a graph which shows the sub external shape signal at the time of skew jam generation. It is a graph which shows the 3rd counter value at the time of skew jam occurrence. It is a graph which shows the 1st main external shape signal at the time of skew jam occurrence. It is a graph which shows the 4th counter value at the time of skew jam occurrence. It is a graph which shows the sub external shape signal at the time of staple jam generation. It is a graph which shows the 3rd counter value at the time of staple jam generation. It is a graph which shows the 1st main outline signal at the time of staple jam generation. It is a graph which shows the 4th counter value at the time of staple jam generation. FIG. 5 is a view of the document feeder 200 as viewed from above with the upper housing 102 removed.

  Hereinafter, a document conveying device, a jam determination method, and a computer program according to an aspect of the present invention will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof.

  FIG. 1 is a perspective view showing a document conveying device 100 configured as an image scanner.

  The document transport apparatus 100 includes a lower casing 101, an upper casing 102, a document table 103, a discharge table 105, an operation button 106, and the like.

  The upper casing 102 is disposed at a position covering the upper surface of the document conveying apparatus 100, and is engaged with the lower casing 101 by a hinge so as to be opened and closed when the document is blocked, for example, when cleaning the inside of the document conveying apparatus 100. Yes.

  The document table 103 is engaged with the lower housing 101 so that a document can be placed thereon. The document table 103 is provided with side guides 104a and 104b that are movable in a direction perpendicular to the document conveyance direction, that is, in the left-right direction with respect to the document conveyance direction. By positioning the side guides 104a and 104b according to the width of the document, the width direction of the document can be regulated.

  The discharge table 105 is engaged with the lower casing 101 by a hinge so as to be rotatable in the direction indicated by the arrow A1, and holds the discharged document when it is opened as shown in FIG. Is possible.

  The operation button 106 is disposed on the surface of the upper casing 102 and, when pressed, generates and outputs an operation detection signal.

  FIG. 2 is a diagram for explaining a transport path inside the document transport apparatus 100.

  The conveyance path inside the document conveying apparatus 100 includes a first document detection unit 110, paper feed rollers 111a and 111b, retard rollers 112a and 112b, microphones 113a, 113b and 113c, a second document detection unit 114, an ultrasonic transmitter 115a, Ultrasonic receiver 115b, first transport rollers 116a and 116b, first driven rollers 117a and 117b, third document detection unit 118, first imaging unit 119a, second imaging unit 119b, second transport rollers 120a and 120b, and second Two driven rollers 121a and 121b are provided.

  Hereinafter, the paper feed rollers 111a and 111b are collectively referred to as the paper feed roller 111, the retard rollers 112a and 112b are collectively referred to as the retard roller 112, the first transport rollers 116a and 116b are collectively referred to as the first transport roller 116, and the first The driven rollers 117a and 117b are generally referred to as a first driven roller 117, the second transport rollers 120a and 120b are generally referred to as a second transport roller 120, and the second driven rollers 121a and 121b are generally referred to as a second driven roller 121. is there.

  The upper surface of the lower casing 101 forms a lower guide 107a of the document conveyance path, and the lower surface of the upper casing 102 forms an upper guide 107b of the document conveyance path. In FIG. 2, an arrow A2 indicates the conveyance direction of the document. Hereinafter, upstream means upstream in the document transport direction A2, and downstream means downstream in the document transport direction A2.

  The first document detection unit 110 includes a contact detection sensor disposed on the upstream side of the paper feed roller 111 and the retard roller 112, and detects whether or not a document is placed on the document table 103. The first document detection unit 110 generates and outputs a first document detection signal whose signal value changes depending on whether the document is placed on the document table 103 or not.

  The first microphone 113a, the second microphone 113b, and the third microphone 113c each collect a sound generated while the document is being conveyed, and output an analog signal generated from the collected sound. The first microphone 113 a is disposed in the vicinity of the paper feed roller 111 and the retard roller 112 and fixed to the frame 108 a inside the lower housing 103. The second microphone 113b and the third microphone 113c are arranged on the downstream side of the paper feed roller 111 and the retard roller 112 and fixed to the frame 108b inside the upper housing 102. A hole 109a is provided at a position of the lower guide 107a facing the first microphone 113a so that the first microphone 113a, the second microphone 113b, and the third microphone 113c can collect sound generated while the document is being conveyed more accurately. And holes 109b and 109c are provided at positions of the upper guide 107b facing the second microphone 113b and the third microphone 113c, respectively.

  The second document detection unit 114 includes a contact detection sensor disposed on the downstream side of the paper feed roller 111 and the retard roller 112 and on the upstream side of the first conveyance roller 116 and the first driven roller 117, and the document is located at that position. Whether or not exists is detected. The second document detection unit 114 generates and outputs a second document detection signal whose signal value changes depending on whether or not a document exists at that position.

  The ultrasonic transmitter 115a and the ultrasonic receiver 115b are examples of an ultrasonic signal output unit, and are arranged in the vicinity of the document conveyance path so as to face each other with the conveyance path interposed therebetween. The ultrasonic transmitter 115a transmits ultrasonic waves. On the other hand, the ultrasonic receiver 115b detects the ultrasonic wave transmitted by the ultrasonic transmitter 115a and passed through the document, and generates and outputs an ultrasonic signal that is an electrical signal corresponding to the detected ultrasonic wave. Hereinafter, the ultrasonic transmitter 115a and the ultrasonic receiver 115b may be collectively referred to as an ultrasonic sensor 115.

  The third document detection unit 118 includes a contact detection sensor disposed on the downstream side of the first conveyance roller 116 and the first driven roller 117 and on the upstream side of the first imaging unit 119a and the second imaging unit 119b. It detects whether or not a document exists at the position. Third document detection unit 118 generates and outputs a third document detection signal whose signal value changes depending on whether or not a document exists at that position.

  The first image pickup unit 119a has a contact image sensor (CIS) of the same magnification optical system that includes image pickup elements of CMOS (Complementary Metal Oxide Semiconductor) arranged linearly in the main scanning direction. This CIS reads the back side of a document and generates and outputs an analog image signal. Similarly, the second imaging unit 119b has an equal magnification optical system type CIS provided with CMOS imaging elements arranged linearly in the main scanning direction. This CIS reads the surface of a document and generates and outputs an analog image signal. Note that only one of the first imaging unit 119a and the second imaging unit 119b may be arranged so that only one side of the document is read. Further, instead of CIS, a reduction optical system type image sensor provided with an image sensor by CCD (Charge Coupled Device) can be used. Hereinafter, the first imaging unit 119a and the second imaging unit 119b may be collectively referred to as an imaging unit 119.

  The document placed on the document table 103 is transported in the document transport direction A2 between the lower guide 107a and the upper guide 107b as the paper feed roller 111 rotates in the direction of arrow A3 in FIG. . The retard roller 112 rotates in the direction of arrow A4 in FIG. When a plurality of documents are placed on the document table 103 by the functions of the paper feed roller 111 and the retard roller 112, only the documents that are in contact with the paper feed roller 111 among the documents placed on the document table 103. Are separated, and the conveyance of originals other than the separated originals is restricted (preventing double feeding). The paper feed roller 111 and the retard roller 112 function as a document separation unit.

  The document is fed between the first conveying roller 116 and the first driven roller 117 while being guided by the lower guide 107a and the upper guide 107b. The original is fed between the first imaging unit 119a and the second imaging unit 119b by the first conveying roller 116 rotating in the direction of the arrow A5 in FIG. The document read by the imaging unit 119 is discharged onto the discharge table 105 when the second conveyance roller 120 rotates in the direction of arrow A6 in FIG.

  FIG. 3 is a view of the document feeder 100 as viewed from above with the upper housing 102 removed, that is, a view as seen in the direction opposite to the arrow A7 in FIG.

  As shown in FIG. 3, the first microphone 113 a is provided in the vicinity of the paper feed roller 111 and the retard roller 112. The first microphone 113a is preferably provided between the paper feed rollers 111a and 111b in a direction orthogonal to the document transport direction, but is provided outside the paper feed rollers 111a and 111b in a direction orthogonal to the document transport direction. Also good.

  FIG. 4 is a view seen from the lower side with the upper casing 102 removed from the document conveying apparatus 100, that is, a view seen in the direction of the arrow A7 in FIG.

  As shown in FIG. 4, the second microphone 113b is provided at one end of the original conveyance path in the direction orthogonal to the original conveyance direction, and the third microphone 113c is provided in the direction orthogonal to the original conveyance direction of the original conveyance path. Provided at the other end.

  FIG. 5 is a block diagram illustrating a schematic configuration of the document conveying apparatus 100.

  In addition to the configuration described above, the document conveying apparatus 100 includes a first image A / D conversion unit 140a, a second image A / D conversion unit 140b, a first sound signal output unit 141a, a second sound signal output unit 141b, It further includes a three-sound signal output unit 141c, a drive unit 145, an interface unit 146, a storage unit 147, a central processing unit 150, and the like.

  The first image A / D conversion unit 140 a performs analog-digital conversion on the analog image signal output from the first imaging unit 119 a to generate digital image data, and outputs the digital image data to the central processing unit 150. Similarly, the second image A / D conversion unit 140b converts the analog image signal output from the second imaging unit 119b from analog to digital, generates digital image data, and outputs the digital image data to the central processing unit 150. Hereinafter, these digital image data are referred to as read images.

  The first sound signal output unit 141a includes a first microphone 113a, a first filter unit 142a, a first amplification unit 143a, a first sound A / D conversion unit 144a, and the like. The first filter unit 142a applies a band-pass filter that passes a signal in a predetermined frequency band to the signal output from the first microphone 113a, and outputs the signal to the first amplifying unit 143a. The first amplification unit 143a amplifies the signal output from the first filter unit 142a and outputs the amplified signal to the first sound A / D conversion unit 144a. The first sound A / D conversion unit 144 a converts the analog signal output from the first amplification unit 143 a into a digital signal and outputs the digital signal to the central processing unit 150. Hereinafter, the signal output from the first sound A / D converter 144a is referred to as a sub original signal.

  The second sound signal output unit 141b includes a second microphone 113b, a second filter unit 142b, a second amplification unit 143b, a second sound A / D conversion unit 144b, and the like. The second filter unit 142b applies a bandpass filter that passes a signal in a predetermined frequency band to the signal output from the second microphone 113b and outputs the signal to the second amplifying unit 143b. The second amplification unit 143b amplifies the signal output from the second filter unit 142b and outputs the amplified signal to the second sound A / D conversion unit 144b. The second sound A / D conversion unit 144 b converts the analog signal output from the second amplification unit 143 b into a digital signal and outputs the digital signal to the central processing unit 150. Hereinafter, the signal output from the second sound A / D converter 144b is referred to as a first main original signal.

  The third sound signal output unit 141c includes a third microphone 113c, a third filter unit 142c, a third amplification unit 143c, a third sound A / D conversion unit 144c, and the like. The third filter unit 142c applies a bandpass filter that passes a signal in a predetermined frequency band to the signal output from the third microphone 113c, and outputs the signal to the third amplifying unit 143c. The third amplification unit 143c amplifies the signal output from the third filter unit 142c and outputs the amplified signal to the third sound A / D conversion unit 144c. The third sound A / D conversion unit 144c converts the analog signal output from the third amplification unit 143c into a digital signal and outputs the digital signal to the central processing unit 150. Hereinafter, the signal output from the third sound A / D converter 144c is referred to as a second main original signal.

  The driving unit 145 includes one or a plurality of motors, and rotates the paper feeding roller 111, the retard roller 112, the first conveying roller 116, and the second conveying roller 120 according to a control signal from the central processing unit 150, so Carry out the transfer operation.

  The interface unit 146 has an interface circuit conforming to a serial bus such as a USB, for example, and is electrically connected to an information processing device (not shown) (for example, a personal computer, a portable information terminal, etc.) to display a read image and various information. Send and receive. Further, a read image may be stored by connecting a flash memory or the like to the interface unit 146.

  The storage unit 147 includes a memory device such as a RAM (Random Access Memory) and a ROM (Read Only Memory), a fixed disk device such as a hard disk, or a portable storage device such as a flexible disk and an optical disk. The storage unit 147 stores a computer program, a database, a table, and the like used for various processes of the document feeder 100. The computer program is stored in a storage unit 147 from a computer-readable portable recording medium such as a CD-ROM (compact disk read only memory) or a DVD-ROM (digital versatile disk read only memory) using a known setup program. May be installed. Further, the storage unit 147 stores the read image.

  The central processing unit 150 includes a CPU (Central Processing Unit) and operates based on a program stored in the storage unit 147 in advance. The central processing unit 150 may be configured by a digital signal processor (DSP), a large scale integration (LSI), an application specific integrated circuit (ASIC), a field-programming gate array (FPGA), or the like.

  The central processing unit 150 includes the operation button 106, the first document detection unit 110, the second document detection unit 114, the ultrasonic sensor 115, the third document detection unit 118, the first imaging unit 119a, the second imaging unit 119b, and the first. Image A / D converter 140a, second image A / D converter 140b, first sound signal output unit 141a, second sound signal output unit 141b, third sound signal output unit 141c, drive unit 145, interface unit 146, and It is connected to the storage unit 147 and controls these units.

  The central processing unit 150 performs drive control of the drive unit 145, document reading control of the imaging unit 119, and the like, and acquires a read image. The central processing unit 150 includes a control unit 151, an image generation unit 152, a sound jam determination unit 153, a position jam determination unit 154, a multifeed determination unit 155, and the like. Each of these units is a functional module implemented by software operating on the processor. Each of these units may be configured by an independent integrated circuit, a microprocessor, firmware, and the like.

  FIG. 6 is a flowchart showing an example of the operation of the entire process of the document feeder 100.

  Hereinafter, an example of the operation of the entire processing of the document conveying apparatus 100 will be described with reference to the flowchart shown in FIG. The operation flow described below is executed mainly by the central processing unit 150 in cooperation with each element of the document conveying apparatus 100 based on a program stored in the storage unit 147 in advance.

  First, the central processing unit 150 waits until the user presses the operation button 106 and receives an operation detection signal from the operation button 106 (step S101).

  Next, the central processing unit 150 determines whether or not a document is placed on the document table 103 based on the first document detection signal received from the first document detection unit 110 (step S102).

  If no document is placed on the document table 103, the central processing unit 150 returns the process to step S101 and waits until a new operation detection signal is received from the operation button 106.

  On the other hand, when the document is placed on the document table 103, the central processing unit 150 drives the drive unit 145 to rotate the paper feed roller 111, the retard roller 112, the first transport roller 116, and the second transport roller 120. Thus, the document is conveyed (step S103).

  Next, the control unit 151 determines whether or not the abnormality occurrence flag is ON (step S104). This abnormality occurrence flag is set to OFF when the document conveying apparatus 100 is activated, and is set to ON when it is determined that an abnormality has occurred in an abnormality determination process described later.

  When the abnormality occurrence flag is ON, the control unit 151 stops the driving unit 145 as the abnormality process to stop the conveyance of the document, and an abnormality is caused by a not-shown speaker, LED (Light Emitting Diode), or the like. The occurrence is notified to the user, the abnormality occurrence flag is set to OFF (step S105), and the series of steps is terminated.

  On the other hand, if the abnormality determination flag is not ON, the image generation unit 152 causes the first imaging unit 119a and the second imaging unit 119b to read the conveyed document, and the first image A / D conversion unit 140a and the second image A A read image is acquired via the / D conversion unit 140b (step S106).

  Next, the central processing unit 150 transmits the acquired read image to the information processing apparatus (not shown) via the interface unit 146 (step S107). If the information processing apparatus is not connected, the central processing unit 150 stores the acquired read image in the storage unit 147.

  Next, central processing unit 150 determines whether or not a document remains on document table 103 based on the first document detection signal received from first document detection unit 110 (step S108).

  If a document remains on the document table 103, the central processing unit 150 returns the process to step S103 and repeats the processes of steps S103 to S108. On the other hand, if no document remains on the document table 103, the central processing unit 150 ends the series of processes.

  FIG. 7 is a flowchart illustrating an example of the operation of the abnormality determination process of the document feeder 100.

  The flow of operations described below is mainly executed by the central processing unit 150 in cooperation with each element of the document feeder 100 based on a program stored in the storage unit 147 in advance.

  First, the sound jam determination unit 153 performs a sound jam determination process (step S201). The sound jam determination unit 153 determines the difference between the sub original signal acquired from the first sound signal output unit 141a and the second main original signal acquired from the second sound signal output unit 141b and the sub original signal in the sound jam determination process. And whether or not a jam has occurred is determined based on the difference between the third main signal and the third main signal acquired from the third sound signal output unit 141c. Hereinafter, the jam in which the sound jam determination unit 153 determines whether or not the sound jam occurs based on the difference between the original signals may be referred to as a sound jam. Details of the sound jam determination process will be described later.

  Next, the position jam determination unit 154 performs position jam determination processing (step S202). The position jam determination unit 154 generates a jam based on the second document detection signal acquired from the second document detection unit 114 and the third document detection signal acquired from the third document detection unit 118 in the position jam determination process. Determine whether or not. Hereinafter, the jam in which the position jam determination unit 154 determines whether or not it occurs based on the second document detection signal and the third document detection signal may be referred to as a position jam. Details of the position jam determination process will be described later.

  Next, the double feed determination unit 155 performs a double feed determination process (step S203). In the double feed determination process, the double feed determination unit 155 determines whether double feed of the document has occurred based on the ultrasonic signal acquired from the ultrasonic sensor 115. Details of the double feed determination process will be described later.

  Next, the control unit 151 determines whether or not an abnormality has occurred in the document conveyance process (step S204). The control unit 151 determines that an abnormality has occurred when at least one of a sound jam, a position jam, and a document double feed has occurred. That is, it is determined that no abnormality has occurred only when none of the sound jam, the position jam, or the double feed of the document has occurred.

  When an abnormality occurs in the document conveyance process, the control unit 151 sets the abnormality occurrence flag to ON (step S205) and ends a series of steps. On the other hand, if no abnormality has occurred in the document conveying process, no particular process is performed and the series of steps is terminated. Note that the flowchart shown in FIG. 7 is executed at predetermined time intervals.

  FIG. 8 is a flowchart showing an example of the operation of the sound jam determination process.

  The operation flow shown in FIG. 8 is executed in step S201 of the flowchart shown in FIG.

  First, the sound jam determination unit 153 acquires the sub original signal from the first sound signal output unit 141a, acquires the first main original signal from the second sound signal output unit 141b, and outputs the first main signal from the third sound signal output unit 141c. A second main original signal is acquired (step S301).

  Next, the sound jam determination unit 153 determines the sub absolute value signal obtained from the absolute value of the sub original signal, the first main absolute value signal obtained from the absolute value of the first main original signal, and the second main original signal. A second main absolute value signal having an absolute value is generated (step S302).

  Next, the sound jam determination unit 153 extracts the sub external shape signal obtained by extracting the external shape of the sub absolute value signal, the first main external shape signal obtained by extracting the external shape of the first main absolute value signal, and the external shape of the second main absolute value signal. The second main outline signal is extracted (step S303). The sound jam determination unit 153 takes the peak hold for the sub absolute value signal, the first main absolute value signal, and the second main absolute value signal as the sub external shape signal, the first main external shape signal, and the second main external shape signal, respectively. Is generated. The sound jam determination unit 153 generates each outline signal by holding the local maximum value of each absolute value signal for a fixed hold period and then attenuating it at a constant attenuation rate.

  Next, the sound jam determination unit 153 generates a first difference signal that represents the difference between the first main outline signal and the sub outline signal, and a second difference signal that represents the difference between the second main outline signal and the sub outline signal. (Step S304). The sound jam determination unit 153 calculates a difference between signal values at the same time for the first main outline signal and the sub outline signal, and generates a signal in which the calculated differences are arranged in time order as a first difference signal. In addition, when the difference of signal value takes a negative value less than 0, the difference of signal value is set to 0. Similarly, the sound jam determination unit 153 calculates a signal value difference at the same time for the second main outline signal and the sub outline signal, and generates a signal in which the calculated differences are arranged in time order as a second difference signal.

  Next, the sound jam determination unit 153 calculates a first counter value that increases when the signal value of the first difference signal is equal to or greater than the first threshold Th1 and decreases when the signal value is less than the first threshold Th1. To do. Similarly, the sound jam determination unit 153 calculates a second counter value that increases when the signal value of the second difference signal is equal to or greater than the first threshold Th1 and decreases when the signal value is less than the first threshold Th1. (Step S305).

  The sound jam determination unit 153 determines whether the signal value of the first difference signal is greater than or equal to the first threshold Th1 at every predetermined time interval (for example, the sampling interval of the sound signal). When the signal value is equal to or greater than the first threshold value Th1, the first counter value is incremented. When the signal value is less than the first threshold value Th1, the first counter value is decremented. Similarly, the sound jam determination unit 153 determines whether the signal value of the second difference signal is equal to or greater than the first threshold Th1 at every predetermined time interval, and the signal value of the second difference signal is the first value. If the threshold value Th1 is equal to or greater than the threshold value Th1, the second counter value is incremented.

  Next, the sound jam determination unit 153 determines whether at least one of the first counter value and the second counter value is equal to or greater than the second threshold Th2 (step S306). The sound jam determination unit 153 determines that a sound jam has occurred if at least one of the first counter value and the second counter value is equal to or greater than the second threshold Th2 (step S307). On the other hand, if both the first counter value and the second counter value are less than the second threshold value Th2, the sound jam determination unit 153 determines that no sound jam has occurred (step S308), and ends the series of steps. To do.

  The sound jam determination unit 153 determines whether or not a jam has occurred based on the difference obtained by subtracting the sub external shape signal from the first main external shape signal and the second main external shape signal. That is, the sound jam determination unit 153 determines whether or not a jam has occurred based on the first main contour signal and the second main contour signal, and changes the determination method for the jam based on the sub contour signal. Yes.

  In addition, the 1st sound signal output part 141a is not limited to the structure shown in FIG. The first sound signal output unit 141a includes only the first microphone 113a, and the first filter unit 142a, the first amplification unit 143a, and the first sound A / D conversion unit 144a are provided outside the first sound signal output unit 141a. It may be provided. The first sound signal output unit 141a may include only the first microphone 113a and the first filter unit 142a, or only the first microphone 113a, the first filter unit 142a, and the first amplification unit 143a. Furthermore, the first sound signal output unit 141a may include an absolute value signal generation unit that generates a first absolute value signal from the first original signal in addition to the units illustrated in FIG. Further, in addition to the components shown in FIG. 4, the first sound signal output unit 141a includes an absolute value signal generation unit that generates a sub absolute value signal from the sub original signal, and an external shape that generates the sub external shape signal from the sub absolute value signal. A signal generation unit may be provided.

  Similarly, the second sound signal output unit 141b is not limited to the configuration shown in FIG. The second sound signal output unit 141b includes only the second microphone 113b, and the second filter unit 142b, the second amplification unit 143b, and the second sound A / D conversion unit 144b are provided outside the second sound signal output unit 141b. It may be provided. The second sound signal output unit 141b may include only the second microphone 113b and the second filter unit 142b, or only the second microphone 113b, the second filter unit 142b, and the second amplification unit 143b. Further, the second sound signal output unit 141b may include an absolute value signal generation unit that generates a second absolute value signal from the second original signal in addition to the units illustrated in FIG. Further, the second sound signal output unit 141b includes an absolute value signal generation unit that generates a first main absolute value signal from the first main original signal, and a first main absolute value signal from the first main absolute value signal, in addition to the units shown in FIG. You may provide the external shape signal production | generation part which produces | generates 1 main external shape signal.

  Similarly, the third sound signal output unit 141c is not limited to the configuration shown in FIG. The third sound signal output unit 141c includes only the third microphone 113c, and the third filter unit 142c, the third amplification unit 143c, and the third sound A / D conversion unit 144c are provided outside the third sound signal output unit 141c. It may be provided. The third sound signal output unit 141c may include only the third microphone 113c and the third filter unit 142c, or only the third microphone 113c, the third filter unit 142c, and the third amplification unit 143c. Furthermore, the third sound signal output unit 141c may include an absolute value signal generation unit that generates a second main absolute value signal from the second main original signal in addition to the units shown in FIG. Further, the third sound signal output unit 141c includes, in addition to the units shown in FIG. 5, an absolute value signal generation unit that generates a second main absolute value signal from the second main original signal and a second main absolute value signal. You may provide the external shape signal production | generation part which produces | generates 2 main external shape signals.

  In addition, the sound jam determination unit 153 determines a difference obtained by subtracting the signal output from the first microphone 113a from the signal output from the second microphone 113b and the signal output from the first microphone 113a from the signal output from the third microphone 113c. Based on the subtracted difference, it may be determined whether or not a jam has occurred. In that case, a predetermined band-pass filter is applied to the difference signal obtained by subtracting the signal output from the first microphone 113a from the signal output from the second microphone 113b, and then amplified, digitally converted, and the outer shape is extracted to determine the jam. To use. Similarly, a predetermined band-pass filter is applied to the difference signal representing the difference obtained by subtracting the signal output from the first microphone 113a from the signal output from the third microphone 113c, amplified, digitally converted, and the outer shape is extracted. And use it for jam detection.

  In addition, the sound jam determination unit 153 is configured such that the first filter unit 142a determines the difference between the signal output from the first filter unit 142a from the signal output from the second filter unit 142b and the signal output from the third filter unit 142c. Whether or not a jam has occurred may be determined based on the difference obtained by subtracting the output signal. In that case, the differential signal obtained by subtracting the signal output from the first filter unit 142a from the signal output from the second filter unit 142b is amplified, digitally converted, the outer shape is extracted, and used for jam determination. Similarly, a differential signal obtained by subtracting the signal output from the first filter unit 142a from the signal output from the third filter unit 142c is amplified, digitally converted, the outer shape is extracted, and used for jam determination.

  In addition, the sound jam determination unit 153 is configured such that the first amplification unit 143a determines the difference obtained by subtracting the signal output from the first amplification unit 143a from the signal output from the second amplification unit 143b and the signal output from the third amplification unit 143c. Whether or not a jam has occurred may be determined based on the difference obtained by subtracting the output signal. In that case, the differential signal obtained by subtracting the signal output from the first amplifying unit 143a from the signal output from the second amplifying unit 143b is digitally converted, and the outer shape is extracted and used for jam determination. Similarly, the difference signal obtained by subtracting the signal output from the first amplifying unit 143a from the signal output from the third amplifying unit 143c is digitally converted, and the outer shape is extracted and used for jam determination.

  Further, the sound jam determination unit 153 determines whether or not a jam has occurred based on a difference obtained by subtracting the sub original signal from the first main original signal and a difference obtained by subtracting the sub original signal from the second main original signal. You may judge. In this case, the sound jam determination unit 153 extracts the outer shape of the difference signal obtained by subtracting the sub original signal from the first main original signal and uses it for the jam determination. Similarly, the sound jam determination unit 153 extracts the outer shape of the difference signal obtained by subtracting the sub original signal from the second main original signal and uses it for the jam determination.

  The sound jam determination unit 153 generates a jam based on a difference obtained by subtracting the sub absolute value signal from the first main absolute value signal and a difference obtained by subtracting the sub absolute value signal from the second main absolute value signal. It may be determined whether or not. In this case, the sound jam determination unit 153 extracts the outer shape of the difference signal obtained by subtracting the sub absolute value signal from the first main absolute value signal and uses it for the jam determination. Similarly, the sound jam determination unit 153 extracts the outer shape of the difference signal obtained by subtracting the sub absolute value signal from the second main absolute value signal and uses it for the jam determination.

  Hereinafter, the significance of changing the jam determination method based on the sub contour signal will be described.

  FIG. 9 is a diagram for explaining skew jam.

  As shown in FIG. 9, when the document P is conveyed while being inclined with respect to the document conveyance direction, the rear end of the document P gets over the side guide 104 a on the document table 103. When the document P is further conveyed, the edge of the document P collides with the side wall of the document conveyance path at a position L1 in the vicinity of the position where the lower housing 101 and the document table 103 are engaged, and a loud sound is produced. Occur. The occurrence of a jam as a result of the document being conveyed at an incline is called skew jam.

  FIG. 10 is a diagram for explaining the staple jam.

  FIG. 10 shows an example in which the original P bound by the staple S is conveyed with the bound portion directed downstream. When a plurality of originals are stapled, one of the four corners of the original is generally stapled. When the document P bound by the staple S is transported by the document transport device 100 with the bound portion facing downstream, the paper feed roller 111 of the document P is fed by the paper feed roller 111 and the retard roller 112. Only the document P1 that is in contact with the paper is about to be conveyed. However, documents other than the document P1 are not conveyed because they are bound by the staple S.

  Accordingly, the document P1 rotates around the staple S, and the rear end of the document P1 gets over the side guide 104b on the document table 103. When the document P1 further rotates, the edge of the document P1 collides with the side wall of the document transport path at a position L2 near the position where the lower casing 101 and the document table 103 are engaged, and a loud sound is generated. . Further, the document P1 is also distorted and wrinkled at a position L3 around the portion bound by the staple S, and a loud sound is generated. The occurrence of a jam as a result of transporting an original document stapled in this manner is called a staple jam.

  FIG. 11 is a diagram for explaining a case where a document having wrinkles is conveyed.

  As shown in FIG. 11, when a document P having wrinkles is conveyed, even if no jam occurs when the document P passes between the feed roller 111 and the retard roller 112, a loud sound is generated by the wrinkles. Occur. The first microphone 113a, the second microphone 113b, and the third microphone 113c collect sound generated by the wrinkles.

  In particular, the first microphone 113a disposed in the vicinity of the paper feed roller 111 and the retard roller 112 collects a loud sound generated by wrinkles. On the other hand, since the second microphone 113b and the third microphone 113c are arranged at positions away from the paper feed roller 111 and the retard roller 112, the sound generated by the wrinkles is not collected as loud as the first microphone 113a.

  FIG. 12 is a graph showing an example of each signal regarding sound jam determination when a document having wrinkles is conveyed.

  12A, 12B, 12C, and 12D, the horizontal axis indicates time, the vertical axes in FIGS. 12A, 12B, and 12C indicate signal values, and the vertical axis in FIG. 12D indicates counter values. The graph of FIG. 12A represents an example of a first main absolute value signal 1201 when a document having wrinkles is conveyed and a first main outline signal 1202 generated from the first main absolute value signal 1201 (FIG. 8). (See steps S302 and S303). The graph of FIG. 12B represents an example of a sub absolute value signal 1211 when a document having wrinkles is conveyed and a sub external shape signal 1212 generated from the sub absolute value signal 1211 (see steps S302 and S303 in FIG. 8). . The graph of FIG. 12C represents an example of the first main outline signal 1202 and the first difference signal 1221 generated from the sub outline signal 1212 (see step S304 in FIG. 8). The graph in FIG. 12D represents an example of the first counter value 1231 calculated for the first difference signal 1221 (see step S305 in FIG. 8).

  As shown in FIGS. 12A and 12B, the sub external shape signal 1212 based on the sound collected by the first microphone 113a has a certain degree of comparison with the first main external shape signal 1202 based on the sound collected by the second microphone 113b. It has a size. As shown in FIG. 12C, the signal value of the first difference signal 1221 is not frequently equal to or higher than the first threshold Th1. Therefore, as shown in FIG. 12D, the first counter value 1231 does not exceed the second threshold Th2, and it is not determined that a sound jam has occurred when a document having wrinkles is conveyed.

  Since the first difference signal 1221 is generated by subtracting the sub outer shape signal 1212 from the first main outer shape signal 1202, it is a signal obtained by substantially removing the sound component generated by the wrinkle of the document. Similarly, since the second differential signal is generated by subtracting the sub contour signal from the second main contour signal, the second difference signal is a signal obtained by substantially removing the sound component generated by the wrinkles of the document. Here, “the sound component generated by the wrinkle of the original” means that the original having wrinkles out of the signal values based on the sound collected by the second microphone 113b or the third microphone 113c is the paper feed roller 111. It means a portion that becomes higher due to the sound generated when it passes between the retard roller 112. “Signal in which the sound component generated by the wrinkle of the document is substantially removed” means that the influence of the sound generated by the wrinkle of the document from each signal based on the sound collected by the second microphone 113b or the third microphone 113c is reduced. Signal. The sound jam determination unit 153 determines whether or not a jam has occurred based on the difference signal that “substantially removes the sound component generated by the wrinkles of the document”, so that the jam determination is performed based on the sound generated by the wrinkles of the document. Errors can be suppressed.

  FIG. 13 is a graph showing a counter value 1301 calculated for the first main outline signal 1202 of FIG. 12A.

  In FIG. 13, the horizontal axis represents time, and the vertical axis represents the counter value. In FIG. 13, the counter value 1301 is calculated so that the first main outline signal 1202 is increased when it is equal to or greater than the first threshold Th1, and is decreased when it is less than the first threshold Th1. As shown in FIG. 13, the counter value 1301 calculated for the first main outline signal 1202 is equal to or greater than the second threshold Th2 at time T1. That is, when it is determined whether or not a jam has occurred based on only one of the sound collected by the second microphone 113b and the sound collected by the third microphone 113c, the jam is caused by the sound generated by the wrinkle of the document. There is a possibility of misjudgment of occurrence.

  FIG. 14 is a graph showing an example of each signal regarding sound jam determination when a document having no wrinkles is conveyed and the skew jam shown in FIG. 9 occurs.

  14A, 14B, 14C, and 14D, the horizontal axis indicates time, the vertical axes in FIGS. 14A, 14B, and 14C indicate signal values, and the vertical axis in FIG. 14D indicates counter values. The graph of FIG. 14A shows a first main absolute value signal 1401 and a first main outline signal 1402 generated from the first main absolute value signal 1401 when a document having no wrinkles is conveyed and skew jam occurs. An example is shown. The graph of FIG. 14B shows an example of a sub absolute value signal 1411 and a sub external shape signal 1412 generated from the sub absolute value signal 1411 when a document having no wrinkles is conveyed and skew jam occurs. The graph of FIG. 14C represents an example of the first main outline signal 1402 and the first difference signal 1421 generated from the sub outline signal 1412. The graph of FIG. 14D represents an example of the first counter value 1431 calculated for the first difference signal 1421.

  When the skew jam shown in FIG. 9 occurs, the sound generated by the skew jam is collected well by the second microphone 113b near the position L1, but the second microphone 113b is collected by the first microphone 113a far from the position L1. Sounds that are not so loud are not collected.

  Accordingly, as shown in FIGS. 14A and 14B, the first main outline signal 1402 based on the sound collected by the second microphone 113b is generally more than the sub outline signal 1412 based on the sound collected by the first microphone 113a. Taking a large value. As shown in FIG. 14C, the signal value of the first differential outline signal 1421 becomes equal to or higher than the first threshold Th1 at time T2, and then frequently becomes equal to or higher than the first threshold Th1. As shown in FIG. 14D, the first counter value 1431 increases from time T2, and after that, while increasing and decreasing, becomes the second threshold value Th2 or more at time T3, and it is determined that a sound jam has occurred.

  FIG. 15 is a graph showing an example of each signal for sound jam determination when a document having no wrinkles is conveyed and the staple jam shown in FIG. 10 occurs.

  The horizontal axis of FIGS. 15A, 15B, 15C, and 15D indicates time, the vertical axis of FIGS. 15A, 15B, and 15C indicates a signal value, and the vertical axis of FIG. 15D indicates a counter value. The graph of FIG. 15A represents an example of a first main absolute value signal 1501 and a first main external shape signal 1502 generated from the first main absolute value signal 1501 when a staple jam occurs. The graph of FIG. 15B represents an example of a sub absolute value signal 1511 when a staple jam occurs and a sub external shape signal 1512 generated from the sub absolute value signal 1511. The graph of FIG. 15C represents an example of the first main outline signal 1502 and the first difference signal 1521 generated from the sub outline signal 1512. The graph of FIG. 15D represents an example of the first counter value 1531 calculated for the first difference signal 1521.

  When the staple jam shown in FIG. 10 occurs, the sound generated by the staple jam is collected well by the third microphone 113c near the position L2 and the second microphone 113b near the position L3. On the other hand, in the first microphone 113a far from both the position L2 and the position L3, the sound generated by the staple jam is not collected as loud as the second microphone 113b and the third microphone 113c.

  Therefore, as shown in FIGS. 15A and 15B, the first main outline signal 1502 based on the sound collected by the second microphone 113b is generally more than the sub outline signal 1512 based on the sound collected by the first microphone 113a. Taking a large value. As shown in FIG. 15C, the signal value of the first difference signal 1521 is frequently equal to or higher than the first threshold Th1. As shown in FIG. 15D, the first counter value 1531 becomes equal to or greater than the second threshold Th2 at time T4, and it is determined that a sound jam has occurred.

  When a folded document is transported, the folded portion works in the same way as a stapled portion, causing jamming, and generating a loud sound at both ends of the document transport path. . For this reason, the document conveying apparatus 100 can determine that a sound jam has occurred even when a jammed document is conveyed after the folded document is conveyed, as in the case of a staple jam.

  FIG. 16 is a graph illustrating an example of each signal regarding sound jam determination when a document having wrinkles is conveyed and skew jam occurs.

  The horizontal axis of FIGS. 16A, 16B, 16C, and 16D indicates time, the vertical axis of FIGS. 16A, 16B, and 16C indicates a signal value, and the vertical axis of FIG. 16D indicates a counter value. The graph of FIG. 16A shows an example of a first main absolute value signal 1601 and a first main outline signal 1602 generated from the first main absolute value signal 1601 when a skewed document is conveyed and skew jam occurs. Represent. The graph of FIG. 16B shows an example of the sub absolute value signal 1611 and the sub external shape signal 1612 generated from the sub absolute value signal 1611 when a skew jam occurs when a document having wrinkles is conveyed. The graph of FIG. 16C represents an example of the first difference signal 1621 generated from the first main outline signal 1602 and the sub outline signal 1612. The graph of FIG. 16D represents an example of the first counter value 1631 calculated for the first difference signal 1621.

  As shown in FIG. 16C, the first difference signal 1621 is smaller than the first main outline signal 1602 in FIG. 16A because the sound generated by the wrinkles of the document is substantially removed. However, since the sound generated by the skew jam is sufficiently loud, as shown in FIG. 16D, the counter value 1631 becomes equal to or greater than the second threshold Th2 at time T5, and it is determined that the sound jam has occurred.

  FIG. 17 is a graph showing an example of each signal regarding sound jam determination when a document having wrinkles is conveyed and staple jam occurs.

  The horizontal axis of FIGS. 17A, 17B, 17C, and 17D represents time, the vertical axis of FIGS. 17A, 17B, and 17C represents the signal value, and the vertical axis of FIG. 17D represents the counter value. The graph of FIG. 17A shows an example of a first main absolute value signal 1701 and a first main external shape signal 1702 generated from the first main absolute value signal 1701 when a skewed document is conveyed and skew jam occurs. Represent. The graph of FIG. 17B shows an example of a sub absolute value signal 1711 and a sub external shape signal 1712 generated from the sub absolute value signal 1711 when a document having wrinkles is conveyed and skew jam occurs. The graph of FIG. 17C represents an example of the first difference signal 1721 generated from the first main outline signal 1702 and the sub outline signal 1712. The graph of FIG. 17D represents an example of the first counter value 1731 calculated for the first difference signal 1721.

  As shown in FIG. 17C, the first difference signal 1721 is smaller than the first main outline signal 1702 in FIG. 17A because the sound generated by the wrinkles of the document is substantially removed. However, since the sound generated by the staple jam is sufficiently loud, as shown in FIG. 17D, the counter value 1731 becomes equal to or greater than the second threshold Th2 at time T6, and it is determined that a sound jam has occurred.

  As described above, the sound jam determination unit 153 does not determine that a sound jam has occurred when a skew jam and a staple jam have not occurred even when a document having wrinkles is conveyed. On the other hand, when a jam or a staple jam occurs, the sound jam determination unit 153 can determine that a sound jam has occurred regardless of whether the document has wrinkles.

  Note that one of the second microphone 113b and the third microphone 113c may be omitted, and the sound jam determination may be omitted for either one of the first main original signal and the second main original signal. As described above, when a staple jam occurs, a loud sound is generated at both ends of the document conveyance path. Even in this case, the staple jam can be detected with high accuracy.

  FIG. 18 is a flowchart illustrating an example of the operation of the position jam determination process.

  The operation flow shown in FIG. 18 is executed in step S202 of the flowchart shown in FIG.

  First, the position jam determination unit 154 waits until the second document detection unit 114 detects the leading edge of the document (step S401). When the value of the second document detection signal from the second document detection unit 114 changes from a value indicating the state where no document exists to a value indicating the state where the document exists, the position jam determination unit 154 It is determined that the leading edge of the document is detected at the position, that is, downstream of the paper feed roller 111 and the retard roller 112 and upstream of the first transport roller 116 and the first driven roller 117.

  Next, when the leading edge of the document is detected by the second document detection unit 114, the position jam determination unit 154 starts measuring time (step S402).

  Next, the position jam determination unit 154 determines whether or not the leading edge of the document is detected by the third document detection unit 118 (step S403). When the value of the third document detection signal from the third document detection unit 118 changes from the value indicating the state where no document exists to the value indicating the state where the document exists, the position jam determination unit 154 It is determined that the leading edge of the document is detected at the position, that is, downstream of the first conveying roller 116 and the first driven roller 117 and upstream of the imaging unit 119.

  When the third document detection unit 118 detects the leading edge of the document, the position jam determination unit 154 determines that no position jam has occurred (step S404), and ends a series of steps.

  On the other hand, if the leading edge of the document is not detected by the third document detection unit 118, the position jam determination unit 154 determines whether or not a predetermined time (for example, 1 second) has elapsed since the start of time measurement (step 1) S405). If the predetermined time has not elapsed, the position jam determination unit 154 returns the process to step S403, and again determines whether the third document detection unit 118 has detected the leading edge of the document. On the other hand, when the predetermined time has elapsed, the position jam determination unit 154 determines that a position jam has occurred (step S406), and ends a series of steps. If the position detection process is not required in the document feeder 100, it may be omitted.

  When central processing unit 150 detects the leading edge of the document downstream of first conveyance roller 116 and first driven roller 117 based on the third document detection signal from third document detection unit 118, the next document is sent. The rotation of the paper feed roller 111 and the retard roller 112 is stopped by controlling the one-end driving unit 145 so that there is no such problem. Thereafter, when the central processing unit 150 detects the trailing edge of the document downstream of the paper feed roller 111 and the retard roller 112 based on the second document detection signal from the second document detection unit 114, the central processing unit 150 controls the drive unit 145 again. The paper feed roller 111 and the retard roller 112 are rotated to convey the next document. As a result, the central processing unit 150 prevents a plurality of documents from overlapping in the conveyance path. Therefore, the position jam determination unit 154 starts timing when the central processing unit 150 controls the drive unit 145 to rotate the paper feed roller 111 and the retard roller 112, and the third document detection unit 118 within a predetermined time. If the leading edge of the document is not detected in step 1, it may be determined that a position jam has occurred.

  FIG. 19 is a flowchart illustrating an example of the operation of the double feed determination process.

  The operation flow shown in FIG. 19 is executed in step S203 of the flowchart shown in FIG.

  First, the double feed determination unit 155 acquires an ultrasonic signal from the ultrasonic sensor 115 (step S501).

  Next, the multifeed determination unit 155 determines whether or not the signal value of the acquired ultrasonic signal is less than a multifeed determination threshold (step S502).

  FIG. 20 is a diagram for explaining the characteristics of the ultrasonic signal.

  In the graph 2000 of FIG. 20, a solid line 2001 indicates the characteristic of the ultrasonic signal when a single original is being conveyed, and a dotted line 2002 indicates the characteristic of the ultrasonic signal when the double feeding of the original is occurring. The horizontal axis of the graph 2000 indicates time, and the vertical axis indicates the signal value of the ultrasonic signal. Due to the occurrence of double feed, the signal value of the ultrasonic signal of the dotted line 2002 is lowered in the section 2003. For this reason, it is possible to determine whether or not a document double feed has occurred depending on whether or not the signal value of the ultrasonic signal is less than the double feed determination threshold ThA.

  If the signal value of the ultrasonic signal is less than the double feed determination threshold, the double feed determination unit 155 determines that a double feed of the document has occurred (step S503), while the signal value of the ultrasonic signal is determined to be double feed. If it is equal to or greater than the threshold value, it is determined that no double feed of the document has occurred (step S504), and the series of steps is terminated. It should be noted that if the multi-feed determination process is not required in the document feeder, it may be omitted.

  As described in detail above, the document conveying apparatus 100 operates according to the flowcharts shown in FIGS. 6, 7, and 9, so that the first microphone 113 a provided in the vicinity of the paper feed roller 111 and the retard roller 112 is provided. Based on the sub-original signal generated from the collected sound, it is possible to substantially eliminate the sound generated when the document is conveyed, particularly the sound generated by the wrinkle of the document. Therefore, the document conveying apparatus 100 can suppress erroneous determination of the occurrence of jam due to sound due to the sound generated as the document is conveyed.

  FIG. 21 is a flowchart showing another example of the sound jam determination process.

  This flowchart can be executed in the document feeder 100 in place of the flowchart shown in FIG. In the flowchart illustrated in FIG. 21, unlike the flowchart illustrated in FIG. 9, the sound jam determination unit 153 replaces the sound jam determination based on the first difference signal and the second difference signal with the first main original signal and Sound jam determination is performed based on the second main original signal. The sound jam determination unit 153 determines whether or not the document has wrinkles based on the sub-original signal, and changes the jam determination method when determining that the document has wrinkles.

  First, the sound jam determination unit 153 acquires a sub original signal from the first sound signal output unit 141a (step S701).

  Next, the sound jam determination unit 153 generates a sub absolute value signal obtained by taking an absolute value for the sub original signal (step S702).

  Next, the sound jam determination unit 153 generates a sub contour signal obtained by extracting the contour of the sub absolute value signal (step S703).

  Next, the sound jam determination unit 153 calculates a third counter value that is increased when the sub contour signal is equal to or greater than the first threshold Th1 and is decreased when it is less than the first threshold Th1 (step S704). ).

  Next, the sound jam determination unit 153 determines whether or not the third counter value is greater than or equal to the third threshold Th3 (step S705). If the third counter value is equal to or greater than the third threshold value Th3, the sound jam determination unit 153 determines that the conveyed document has wrinkles (step S706), and sets the fourth threshold value Th4 and the fifth threshold value Th5. The value is changed to a predetermined value larger than the normal value (step S707). Details of the fourth threshold Th4 and the fifth threshold Th5 will be described later. On the other hand, if the third counter value is less than the third threshold Th3, the sound jam determination unit 153 determines that the conveyed document does not have wrinkles (step S708).

  Next, the sound jam determination unit 153 acquires the first main original signal from the second sound signal output unit 141b, and acquires the second main original signal from the third sound signal output unit 141c (step S709).

  Next, the sound jam determination unit 153 generates a first main absolute value signal that takes an absolute value for the first main original signal and a second main absolute value signal that takes an absolute value for the second main original signal. (Step S710).

  Next, the sound jam determination unit 153 generates a first main outline signal obtained by extracting the outline of the first main absolute value signal, and a second main outline signal obtained by extracting the outline of the second main absolute value signal (Step). S711).

  Next, the sound jam determination unit 153 calculates a fourth counter value that is increased when the first main outline signal is equal to or greater than the first threshold Th1 and is decreased when it is less than the first threshold Th1. Similarly, the sound jam determination unit 153 calculates a fifth counter value that is increased when the second main outline signal is equal to or greater than the first threshold Th1 and is decreased when it is less than the first threshold Th1 ( Step S712).

  Next, the sound jam determination unit 153 determines whether or not at least one of the fourth counter value and the fifth counter value is equal to or greater than a fourth threshold Th4 (step S713). The sound jam determination unit 153 determines that a sound jam has occurred if at least one of the fourth counter value and the fifth counter value is equal to or greater than the fourth threshold Th4 (step S714). On the other hand, if both the fourth counter value and the fifth counter value are less than the fourth threshold Th4, the sound jam determination unit 153 determines that no sound jam has occurred (step S715), and ends the series of steps. To do.

  Note that the sound jam determination unit 153 increments the fourth counter value and the fifth counter value instead of changing the fourth threshold value Th4 and the fifth threshold value Th5 to a predetermined value larger than the normal value in step S707. Alternatively, the first threshold Th1 for determining whether to decrement may be changed to a predetermined value larger than the normal value.

  FIG. 22 is a graph showing an example of each signal for sound jam determination when a document having wrinkles is conveyed and no jam has occurred.

  22A, 22B, 22C, and 22D, the horizontal axis indicates time, the vertical axes in FIGS. 22A and 22C indicate signal values, and the vertical axes in FIGS. 22B and 22D indicate counter values. The graph of FIG. 22A represents an example of a sub absolute value signal 2201 when a document having wrinkles is conveyed and a jam does not occur, and a sub external shape signal 2202 generated from the sub absolute value signal 2201 (FIG. 21). Steps S702 and S703). The graph of FIG. 22B represents an example of the third counter value 2211 calculated for the sub external shape signal 2202 (see step S704 of FIG. 21). The graph of FIG. 22C shows a first main absolute value signal 2221 and a first main external shape signal 2222 generated from the first main absolute value signal 2221 when a document having wrinkles is conveyed and a jam does not occur. An example is shown (see steps S710 and S711 in FIG. 21). The graph of FIG. 22D represents an example of the fourth counter value 2231 calculated for the first main outline signal 2222 (see step S712 of FIG. 21).

  As shown in FIG. 22A, the signal value of the sub external shape signal 2202 is frequently equal to or higher than the first threshold Th1 due to the sound generated by the paper feed roller 111 and the retard roller 112 due to the wrinkled original. As shown in FIG. 22B, the third counter value becomes equal to or greater than the third threshold Th3 at time T7, and it is determined that the document has wrinkles. Therefore, in this case, the fourth threshold Th4 is changed at time T7.

  On the other hand, as shown in FIG. 22C, the signal value of the first main outline signal 2222 frequently becomes equal to or higher than the first threshold Th1 due to the sound generated by the paper feed roller 111 and the retard roller 112 due to the wrinkled document. Yes. However, as shown in FIG. 22D, since the fourth threshold value Th4 is changed to a large value at time T7, the fourth counter value does not exceed the fourth threshold value Th4, and a document having wrinkles is conveyed. It is not determined that a sound jam has occurred.

  FIG. 23 is a graph showing an example of each signal regarding sound jam determination when a document having no wrinkles is conveyed and skew jam occurs.

  The horizontal axes of FIGS. 23A, 23B, 23C, and 23D indicate time, the vertical axes of FIGS. 23A and 23C indicate signal values, and the vertical axes of FIGS. 23B and 23D indicate counter values. The graph of FIG. 23A shows an example of a sub absolute value signal 2301 and a sub external shape signal 2302 generated from the sub absolute value signal 2301 when a document having no wrinkles is conveyed and skew jam occurs. The graph of FIG. 23B represents an example of the third counter value 2311 calculated for the sub external shape signal 2302. The graph of FIG. 23C shows the first main absolute value signal 2321 and the first main external shape signal 2322 generated from the first main absolute value signal 2321 when a document having no wrinkles is conveyed and skew jam occurs. An example is shown. The graph of FIG. 23D represents an example of the fourth counter value 2331 calculated for the first main outline signal 2322.

  As shown in FIG. 23A, since the conveyed document does not have wrinkles, the signal value of the sub external shape signal 2302 is not frequently equal to or higher than the first threshold Th1. As shown in FIG. 23B, the third counter value 2311 does not exceed the third threshold Th3, and it is determined that the document does not have wrinkles. Therefore, in this case, the fourth threshold Th4 is not changed.

  On the other hand, as shown in FIG. 23C, the signal value of the first main absolute value signal 2321 is frequently greater than or equal to the first threshold Th1 due to the sound generated by the skew jam. Therefore, as shown in FIG. 23D, the fourth counter value 2331 becomes equal to or greater than the fourth threshold Th4 at time T8, and it is determined that a sound jam has occurred.

  FIG. 24 is a graph showing an example of each signal for sound jam determination when a document having no wrinkles is conveyed and staple jam occurs.

  The horizontal axes of FIGS. 24A, 24B, 24C, and 24D indicate time, the vertical axes of FIGS. 24A and 24C indicate signal values, and the vertical axes of FIGS. 24B and 24D indicate counter values. The graph of FIG. 24A shows an example of a sub absolute value signal 2401 and a sub external shape signal 2402 generated from the sub absolute value signal 2401 when a document having no wrinkles is conveyed and a staple jam occurs. The graph of FIG. 24B represents an example of the third counter value 2411 calculated for the sub external shape signal 2402. The graph of FIG. 24C shows a first main absolute value signal 2421 and a first main external shape signal 2422 generated from the first main absolute value signal 2421 when a document having no wrinkles is conveyed and a staple jam occurs. An example is shown. The graph of FIG. 24D represents an example of the fourth counter value 2431 calculated for the first main outline signal 2422.

  As shown in FIG. 24A, since the conveyed document does not have wrinkles, the signal value of the sub contour signal 2402 is not frequently equal to or greater than the first threshold Th1. As shown in FIG. 24B, the third counter value 2411 does not exceed the third threshold Th3, and it is determined that the document does not have wrinkles. Therefore, in this case, the fourth threshold Th4 is not changed.

  On the other hand, as shown in FIG. 24C, the signal value of the first main outline signal 2422 is frequently equal to or higher than the first threshold Th1 due to the sound generated by the stapling. Therefore, as shown in FIG. 24D, the fourth counter value 2431 becomes equal to or greater than the fourth threshold Th4 at time T9, and it is determined that a sound jam has occurred.

  FIG. 25 is a graph showing an example of each signal for sound jam determination when a document having wrinkles is conveyed and skew jam occurs.

  The horizontal axes of FIGS. 25A, 25B, 25C, and 25D indicate time, the vertical axes of FIGS. 25A and 25C indicate signal values, and the vertical axes of FIGS. 25B and 25D indicate counter values. The graph of FIG. 25A shows an example of a sub absolute value signal 2501 and a sub external shape signal 2502 generated from the sub absolute value signal 2501 when a document having wrinkles is conveyed and skew jam occurs. The graph of FIG. 25B represents an example of the third counter value 2511 calculated for the sub external shape signal 2502. The graph of FIG. 25C shows an example of the first main absolute value signal 2521 and the first main external shape signal 2522 generated from the first main absolute value signal 2521 when the skewed original is conveyed and skew jam occurs. Represent. The graph of FIG. 25D represents an example of the fourth counter value 2531 calculated for the first main outline signal 2522.

  As shown in FIG. 25A, the signal value of the sub external shape signal 2502 is frequently greater than or equal to the first threshold Th1 due to the sound generated by the paper feed roller 111 and the retard roller 112 due to the wrinkled document. As shown in FIG. 25B, the third counter value 2511 becomes equal to or greater than the third threshold Th3 at time T10, and it is determined that the document has wrinkles. Therefore, in this case, the fourth threshold Th4 is changed at time T10.

  On the other hand, as shown in FIG. 25C, the signal value of the first main outline signal 2522 is frequently greater than or equal to the first threshold Th1 due to the sound generated by the skew jam. Therefore, as shown in FIG. 25D, the fourth counter value 2531 becomes equal to or greater than the fourth threshold Th4 at time T11 before time T10 when the fourth threshold Th4 is changed, and it is determined that a sound jam has occurred. . The fourth counter value 2531 is larger than the fourth threshold value Th4 after the change. Therefore, even when the time T10 when the fourth threshold value Th4 is changed is before the time T11, a sound jam has occurred. It is determined.

  FIG. 26 is a graph showing an example of each signal for sound jam determination when a document having wrinkles is conveyed and staple jam occurs.

  The horizontal axis of FIGS. 26A, 26B, 26C, and 26D represents time, the vertical axis of FIGS. 26A and 26C represents the signal value, and the vertical axes of FIGS. 26B and 26D represent the counter value. The graph in FIG. 26A shows an example of a sub absolute value signal 2601 and a sub external shape signal 2602 generated from the sub absolute value signal 2601 when a document having wrinkles is conveyed and a staple jam occurs. The graph of FIG. 26B represents an example of the third counter value 2611 calculated for the sub external shape signal 2602. The graph of FIG. 26C shows an example of the first main absolute value signal 2621 and the first main external shape signal 2622 generated from the first main absolute value signal 2621 when a document having wrinkles is conveyed and a staple jam occurs. Represent. The graph of FIG. 26D represents an example of the fourth counter value 2631 calculated for the first main outline signal 2622.

  As shown in FIG. 26A, the signal value of the sub external shape signal 2602 generated from the sub sound signal due to the sound generated by the paper feed roller 111 and the retard roller 112 due to the wrinkled document is frequently greater than or equal to the first threshold Th1. It has become. As shown in FIG. 26B, the third counter value 2611 becomes equal to or greater than the third threshold Th3 at time T12, and it is determined that the document has wrinkles. Therefore, in this case, the fourth threshold Th4 is changed at time T12.

  On the other hand, as shown in FIG. 26C, the signal value of the first main outline signal 2622 is frequently greater than or equal to the first threshold Th1 due to the sound generated by the skew jam. Therefore, as shown in FIG. 26D, the fourth counter value 2631 becomes equal to or greater than the fourth threshold Th4 at time T13 prior to time T12 when the fourth threshold Th4 is changed, and it is determined that a sound jam has occurred. . Since the fourth counter value 2631 is larger than the changed fourth threshold Th4, a sound jam has occurred even when the time T12 when the fourth threshold Th4 is changed is before the time T13. It is determined.

  As described above, the sound jam determination unit 153 does not determine that a sound jam has occurred when a skew jam and a staple jam have not occurred even when a document having wrinkles is conveyed. On the other hand, when a jam or a staple jam occurs, the sound jam determination unit 153 can determine that a sound jam has occurred regardless of whether the document has wrinkles.

  As described above in detail, the document conveying apparatus 100 operates according to the flowcharts shown in FIGS. 6, 7, and 21 to determine whether or not the document has wrinkles based on the sub-original signal. The threshold used to determine the occurrence of jamming due to sound can be changed when it is determined that has a wrinkle. Therefore, the document conveying apparatus 100 can suppress erroneous determination of the occurrence of jam due to sound due to sound generated along with document conveyance.

  FIG. 27 is a view of another document feeder 200 as viewed from above with the upper housing 102 removed, that is, a view as seen in the direction opposite to the arrow A7 in FIG.

  An original conveying apparatus 200 shown in FIG. 27 is an original conveying apparatus of a type that feeds paper on one side reference in which one of two side guides is fixed.

  The document feeder 200 includes a document table 203, side guides 204a and 204b, paper feed rollers 211a and 211b, a first microphone 213a, a second microphone 213b, first driven rollers 217a, 217b, 217c, and 217d, an imaging unit 219b, 2 driven rollers 221a, 221b, 221c, 221d, a discharge table 205, and the like.

  In the document conveying device 200, the side guide 204a is fixed, and only the side guide 204b is movable in the left-right direction with respect to the document conveying direction, and the width of the document is determined by positioning the side guide 204b according to the width of the document. The direction can be regulated.

  The first microphone 213a is provided in the vicinity of the paper feed rollers 211a and 211b. The second microphone 213b is provided at one end of the document conveyance path on the fixed side guide 204a side.

  In the document conveying apparatus 200 of the type that feeds on one side reference, the side guide 204a and the side wall of the document conveyance path on the side guide 204a side are arranged at close positions, so the document is inclined toward the side guide 204a. When conveyed, skew jam is likely to occur. However, since the side guide 204b and the side wall of the document conveyance path on the side guide 204b side are arranged apart from each other, even if the document is conveyed while being inclined toward the side guide 204b, skew jam hardly occurs. Therefore, in the document conveying device 200, skew jam can be accurately detected without providing a microphone at one end on the side guide 204b side of the document conveying path.

  As described above in detail, in the document conveying apparatus 200, the second microphone 213b is provided at one end of the document conveying path on the side of the fixed side guide 204a. It has become possible to accurately detect skew jam in the apparatus.

100, 200 Document conveying device 110 First document detection unit 111, 211 Paper feed roller 112 Retard roller 114 Second document detection unit 115 Ultrasonic sensor 118 Third document detection unit 119, 219 Imaging unit 141a First sound signal output unit 141b Second sound signal output unit 141c Third sound signal output unit 144 Drive unit 145 Interface unit 146 Storage unit 150 Central processing unit 151 Control unit 152 Image generation unit 153 Sound jam determination unit 154 Position jam determination unit 155 Double feed determination unit

Claims (10)

A separation unit;
A first sound signal output unit that is provided at least partially in the vicinity of the separation unit and outputs a first sound signal corresponding to a sound generated while the document is being conveyed;
A second sound signal output unit that is provided at least at one end of the document conveyance path in a direction orthogonal to the document conveyance direction and outputs a second sound signal corresponding to a sound generated during conveyance of the document;
A sound jam determination unit for determining whether or not a jam has occurred based on the second sound signal;
The sound jam determining unit is a document conveying device that changes a jam determination method based on the first sound signal.   The document conveying apparatus according to claim 1, wherein at least a part of the second sound signal output unit is provided at each end of the document conveying path in a direction orthogonal to the document conveying direction.   The sound jam determination unit determines whether or not the document has wrinkles based on the first sound signal, and changes the jam determination method when determining that the document has wrinkles. 2. The document conveying device according to 2.   The document conveying apparatus according to claim 1, wherein the sound jam determination unit determines whether a jam has occurred based on a difference obtained by subtracting the first sound signal from the second sound signal.   5. The document according to claim 1, wherein each of the first sound signal and the second sound signal is a signal obtained by extracting an outer shape of a signal generated from a sound generated while the document is being conveyed. Conveying device.   5. The document conveyance according to claim 1, wherein each of the first sound signal and the second sound signal is a signal obtained by digitizing a signal generated from a sound generated during conveyance of the document. apparatus.   6. The sound jam determination unit according to claim 1, wherein the sound jam determination unit determines whether or not a jam has occurred by comparing information based on the second sound signal and a predetermined threshold value. 7. Document transport device.   In the first sound signal output unit, a portion provided in the vicinity of the separation unit is a first sound collecting unit, and a portion provided in the document conveyance path in the second sound signal output unit is The document conveying device according to claim 1, which is a second sound collecting unit. First sound signal acquisition for acquiring the first sound signal from a first sound signal output unit that is provided at least partially in the vicinity of the separation unit and outputs a first sound signal corresponding to a sound generated while the document is being conveyed. Steps,
The second sound signal output unit is provided with at least a part at least one end of the document transport path in a direction orthogonal to the document transport direction and outputs a second sound signal corresponding to a sound generated while the document is transported. A second sound signal acquisition step of acquiring a two sound signal;
Determining whether or not a jam has occurred based on the second sound signal,
In the determination step, a jam determination method is changed based on the first sound signal. First sound signal acquisition for acquiring the first sound signal from a first sound signal output unit that is provided at least partially in the vicinity of the separation unit and outputs a first sound signal corresponding to a sound generated while the document is being conveyed. Steps,
The second sound signal output unit is provided with at least a part at least one end of the document transport path in a direction orthogonal to the document transport direction and outputs a second sound signal corresponding to a sound generated while the document is transported. A second sound signal acquisition step of acquiring a two sound signal;
Determining whether or not a jam has occurred based on the second sound signal;
A computer program characterized in that, in the determination step, a jam determination method is changed based on the first sound signal.

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