Sheet conveyance device, automatic document conveyance device and image forming device

Abstract

To provide a sheet conveyance device capable of achieving improvement in work efficiency after jam occurrence, to provide an automatic document conveyance device and to provide an image forming device.SOLUTION: When a controller serving as detection means has detected a binding position as a conveyance abnormality occurrence factor in a sheet being conveyed, based on a sound collected by a sound collection microphone serving as a sound collection part, it stops the conveyance of the sheet and identifies the position of the conveyance abnormality occurrence factor such as a binding position. Then, at a display panel 902a serving as notification means, information showing the binding position of the sheet is displayed, and a user is notified of the binding position.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to a sheet transport device, an automatic document transport device, and an image forming apparatus. [Background technology]

[0002] Conventionally, a sheet transport device is known that includes a transport member for transporting a sheet, a sound collection section for collecting sound generated when the sheet is transported, and a detection means for detecting whether or not there is a factor causing a transport abnormality in the sheet being transported based on the sound collected by the sound collection section.

[0003] Patent document 1 describes a sheet transport device that detects whether or not there are any areas on the sheet being transported where stapled processing has been applied as a cause of transport abnormalities, from the sound collected by a sound collection section during sheet transport, and if there are any areas on the sheet where stapled processing has been applied, stops transporting the sheet and displays information on an information display section indicating that the sheet has been stapled. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there was a problem with the efficiency of work after a jam occurred. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a sheet transporting device comprising a transport member for transporting a sheet, a sound collecting section for collecting sound during sheet transport, and a detection means for detecting whether or not a factor causing a transport abnormality exists in the sheet being transported based on the sound collected by the sound collecting section, wherein, when the detection means detects the presence of the factor causing the transport abnormality, the position of the factor causing the transport abnormality in the sheet detected as having the factor causing the transport abnormality is identified, and the position of the factor causing the transport abnormality in the sheet is notified to the user by an alarm means. Effect of the Invention

[0006] According to the present invention, it is possible to improve the efficiency of work after a jam occurs. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a copying machine according to an embodiment. [Diagram 2] FIG. 2 is a partially enlarged view showing an internal configuration of an image forming unit. [Diagram 3] An enlarged partial view showing a part of the tandem section consisting of four process units. [Figure 4] FIG. 2 is a perspective view showing a scanner and an ADF of a copier. [Diagram 5] FIG. 2 is an enlarged diagram showing the main components of the ADF together with the top of the scanner. [Figure 6] FIG. [Figure 7] FIG. 2 is a block diagram showing a part of the electrical circuitry of the ADF and the scanner. [Figure 8] 13 is a flowchart of a transport abnormality determination process. [Figure 9] FIG. 13 is a diagram showing an example of a spectrogram of a sound collected by a sound collecting microphone on the far side. [Figure 10] FIG. 13A is a diagram showing two-point binding, FIG. 13B is a diagram showing rear binding, and FIG. 13C is a diagram showing front binding. [Figure 11] Graph (a) shows the average power over time of the sound collected when transporting a stack of documents bound in two places, graph (b) shows the average power over time of the sound collected when transporting a stack of documents bound at the back, and graph (c) shows the average power over time of the sound collected when transporting a stack of documents bound at the front. [Figure 12] 13 is a flowchart of a binding position specifying process. [Figure 13] 4A to 4C are diagrams illustrating examples of displays on a display panel of a main body operation unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The best mode for carrying out the present invention will be described below with reference to the drawings. Note that a person skilled in the art can easily modify and alter the present invention within the scope of the claims to create other embodiments, and these modifications and alterations are included in the scope of the claims. The following description is an example of the best mode for carrying out the present invention, and does not limit the scope of the claims.

[0009] Hereinafter, an embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter simply referred to as a copying machine) which is an image forming apparatus will be described. First, the basic configuration of the copying machine according to the embodiment will be described. Fig. 1 is a schematic diagram showing the copying machine according to the embodiment. This copying machine includes an image forming unit 1, a blank paper supplying device 40, and a document reading device 50. The document reading device 50 includes a scanner 150 fixed on the image forming unit 1, and an ADF 51, which is a document transport device, supported by the scanner 150.

[0010] The blank paper supply device 40 has two paper feed cassettes 42 arranged in multiple stages in a paper bank 41, a delivery roller 43 that delivers transfer paper from the paper feed cassette 42, a separation roller 45 that separates the delivered transfer paper and delivers it to a paper feed path 44, etc. It also has a plurality of transport rollers 46 that transport the transfer paper to the paper feed path 37 of the image forming unit 1. Then, the transfer paper in the paper feed cassette is fed into the paper feed path 37 in the image forming unit 1.

[0011] FIG. 2 is a partially enlarged diagram showing an internal configuration of the image forming unit 1. The image forming unit 1 as an image forming means includes an optical writing device 2, four process units 3K, Y, M, and C for forming K, Y, M, and C color toner images, and a transfer unit 24. It also includes a paper transport unit 28, a pair of registration rollers 33, a fixing device 34, a switchback device 36, and a paper feed path 37. A light source such as a laser diode or an LED disposed in the optical writing device 2 is driven to irradiate laser light L toward the four drum-shaped photoconductors 4K, Y, M, and C. This irradiation forms an electrostatic latent image on the surface of the photoconductors 4K, Y, M, and C, and the latent image is developed into a toner image through a predetermined development process. The subscripts K, Y, M, and C added after the reference numerals indicate that the specifications are for black, yellow, magenta, and cyan.

[0012] Each of the process units 3K, Y, M, and C supports the photoconductor 4 and various devices disposed around it as one unit on a common support, and is detachable from the main body of the image forming section 1. Taking the black process unit 3K as an example, it has a developing device 6K for developing the electrostatic latent image formed on the surface of the photoconductor 4K into a black toner image in addition to the photoconductor 4K. It also has a drum cleaning device 15 for cleaning the transfer residual toner adhering to the surface of the photoconductor 4K after passing through the K primary transfer nip, which will be described later. In this copier, the four process units 3K, Y, M, and C are arranged opposite to each other along the endless movement direction of the intermediate transfer belt 25, which will be described later, in a so-called tandem configuration.

[0013] 3 is a partially enlarged view showing a part of a tandem section consisting of four process units 3K, Y, M, and C. The four process units 3K, Y, M, and C have almost the same configuration except for the toner colors they use, so the subscripts K, Y, M, and C attached to each reference number are omitted in the figure. As shown in the figure, the process unit 3 has a charging device 5, a developing device 6, a drum cleaning device 15, a static elimination lamp 22, etc. around the photoconductor 4.

[0014] The photoreceptor 4 is a drum-shaped one having a photosensitive layer formed by coating an organic photosensitive material having photosensitivity on a bare tube such as aluminum, etc. However, an endless belt-shaped one may also be used.

[0015] The developing device 6 is adapted to develop a latent image using a two-component developer containing a magnetic carrier and a non-magnetic toner. The developing device 6 has an agitating section 7 that agitates and transports the two-component developer contained therein, and supplies it to the developing sleeve 12, and a developing section 11 that transfers the toner in the two-component developer carried on the developing sleeve 12 to the photoconductor 4.

[0016] The stirring section 7 is located at a lower position than the developing section 11, and includes two transport screws 8 arranged parallel to each other, a partition plate provided between these screws, and a toner concentration sensor 10 provided on the bottom surface of the developing case 9.

[0017] The developing section 11 includes a developing sleeve 12 that faces the photoconductor 4 through the opening of the developing case 9, a magnet roller 13 that is non-rotatably provided inside the developing sleeve, and a doctor blade 14 that brings the tip of the developing sleeve 12 close to the developing sleeve. The developing sleeve 12 is a non-magnetic rotatable cylinder. The magnet roller 13 has a plurality of magnetic poles that are arranged in sequence from a position facing the doctor blade 14 toward the rotation direction of the sleeve. Each of these magnetic poles exerts a magnetic force on the two-component developer on the sleeve at a predetermined position in the rotation direction. As a result, the two-component developer sent from the stirring section 7 is attracted to the surface of the developing sleeve 12 and carried thereon, and a magnetic brush is formed on the sleeve surface along the magnetic lines.

[0018] The magnetic brush is regulated to an appropriate layer thickness when passing the position facing the doctor blade 14 with the rotation of the developing sleeve 12, and then conveyed to the developing area facing the photoconductor 4. The toner is transferred onto the electrostatic latent image by the potential difference between the developing bias applied to the developing sleeve 12 and the electrostatic latent image on the photoconductor 4, contributing to development. Furthermore, the toner returns to the developing section 11 again with the rotation of the developing sleeve 12, and is detached from the sleeve surface by the influence of the repulsive magnetic field formed between the magnetic poles of the magnet roller 13, and is returned to the stirring section 7. In the stirring section 7, an appropriate amount of toner is replenished to the two-component developer based on the detection result by the toner concentration sensor 10. As the developing device 6, a developer using a one-component developer without a magnetic carrier may be adopted instead of a developer using a two-component developer.

[0019] The drum cleaning device 15 uses a cleaning blade 16 made of polyurethane rubber that presses against the photoconductor 4, but other types may be used. In order to improve cleaning performance, this example uses a type having a contact conductive fur brush 17 that contacts the photoconductor 4 with its outer circumferential surface and is rotatable in the direction of the arrow in the figure. This fur brush 17 also serves to scrape off the lubricant from the solid lubricant, turn it into fine powder, and apply it to the surface of the photoconductor 4. A metal electric field roller 18 that applies a bias to the fur brush 17 is provided rotatable in the direction of the arrow in the figure, and the tip of a scraper 19 is pressed against this. The toner that adheres to the fur brush 17 is transferred to the electric field roller 18 to which a bias is applied while rotating in a counter direction in contact with the fur brush 17. Then, after being scraped off from the electric field roller 18 by the scraper 19, it falls onto the recovery screw 20. The recovery screw 20 transports the recovered toner toward the end of the drum cleaning device 15 in the direction perpendicular to the plane of the drawing, and delivers it to an external recycling transport device 21. The recycling transport device 21 sends the delivered toner to the developing device 6 for recycling.

[0020] The static elimination lamp 22 eliminates static electricity from the photoconductor 4 by irradiating it with light. The surface of the photoconductor 4 from which static electricity has been eliminated is uniformly charged by the charging device 5, and then optical writing processing is performed by the optical writing device 2. Note that the charging device 5 used is one in which a charging roller to which a charging bias is applied is rotated while being brought into contact with the photoconductor 4. A scorotron charger or the like that performs charging processing without contacting the photoconductor 4 may also be used.

[0021] In FIG. 2 shown above, K, Y, M, and C toner images are formed on the photoconductors 4K, Y, M, and C of the four process units 3K, Y, M, and C by the process described above.

[0022] A transfer unit 24 is disposed below the four process units 3K, Y, M, and C, as shown in FIG. 2. The transfer unit 24 moves an intermediate transfer belt 25, which is stretched by a plurality of rollers, endlessly in a clockwise direction in the drawing while contacting the photoconductors 4K, Y, M, and C. This forms a primary transfer nip for K, Y, M, and C where the photoconductors 4K, Y, M, and C contact the intermediate transfer belt 25. In the vicinity of the primary transfer nip for K, Y, M, and C, the intermediate transfer belt 25 is pressed against the photoconductors 4K, Y, M, and C by primary transfer rollers 26K, Y, M, and C disposed inside the belt loop. A primary transfer bias is applied to each of the primary transfer rollers 26K, Y, M, and C by a power source. As a result, a primary transfer electric field is formed in the primary transfer nips for K, Y, M, and C, which electrostatically moves the toner images on the photoconductors 4K, Y, M, and C toward the intermediate transfer belt 25. As the intermediate transfer belt 25 moves endlessly in the clockwise direction in the figure, the toner images are sequentially superimposed and primarily transferred to the front surface of the intermediate transfer belt 25 at each primary transfer nip. As a result of this superimposed primary transfer, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the front surface of the intermediate transfer belt 25.

[0023] Below the transfer unit 24 in the figure, a paper transport unit 28 is provided, which loops an endless paper transport belt 29 between a drive roller 30 and a secondary transfer roller 31 and moves it endlessly. The intermediate transfer belt 25 and the paper transport belt 29 are sandwiched between the secondary transfer roller 31 itself and a lower tension roller 27 of the transfer unit 24. This forms a secondary transfer nip where the front surface of the intermediate transfer belt 25 and the front surface of the paper transport belt 29 come into contact with each other. A secondary transfer bias is applied to the secondary transfer roller 31 by a power source. Meanwhile, the lower tension roller 27 of the transfer unit 24 is grounded. This forms a secondary transfer electric field in the secondary transfer nip.

[0024] A pair of registration rollers 33 are disposed on the right side of this secondary transfer nip in the figure, and the transfer paper sandwiched between the rollers is sent to the secondary transfer nip at a timing that allows it to be synchronized with the four-color toner image on the intermediate transfer belt 25. In the secondary transfer nip, the four-color toner image on the intermediate transfer belt 25 is secondarily transferred en bloc onto the transfer paper due to the influence of the secondary transfer electric field and nip pressure, and becomes a full-color image combined with the white color of the transfer paper. The transfer paper that has passed through the secondary transfer nip is separated from the intermediate transfer belt 25 and, while being held on the front surface of the paper transport belt 29, is transported to the fixing device 34 as it moves endlessly.

[0025] Residual toner that was not transferred to the transfer paper at the secondary transfer nip adheres to the surface of the intermediate transfer belt 25 that has passed through the secondary transfer nip. This residual toner is scraped off and removed by a belt cleaning device that comes into contact with the intermediate transfer belt 25.

[0026] The transfer paper transported to the fixing device 34 has the full-color image fixed thereon by pressure and heat, and is then sent from the fixing device 34 to a pair of paper discharge rollers 35 (see FIG. 1) and then discharged outside the machine.

[0027] 1, a switchback device 36 is disposed below the paper transport unit 28 and the fixing device 34. As a result, the transfer paper, which has completed the image fixing process on one side, has its path switched by a switching claw to the transfer paper reversing device side, where it is reversed and enters the secondary transfer nip again. Then, the secondary image transfer process and fixing process are performed on the other side, and the paper is discharged onto the paper discharge tray.

[0028] Scanner 150 fixed on image forming unit 1 has a first-side fixed reading unit 151 as a first-side reading means and a moving reading unit 152 as a first-side reading means.

[0029] The moving reading unit 152 as a first surface reading means is disposed directly below a second contact glass 155 (see FIG. 4) fixed to the upper wall of the casing of the scanner 150 so as to come into contact with the document MS. The moving reading unit 152 can move an optical system consisting of a light source, a reflecting mirror, etc. in the left-right direction in the figure. Then, in the process of moving the optical system from the left side to the right side in the figure, light emitted from the light source is reflected by the document MS placed on the second contact glass, and then passes through multiple reflecting mirrors before being received by an image reading sensor 153 fixed to the scanner body.

[0030] First-side fixed reading unit 151 as a first-side reading means is disposed directly below first contact glass 154 (see FIG. 4) fixed to the upper wall of the casing of scanner 150 so as to come into contact with original document MS. When original document MS transported by ADF 51 (described later) passes over the first contact glass, light emitted from a light source is sequentially reflected by the original document surface, passes through multiple reflecting mirrors, and is received by image reading sensor 153. This allows the first side of original document MS to be scanned without moving an optical system consisting of a light source, reflecting mirrors, etc.

[0031] The ADF 51 of the document reading device 50 also has a contact type image sensor 95 (see FIG. 5) that reads the second side of the document MS. This contact type image sensor 95 will be described later.

[0032] The ADF 51 disposed on the scanner 150 holds, on a main body cover 52, a document placement platform 53 on which the original MS to be read is placed, a transport unit 54 for transporting the original MS, and a document stack platform 55 on which the original MS to be read is stacked. As shown in FIG. 4, the ADF 51 is supported by a hinge 159 fixed to the scanner 150 so as to be swingable in the vertical direction. The swinging motion causes the scanner 150 to move like an opening and closing door, and when opened, the first contact glass 154 and the second contact glass 155 on the top surface of the scanner 150 are exposed. In the case of a single-sided bound original such as a book bound at one corner of a document stack, the original MS cannot be separated one by one, and therefore the ADF 51 cannot transport the original. In the case of a single-sided bound original, the ADF 51 is opened as shown in FIG. 4, and then the single-sided bound original with the page to be read open is placed face down on the second contact glass 155, and the ADF 51 is closed. Then, the image of the page is read by the moving reading unit 152 of the scanner 150 shown in FIG. 1.

[0033] On the other hand, in the case of a stack of originals MS that are simply stacked and independent of one another, the originals MS can be automatically transported one by one by the ADF 51 while being sequentially read by the first-side fixed reading unit 151 in the scanner 150 and the contact-type image sensor 95 in the ADF 51. In this case, after the original stack is set on the original placement table 53, the copy start button is pressed. Then, the ADF 51 feeds the originals MS of the original stack placed on the original placement table 53 in order from the top, and transports them toward the original stack table 55 while inverting them. During this transport process, the originals MS are passed directly above the first-side fixed reading unit 151 of the scanner 150 immediately after being inverted. At this time, the image of the first side of the originals MS is read by the first-side fixed reading unit 151 of the scanner 150.

[0034] Fig. 5 is an enlarged configuration diagram showing the main configuration of ADF 51 together with the upper part of scanner 150, and Fig. 6 is a perspective view of ADF 51. Fig. 7 is a block diagram showing a part of the electric circuit of ADF 51 and scanner 150. As shown in Fig. 5, ADF 51 is equipped with a document setting section A, a separation conveying section B, a registration section C, a turning section D, a first reading conveying section E, a second reading conveying section F, a paper discharge section G, a stacking section H, etc.

[0035] As shown in FIG. 7, the ADF 51 has a controller 904 consisting of an ASIC (Application Specific Integrated Circuit) and the like, which can control various devices and sensors. The controller 904 is connected to the registration sensor 65, the document set sensor 63, the paper discharge sensor 61, the bump sensor 72, the document width sensor 73, the reading entrance sensor 67, the length sensors 57 and 58, and the like. Also connected to the controller 904 are the paper feed motor 191, the transport motor 192, the pull-out clutch 193, the paper discharge clutch 194, the pickup motor 56, and the like. Also connected to the controller 904 are two sound collecting microphones 201a and 201b as sound collecting units. The sound collecting microphones 201a and 201b are for capturing sounds when the document MS is transported, and as shown in FIG. 6, the sound collecting microphone 201b is disposed on the front side of the device (one end side in the document width direction), and the sound collecting microphone 201a is disposed on the back side (the other end side in the document width direction).

[0036] 7, the scanner 150 has a read control unit 903 including a CPU (Central Processing Unit), a RAM (Random Access Memory), etc. This allows the scanner 150 to control various devices and sensors inside the scanner 150. The read control unit 903 is also connected to a controller 904 of the ADF 51 via an I / F, and the read control unit 903 can also indirectly control various devices and sensors inside the ADF 51 via the controller 904.

[0037] In FIG. 5, the document setting section A has a document placement table 53 on which a stack of documents MS is set, etc. The separation and transport section B separates and feeds documents MS one by one from the set stack of documents MS. The registration section C temporarily hits the fed document MS to align the document MS and then sends it out. The turn section D has a curved transport section that curves in a C shape, and turns the document MS upside down while folding it back inside the curved transport section. The first reading and transport section E transports the document MS on the first contact glass 154, while having the first surface fixed reading section 151 disposed inside the scanner 150 below the first contact glass 154 read the first surface of the document MS. The second reading and transport section F transports the document MS below the contact image sensor 95, while having the contact image sensor 95 read the second surface of the document MS. The paper discharge section G discharges the document MS, the images of both sides of which have been read, toward the stack section H. The stack section H stacks the document MS on a document stack table 55.

[0038] The document MS is set with its leading edge placed on the movable document table 53a, which is a sheet tray that can be swung in the directions of the arrows a and b in the figure according to the thickness of the stack of documents MS, and its trailing edge placed on the document placement platform 53. At this time, the side guides are abutted against both ends of the document placement platform 53 in the width direction (the direction perpendicular to the paper surface), so that the position in the width direction is adjusted. The document MS set in this way pushes up the lever member 62 that is arranged to be swung above the movable document table 53a. Then, the document set sensor 63 detects the setting of the document MS and transmits a detection signal to the controller 904 (see FIG. 7). Then, this detection signal is sent from the controller 904 to the reading control unit 903 via the I / F.

[0039] A first length sensor 57 and a second length sensor 58, which are made of a reflective photosensor or an actuator-type sensor that detects the length of the original MS in the transport direction, are held on the original placement table 53. These length sensors detect the length of the original MS in the transport direction.

[0040] A pickup roller 80 is disposed above the stack of originals MS placed on the movable original table 53a and supported by a cam mechanism so as to be movable in the vertical direction (the directions of the arrows c and d in the figure). This cam mechanism can move the pickup roller 80 up and down by being driven by the pickup motor 56. When the pickup roller 80 moves upward, the movable original table 53a swings accordingly in the direction of the arrow a in the figure, and the pickup roller 80 comes into contact with the topmost original MS in the stack of originals MS. When the movable original table 53a further moves upward, the table lift sensor 59 eventually detects that the movable original table 53a has risen to its upper limit. This stops the pickup motor 56 and stops the upward movement of the movable original table 53a.

[0041] An operator operates the keys on the main body operation unit 902, which is made up of a numeric keypad, a display, etc., provided on the main body of the copier, to set the reading mode, indicating whether the reading mode is double-sided or single-sided, and presses the copy start key. The reading modes also include a thin paper mode for reading thin paper, and a mixed load mode for loading and transporting documents MS of different sizes, and the thin paper mode and mixed load mode can be set by the operator operating the keys on the main body operation unit 902. In the thin paper mode and mixed load mode, the document MS is transported at a slower overall transport speed than in the normal reading mode.

[0042] When the copy start key is pressed, a document feed signal is sent from the main body control unit 901 via the I / F to the controller 904 of the ADF 51. Then, the pickup roller 80 is rotated by the forward rotation of the feed motor 191, and the document MS on the movable document table 53a is sent out from above the movable document table 53a.

[0043] When setting the double-sided reading mode or single-sided reading mode, it is possible to collectively set double-sided or single-sided reading for all the originals MS placed on the movable original table 53a. It is also possible to set the reading mode individually for each original MS, for example, to set the first and tenth originals MS to the double-sided reading mode while setting the other originals MS to the single-sided reading mode.

[0044] The document MS sent out by the pickup roller 80 enters the separation and transport section B and is sent to a contact position with the paper feed belt 84. The paper feed belt 84 is stretched by a drive roller 82 and a driven roller 83, and is moved endlessly in the clockwise direction in the figure by the rotation of the drive roller 82 accompanying the forward rotation of the paper feed motor 191. A separation roller 85, which is rotated clockwise in the figure by the forward rotation of the paper feed motor 191, contacts the lower stretching surface of the paper feed belt 84. At the contact portion, the surface of the paper feed belt 84 moves in the paper feed direction. In contrast, the separation roller 85 contacts the paper feed belt 84 with a predetermined pressure, and when the separation roller 85 is directly in contact with the paper feed belt 84 or when only one document MS is sandwiched in the contact portion, it rotates with the belt or the document MS. However, when multiple originals MS are sandwiched in the contact portion, the accompanying rotation force becomes lower than the torque of the torque limiter, so the roller 85 rotates in the opposite direction to the accompanying rotation, clockwise in the figure. As a result, the separation roller 85 applies a moving force in the opposite direction to the paper feed to the originals MS below the topmost one, and only the topmost original MS is separated from the several originals MS.

[0045] The document MS separated into one sheet by the action of the feed belt 84 and the separation roller 85 enters the registration section C. Then, when the document MS passes directly under the abutment sensor 72, its leading edge is detected. At this time, the pickup roller 80, which receives the driving force of the feed motor 191, is still rotating, but since the movable document table 53a is lowered and separated from the document MS, the document MS is transported only by the endless moving force of the feed belt 84. Then, the endless movement of the feed belt 84 continues for a predetermined time from the timing when the leading edge of the document MS is detected by the abutment sensor 72. After that, the leading edge of the document MS abuts against the abutment portion between the pull-out driven roller 86 and the pull-out driving roller 87 which is rotated while abutting against the pull-out driven roller 86. With the leading edge of the document MS abutting against the abutment portion of both rollers, the trailing edge side of the document MS is sent in the feed direction, so that the leading edge of the document MS is positioned at the abutment portion while being bent by a predetermined amount. As a result, the skew (inclination) of the original MS is corrected, and the original MS is brought into a position that is aligned with the paper feed direction.

[0046] The pull-out drive roller 87 not only corrects the skew of the document MS, but also transports the document MS, the skew of which has been corrected, to the intermediate roller pair 66 downstream in the document transport direction. The pickup roller 80, the drive roller 82 that stretches the paper feed belt 84, the pull-out drive roller 87, and the drive roller of the intermediate roller pair 66 are connected to the paper feed motor 191 via a one-way clutch. The one-way clutch connected to the pull-out drive roller 87 and the drive roller of the intermediate roller pair 66 transmits the drive force when the paper feed motor 191 rotates in the reverse direction, and the one-way clutch connected to the drive roller 82 transmits the drive force when the paper feed motor 191 rotates in the forward direction. Therefore, when the paper feed motor 191 rotates in the reverse direction, the pull-out drive roller 87 and the drive roller of the intermediate roller pair 66 start to rotate, and the endless movement of the paper feed belt 84 stops. At this time, the rotation of the pickup roller 80 also stops.

[0047] The original MS sent out from the pull-out drive roller 87 passes directly below the original width sensor 73. The original width sensor 73 has a plurality of paper detection units each consisting of a reflective photosensor or the like, and these paper detection units are lined up in the original width direction (the direction perpendicular to the drawing sheet). The widthwise size of the original MS is detected based on which paper detection unit detects the original MS. In addition, the length of the original MS in the transport direction is detected based on the timing from when the leading edge of the original MS is detected by the abutment sensor 72 to when the trailing edge of the original MS is no longer detected by the abutment sensor 72.

[0048] The leading edge of the document MS, the width of which has been detected by the document width sensor 73, enters the turning section D and is sandwiched in the contact area between the rollers of the intermediate roller pair 66. The transport speed of the document MS by this intermediate roller pair 66 is set to be faster than the transport speed of the document MS in the first reading and transporting section E, which will be described later. This shortens the time it takes for the document MS to be sent to the first reading and transporting section E.

[0049] The leading edge of the document MS transported within the turning section D passes a position facing the reading entrance sensor 67. When the leading edge of the document MS is detected by the reading entrance sensor 67, the document transport speed by the intermediate roller pair 66 is decelerated until the leading edge is transported to the position of the reading entrance roller pair (the pair of 89 and 90) on the downstream side in the transport direction. In addition, as the transport motor 192 starts to rotate, one roller of the reading entrance roller pair (89, 90), one roller of the reading exit roller pair 92, and one roller of the second reading exit roller pair 93 each start to rotate.

[0050] In the turning section D, the document MS is turned upside down and the transport direction is reversed while being transported on the curved transport path between the pair of intermediate rollers 66 and the pair of reading entrance rollers (89, 90). Then, the leading edge of the document MS that has passed through the nip between the pair of reading entrance rollers (89, 90) passes directly below the registration sensor 65. At this time, when the leading edge of the document MS is detected by the registration sensor 65, the document transport speed is decelerated over a predetermined transport distance, and the transport of the document MS is temporarily stopped just before the first reading transport section E. Also, a temporary stop signal is sent to the reading control section 903 (see FIG. 7) via the I / F.

[0051] When the reading control unit 903 receives the temporary stop signal and transmits a reading start signal, the rotation of the transport motor 192 is resumed under the control of the controller 904, and the transport speed of the original MS is increased to a predetermined transport speed until the leading edge of the original MS reaches inside the first reading transport unit E. Then, at the timing when the leading edge of the original MS reaches the reading position by the first-side fixed reading unit 151, the controller 904 transmits a gate signal indicating the sub-scanning direction effective image area of ​​the first side of the original MS to the reading control unit 903. This transmission is continued until the rear end of the original MS leaves the reading position by the first-side fixed reading unit 151, and the first side of the original MS is read by the first-side fixed reading unit 151. The timing when the leading edge of the original MS reaches the reading position by the first-side fixed reading unit 151 is calculated based on the pulse count of the transport motor 192.

[0052] The document MS that has passed through the first reading conveyance section E passes through a pair of reading exit rollers 92, which will be described later, and then its leading edge is detected by the paper discharge sensor 61. When the single-sided reading mode is set, it is not necessary to read the second side of the document MS by the contact image sensor 95, which will be described later. Therefore, when the leading edge of the document MS is detected by the paper discharge sensor 61, the driving force of the conveyance motor 192 is connected to the pair of paper discharge rollers 94 by the paper discharge clutch 194, and the lower paper discharge roller in the pair of paper discharge rollers 94 in the figure is rotated clockwise in the figure. In addition, based on the pulse count of the conveyance motor 192 after the leading edge of the document MS is detected by the paper discharge sensor 61, the timing at which the rear edge of the document MS leaves the nip of the pair of paper discharge rollers 94 is calculated. Then, based on the result of this calculation, the paper discharge clutch 194 cuts off the driving force of the conveyance motor 192 to stop the pair of paper discharge rollers 94.

[0053] On the other hand, when the double-sided reading mode is set, the timing until the leading edge of the original MS is detected by the discharge sensor 61 and then the original reaches the contact image sensor 95 is calculated based on the pulse count of the transport motor 192. Then, at that timing, the controller 904 transmits a gate signal indicating the effective image area in the sub-scanning direction on the second side of the original MS to the reading control unit 903. This transmission continues until the trailing edge of the original MS leaves the reading position of the contact image sensor 95, and the second side of the original MS is read by the contact image sensor 95.

[0054] The contact image sensor 95 (CIS) as the second surface reading means has a coating treatment applied to its reading surface in order to prevent vertical reading streaks caused by glue-like foreign matter adhering to the document MS adhering to the reading surface. A second reading roller 96 is disposed opposite the contact image sensor 95 as a document supporting means for supporting the document MS from the non-reading surface side (first surface side). This second reading roller 96 prevents the document MS from floating at the reading position by the contact image sensor 95, and also functions as a reference white area for acquiring shading data in the contact image sensor 95. In this copying machine, the second reading roller 96 is used as a document supporting means for supporting the document MS opposite the contact image sensor 95, but a guide plate-like roller may also be used.

[0055] A user may inadvertently place a stack of multiple originals MS bound together with staples or clips on the original placement table 53. When the leading edge of such a stack of multiple originals MS bound together with metal pieces such as staples or clips enters the separation section where the separation roller 85 abuts against the paper feed belt 84, the top original of the stack of originals MS continues to be transported by the paper feed belt 84. However, the second and subsequent originals are subjected to a return transport force by the separation roller 85. As a result, the top original MS becomes distorted, resulting in folds, creases, and the like.

[0056] Conventionally, if the abutment sensor 72 does not detect the leading edge of the document MS by the specified timing and a paper jam is detected, the document MS continues to be conveyed in a state where the topmost document MS is folded or wrinkled in the separation section. As a result, the document becomes more wrinkled and folded, and ultimately the part bound by the metal pieces is subjected to a large stress, causing it to tear and causing serious damage to the document MS.

[0057] Therefore, in this embodiment, whether or not a bound document stack is being transported is detected from the sound collected by the sound collecting microphones 201a and 201b during the paper feeding / separating operation. In the case of a bound document stack, a paper jam is predicted as a transport abnormality, so it is determined that a paper jam will occur and the transport of the document MS is stopped. This makes it possible to stop the transport of the document before the abutment sensor 72 detects a paper jam. As a result, the transport of the document can be stopped before major damage such as tearing occurs to the document MS.

[0058] The sound collecting microphones 201a, 201b are attached to the inner circumferential surface of the openable and closable paper feed cover 98, as shown in Fig. 5. By attaching the sound collecting microphones 201a, 201b to the inner circumferential surface of the paper feed cover 98, external noise can be blocked by the paper feed cover 98, making it difficult for the sound collecting microphones 201a, 201b to pick up external noise. In addition, when attaching the sound collecting microphones 201a, 201b to the inner circumferential surface of the paper feed cover 98, a rubber-like vibrating member may be attached between the sound collecting microphones 201a, 201b and the inner circumferential surface of the paper feed cover 98, making it difficult for noise caused by vibrations from the paper feed cover 98 to be picked up.

[0059] Each of the sound collecting microphones 201a and 201b is disposed upstream of the separation unit in the document transport direction, more specifically, above the pickup roller 80, between a pair of side fences, one of which can move in the document width direction that regulates the movement of the document in the direction perpendicular to the document transport direction (document width direction), when the pair of side fences is at its narrowest. This allows sound from the area upstream of the separation unit in the document transport direction to be collected well, and allows sound from the document transport upstream of the separation unit to be collected well. The placement positions of the sound collection microphones 201a and 201b are not limited to the above, and they may be placed appropriately in a location where there is no component that blocks the sound of the document being transported upstream of the separation unit and where the sound of the document being transported in the area upstream of the separation unit can be collected effectively.

[0060] FIG. 8 is a flowchart of the transport abnormality determination process executed by the controller 904. When a document feed signal is sent from the main body control unit 901 to the controller 904, the pickup roller 80 is rotated by the forward rotation of the feed motor 76. Then, the document MS on the movable document table 53a is sent out from the movable document table 53a, and document transport is started (S1). At the same time as the document transport starts, sound collection by the sound collecting microphones 201a and 201b starts (S2).

[0061] Then, sound collection is stopped at the timing when only the topmost original MS starts to be separated from several originals in the separation section. Specifically, sound collection is stopped at the timing when the leading edge of the original MS is located slightly downstream from the separation section (the leading edge of the original leaves the separation section and the trailing edge is located upstream of the separation section). This makes it possible to collect the sound of the topmost original beginning to deform, such as wrinkles or creases, and to stop the transport of the original before it is severely damaged, such as when it is severely folded or creased, or torn.

[0062] The timing to stop collecting sound is determined based on the number of drive pulses of the paper feed motor 76 and the time elapsed since the start of driving the paper feed motor 76. The collected sound signal is converted to PCM data by an AD converter in the controller 904 and temporarily stored in the RAM of the controller 904.

[0063] Fig. 9 is a diagram showing an example of a spectrogram of the sound collected by the rear sound collecting microphone 201a. Fig. 9(a) is an example of a spectrogram during normal transport, and Fig. 9(b) is an example of a spectrogram during transport of a two-point bound original stack. Fig. 9(c) is an example of a spectrogram during transport of a one-point bound original stack where the binding point is located at the rear side of the device (hereinafter referred to as rear binding). Fig. 9(d) is an example of a spectrogram during transport of a one-point bound original stack where the binding point is located at the front side of the device (hereinafter referred to as front binding). In FIG. 9, the horizontal axis represents time, the vertical axis represents sound frequency, and the sound intensity (sound pressure) is indicated by light and dark, with whiter indicating stronger sound.

[0064] The "two-point binding" is a binding method in which the end of the document on the downstream side in the transport direction is bound in two places with a specified distance between them, as shown in Fig. 10(a). The "rear binding" is a binding method in which the rear end of the document on the downstream side in the transport direction is bound, as shown in Fig. 10(b). The "front binding" is a binding method in which the front end of the document on the downstream side in the transport direction is bound, as shown in Fig. 10(c).

[0065] In all of Figures 9(a) to 9(d), loud sounds are generated at frequencies below 7500 Hz. The sound-collecting microphone picks up the driving sounds of the motor and the like in addition to the transport sounds of the original documents when the original documents are transported, and the loud sounds below 7500 Hz are the driving sounds of the motor and the like. On the other hand, as shown in Figures 9(b) to 9(d), when a bound stack of original documents is transported, loud sounds in the high-pitched range of frequencies above 7500 Hz are generated as the transport sounds of the original documents, but as shown in Figure 9(a), no loud sounds in the high-pitched range of frequencies above 7500 Hz are generated during normal transport.

[0066] As described above, when transporting a bound stack of documents, a loud noise is generated in the high-frequency range of frequencies above 7500 Hz. Therefore, it is preferable to cut out sounds below 7500 Hz using a high-pass filter, remove the driving sounds from the sounds picked up by the sound collection microphone, and temporarily store the sound signal extracting the document transport sounds in the RAM of the controller 904.

[0067] Next, the controller 904 calculates the feature amount of the sound stored in the RAM (S3). Specifically, a short-time Fourier transform (STFT) is performed on the sound signal stored in the RAM to calculate the time sequence of the power spectrum of the sound signal. Next, a characterization process is performed on the time sequence of the calculated power spectrum to calculate the feature amount of the sound. The characterization process may use a time integral of power in a predetermined frequency band or a spectral flux between consecutive frames. That is, in this embodiment, the controller 904 functions as a feature amount extraction unit. Note that the feature amount quantitatively expressing the feature of the sound used for state discrimination is not limited to the above, and a well-known feature amount of the sound such as a Mel frequency cepstrum coefficient may be used. The feature amount may be calculated using the sound collected by either one of the two sound collecting microphones 201a and 201b. The feature amount may be calculated for each of the sounds collected by both sound collecting microphones, and the average value of the feature amounts may be used as the "feature amount" to determine whether or not a transport abnormality occurs, as described below.

[0068] After the characteristic amount is calculated, it is detected whether the document stack is a bound document stack based on the calculated characteristic amount, and it is determined whether a transport abnormality occurs (S4). In this embodiment, the transport abnormality judgment is performed by the MT method (Mahalanobis Taguchi method). The MT method is one of the MT (Mahalanobis Taguchi) systems known in the field of quality engineering and the like for prediction, diagnosis, and analysis using multidimensional information data. The MT method is one of the methods that can judge whether data is normal or abnormal by using the Mahalanobis distance, and is a method that can judge normality / abnormality simply and relatively accurately. The MT method is a well-known method described in, for example, JP Patent Publication No. 2003-141306 and Genichi Taguchi's "Mathematics of Quality Engineering" (published by the Japanese Standards Association in 1999), so a detailed description will be omitted.

[0069] The following data is stored in the ROM of the controller 904 as index data used to determine whether a transport abnormality has occurred: an inverse matrix R-1 of the correlation matrix of the unit space data set (reference data set) used to calculate the Mahalanobis distance, and a threshold value Th as a judgment criterion for classifying the calculated Mahalanobis distance into normal transport (unbound document) and transport abnormality (stack of bound documents).

[0070] The inverse matrix R-1 is obtained by creating a unit space data set (reference data set) based on feature quantities obtained from the sound of the document MS being normally conveyed under various error factor conditions of the ADF 51. The threshold value Th, which is the criterion for determining whether the calculated Mahalanobis distance indicates normal conveyance or abnormal conveyance, is set by obtaining the Mahalanobis distance with the target values ​​being the false negative rate (misjudgment rate of normal judgement) and the false positive rate (misjudgment rate of abnormal conveyance) of the ADF 51.

[0071] When the calculated Mahalanobis distance is equal to or less than the threshold Th and it is determined that the transport is normal, the controller 904 continues the document transport operation (S8). Specifically, as described above, the feed motor 191 is rotated in the reverse direction, and the pull-out operation is performed to feed the skew-corrected document by the pull-out drive roller 87. Then, a temporary stop process is performed to temporarily stop the transport of the document MS before the first reading transport unit E. Then, the controller 904 waits for reception of a reading start signal from the reading control unit 903. Then, when the reading start signal is received and reading is started (Y in S10), the transport of the document is resumed, and the document is transported to the first reading transport unit E and the second reading transport unit F, and a reading transport process is performed in which the image of the document is read. Then, the document is transported to the paper discharge unit G, and the document is discharged to the paper discharge tray, completing the reading.

[0072] On the other hand, when a bound document stack is transported (abnormal transport), the calculated Mahalanobis distance exceeds the threshold value Th. This detects that a bound document stack has been transported, and determines that a transport abnormality has occurred. When it is determined that a transport abnormality has occurred, the controller 904 stops the document transport operation and the reading operation (S5). In addition, a binding position identification process is performed to identify the position of the binding process that is the cause of the sheet transport abnormality (S6).

[0073] FIG. 11(a) is a graph showing the average power over time of the sound collected when a stack of documents is transported with two-point binding (see FIG. 10(a)). FIG. 11(b) is a graph showing the average power over time of the sound collected when a stack of documents is transported with rear binding (see FIG. 10(b)). FIG. 11(c) is a graph showing the average power over time of the sound collected when a stack of documents is transported with front binding (see FIG. 10(c)). Note that the graph shown in FIG. 10 is the average power over time of the sound signal from which sounds below 7500 Hz have been cut by a high-pass filter and the drive sound has been removed from the sounds collected by the sound collection microphone.

[0074] As shown in Figure 11(a), when a stack of documents bound in two places is transported, the difference between the average power over time of the sound collected by the front-side sound collecting microphone (hereinafter referred to as the front-side sound) and the average power over time of the sound collected by the rear-side sound collecting microphone (hereinafter referred to as the rear-side sound) is small.

[0075] On the other hand, as shown in Figures 11(b) and 11(c), when a single-stitched document stack is transported, the power average of the sound collected by one of the two sound collecting microphones becomes larger than the power average of the sound collected by the other sound collecting microphone from 0.08 [sec] onwards. As a result, when a single-stitched document stack is transported, the difference between the power average of the sound on the front side per unit time and the power average of the sound on the back side per unit time becomes large.

[0076] Also, as shown in Fig. 11(b), when the binding is performed at the back, the average power of the sound on the near side is greater than the average power of the sound on the far side. On the other hand, as shown in Fig. 10(c), when the binding is performed at the front, the average power of the sound on the far side is greater than the average power of the sound on the near side. This is because, on the unbound side, the top document of the bound document stack advances further than the documents on the bottom, causing rubbing between the sheets. It is believed that the rubbing sound at that time is picked up by the sound collecting microphone on the unbound side, causing the average power to be greater than that on the bound side.

[0077] In this way, the power average relationship over time between the sound on the far side collected by the far side sound collecting microphone 201a and the sound on the near side collected by the near side sound collecting microphone 201b differs between two-point binding, far-point binding, and front-point binding. Therefore, the binding method (one-point binding, two-point binding) and the binding position (front side, far side) can be grasped from the power average relationship over time between the sound on the far side and the sound on the near side.

[0078] FIG. 12 is a flowchart of the binding position specifying process. As described above, when it is determined that a conveyance abnormality occurs, the controller 904 as a cause position specifying unit executes a binding position specifying process. First, the controller 904 obtains the power average for each time period for the sound signals collected by the sound collecting microphones 201a and 201b, from which sounds below 7500 Hz have been cut by a high-pass filter temporarily stored in the RAM. Then, the controller 904 calculates the difference value (absolute value) between the power average of the sound on the front side and the power average of the sound on the back side for each time period, and adds up the calculated difference values ​​(S11).

[0079] Next, the controller 904 judges whether the sum of the power average difference values ​​(absolute values) is less than the threshold value (S12). As shown in FIG. 11, in the case of two-point binding, the power average difference value (absolute value) for each time is smaller than in the case of one-sided binding (rear binding, front binding). Therefore, the sum of the power average difference values ​​(absolute values) is smaller than in the case of one-sided binding and is less than the threshold value. Therefore, if the sum of the power average difference values ​​(absolute values) is less than the threshold value (Yes in S12), the controller 904 judges that the binding is two-point binding (S13).

[0080] In addition, whether or not the document is bound at two points may be determined based on the average value of the difference values ​​(absolute values) between the power average of the sound on the front side and the power average of the sound on the back side for each time period. In this case, the average value of the difference values ​​(absolute values) is smaller for the two-point binding than for the one-sided binding (back binding, front binding). Therefore, if the average value of the difference values ​​(absolute values) is less than the threshold value, it is possible to determine whether or not the document is bound at two points. In addition, the sum of the power average values ​​for each time period of the sound on the back side and the sum of the power average values ​​for each time period of the sound on the front side may be calculated, and whether or not the document is bound at two points may be determined based on the difference value between the sum of the power average values ​​for each time period of the sound on the back side and the sum of the power average values ​​for each time period of the sound on the front side.

[0081] On the other hand, if the sum of the power average difference values ​​(absolute values) is equal to or greater than the threshold value (No in S12), the controller 904 calculates the sum of the time average power values ​​of the sounds on the far side and the sum of the time average power values ​​of the sounds on the near side, and then determines whether the sum of the power average values ​​of the sounds on the far side is greater than the sum of the power average values ​​of the sounds on the near side (S14).

[0082] As shown in FIG. 11(b), in the case of front binding, the power average of the sound on the rear side is higher than the power average of the sound on the front side. Therefore, in the case of front binding, the total power average of the sound on the rear side is larger than the total power average of the sound on the front side. On the other hand, in the case of back binding, as shown in FIG. 11(c), the power average of the sound on the front side is higher than the power average of the sound on the rear side, and the total power average of the sound on the rear side is smaller than the total power average of the sound on the front side.

[0083] Therefore, if the total power average value of the sounds on the rear side is greater than the total power average value of the sounds on the front side (Yes in S14), the controller 904 determines that the binding is to be performed at the front (S15). On the other hand, if the total power average value of the sounds on the rear side is less than the total power average value of the sounds on the front side (No in S14), the controller 904 determines that the binding is to be performed at the rear (S16).

[0084] When the process of specifying the binding position is completed, as shown in FIG. 8, the binding position is displayed on the display panel of the main body operation unit 902, which serves as a notification means, to notify the user of the binding position (S7).

[0085] Fig. 13 is a diagram for explaining a display example of the display panel 902a which is a notification means and a display unit of the main body operation unit 902. Fig. 13(a) shows a display example when the binding position identification process determines that the binding is two-point binding, Fig. 13(b) shows a display example when the binding position identification process determines that the binding is front binding, and Fig. 13(c) shows a display example when the binding position identification process determines that the binding is rear binding.

[0086] When the binding position identification process identifies two-point binding, the location corresponding to the binding position for two-point binding shown in Fig. 13(a) is displayed with a circle to notify the user. When the binding position identification process identifies front binding, the location corresponding to the binding position for front binding is displayed with a circle to notify the user, as shown in Fig. 13(b). When the binding position identification process identifies rear binding, the location corresponding to the binding position for rear binding is displayed with a circle to notify the user, as shown in Fig. 13(c).

[0087] By displaying the binding position on the display panel 902a, the user can easily grasp the binding position of the bound document stack that has stopped in front of the separation unit from the display contents of the display panel 902a. This allows the staple removal work to be started immediately, improving the work efficiency of jam clearance.

[0088] In the above description, the binding position is notified to the user by displaying it on the display panel 902a of the main body operation unit 902. However, the binding position may be notified to the user by voice, for example.

[0089] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the spirit of the present invention described in the claims, unless otherwise specifically limited in the above description.

[0090] For example, in the above description, the present invention is applied to the ADF 51 as a sheet feeding device, but the present invention can also be applied to the blank paper feeder 40 as a sheet feeding device. When a transfer paper sheet with an image printed on its front side is reused as a backing paper sheet, there is a risk that metal pieces such as staples and clips are forgotten to be removed and set in the paper feed cassette 42 of the blank paper feeder 40. As a result, as in the above description, a bound stack of transfer paper sheets may be fed, causing a paper jam. Therefore, in the blank paper feeder 40, as in the above description, a sound collecting microphone that collects the transport sound of one end of the transfer paper sheet in the width direction and a sound collecting microphone that collects the transport sound of the other end of the transfer paper sheet in the width direction are arranged between the delivery roller 43 and the separation roller 45. Then, from the sounds collected by these sound collecting microphones, it is detected whether or not a bound stack of sheets is being transported. When a bound stack of transfer papers is detected, the binding position is identified from the sounds collected by these sound collecting microphones, and the identified binding position is displayed on the display panel 902a of the main body operation unit 902. This allows the user to easily grasp the binding position of the bound stack of transfer papers that has stopped in front of the separation roller 45 from the contents displayed on the display panel 902a. This allows the user to immediately start work such as removing staples, improving the efficiency of jam clearance work. The blank paper supply device 40 to which the present invention is applied can be used not only in electrophotographic image forming apparatuses, but also in inkjet image forming apparatuses.

[0091] In the above description, the binding position is identified as the position of the cause of the transport abnormality based on the sound collected by the sound collecting microphones 201a and 201b. However, the sheet fold position or the sheet curl position may be identified as the position of the cause of the transport abnormality (jam) based on the sound collected by the sound collecting microphones 201a and 201b, and the sheet fold position or the sheet curl position may be notified to the user.

[0092] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) In a sheet transport device equipped with a transport member such as a pickup roller 80 that transports sheets such as a document MS, a sound collection unit such as sound collection microphones 201a, 201 that collect sounds during sheet transport, and a detection means such as a controller 904 that detects whether or not there is a cause for a transport abnormality such as a binding point in the sheet being transported based on the sounds collected by the sound collection unit, when the detection means detects that there is a cause for a transport abnormality in the sheet, the position of the cause of the transport abnormality in the sheet detected as having the cause of the transport abnormality is identified, and the position of the cause of the transport abnormality in the sheet is notified to the user by an alerting means such as a display panel 902a. In Patent Document 1, the information display unit, which serves as a notification means, only notifies the user that there is a cause of a transport abnormality in the sheet, such as stapling processing, and therefore it may take time to identify the location of the cause of the sheet transport abnormality, resulting in poor work efficiency after a jam occurs. In contrast, in the first aspect, the user is notified of the location of the cause of the abnormality in conveyance, such as the binding position of the sheets, so that the user can identify the location of the cause of the abnormality in conveyance in a short time. This allows the user to immediately begin the task of removing the cause of the abnormality in conveyance, such as removing the binding tool, such as a staple, and improves the efficiency of work after a jam occurs.

[0093] (Aspect 2) In the first aspect, when the detection is performed, the position of the cause of the transport abnormality, such as the binding position of the sheet of the document MS, is identified based on the sound collected by the sound collecting unit, such as the sound collecting microphones 201a and 201b. According to this, as described in the embodiment, the sheet transport sound differs depending on the location of the cause of the transport abnormality, such as the binding position of the sheet, etc. Therefore, it is possible to accurately identify the location of the cause of the transport abnormality based on the sound collected by the sound collecting units such as the sound collecting microphones 201a and 201b.

[0094] (Aspect 3) In aspect 2, sound collection units such as sound collection microphones 201a, 201b are arranged at a position facing one end of a sheet such as an original MS in a perpendicular direction, such as the width direction perpendicular to the sheet transport direction, and at a position facing the other end of the sheet in the perpendicular direction, and the location of the cause of the sheet transport abnormality is identified from the difference value between the power average over time of the sound collected by one of the two sound collection units and the power average over time of the sound collected by the other sound collection unit. According to this, as described in the embodiment, a difference occurs between the power average of the sound collected by one sound collection unit and the power average of the sound collected by the other sound collection unit depending on the position in the sheet width direction of the cause of the abnormality in conveyance, such as the binding position. Therefore, the position of the cause of the abnormality in conveyance of the sheet can be identified from the difference value between the power average of the sound collected by one sound collection unit per hour and the power average of the sound collected by the other sound collection unit per hour.

[0095] (Aspect 4) In any one of the aspects 1 to 3, the position at which the transport abnormality occurs is the binding position. According to this, as described in the embodiment, the user can quickly grasp the binding position of the sheets based on the binding position notified by the notifying means such as the display panel 902a, and can immediately start the work of removing the binding tool such as a stapler. This can improve the efficiency of the jam clearance work.

[0096] (Aspect 5) In any of the first to fourth aspects, the notification unit is a display unit such as a display panel 902a that displays the location of the cause of the conveyance abnormality, such as the binding position of the sheets. According to this, as described in the embodiment, the user can easily identify the location of the cause of the jammed paper abnormality based on the location of the cause of the transport abnormality, such as the binding position, displayed on a display unit such as the display panel 902a, thereby making it possible to efficiently clear the jam.

[0097] (Aspect 6) In any of the first to fifth aspects, when a transport abnormality prediction unit such as the controller 904 predicts that a transport abnormality will occur, transport of the sheet is stopped. According to this, as described in the embodiment, the conveyance of the sheet can be stopped before the sheet is seriously damaged, such as torn, and the sheet can be prevented from being seriously damaged.

[0098] (Aspect 7) In an automatic document feeder having a document sheet transport unit that transports document sheets such as documents MS and transports the document sheets to an image reading unit by the document sheet transport unit, the sheet transport device according to any one of aspects 1 to 7 was used as the document sheet transport unit. This makes it possible to prevent the original sheets from being torn or otherwise seriously damaged, and also to improve the efficiency of the jam clearance process.

[0099] (Aspect 8) An image forming apparatus for forming an image on a sheet includes the sheet conveying device according to any one of the first to seventh aspects, or includes an automatic document conveying device such as the ADF 51 according to the eighth aspect. This makes it possible to prevent serious damage to the sheet or the original sheet, and also to improve the efficiency of the jam clearance process. [Explanation of symbols]

[0100] 50: Document reader 51: ADF 52: Main body cover 53: Manuscript stand 54: Movable manuscript table 55: Manuscript stacking table 56: Pickup motor 80: Pickup roller 84: Paper feed belt 85: Separation roller 86: Pull-out driven roller 87: Pull-out drive roller 92: Reading exit roller pair 93: Second reading exit roller pair 94: Paper ejection roller pair 95: Contact type image sensor 96: Second reading roller 98: Paper feed cover 150: Scanner 151: 1st surface fixed reading unit 152: Mobile reading unit 153: Image reading sensor 154: First contact glass 155: 2nd contact glass 191: Paper feed motor 192: Transport motor 194: Discharge clutch 201a: Sound collection microphone 201b: Sound collection microphone 901: Main unit control section 902: Main unit operation section 902a: Display panel 903: Reading control unit 904: Controller [Prior art documents] [Patent documents]

[0101] [Patent Document 1] Patent No. 6653471

Claims

1. A conveying member that conveys a sheet; a sound collection unit that collects sound generated during sheet transport; a detection unit that detects whether or not a cause of a transport abnormality exists in the sheet being transported based on the sound collected by the sound collecting unit, When the detection means detects that there is a cause of the transport abnormality, the detection means identifies a position of the cause of the transport abnormality on the sheet in which it has been detected that there is a cause of the transport abnormality, and notifies a user of the position of the cause of the transport abnormality on the sheet by an alarm means.

2. 2. The sheet conveying apparatus according to claim 1, a sound collection unit that collects the sound when the abnormality is detected and determines a location of the cause of the abnormality.

3. 3. The sheet conveying apparatus according to claim 2, the sound collecting unit is disposed at a position facing one end of the sheet in a direction perpendicular to a sheet conveying direction and at a position facing the other end of the sheet in the direction perpendicular to the sheet conveying direction, A sheet conveying device characterized in that the location of the cause of the conveying abnormality is identified from the difference value between the average power over time of the sound collected by one of two sound collecting sections and the average power over time of the sound collected by the other sound collecting section.

4. 2. The sheet conveying apparatus according to claim 1, The sheet conveying device according to claim 1, wherein the position where the conveyance abnormality occurs is a binding position.

5. 2. The sheet conveying apparatus according to claim 1, The sheet conveying device according to claim 1, wherein the notification means is a display unit that displays a position of a cause of the conveyance abnormality of the sheet.

6. 2. The sheet conveying apparatus according to claim 1, a detection unit that detects that the sheet has a cause of the abnormality in conveyance and stops conveying the sheet, the detection unit detecting the abnormality in conveyance of the sheet.

7. a document sheet transport unit for transporting a document sheet; In the automatic document feeder, the document sheet is fed to an image reading unit by the document sheet feed unit, 2. An automatic document feeder, comprising the sheet feeder according to claim 1 as said document sheet feeder.

8. In an image forming apparatus for forming an image on a sheet, 8. An image forming apparatus comprising at least one of the sheet transport device according to claim 1 and the automatic document feeder according to claim 7.

Images