Sheet conveyance device, image reading device, and image formation device

Abstract

The present invention provides more appropriate information to a user.　Provided is a sheet conveyance device (20) comprising: a load-receiving part (21) on which sheets are loaded; a feeding means (22, 23, 24) which separately feeds, one by one, the sheets that are loaded on the load-receiving part (21); a detection means (S20) which detects lifting up of the sheets that are fed by the feeding means(22, 23, 24); a display means (506a) which displays information; and a control means (81) which, when the detection means (S20) detects sheet lifting up after the start of a job of feeding the sheets from the load-receiving part (21), stops feeding of the sheets by the feeding means(22, 23, 24), and causes the display means (506a) to display a message prompting a reduction in the amount of sheet lifting up when resetting a sheet on the load-receiving part(21).

Description

Sheet conveying device, image reading device, and image forming device

[0001] The present disclosure relates to a sheet conveying device that conveys a sheet, an image reading device that reads image information from a sheet, and an image forming apparatus that forms an image on a recording material.

[0002] Patent document 1 describes a method of determining whether a document is a folded document folded in a Z-shape or a bound bundle of documents based on the time and number of times a detection unit located above the document loading surface detects the document floating up.

[0003] Japanese Patent Application Laid-Open No. 2017-222511

[0004] When conveying a folded sheet, the detection means may detect that the sheet has jumped up, and the sheet conveyance may be stopped. In such a case, if the user resets the sheet without understanding the cause of the stoppage, there is a possibility that the stoppage of conveyance due to the detection of the jumping up may be repeated.

[0005] The present disclosure provides a sheet conveying device, an image reading device, and an image forming device that are capable of providing more appropriate information to a user.

[0006] One aspect of the present disclosure is a sheet conveying device that includes a stacking section on which sheets are stacked, a feeding means that separates and feeds the sheets stacked on the stacking section one by one, a detection means that detects any bouncing of the sheets fed by the feeding means, a display means that displays information, and a control means that, when the detection means detects any bouncing of the sheets after the start of a job to feed sheets from the stacking section, stops the feeding of the sheets by the feeding means and causes the display means to display a message urging the user to reduce the amount of bouncing of the sheets when resetting the sheets on the stacking section.

[0007] According to the present disclosure, when a seat bounce is detected, more appropriate information can be provided to the user.

[0008] Other features and advantages of the present disclosure will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar components are designated by the same reference numerals.

[0009] Schematic diagram of a printer. Perspective view of an image reading device. Control block diagram. Example of a setting screen of a display panel. Top view showing the position of a skew detection sensor. Perspective view showing the position of a jump-up detection sensor. Explanatory diagram showing the behavior of a bound document. Explanatory diagram showing the behavior of a bound document. Explanatory diagram showing the behavior of a bound document. Explanatory diagram showing the behavior of an unbound document. Explanatory diagram showing the behavior of an unbound document. Explanatory diagram showing the behavior of a bound document. Explanatory diagram showing the behavior of a bound document. Explanatory diagram showing the behavior of a bound document. Explanatory diagram showing the behavior of a folded document. Flowchart of a document transport operation according to the first embodiment. Flowchart of a jump-up detection process according to the first embodiment. Example of a screen display according to the first embodiment. Flowchart of a document transport operation according to the second embodiment. Example of a screen display according to the second embodiment. Flowchart of a document transport operation according to the third embodiment. Example of a screen display according to the third embodiment. Example of a screen display according to the third embodiment. Explanatory diagram showing the behavior of a bound document. Flowchart of a document transport operation according to a fourth embodiment. Flowchart of a skew detection process according to the fourth embodiment. 10A and 10B are examples of screen displays according to the fourth embodiment.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] First Embodiment First, an image forming apparatus according to the first embodiment will be described. FIG. 1 is a schematic cross-sectional view of a printer 100 as an image forming apparatus according to this embodiment. The printer 100 is an electrophotographic laser beam printer. The printer 100 includes a printer main body 70 and an image reading device 10 attached to the top of the printer main body 70. The printer 100 also includes an operation unit 506 that accepts operations from a user. The operation unit 506 is provided with a display panel 506a that serves as a display unit that displays information to the user. The display panel 506a is a touch panel that the user can operate by touching it with their fingers. In other words, the display panel 506a also functions as an input unit that accepts input from the user. The operation unit 506 may include hard keys such as a numeric keypad and an execute button as an input unit.

[0012] In the following description, the side of printer 100 where operation unit 506 is provided will be referred to as the front side, and the opposite side will be referred to as the rear side. That is, Fig. 1 is a diagram of printer 100 as seen from the front side. In this embodiment, the term "sheet" refers to not only plain paper, but also special paper such as coated paper, recording materials in special shapes such as envelopes and index paper, and plastic film or cloth for overhead projectors, and a document is also an example of a sheet.

[0013] The printer main body 70 has an image forming engine 60 as an image forming means. The image forming engine 60 includes an electrophotographic image forming unit PU and a fixing device 7. When a command to start an image forming operation is received, a photosensitive drum 1, which is a photosensitive member, rotates, and the drum surface is uniformly charged by a charging device 2. An exposure device 3 then modulates and outputs laser light based on image data transmitted from an image reading device 10 or an external computer, and scans the surface of the photosensitive drum 1 to form an electrostatic latent image. This electrostatic latent image is visualized (developed) into a toner image by toner supplied from a developing device 4.

[0014] In parallel with this image forming operation, a feeding operation is performed to feed a sheet S loaded on a cassette 9 or a manual feed tray (not shown) toward the image forming engine 60. The fed sheet S is transported in accordance with the progress of the image forming operation by the image forming unit PU. The toner image carried on the photosensitive drum 1 is then transferred onto the sheet S by a transfer roller 5. Any toner remaining on the photosensitive drum 1 after the toner image transfer is collected by a cleaning device 6. The sheet S onto which the unfixed toner image has been transferred is handed over to a fixing device 7, where it is sandwiched between a pair of rollers and heated and pressurized. The sheet S onto which the toner has been fixed is discharged to a discharge tray 71.

[0015] [Image Reading Device] Next, the image reading device 10 will be described. Fig. 2 is a perspective view of the image reading device 10. As shown in Figs. 1 and 2, the image reading device 10 includes an ADF 20 (Auto Document Feeder) as a sheet conveying device that conveys an original D, and a reading unit 40 as reading means that reads image information from the original conveyed by the ADF 20. The ADF 20 is rotatably supported with respect to the reading unit 40 by a hinge (not shown) so that a document table glass 41 can be opened. Note that the original D, which is an example of a sheet, may be blank paper or may have an image formed on one or both sides.

[0016] The ADF 20 has a document tray 21 as a loading section on which documents D are stacked, and an output tray 32 to which the documents D are discharged. The document tray 21 is provided with a first regulating plate 21a and a second regulating plate 21b as regulating means for regulating the widthwise position of the documents D set in the document tray 21. The first regulating plate 21a is located on the front side and abuts against the front edge of the documents D stacked on the document tray 21. The second regulating plate is located on the rear side and abuts against the rear edge of the documents D stacked on the document tray 21. The pair of regulating plates, the first regulating plate 21a and the second regulating plate 21b, are movable in the widthwise direction in conjunction with each other by an interlocking mechanism (not shown). Specifically, when one of the first regulating plate 21a and the second regulating plate 21b moves in the widthwise direction, the other of the first regulating plate 21a and the second regulating plate 21b moves in the opposite direction. The first and second regulating plates 21a and 21b come into contact with the ends of the document D in the width direction, thereby regulating the position of the document D.

[0017] The width direction is a direction (sheet width direction) perpendicular to the sheet transport direction in which the ADF 20 transports the document D. The width direction is, for example, the same direction as the rotation axis direction of the pickup roller 22 and the rotation axis direction of the feed roller 23. The sheet transport direction is the movement direction of the document D along the transport path from the document tray 21 to the discharge tray 32 via the reading position Rd of the reading unit 40. In particular, the movement direction of the sheet S when the document D is fed from the document tray 21 into the main body of the ADF 20 may be referred to as the sheet feed direction.

[0018] The ADF 20 includes a pickup roller 22, a feed roller 23, a separation roller 24, a conveying roller pair 25, a lead roller pair 26, a lead roller pair 30, and a discharge roller pair 31. The feed unit consisting of the pickup roller 22, the feed roller 23, and the separation roller 24 constitutes the feeding means in this embodiment. Note that this feed unit is an example of the feeding means, and for example, a rotatable belt-like conveying member may be used instead of the pickup roller 22 and the feed roller 23. Furthermore, the separation roller 24 is an example of a separating member, and a pad-like separating member (separation pad) having a friction member may be used.

[0019] The ADF 20 also has a document presence / absence sensor S31 that detects the presence or absence of a document D on the document tray 21, and a first skew detection sensor S11 and a second skew detection sensor S12 that constitute a skew detection unit S10 as detection means (skew detection means) that detects skew of the document D. The first skew detection sensor S11 is an example of a first sensor, and the second skew detection sensor S12 is an example of a second sensor.

[0020] The ADF 20 also has a jump-up detection sensor S20 as a detection unit (jump-up detection unit) that detects jump-up of a document. The jump-up of a document refers to the vertical position of the document D at the detection position of the jump-up detection sensor S20 changing upward beyond a predetermined position when the document D is being fed. As will be described later, the jump-up of the document D occurs when the document D is a stack of documents bound with staples (bound documents) or when the document D has a crease. The jump-up of a document may occur not only when the document D is deformed during feeding, but also when the document D is deformed so that a portion of the document D is raised upward when it is set on the document tray 21.

[0021] The jump-up detection sensor S20 of this embodiment is an optical sensor having a light-emitting unit S21 and a light-receiving unit S22. The light-emitting unit S21 emits detection light. The light-receiving unit S22 emits a signal corresponding to the incident detection light. The light-receiving unit S22 is positioned so that the detection light from the light-emitting unit S21 enters the sensor via an optical path passing above the document tray 21 (loading unit). The jump-up detection sensor S20 detects the jump-up of the document D when the optical path is blocked. The detection position of the jump-up detection sensor S20 in this embodiment is the position of the optical path from the light-emitting unit S21 to the light-receiving unit S22. In other words, the jump-up detection sensor S20 is configured so that the signal of the light-receiving unit S22 changes depending on whether the document D has jumped up, and the CPU 81 ( FIG. 3 ) can determine whether the document D has jumped up based on the signal received from the light-receiving unit S22. The predetermined position in this embodiment can be said to be the height of the optical path from the light-emitting unit S21 to the light-receiving unit S22.

[0022] The reading unit 40 has a flow reading glass 28, a jump table 29, a reference white board 42, a document glass table 41, a first mirror table 43, a second mirror table 44, a lens 45, and a CCD line sensor 46. A lamp 47 and a mirror 48 are disposed inside the first mirror table 43. Mirrors 49 and 50 are disposed inside the second mirror table 44. The first mirror table 43 and the second mirror table 44 are configured to be movable in the sub-scanning direction (left and right direction in the figure) by wires and drive motors (not shown).

[0023] The image reading device 10 can operate in a flow reading mode in which an image of an original D loaded on the original tray 21 is read while the original D is being fed by the ADF 20, and a fixed reading mode in which an image of an original placed on the original platen glass 41 is read. The flow reading mode is selected when the original presence / absence sensor S31 detects an original D loaded on the original tray 21, or when the flow reading mode is explicitly instructed by the operation unit 506.

[0024] When the skimming mode is executed, the pickup roller 22 supported by an arm (not shown) descends and rotates while abutting against the topmost document D on the document tray 21. The document D is then fed by the pickup roller 22 and separated one by one at a separation nip formed by the feed roller 23 and the separation roller 24. The feed roller 23 is made of a material such as rubber that has less friction than the separation roller 24. A torque limiter is disposed in the drive transmission path to the separation roller 24, so that the separation roller 24 rotates together with the feed roller 23 when one document is fed, but does not rotate when two or more documents are fed. This allows the document to be separated one by one by the feed roller 23 and the separation roller 24.

[0025] The document D fed from the document tray 21 is transported by a transport roller pair 25 and then transported toward the flow reading glass 28 by a lead roller pair 26. A platen guide roller 27 is disposed opposite the flow reading glass 28. The platen guide roller 27 guides the document D passing over the flow reading glass 28 so that the document D does not lift off the flow reading glass 28.

[0026] Then, when the original D passes through a reading position Rd opposite the flow reading glass 28, the image on the surface of the original D is read by the reading unit 40 through the flow reading glass 28. Specifically, light from a lamp 47 is irradiated onto the original D being transported, and reflected light from the original D is guided to a lens 45 by mirrors 48, 49, and 50. The light that passes through the lens 45 forms an image on the light receiving section of a CCD line sensor 46, undergoes photoelectric conversion, and transmits the image information to the CPU 81. The reference white board 42 serves as a reference for the reading brightness of the original D. The original D that has passed through the flow reading glass 28 is guided by a jump platform 29 to a pair of read rollers 30, and is discharged to a discharge tray 32 by a pair of discharge rollers 31.

[0027] On the other hand, the fixed reading mode is selected when the reading unit 40 detects an original D placed on the original table glass 41, or when the fixed reading mode is explicitly instructed by the operation unit 506. In the fixed reading mode, the first mirror table 43 and the second mirror table 44 move along the original table glass 41, and scan the original D with light emitted by the lamp 47. Image information photoelectrically converted by the light receiving elements of the CCD line sensor 46 is transferred to the CPU 81.

[0028] In the present embodiment, the reading unit 40 has been described as having a CCD-type reading mechanism, but the reading unit 40 may also have a CIS (contact image sensor)-type reading mechanism. A CIS-type reading mechanism is composed of a lens array (life-size optical system) arranged in the main scanning direction, a CMOS image sensor arranged in the main scanning direction so as to face the original D via the lens array, and a light source that irradiates light onto the original D. Also, a CCD-type or CIS-type reading mechanism may be disposed inside the ADF 20. When reading mechanisms are disposed in both the ADF 20 and the reading unit 40, the image reading device 10 can read image information from both sides of the original D in a single skimming operation.

[0029] [Control Block] FIG. 3 is a control block diagram of the CPU 81 as a control unit. The CPU 81 is connected to the first skew detection sensor S11 and the second skew detection sensor S12 (skew detection unit S10), the light-emitting unit S21 and the light-receiving unit S22 (jump-up detection sensor S20), and the document presence / absence sensor S31. The CPU 81 is also connected to a feed motor 84, a transport motor 85, and an elevator motor 86 via a motor control unit 83. The feed motor 84 drives the pickup roller 22 and the feed roller 23. The transport motor 85 drives the transport roller pair 25, the read roller pair 26, the read roller pair 30, and the discharge roller pair 31. The elevator motor 86 is an example of an elevator unit that raises and lowers the document tray 21. The CPU 81 is also connected to an operation unit 506 and a memory unit 507. The user can operate the operation unit 506 to start an image reading operation (image reading job) and to perform various settings.

[0030] In this embodiment, the second skew detection sensor S12 also serves as a post-separation sensor for determining the timing to start feeding the document. Specifically, the CPU 81 starts feeding the subsequent sheet following the preceding sheet based on the second skew detection sensor S12 detecting the trailing edge of the preceding sheet. In this way, by having the second skew detection sensor S12 also serve as a post-separation sensor, the number of sensors can be reduced, thereby reducing product costs. However, the post-separation sensor may be disposed separately from the skew detection unit S10. Furthermore, the skew detection unit S10 may be disposed downstream in the sheet conveyance direction from the post-separation sensor disposed downstream and near the separation nip.

[0031] The CPU 81 reads and executes programs stored in the storage unit 507 to control the operation of the ADF 20 or the operation of the image reading device 10, which will be described below. The CPU 81 is disposed, for example, on a control board mounted in the housing of the reading unit 40, and is communicably connected to the control unit of the printer main body 70. The CPU 81 may be disposed in the ADF 20. Furthermore, some or all of the processing performed by the CPU 81, which will be described below, may be executed by the control unit of the printer main body 70.

[0032] 4 shows one example of a screen displayed on the display panel 506a of the operation unit 506, which allows the user to set the execution conditions for the image reading operation by the image reading device 10. In other words, the operation unit 506 is an example of a setting unit for setting the execution conditions for the image reading operation.

[0033] 4 displays a read start button 600 for instructing the start of image reading operation, multiple buttons 601 for setting various conditions for image reading, and a button 602 for setting bound document detection. Here, a "bound document" refers to a document stack (sheet stack) consisting of multiple stapled sheets of document D.

[0034] When the user presses the read start button 600, the image reading device 10 starts an image reading operation (image reading job) that reads image information from a document, which is a series of operations including a document transport operation. Note that if the screen of Fig. 4 is displayed when setting a copy job that duplicates an image of document D, pressing the read start button 600 (copy start button) causes the image reading operation in the image reading device 10 and the image forming operation in the printer main body 70 to be executed.

[0035] [Skew Detection Sensor] Next, the first skew detection sensor S11 and the second skew detection sensor S12 will be described. FIG. 5 is a top view showing the positions of the first skew detection sensor S11 and the second skew detection sensor S12. The first skew detection sensor S11 and the second skew detection sensor S12 are disposed downstream of the feed roller 23 in the sheet transport direction (sheet feed direction). The first skew detection sensor S11 and the second skew detection sensor S12 are disposed side by side in the width direction. That is, the first skew detection sensor S11 and the second skew detection sensor S12 are disposed at the same position in the sheet transport direction. Note that although there are two skew detection sensors in this embodiment, the number of skew detection sensors may be three or more.

[0036] The CPU 81 can determine whether the document being fed is skewed or not based on signals from the first skew detection sensor S11 and the second skew detection sensor S12. Furthermore, if the document is significantly skewed, the CPU 81 may determine that the document is stapled (that the document is a bound document).

[0037] The CPU 81 determines that the document is skewed when the first skew detection sensor S11 or the second skew detection sensor S12 does not detect the document within a predetermined time after the other of the first skew detection sensor S11 and the second skew detection sensor S12 detects the document. If the CPU 81 determines that the document is skewed, it stops feeding the document. In other words, the CPU 81 stops feeding when there is a large difference in the detection timing between the first skew detection sensor S11 and the second skew detection sensor S12. The skew detection process executed by the CPU 81 will be described later.

[0038] [Jump-up Detection Sensor] Next, the jump-up detection sensor S20 will be described. As shown in FIG. 2 , the ADF 20 has a first wall portion 33 and a second wall portion 34 that extend perpendicularly to the support surface 21s that supports the originals on the original tray 21. The first wall portion 33 and the second wall portion 34 are a pair of walls that are arranged opposite each other across the support surface of the original tray 21. The first wall portion 33 is arranged closer to the front than the first restricting plate 21a, and the second wall portion 34 is arranged closer to the back than the second restricting plate 21b. The light-emitting unit S21 is arranged on the first wall portion 33, and the light-receiving unit S22 is arranged on the second wall portion. That is, the light-emitting unit S21 and the light-receiving unit S22 are arranged at a distance from each other in the width direction on the support surface 21s of the original tray 21, sandwiching a document set area therebetween. The document set area is the area that is covered by a document when a document of the maximum size that can be set in the document tray 21 is set in the width direction.

[0039] 6 is a perspective view showing the position of the jump-up detection sensor S20. The position of the jump-up detection sensor S20 is based on the position of the optical path from the light-emitting unit S21 to the light-receiving unit S22. As shown in FIG. 6, the jump-up detection sensor S20 is disposed vertically above the support surface 21s of the document tray 21 (stacking unit). The jump-up detection sensor S20 is also disposed upstream of the separation nip formed by the feed roller 23 and the separation roller 24 in the sheet transport direction. In this embodiment, the position (detection position) of the jump-up detection sensor S20 is set upstream of the pickup roller 22 in the sheet feed direction.

[0040] The position (detection position) of the bounce detection sensor S20 is set, for example, at a position where the distance from the reference position of the leading edge of the document D in the document tray 21 in the sheet feed direction is less than 210 mm. In other words, the distance in the sheet feed direction from the reference position of the leading edge of the document (sheet) in the document tray 21 (loading section) to the detection position is less than 210 mm. The reference position is downstream of the pickup roller 22 and upstream of the separation nip in the sheet feed direction, and is, for example, a position where the leading edge of the document D abuts against a retractable shutter member during feeding. This configuration allows for appropriate detection of the bounce of a bound document even when A3-sized Z-folded documents are set in the document tray 21 in the long-edge feed orientation. However, the position (detection position) of the bounce detection sensor S20 can be changed depending on the document size (particularly the maximum size) supported by the document tray 21. Furthermore, to accommodate a wider variety of sheet sizes, multiple bounce detection sensors may be arranged at different positions in the sheet feed direction.

[0041] The CPU 81 can determine whether or not the document D has jumped up based on the signal from the light receiving unit S22. When the optical path from the light emitting unit S21 to the light receiving unit S22 is blocked by the document, the CPU 81 may determine that the document is, for example, a bound document and stop feeding.

[0042] [Jump-up Detection Method] Next, before describing the jump-up detection process, the movement of the document when jumping up will be described. In the following description, the state in which the light-receiving unit S22 receives light from the light-emitting unit S21 of the jump-up detection sensor S20 is referred to as the "non-detection state" or transmission state of the jump-up detection sensor S20. The state in which the light-receiving unit S22 does not receive light from the light-emitting unit S21 is referred to as the "detection state" or light-blocking state of the jump-up detection sensor S20. The detection state is a state in which the jump-up detection sensor S20 detects the jump-up of the document, and the non-detection state is a state in which the jump-up detection sensor S20 does not detect the jump-up of the document.

[0043] 7A to 7C are perspective views showing the movement of the bound document Dst when it is fed. FIG. 7A shows the state in which the bound document Dst is stacked, FIG. 7B shows the state in which the bound document Dst has been fed up to the feed roller 23, and FIG. 7C shows the state in which the bound document Dst has jumped up. Note that the bound document Dst is a stack of documents in which the first document Dst1 and the second document Dst2 are bound together with staples ST. Also, FIGS. 8A and 8B are perspective views showing the movement of the document when an unstapled document D is fed. FIG. 8A shows the state in which the document D is being transported, and FIG. 8B shows the state in which the trailing edge of the transported document D has passed the second skew detection sensor S12.

[0044] When feeding is started with bound documents Dst stacked on document tray 21 as shown in Fig. 7A, the bound documents Dst are transported by pickup roller 22 to the separation nip formed by feed roller 23 and separation roller 24. When the bound documents Dst reach the separation nip as shown in Fig. 7B, the first document Dst1 and the second document Dst2 are transported so as to be separated. At this time, the first document Dst1 advances in the sheet transport direction and passes through the separation nip, while the second document Dst2 is prevented from passing through the separation nip by separation roller 24 and remains on document tray 21. However, because the first document Dst1 and the second document Dst2 are bound together by staples ST, the force applied by each roller may cause the first document Dst1 to jump up.

[0045] 7C, when the first document Dst1 jumps up, the first document Dst1 blocks the optical path from the light-emitting element S21 to the light-receiving element S22, and the light from the light-emitting element S21 does not reach the light-receiving element S22. That is, the jump-up detection sensor S20 switches from a non-detecting state to a detecting state. When the jump-up detection sensor S20 enters the detecting state, the CPU 81 can determine that a document has jumped up.

[0046] On the other hand, when an unstapled document D is transported as shown in Fig. 8A, the jump-up detection sensor S20 is in a non-detecting state. Then, as shown in Fig. 8B, the trailing edge of the document D passes the second skew detection sensor S12, which also serves as a post-separation sensor, while the jump-up detection sensor S20 remains in a non-detecting state. When the document D passes the second skew detection sensor S12 without being detected as jumping up, the CPU 81 can determine that the next document D can be fed (allowing feeding to begin).

[0047] 9A to 9C are perspective views showing the movement of the bound document Dst when the document is fed with its trailing edge stapled. Fig. 9A shows the state in which the bound document Dst is stacked, Fig. 9B shows the state in which the bound document Dst has been fed up to the feed roller 23, and Fig. 9C shows the state in which the bound document Dst has jumped up. While Figs. 7A to 7C illustrate the case in which the leading edge of the bound document Dst is stapled, Figs. 9A to 9C explain the case in which the trailing edge of the bound document Dst is stapled. The leading edge of the document or bound document refers to the downstream edge of the document or bound document in the sheet transport direction, and the trailing edge of the document or bound document refers to the upstream edge of the document or bound document in the sheet transport direction.

[0048] When bound originals Dst with their trailing edges stapled are fed as shown in FIG. 9A, the bound originals Dst are transported to the feed roller 23 without jumping up, as shown in FIG. 9B. However, while the first original Dst1 advances in the sheet transport direction and passes through the separation nip, the second original Dst2 is prevented from passing through the separation nip by the separation roller 24 and remains in the original tray 21. As a result, the stapled trailing edge of the bound original Dst jumps up. This causes the optical path from the light-emitting unit S21 to the light-receiving unit S22 to be blocked by the bound original Dst, and the jump-up detection sensor S20 enters a detection state. In this way, even if the position of the staple ST is different, the CPU 81 can detect the jump-up of the original.

[0049] [Detection of Jumping Up Due to Folded Document] The above has described the detection of jumping up of a stapled bound document Dst when it is conveyed, but if the document D is a folded document, jumping up may be detected even if it is a single document that is not stapled. A folded document (folded sheet) is a document (sheet) that does not lie completely flat even when placed on a flat surface such as a desk due to a crease (fold line), such as a document that has been filed in a Z-fold (one-side fold).

[0050] 10 is a diagram showing an example of a folded document Df that has been folded in a Z-shape at two folds, a valley fold Dv and a mountain fold Dp, and is set in the document tray 21 with the mountain fold Dp at the rear end. As shown in FIG. 10, the folded document Df may be set with a fold remaining so that the mountain fold Dp protrudes upward relative to the leading end of the valley fold Dv.

[0051] When using a folded original Df, if the folded original Df is set in the original tray 21 in a flattened state so that the height of the mountain fold Dp is sufficiently low, the image reading device 10 can normally convey the folded original Df. However, if the folded original Df is set in an insufficiently flattened state, the jump-up detection sensor S20 will detect the jump-up of the original when the protruding portion of the folded original Df passes through the jump-up detection sensor S20 after feeding begins. Specifically, in the case of a folded original Df that has been Z-folded as shown in Figure 10, the portion between the valley fold Dv and the mountain fold Dp of the folded original Df blocks the light path from the light-emitting unit S21 to the light-receiving unit S22, causing the jump-up detection sensor S20 to change from a non-detecting state to a detecting state.

[0052] 10 shows a Z-folded folded document Df, but the document may also be detected as jumping up if the document is folded in a manner other than the Z-fold, such as in half (center fold) or in thirds. In other words, regardless of the folding method, if a folded document is set in the document tray 21 with part of the document protruding upward due to a fold, the jumping up of the document will be detected by the jumping up detection sensor S20 after feeding of the folded document begins.

[0053] [Jump-up Detection Process] The jump-up detection process will now be described. FIG. 12 is a flowchart showing the process of the jump-up detection process executed by the CPU 81. When the jump-up detection process starts, the CPU 81 determines whether the jump-up detection sensor S20 is in a detection state (S201). If the jump-up detection sensor S20 is in a non-detection state (S201: No), the CPU 81 determines whether the second skew detection sensor S12, which also serves as a post-separation sensor, has changed from ON to OFF, i.e., whether the trailing edge of the document has already passed through the separation nip (S202). If the trailing edge of the document has not already passed through the separation nip (S202: No), the process returns to S201. In other words, the CPU 81 monitors whether the jump-up detection sensor S20 is in a detection state from the start of document feeding until the trailing edge of the document passes through the separation nip.

[0054] The start of document feeding refers to the point in time when pickup roller 22 comes into contact with the document to be fed this time (the topmost document on document tray 21) and is being rotated (S103 in FIG. 11). That is, document feeding starts when pickup roller 22, which is stationary, comes into contact with the document and then pickup roller 22 begins to be rotated by feed motor 84, or when pickup roller 22, which is being rotated, descends and comes into contact with the document. Furthermore, CPU 81 can calculate the document transport distance from the start of document feeding based on the elapsed time from the start of document feeding and the document transport speed. The document transport speed may be, for example, the circumferential speed of pickup roller 22.

[0055] If the jump-up detection sensor S20 detects the sheet before the trailing edge of the original passes through the separation nip (S201: Yes), the CPU 81 determines that the original has jumped up and sets the result of the jump-up detection process to "jump-up occurred" (S203). That is, the detection unit of this embodiment detects the sheet jumping up if the light path from the light-emitting unit S21 to the light-receiving unit S22 is blocked during the period from the start of sheet feeding until the downstream detection unit (second skew detection sensor) downstream of the separation nip detects the sheet's passing through. On the other hand, if the jump-up detection sensor S20 remains in the non-detecting state while the trailing edge of the original passes through the separation nip (S202: Yes), the CPU 81 determines that the original has not jumped up and sets the result of the jump-up detection process to "no jump-up" (S204). The result of the jump-up detection process is recorded, for example, in the memory unit 507 and is referenced in the document transport operation flow ( FIG. 11 ).

[0056] [Document Conveyance Operation Flow] Next, the control of document conveyance by the ADF 20 will be described with reference to a flowchart. Fig. 11 is a flowchart showing the process of the document conveyance operation executed by the CPU 81. When the power to the printer 100 is turned on, the CPU 81 starts the process of the flowchart in Fig. 11. Note that the flow in Fig. 11 describes the operation when skew of the document is not detected as a result of skew detection by the first skew detection sensor S11 and the second skew detection sensor S12.

[0057] First, the CPU 81 determines whether or not a document has been set on the document tray 21 based on a signal from the document presence / absence sensor S31 (S101). If no document is present on the document tray 21 (S101: No), the CPU 81 does not proceed to the next process and waits until a document is placed on the document tray 21.

[0058] If it is determined that originals are loaded on the original tray 21 (S101: Yes), the CPU 81 determines whether or not a feeding start command has been issued by the user (S102). The CPU 81 determines that a feeding start command has been issued when, for example, the user presses the reading start button 600 on the screen in Fig. 4. If a feeding start command has not been issued (S102: No), the CPU 81 does not proceed to the next process and waits until a feeding start command is issued.

[0059] If a feeding start command is received (S102: Yes), the CPU 81 starts feeding the originals (S103). Specifically, the CPU 81 starts driving the feeding units (22, 23, 24) using the feeding motor 84, and lowers the pickup roller 22 to contact the topmost original. Furthermore, if the original tray 21 (or a portion thereof) can be raised and lowered, the CPU 81 raises the original tray 21 before lowering the pickup roller 22. Once feeding of the originals has started, the CPU 81 starts a jump-up detection process (S104). The contents of the jump-up detection process are as described above.

[0060] The CPU 81 determines whether or not a jumping-up of the original document has been detected in the jumping-up detection process (S105). If a jumping-up of the original document has been detected (S105: Yes), the CPU 81 stops the feed motor 84 and the transport motor 85 to stop the transport of the original document (S106). Furthermore, if a jumping-up of the original document has been detected, the CPU 81 displays a predetermined screen on the display panel 506a (S107). This screen display (FIG. 13) includes a message urging the user to reduce the amount of jumping-up of the original document by, for example, straightening the folds of the folded original document when resetting the original document on the original tray 21. Details of the screen display in S107 will be described later.

[0061] The screen display of S107 may be displayed simultaneously with the stop of document transport based on the detection of a document jumping up, or may be displayed after the document transport is stopped. For example, a screen showing the jam clearance method may be displayed on the display panel 506a immediately after the document transport is stopped, and the screen display of S107 may be performed after the jam is cleared. In this case, after displaying the jam clearance screen, the CPU 81 displays the screen of S107 when it detects the removal of the jammed document based on a signal from the sensor that detected the jam, or when the user inputs completion of jam clearance via the display panel 506a.

[0062] Thereafter, the CPU 81 determines the result of the user's selection on the screen display in S107 (S108), and branches the subsequent processing.

[0063] If the user selects the "Reload and continue job" button B2 (FIG. 13), the CPU 81 waits for the user to reload the document and resumes document transport when the user instructs the job to resume (S102: Yes). In this case, the document is removed from the position at which the document transport was stopped due to the detection of the document jump, and the document set in the predetermined position (reference position) on the document tray 21 is fed. To facilitate document reloading, the CPU 81 preferably moves the pickup roller 22 upward from the top document on the document tray 21 while waiting for the user to reload the document. If the document tray 21 (or a portion thereof) is capable of being raised or lowered, the CPU 81 preferably lowers the document tray 21 while waiting for the user to reload the document.

[0064] If the user selects the "Turn off bounce detection and continue job" button B3 (FIG. 13), the CPU 81 disables the bounce detection function (S109) and waits for the user to reload the document. Then, if the user instructs the user to resume the job after the document is reloaded (S102: Yes), the CPU 81 resumes document transport. Because the bounce detection function is disabled after the job is resumed, the CPU 81 determines that document transport can continue regardless of the detection / non-detection state of the bounce detection sensor S20. In other words, even if the bounce detection sensor S20 changes from a non-detection state to a detection state after the transport of the document reloaded by the user begins, the CPU 81 determines that document transport can continue. Note that the bounce detection function can be disabled by disabling the bounce detection sensor S20 itself (by stopping power supply to the light-emitting unit S21 and the light-receiving unit S22 and not accepting signals from the light-receiving unit S22).

[0065] However, when the resumed job is completed, the disablement of the jump-up detection function is released. Therefore, in the next job that is started after the resumed job is completed, the jump-up detection process (S104) is executed, and if a jump-up is detected, the document transport is stopped and a screen display is executed on the operation unit 506 (S106, S107).

[0066] Furthermore, in the case of "turn off bounce detection and continue job," the document set in a predetermined position (reference position) on document tray 21 is fed, as in the case of "reset and continue job." To facilitate document resetting, it is preferable that CPU 81 moves pickup roller 22 upward from the top document on document tray 21 while waiting for the user to reset the document. Furthermore, if document tray 21 (or a part thereof) can be raised and lowered, it is preferable that CPU 81 lowers document tray 21 while waiting for the user to reset the document.

[0067] If the user selects the "Cancel Job" button B4 (FIG. 13), the CPU 81 ends the image reading job. In this case, the setting information input by the user when inputting the image reading job (for example, the execution conditions that can be set by operating button 601 on the setting screen in FIG. 4) is cleared (S114), and the user must input new setting information when inputting a new image formation job. Alternatively, setting information such as the document size acquired by the CPU 81 using a sensor on the document tray 21 is automatically used, or preset values ​​are used as the initial values ​​of the execution conditions. Note that if any of the above-mentioned buttons B1 to B3 is selected, the setting information input by the user when inputting the image reading job is maintained, and the document transport operation is executed based on the same execution conditions as before the job was interrupted, even after the job is resumed.

[0068] On the other hand, if no jumping of the document is detected in the jumping detection process (S105: No), the CPU 81 determines that the document transport can continue (S111). In this case, the CPU 81 controls the drive of the feed motor 84 and the transport motor 85 according to a predetermined transport schedule to continue the document transport. Note that even if the CPU 81 determines that the document transport can continue in S111, the CPU 81 may stop the document transport if a document transport abnormality is detected. A transport abnormality is, for example, a document stuck or delayed on the document transport path in the ADF 20 (collectively referred to as a jam). The CPU 81 controls the document transport while monitoring for jams and other transport abnormalities based on the detection results of each sensor (e.g., the second skew detection sensor S12 as a post-separation sensor) arranged on the document transport path.

[0069] Thereafter, the CPU 81 determines whether the document being transported is the last document based on a signal from the document presence / absence sensor S31 (S112). If the document being transported is the last document (S112: Yes), the CPU 81 stops the feed motor 84 and the transport motor 85 to stop transport of the document (S113). If the document being transported is not the last document (S112: No), the CPU 81 returns to S103 and starts feeding the next document. The CPU 81 repeats the above process, and when transport of the last document is completed, the job setting information is cleared (S114) and the job is ended.

[0070] [Screen Display] Incidentally, as described above, when a sheet with a crease (folded original) is transported, the jump-up detection sensor S20 detects the original being jumped up. A configuration in which sheet transport is stopped based on the detection of the original being jumped up may reduce usability. That is, even though the original is a folded original and the jump-up is detected, if the user resets the sheet without understanding the cause of the transport stop, there is a possibility that transport stops based on the detection of the jump-up may be repeated.

[0071] Therefore, in this embodiment, an attempt is made to provide the user with appropriate information by displaying (UI display, screen display) on the display panel 506a (display means).

[0072] An example of a screen display on the display panel 506a will be described with reference to Fig. 13. Fig. 13 shows an example of a screen display that is displayed when a jump-up of the document is detected by the jump-up detection process.

[0073] 13, a message M0 informing the user of an abnormal document transport, messages M2a and M2b informing the user of reloading the document, and a message M3 informing the user of disabling the document bounce detection function are displayed. Also displayed in this display are a button B2 for "Reload and continue job," a button B3 for "Turn off document bounce detection and continue job," and a button B4 for "Cancel job." The operations of the ADF 20 and the image reading device 10 when buttons B2 to B4 are selected are as described using the flowchart in FIG. 11.

[0074] 13 includes information prompting the user to reset the bound document and information prompting the user to remove staples from the document when resetting the bound document. However, message M2a may not include information prompting the user to reset the bound document, but may simply prompt the user to remove staples when resetting the bound document (for example, "Please remove staples when resetting stapled documents"). Furthermore, the information prompting the user to reset the bound document and the information prompting the user to remove staples from the document may be displayed as separate messages or images.

[0075] 13 includes information urging the user to reload the folded document and information urging the user to reduce the amount of document bounce when reloading the folded document. However, message M2b may not include information urging the user to reload the folded document, but may simply urge the user to reduce the amount of document bounce when reloading the folded document (for example, "If you are reloading a document with creases, please straighten the creases."). Furthermore, the information urging the user to reload the folded document and the information urging the user to reduce the amount of document bounce may be displayed as separate messages or images.

[0076] [Summary of this embodiment] According to this embodiment, when the bounce detection sensor S20 enters a detection state during an image reading job, the CPU 81 stops the transport of the document (S106) and displays a message M2b on the display panel 506a. The message M2b includes information urging the user to reduce the amount of bounce of the document when resetting the folded document. In other words, when the detection unit detects a sheet bounce after starting a job to feed sheets from the stacking unit, the control unit of this embodiment stops the feeding of the sheet by the feeding unit and displays a message on the display unit urging the user to reduce the amount of bounce of the sheet when resetting the sheet in the stacking unit.

[0077] With this configuration, a user who sees message M2b can realize that the document has been detected as being folded and that the document has been jumped up, and can straighten the fold of the folded document to reduce the amount of jumping up and reset the document. Furthermore, repeated stops of transport due to the detection of the document being folded up can be avoided, thereby improving usability.

[0078] Therefore, according to this embodiment, it is possible to provide a sheet conveying device, an image reading device, and an image forming device that can provide more appropriate information to the user when a sheet jump is detected.

[0079] Furthermore, according to this embodiment, when the bounce detection sensor S20 enters a detection state during an image reading job, a message M2a regarding re-setting of the bound document is displayed on the display panel 506a together with a message M2b. In other words, the message urging the user to reduce the amount of bounce of the sheets when re-setting the sheets in the stacking section is set as the first message. In this case, when the detection unit detects a bounce of the sheets after the start of the job, the control unit of this embodiment causes the display unit to display, together with the first message, a second message urging the user to unbind the bound sheet bundle if there is a bound sheet bundle.

[0080] With this configuration, a user who sees message M2a can realize that the document is bound and that the document has been detected as being jumping up, and can reset the document after releasing the bound document by removing the staples, etc. In other words, it is possible to provide the user with more appropriate information so that the user can take appropriate measures depending on whether the cause of the jumping up is a folded document or a bound document.

[0081] Furthermore, according to this embodiment, when the bounce detection sensor S20 enters a detection state during an image reading job, a "Reset and continue job" button B2 is displayed on the display panel 506a. In other words, when the detection unit detects a sheet bounce after the job has started, the control unit of this embodiment causes the display unit to display a first button that instructs the user to continue the job after resetting the sheet in the stacking unit. This allows the user to select to continue the job by resetting the document after eliminating the cause of the bounce.

[0082] Furthermore, according to this embodiment, when the bounce detection sensor S20 enters a detection state during an image reading job, a button B3 "Turn off bounce detection and continue job" is displayed on the display panel 506a. In other words, when the detection unit detects a sheet bounce after the start of a job, the control unit of this embodiment causes the display unit to display a button instructing the user to continue the job without detecting the bounce by the detection unit. This allows the user to select to continue the job regardless of the result of the bounce detection. For example, in cases where the user is aware that a malfunction of the bounce detection sensor S20 has resulted in an erroneous detection of a document bounce, disabling the bounce detection function may be desirable.

[0083] Furthermore, according to this embodiment, a button B2 (first button) for "Reset and continue the job" and a button B3 (second button) for "Turn off bounce detection and continue the job" are displayed, so the user can select an appropriate option depending on the condition of the document, etc.

[0084] When button B2 (first button) is operated (S108: B2), if the jump-up detection sensor S20 enters a detection state after document feeding is resumed based on a job restart instruction (S102: Yes), document transport is stopped again (S106). On the other hand, when button B3 (second button) is operated (S108: B3), document transport continues (S109, S111) even if the jump-up detection sensor S20 enters a detection state after document feeding is resumed based on a job restart instruction (S102: Yes). This allows the ADF 20 to operate appropriately according to the user's wishes.

[0085] Furthermore, according to this embodiment, when the bounce detection sensor S20 enters a detection state during an image reading job, a "Cancel Job" button B4 is displayed on the display panel 506a. In other words, the control unit of this embodiment causes the display unit to display a button for instructing the user to cancel the job when the detection unit detects a sheet bounce after the job has started. This allows the user to select canceling the job, for example, when the user knows that the cause of the document bounce cannot be resolved.

[0086] Furthermore, according to this embodiment, a button B2 (first button) for "Reset and continue job" and a button B4 (third button) for "Cancel job" are displayed, so that the user can select an appropriate option depending on the condition of the original, etc.

[0087] When button B2 (first button) is operated (S108: B2), the job is resumed using the execution conditions that were set on the setting screen (FIG. 4) or the like when the job started. On the other hand, when button B4 (third button) is operated (S108: B4), the set execution conditions are cleared, and a new job is executed using the execution conditions that were newly set on the setting screen (FIG. 4) or the like after the job was stopped. Therefore, if the user wishes to reset the execution conditions, the job can be quickly resumed using the set execution conditions, and if the user wishes to stop the job, a new job can be executed with new execution conditions.

[0088] Second Embodiment An image forming apparatus according to a second embodiment will be described. In this embodiment, the display content on the display panel 506a when a document is detected as being jumped up is different from that of the first embodiment. Hereinafter, elements with the same reference symbols as those in the first embodiment will be considered to have basically the same configurations and functions as those described in the first embodiment unless otherwise specified, and differences from the first embodiment will be mainly described.

[0089] [Document Conveyance Operation Flow] Figure 14 is a flowchart showing the process of the document conveyance operation in this embodiment. The flow in Figure 14 explains the operation when skew of the document is not detected as a result of skew detection by the first skew detection sensor S11 and the second skew detection sensor S12. The processes of S301 to S306, S309, and S311 to S314 are the same as S101 to S106, S109, and S111 to S114 in the first embodiment (Figure 11), respectively, and therefore will not be described again.

[0090] If the CPU 81 detects that the document has jumped up in the jump-up detection process (S305: Yes), it stops the transport of the document (S306) and displays a predetermined screen on the display panel 506a (S307). This screen display (FIG. 16) includes a message M1 and a button B1 related to continuing the job without resetting the document in the document tray 21. Details of the screen display in S307 will be described later. Note that the screen display in S307 may be displayed simultaneously with the stop of the document transport based on the detection of the document jump-up, or may be displayed after the document transport is stopped.

[0091] Thereafter, the CPU 81 determines the result of the user's selection on the screen display in S307 (S308) and branches the subsequent processing. The processing when buttons B2, B3, and B4 are selected is the same as in the first embodiment, and therefore a description thereof will be omitted.

[0092] If the user selects the "Continue job without resetting" button B1 (FIG. 16), the CPU 81 resumes document transport upon pressing of button B1 without waiting for the user to reset the document (S310). In this case, the CPU 81 determines that document transport can be continued (S311). Document transport resumes from the position at which the document transport was stopped upon detection of the document jumping up. The CPU 81 also waits without raising the pickup roller 22 or lowering the document tray 21, and upon pressing of button B1, starts the feed motor 84 and the transport motor 85 to resume document transport. After transport resumes, the process returns to S311.

[0093] Note that when the transport of the original is resumed by pressing the "Continue job without resetting" button B1, the jump-up detection function may be disabled while the original is being transported. In other words, even if the jump-up detection sensor S20 is in a detection state again after the transport of the original is resumed (S310), the CPU 81 determines that the transport of the original can be continued. However, for the original following the original whose transport is resumed by pressing the button B1, the jump-up detection process (S304) may be executed, and if a jump-up is detected, the transport of the original may be stopped and a screen display (S307) may be executed on the operation unit 506.

[0094] [Screen Display] A screen display that is displayed on the display panel 506a when a jump-up of the document is detected by the jump-up detection process in this embodiment will be described with reference to FIG.

[0095] In this example, a message M0 informing of an error in document transport, a message M1 regarding continuing the job without resetting the document, messages M2a and M2b regarding resetting the document, and a message M3 regarding disabling the bounce-up detection function are displayed. Also displayed in this example are a button B1 for "Continue job without resetting," a button B2 for "Reset and continue job," a button B3 for "Turn off bounce-up detection and continue job," and a button B4 for "Cancel job." The operation of the ADF 20 and image reading device 10 when button B1 is selected is as described above. The operation of the ADF 20 and image reading device 10 when buttons B2 to B4 are selected is as described in the first embodiment ( FIG. 11 ).

[0096] [Summary of this embodiment] As in the first embodiment, when a jumping up of the original is detected, the CPU 81 stops the transport of the original (S306) and displays a message M2b on the display panel 506a that urges the user to reduce the amount of jumping up of the original when resetting the folded original (S307). Therefore, according to this embodiment, it is possible to provide a sheet transport device, an image reading device, and an image forming device that can provide more appropriate information to the user when a jumping up of the sheet is detected.

[0097] Furthermore, according to this embodiment, when the jump-up detection sensor S20 enters a detection state during an image reading job, a button B1 for "Continue job without resetting" is displayed on the display panel 506a. In other words, when the detection unit detects a sheet jumping up after the job has started, the control unit of this embodiment causes the display unit to display a button for instructing the user to continue the job without resetting the sheet on the stacking unit. This allows the user to select to quickly resume the job without resetting the document.

[0098] Furthermore, according to this embodiment, a button B1 (fourth button) for "Continue job without resetting" is displayed along with a button B2 (first button) for "Reset and continue job," allowing the user to select an appropriate option depending on the state of the original, etc. For example, if the user understands that there is a low risk of a transport error occurring, such as when only one folded original is set, the user selects button B1.

[0099] When button B2 (first button) is operated (S308: B2), the CPU 81 lowers the document tray 21 (stacking section) without resuming document feeding and waits for reloading, and then raises the document tray 21 based on an instruction to start feeding (S302: Yes). On the other hand, when button B1 (fourth button) is operated (S308: B1), the CPU 81 resumes document transport without lowering the document tray 21 (stacking section) (S310). Therefore, if the user wishes to reload documents, the document tray 21 is lowered to make it easier for the user to reload documents, and if the user determines that reloading is not necessary, transport can be resumed quickly without lowering the document tray 21.

[0100] Third Embodiment An image forming apparatus according to a third embodiment will be described. This embodiment differs from the second embodiment in that the display content on the display panel 506a changes depending on the stopping position of the document when a document jump is detected. Below, elements with the same reference numerals as those in the first and second embodiments will be considered to have basically the same configurations and functions as those described in the first and second embodiments unless otherwise specified, and differences from the first and second embodiments will be mainly described.

[0101] [Document Conveyance Operation Flow] Fig. 16 is a flowchart showing the process of the document conveyance operation in this embodiment. The flow in Fig. 16 explains the operation when skew of the document is not detected as a result of skew detection by the first skew detection sensor S11 and the second skew detection sensor S12. The processes of S401 to S406 and S410 to S416 are the same as S301 to S306 and S308 to S314 in the second embodiment (Fig. 14), respectively, and therefore will not be described again.

[0102] If the CPU 81 detects that the document has jumped up in the jump-up detection process (S405: Yes), it stops the transport of the document (S406) and displays a predetermined screen on the display panel 506a (S408, S409). At this time, it determines the position of the document at the time when the transport of the document was stopped due to the detection of the jump-up (S407) and switches between the first screen display (S408, FIG. 17A) and the second screen display (S409, FIG. 17B). The first screen display and the second screen display will be described in detail later.

[0103] The CPU 81 determines the position of the document when the document feed stopped based on the time when the document jump was detected, the time when the leading edge of the document was detected by a sensor on the feed path of the ADF 20 immediately before the jump was detected, and the document feed speed. In this embodiment, if the leading edge of the document has not yet passed the reading position Rd ( FIG. 1 ) of the reading unit 40 when the document feed stopped ( S407: Yes), the CPU 81 displays the first screen ( S408 ). On the other hand, if the leading edge of the document has already passed the reading position Rd when the document feed stopped ( S407: No), the CPU 81 displays the second screen ( S409 ). The processing when the user selects buttons B1 to B4 on the first screen display or the second screen display may be the same as the processing described in the second embodiment ( FIG. 14 ).

[0104] The first screen display and the second screen display (S408, S409) may be displayed simultaneously with the stop of document transport (S406) or after the document transport is stopped. Also, if the leading edge of the document has already passed the reading position Rd of the reading unit 40 at the time the document transport is stopped (S407: No), the image information that has been read partway by the reading unit 40 is discarded. In other words, the storage area in the storage unit 507 for storing read image data that was allocated to the document for which jumping up was detected is released, and new read image data can be written.

[0105] [Screen Display] The screen display that is displayed on the display panel 506a when a document is detected to jump up in this embodiment will be described with reference to FIGS. 17A and 17B.

[0106] 17A is an example of a screen display when the transport of the document is stopped before the leading edge of the document passes the reading position Rd. The screen display in this case may be the same as the screen display (FIG. 15) when a document jump is detected in the second embodiment. In other words, the screen display when the transport of the document is stopped before the leading edge of the document passes the reading position Rd includes a message M1 and a button B1 related to continuing the job without reloading the document.

[0107] 17B is an example of a screen display when the transport of the document is stopped after the leading edge of the document has passed the reading position Rd. The screen display in this case may be the same as the screen display ( FIG. 13 ) when the document jumping up is detected in the first embodiment. In other words, the screen display when the transport of the document is stopped before the leading edge of the document has passed the reading position Rd does not include the message M1 and button B1 regarding continuing the job without resetting the document.

[0108] [Summary of this embodiment] As in the first embodiment, when a jumping up of the original is detected, the CPU 81 stops the transport of the original (S406) and displays a message M2b on the display panel 506a urging the user to reduce the amount of jumping up of the original when resetting the folded original (S408, S409). Therefore, according to this embodiment, it is possible to provide a sheet transport device, an image reading device, and an image forming device that can provide more appropriate information to the user when a jumping up of the sheet is detected.

[0109] Furthermore, according to this embodiment, if the transport of the original document is stopped before the leading edge of the original document passes the reading position Rd, the "Continue job without resetting" button B1 is displayed on the display panel 506a (S408, FIG. 17A). On the other hand, if the transport of the original document is stopped before the leading edge of the original document passes the reading position Rd, the "Continue job without resetting" button B1 is not displayed on the display panel 506a (S409, FIG. 17B). In other words, if the detection unit detects the sheet jumping up before the leading edge of the sheet reaches the reading position where image information is read from the sheet, the control unit causes the display unit to display the fourth button. Furthermore, if the detection unit detects the sheet jumping up after the leading edge of the sheet reaches the reading position, the control unit does not cause the display unit to display the fourth button.

[0110] As explained in the second embodiment, if only one folded document is set, the document may continue to be fed without any problems even if the document jump detection sensor S20 detects the document jumping up. However, if the leading edge of the document has already reached the reading position Rd, the image information may not be read correctly even if the document is fed again. For example, the document feed speed may not be stable immediately after the resumption of feeding, which may cause the magnification of the scanned image information in the sub-scanning direction to change within a single image. Furthermore, in a configuration where the drive timing of the CCD line sensor 46 is synchronized based on the timing of the passage of a sensor located near the reading position, reading may not be able to start due to a loss of synchronization (or a timing shift) after feeding is resumed.

[0111] According to this embodiment, if the transport of the document is stopped when the leading edge of the document has already reached the reading position Rd, the option to continue the job without reloading the document is not displayed on the display panel 506a, thereby avoiding the above-mentioned inconvenience. On the other hand, if the transport of the document is stopped before the leading edge of the document reaches the reading position Rd, the option to continue the job without reloading the document is presented to the user, thereby achieving the same advantages as in the second embodiment.

[0112] Fourth Embodiment An image forming apparatus according to a fourth embodiment will be described. In this embodiment, an example of control for detecting skew of an original document in parallel with detecting a jump-up of the original document will be described. Below, elements with the same reference numerals as those in the first and second embodiments will have basically the same configurations and functions as those described in the first and second embodiments unless otherwise specified, and differences from the first and second embodiments will be mainly described.

[0113] [Method for detecting skew] First, before describing the flowchart of the skew detection process, the movement of the document when skew occurs will be described. Figures 18A and 18B are perspective views showing the movement of the document when bound documents Dst are fed. Figure 18A shows a state in which bound documents Dst are stacked, and Figure 18B shows a state in which bound documents Dst are fed and skew occurs.

[0114] 18A, when feeding is started with the bound document Dst stacked on the document tray 21, the bound document Dst is conveyed by the pickup roller 22 to the separation nip formed by the feed roller 23 and the separation roller 24. When the bound document Dst reaches the separation nip as shown in FIG. 18B, the first document Dst1 and the second document Dst2 are conveyed so as to be separated.

[0115] The first document Dst1 advances in the sheet conveyance direction and passes through the separation nip, while the second document Dst2 is prevented from passing through the separation nip by the separation roller 24 and remains in the document tray 21. However, because the first document Dst1 and the second document Dst2 are stapled together with staples ST, the first document Dst1 may rotate around the staple ST. In this case, the side of the document Dst1 that is stapled with staples ST is not conveyed, so the first skew detection sensor S11 is turned OFF. On the other hand, the side of the document Dst1 that is not stapled with staples ST is conveyed downstream, so the second skew detection sensor S12 is turned ON.

[0116] In this way, the CPU 81 can determine whether the document is skewed based on the difference in timing at which the two skew detection sensors turn ON. Note that, although the reason why skew occurs when the document is a bound document Dst has been explained here, skew can also occur in documents that are not bound due to various causes such as improper setting position or roller wear. The skew detection unit S10 can detect skew of the document regardless of whether the document is a bound document Dst or not.

[0117] [Skew Detection Process] Next, the skew detection process (S505 in FIG. 20) will be described with reference to a flowchart. FIG. 19 is a flowchart showing the skew detection process executed by the CPU 81.

[0118] First, the CPU 81 waits until either the first skew detection sensor S11 or the second skew detection sensor S12 is turned ON (S601, S602).

[0119] If the second skew detection sensor S12 turns ON first (S602: Yes), the CPU 81 measures the time difference until the first skew detection sensor S11 turns ON (S603, S604). That is, if a predetermined time Tth [ms] has elapsed since the second skew detection sensor S12 turned ON while the first skew detection sensor S11 remains OFF (S604: Yes), the CPU 81 determines that skew has occurred (S605) and ends the skew detection process. On the other hand, if the first skew detection sensor S11 turns ON before the predetermined time Tth has elapsed since the second skew detection sensor S12 turned ON (S603: Yes), the CPU 81 determines that skew has not occurred (S609) and ends the skew detection process.

[0120] If the first skew detection sensor S11 turns ON first (S601: Yes), the CPU 81 measures the time difference until the second skew detection sensor S12 turns ON (S606, S607). That is, if a predetermined time Tth has elapsed since the first skew detection sensor S11 turned ON while the second skew detection sensor S12 remains OFF (S607: Yes), the CPU 81 determines that skew has occurred (S605) and ends the skew detection process. On the other hand, if the second skew detection sensor S12 turns ON before the predetermined time Tth has elapsed since the first skew detection sensor S11 turned ON (S606: Yes), the CPU 81 determines that skew has not occurred (S609) and ends the skew detection process.

[0121] Here, the predetermined time Tth is a value determined according to the document transport speed, etc., and is, for example, 30 ms. However, the value of the predetermined time Tth is not limited to this. Furthermore, the value of the predetermined time Tth in S604 may be different from that in S607.

[0122] In addition, in S605, the CPU 81 sets the result of the skew detection process to "skew present." Specifically, the CPU 81 records information indicating that skew of the original document has not occurred in the storage unit 507. In S606, the CPU 81 sets the result of the skew detection process to "skew absent." Specifically, the CPU 81 records information indicating that skew of the original document has not occurred in the storage unit 507.

[0123] The CPU 81 waits until the second skew detection sensor S12 turns OFF (S608) before S609. If the predetermined time limit has elapsed while the second skew detection sensor S12 remains ON (S608: No) (i.e., if it has not been detected that the trailing edge of the document has passed through the separation nip), the CPU 81 may determine that a jam has occurred.

[0124] In this way, the skew detection unit S10 of this embodiment detects skew of the document based on the difference in the detection timing of the leading edge of the document by the first skew detection sensor S11 (first sensor) and the second skew detection sensor S12 (second sensor).

[0125] 19 is a flowchart showing the process of the document transport operation in this embodiment. The processes of S501 to S504 and S510 to S516 are the same as S301 to S304 and S308 to S314 in the second embodiment (FIG. 12), respectively, and therefore will not be described again.

[0126] After starting feeding of the document in S503, the CPU 81 executes a jump-up detection process (S504) and a skew detection process (S505) described with reference to Fig. 20 in parallel. Subsequent processing branches based on the results of the jump-up detection process and the skew detection process (S506).

[0127] If a jumping-up of the original document is detected and a skewed original document is also detected, the CPU 81 stops the transport of the original document (S507a) and displays screen display A on the display panel 506a (S508). If a jumping-up of the original document is not detected and a skewed original document is also detected, the CPU 81 also stops the transport of the original document (S507a) and displays screen display A on the display panel 506a (S508). In other words, in this embodiment, the processing when a skewed original document is detected is the same regardless of whether a jumping-up of the original document is detected or not. However, for example, the message on screen display A may be changed depending on whether a jumping-up of the original document is detected or not.

[0128] If the document is detected as jumping up but not as skewing, the CPU 81 stops the document transport (S507b) and displays screen display B on the display panel 506a (S509). If neither the document is detected as jumping up nor as skewing, the CPU 81 determines that the document transport can be continued (S513) and continues the document transport.

[0129] [Screen Display] The screen display that is displayed on the display panel 506a when a document jump or skew is detected in this embodiment will be described with reference to FIGS. 21A and 21B.

[0130] 21A is an example of screen display A when skewed document feed is detected. Screen display A includes a message M0 informing the user of a document feed abnormality, a message M2a and button B2 for resetting the document, a message M3 and button B3 for disabling the document bounce detection function, and a button B4 for canceling the job. On the other hand, screen display A does not include any messages or buttons related to a folded document. For example, screen display A does not include a message M2b ( FIG. 21B ) that includes information urging the user to reduce the amount of document bounce when resetting the document.

[0131] 21B is an example of screen display B when no skew of the document is detected and only a document jump is detected. Screen display B includes a message M0 notifying the user of a document transport abnormality, messages M2a and M2b and a button B2 related to reloading the document, a message M3 and a button B3 related to disabling the document jump detection function, and a button B4 for instructing the user to cancel the job. The message related to reloading the document includes a message M2b containing information urging the user to reduce the amount of document jump when reloading the document. Screen display B also includes a message M1 and a button B1 related to continuing the job without reloading the document.

[0132] The operation when the user selects buttons B1 to B4 on screen display A or B may be the same as that described in the first to third embodiments. Note that in this embodiment, when button B3 is operated on screen display A or B, the skew detection function may be disabled in addition to the jump-up detection function. In other words, button B3 may be a button that disables all abnormal document detection functions at once. Furthermore, message M3 may be a message that suggests that all abnormal document detection functions will be disabled at once.

[0133] [Summary of this embodiment] As in the first embodiment, when a jumping up of the original is detected, the CPU 81 stops the transport of the original (S507a) and displays a message M2b on the display panel 506a urging the user to reduce the amount of jumping up of the original when resetting the folded original (S509). Therefore, according to this embodiment, it is possible to provide a sheet transport device, an image reading device, and an image forming device that can provide more appropriate information to the user when a jumping up of the sheet is detected.

[0134] Furthermore, according to this embodiment, if the skew detection unit S10 detects skew of the original, the message M2b is not displayed regardless of whether the jump-up detection sensor S20 detects the original jump (S508, FIG. 21A). On the other hand, if the skew detection unit S10 does not detect skew of the original and the jump-up detection sensor S20 detects the original jump, the message M2b is displayed (S509, FIG. 21B). In other words, if the skew detection unit detects skew of the sheet after the start of the job, the control unit does not cause the display unit to display a message regardless of whether the detection unit detects the sheet jump. Furthermore, if the skew detection unit does not detect skew of the sheet after the start of the job and the detection unit detects the sheet jump, the control unit causes the display unit to display a message. The message referred to here is the message M2b containing information urging the user to reduce the amount of jump-up of the original when reloading the folded original.

[0135] If skewed document feed is detected, it is highly likely that skew and / or jumping is occurring for reasons other than a folded document. Therefore, by not displaying message M2b when skewed document feed is detected, it is possible to avoid inconveniences such as user confusion caused by presenting unnecessary information. Furthermore, by displaying message M2b when skewed document feed is not detected and only jumping is detected, it is possible to provide the user with more appropriate information, including how to deal with the folded document.

[0136] Other Examples The elements described as the above-described embodiments and their modified examples may be combined and applied to a single device. For example, in the document transport operation flow described in the first to third embodiments, the skew detection process described in the fourth embodiment may be performed in parallel with the jump-up detection process.

[0137] Furthermore, the contents of the screen display described in each embodiment can be changed according to the specific configuration and specifications of the ADF 20 and the image reading device 10. For example, in the screen display (FIG. 15) exemplified in the second embodiment, any of the messages M0 to M3 and / or any of the buttons B1 to B4 may not be displayed. As an example, the message M3 and button B3 regarding disabling the jump-up detection may not be displayed. Furthermore, the wording of the messages and the layout of the buttons may be changed.

[0138] Furthermore, instead of displaying multiple messages and buttons on one screen, messages may be displayed in order on the screen. For example, a message or button corresponding to the most likely cause of the detected jumping or skewing (e.g., a bound document) may be displayed, and if the user inputs that the problem has not been resolved, a message or button corresponding to the next cause (e.g., a folded document) may be displayed.

[0139] Furthermore, the same content as the screen display described in each embodiment may be displayed on the display of an external computer (for example, a personal computer or a smartphone) communicably connected to the ADF 20 or the image reading device 10.

[0140] In each of the above-described embodiments, the image reading device 10 is described as being attached to the main body of the image forming device (printer main body 70), but the present technology may also be applied to an image reading device that is independent of the main body of the image forming device.

[0141] The electrophotographic image forming unit PU described in each of the above-mentioned embodiments is merely one example of an image forming means, and the image forming device may be equipped with an image forming unit of another type (e.g., an inkjet type) as an image forming means.

[0142] The present disclosure can also be realized by a process in which a program that realizes one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present disclosure can also be realized by a circuit (e.g., an ASIC) that realizes one or more functions.

[0143] The present disclosure can be used in a sheet conveying device that conveys a sheet, an image reading device that reads image information from a sheet, and an image forming device that forms an image on a recording material.

[0144] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention.

[0145] This application claims priority based on Japanese Patent Application No. 2024-149808, filed August 30, 2024, the entire contents of which are incorporated herein by reference.

[0146] 20...sheet conveying device (ADF) / 21...loading section (document tray) / 22, 23, 24...feeding means / 81...control means (CPU) / 506a...display means (display panel) / S20...detection means (jump-up detection sensor)

Claims

1. A sheet transport device comprising: a loading section on which sheets are loaded; a feeding means for separating and feeding the sheets loaded in the loading section one by one; a detection means for detecting any jumping up of the sheets fed by the feeding means; a display means for displaying information; and a control means for, when the detection means detects any jumping up of the sheets after the start of a job to feed sheets from the loading section, stopping the feeding of the sheets by the feeding means and causing the display means to display a message urging the user to reduce the amount of jumping up of the sheets when resetting the sheets in the loading section.

2. The sheet conveying device of claim 1, wherein the control means, when the detection means detects a sheet bouncing up after the job is started, causes the display means to display a second message together with the first message, encouraging the user to unbind a bound stack of sheets if there is a bound stack of sheets.

3. The sheet conveying device according to claim 1 or 2, wherein the control means, when the detection means detects a sheet bouncing up after the job has started, causes the display means to display a first button that instructs the user to continue the job after resetting the sheet in the stacking section.

4. The sheet conveying device according to claim 3, wherein the control means, when the detection means detects a sheet jumping up after the job has started, causes the display means to display, together with the first button, a second button that instructs the job to be continued without the detection means detecting the sheet jumping up.

5. The sheet transport device according to claim 4, wherein when the detection means detects a sheet bouncing up after the job has started, if the first button is operated, the control means starts feeding of the sheet by the feeding means based on an instruction to resume the job, and then stops feeding of the sheet by the feeding means if the detection means detects a sheet bouncing up, and when the second button is operated, after starting feeding of the sheet by the feeding means based on an instruction to resume the job, continues conveying the sheet without stopping the feeding means if the detection means detects a sheet bouncing up.

6. A sheet conveying device according to any one of claims 3 to 5, wherein the control means causes the display means to display a third button, which instructs the job to be stopped, together with the first button, when the detection means detects that the sheet has bounced up after the job has started.

7. A sheet conveying device according to claim 6, further comprising a setting means for setting execution conditions for the job, wherein the control means, when the detection means detects a sheet jumping up after the job has been started, resumes the job using the execution conditions at the start of the job when the first button is operated, and when the third button is operated, executes a new job using the execution conditions set by the setting means after the job has been stopped.

8. A sheet conveying device according to any one of claims 3 to 7, wherein the control means, when the detection means detects a sheet bouncing up after the job has started, causes the display means to display, together with the first button, a fourth button that instructs the job to continue without resetting the sheet in the stacking section.

9. A sheet transport device according to claim 8, further comprising a lifting means for raising and lowering the stacking unit, wherein when the detection means detects a sheet bouncing up after the job is started, the control means lowers the stacking unit without resuming sheet feeding by the feeding means when the first button is operated, and then raises the stacking unit based on an instruction to start feeding, and when the fourth button is operated, resumes sheet feeding by the feeding means without lowering the stacking unit.

10. A sheet conveying device as described in claim 8 or 9, wherein the control means causes the display means to display the fourth button if the detection means detects the sheet bouncing up before the leading edge of the sheet reaches a reading position where image information is read from the sheet, and does not cause the display means to display the fourth button if the detection means detects the sheet bouncing up after the leading edge of the sheet reaches the reading position.

11. A sheet conveying device according to any one of claims 1 to 3, wherein, when the detection means detects a sheet bouncing up after the job has started, the control means causes the display means to display a button instructing the job to be continued without the detection means detecting the bouncing up.

12. A sheet conveying device according to any one of claims 1 to 5, wherein the control means causes the display means to display a button for instructing the user to stop the job when the detection means detects that the sheet has bounced up after the job has started.

13. A sheet conveying device according to any one of claims 1 to 7, wherein the control means, when the detection means detects a sheet bouncing up after the job has started, causes the display means to display a button instructing the user to continue the job without resetting the sheet in the stacking section.

14. A sheet conveying device according to any one of claims 1 to 13, further comprising a skew detection means for detecting skew of the sheet, wherein the control means, if the skew detection means detects skew of the sheet after the start of the job, does not cause the display means to display the message regardless of whether the detection means has detected a jumping up of the sheet, and, if the skew detection means does not detect skew of the sheet after the start of the job and the detection means has detected a jumping up of the sheet, causes the display means to display the message.

15. A sheet conveying device according to claim 14, wherein the skew detection means includes a first sensor that detects the sheet, and a second sensor that is arranged at a different position from the first sensor in the sheet width direction perpendicular to the sheet feeding direction and detects the sheet, and detects skew of the sheet based on the difference in detection timing of the leading edge of the sheet by the first sensor and the second sensor.

16. The sheet transport device according to claim 1, wherein the detection means comprises a light-emitting unit that emits light, and a light-receiving unit that is positioned so that the light is incident via an optical path that passes above the loading unit and that emits a signal in response to the incident light.

17. A sheet conveying device according to claim 16, wherein the feeding means has a separation nip where sheets are separated one by one, and further comprises downstream detection means for detecting the passage of a sheet downstream of the separation nip in the sheet feeding direction, and the detection means detects the jumping up of the sheet if the optical path is blocked during the period from when the feeding means starts feeding the sheet until the downstream detection means detects the passage of the trailing end of the sheet.

18. An image reading device comprising: a sheet conveying device according to any one of claims 1 to 17; and reading means for reading image information from a sheet conveyed by said sheet conveying device.

19. An image forming apparatus comprising: the image reading device according to claim 18; and image forming means for forming an image on a recording material based on image information read by said image reading device.

Images