Sheet conveying device, image processing device, and sheet conveying method

Abstract

To provide a sheet conveyance device capable of performing sheet conveyance processing which a user intends in reading an image of a thick sheet, to provide an image processing device and to provide a sheet conveyance method.SOLUTION: An image forming device 100 includes: a determination processing part 52 for determining whether or not thickness of a document passing a predetermined detection position P1 in a conveyance passage for conveying the document is equal to or greater than a threshold value; a conveyance control part 53 for conveying the document along one of a first conveyance path leading to a first discharge part 29 from a document placement part 21 via a first conveyance passage 22A, and a second conveyance path leading to a second discharge part 33 different from the first discharge part 29 via a second conveyance passage 22D containing a curve part 22C which is branched from the first conveyance passage 22A and curves; and a notification processing part 54 for notifying of predetermined information for allowing a user to select a conveyance method of the document when the thickness of the document is determined to be equal to or greater than the threshold value in the case that the conveyance path of the document is set to be the second conveyance path..SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sheet conveying device, an image processing apparatus including the sheet conveying device, and a sheet conveying method. [Background technology]

[0002] There is known an image processing apparatus equipped with a sheet transport device that transports a document to be read. Also known is an image reading apparatus equipped with a first transport path (straight path) that transports the document from a sheet placement unit downstream in a straight line and discharges it to a first discharge unit, and a second transport path (U-shaped path, U-turn path) that transports the document to a curved section that branches upstream from the first transport path and discharges it to a second discharge unit (see Patent Documents 1 and 2). When the image reading apparatus detects a document that is thicker than a threshold, it either stops transport of the document or switches the transport path from the U-shaped path to the straight path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-052929 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-282349 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional technology, when a thick document is automatically switched from a U-shaped path to a straight path, the order of the pages of the document ejected after the reading process is completed is reversed, resulting in a problem where the transport process is performed unintended by the user.

[0005] An object of the present invention is to provide a sheet conveying device, an image processing device, and a sheet conveying method that are capable of carrying out sheet conveying processing as intended by the user when reading an image on a thick sheet. [Means for solving the problem]

[0006] According to one aspect of the present invention, a sheet conveying device includes a determination processor, a conveyance controller, and a notification processor. The determination processor determines whether the thickness of a sheet passing a predetermined detection position on a conveyance path along which the sheet is conveyed is equal to or greater than a threshold value. The conveyance controller conveys the sheet along either a first conveyance path from a sheet placement unit on which the sheet is placed to a first discharge unit via a first conveyance path, or a second conveyance path from the first conveyance path to a second discharge unit different from the first discharge unit via a second conveyance path including a curved portion that branches off from the first conveyance path. When the sheet conveyance path is set to the second conveyance path, the notification processor notifies a user of predetermined information that prompts a user to select a sheet conveyance method if the determination processor determines that the sheet thickness is equal to or greater than the threshold value.

[0007] An image processing apparatus according to another aspect of the present invention includes the sheet conveying device and an image reading section, wherein the image reading section reads an image on a sheet conveyed by the sheet conveying device.

[0008] A sheet transport method according to another aspect of the present invention includes a determination step, a transport control step, and a notification step. In the determination step, it is determined whether the thickness of a sheet passing a predetermined detection position on a transport path along which the sheet is transported is equal to or greater than a threshold value. In the transport control step, the sheet is transported along either a first transport path extending from a sheet placement section on which the sheet is placed to a first discharge section via a first transport path, or a second transport path extending from the first transport path to a second discharge section different from the first discharge section via a second transport path including a curved section that branches off from the first transport path. In the notification step, when the sheet transport path is set to the second transport path, if it is determined in the determination step that the sheet thickness is equal to or greater than the threshold value, predetermined information is notified to allow a user to select a sheet transport method. [Effects of the Invention]

[0009] According to the present invention, when reading an image on a thick sheet, it is possible to carry out the sheet transport process as intended by the user. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing the system configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the configuration of the ADF and image reading unit of the image forming apparatus according to the embodiment of the present invention. [Figure 3] FIG. 3 is a diagram showing an example of selection information displayed on the image forming apparatus according to the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing an example of a transport path in the image forming apparatus according to the embodiment of the present invention. [Figure 5] FIG. 5 is a flowchart showing an example of a document reading process executed by the image forming apparatus according to the embodiment of the present invention. [Figure 6] FIG. 6 is a flowchart showing an example of a document reading process executed by the image forming apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following embodiment is an example of a specific embodiment of the present invention and does not limit the technical scope of the present invention.

[0012] [Configuration of image forming apparatus 100] First, with reference to FIG. 1, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described.

[0013] The image forming apparatus 100 is a multifunction peripheral having multiple functions, such as a scanning function for reading an image from a document, a printing function for forming an image based on image data, a facsimile function, and a copy function. The image forming apparatus 100 is an example of an image processing apparatus of the present invention. The image processing apparatus of the present invention may also be a scanner, a facsimile machine, a copy machine, or the like.

[0014] As shown in FIG. 1, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, an operation display unit 5, a storage unit 6, and a control unit .

[0015] The ADF 1 conveys a document (an example of a sheet of the present invention) to be read by the scanning function.

[0016] The image reading unit 2 realizes the scanning function. Specifically, the image reading unit 2 reads an image from a document conveyed by the ADF 1. The image reading unit 2 also reads an image from a document placed on a document table 41 (see FIG. 2).

[0017] The image forming unit 3 realizes the printing function. For example, the image forming unit 3 forms an image on a sheet supplied from the paper feed unit 4 by electrophotography. For example, the image forming unit 3 includes a photosensitive drum, a charging roller, an optical scanning device, a developing device, a transfer roller, a cleaning device, a fixing device, and a paper output tray.

[0018] The paper feed unit 4 supplies sheets to the image forming unit 3. For example, the paper feed unit 4 includes a paper feed cassette, a manual feed tray, a sheet transport path, and a plurality of transport rollers.

[0019] The operation display unit 5 is a user interface of the image forming apparatus 100. For example, the operation display unit 5 has a display unit such as a liquid crystal display that displays various information in response to control instructions from the control unit 7, and an operation unit such as operation keys or a touch panel that inputs various information to the control unit 7 in response to user operations.

[0020] The storage unit 6 is a nonvolatile storage device, such as a nonvolatile memory such as a flash memory or an EEPROM (registered trademark), a solid state drive (SSD), or a hard disk drive (HDD).

[0021] The control unit 7 performs overall control of the image forming apparatus 100. As shown in FIG. 1, the control unit 7 includes a CPU 11, a ROM 12, and a RAM 13. The CPU 11 is a processor that executes various types of arithmetic processing. The ROM 12 is a non-volatile storage device that stores in advance information such as control programs for causing the CPU 11 to execute various types of processing. The RAM 13 is a volatile or non-volatile storage device that is used as a temporary storage memory (work area) for the various types of processing executed by the CPU 11. In the control unit 7, the CPU 11 executes the various control programs that are pre-stored in the ROM 12. In this way, the control unit 7 performs overall control of the image forming apparatus 100.

[0022] [Configuration of ADF 1 and image reading unit 2] Next, the configurations of the ADF 1 and the image reading unit 2 will be described with reference to Figures 1 and 2. Figure 2 is a cross-sectional view showing the configurations of the ADF 1 and the image reading unit 2.

[0023] As shown in FIG. 2, the ADF 1 includes a document placement section 21, a housing 22, a pickup roller 23, a paper feed belt 24, a separation roller 25, a registration roller 26, a switching section 27, a first discharge roller 28, a first discharge section 29, a first conveying roller 30, a second conveying roller 31, a second discharge roller 32, a second discharge section 33, a first detection section 21A, and a second detection section 21B.

[0024] A document to be transported is placed on document placement section 21. In ADF 1, the document placed on document placement section 21 is transported in transport direction D1 shown in Fig. 2. Document placement section 21 is an example of a sheet placement section of the present invention.

[0025] 1 is provided in the document placement unit 21. The first detection unit 21A detects whether or not a document is present on the document placement unit 21. For example, the first detection unit 21A is a reflective optical sensor provided on the document placement surface of the document placement unit 21.

[0026] Further, a lift plate (not shown) is provided on the document placement section 21. The lift plate lifts the document stack placed on the document placement section 21 up to a contact position with the pickup roller 23.

[0027] The housing 22 houses rollers and the like used to transport the document. As shown in FIG. 2, a first transport path 22A and a second transport path 22D for guiding the document are formed inside the housing 22. The first transport path 22A advances straight from the document placement unit 21 to the first discharge unit 29. The second transport path 22D includes a curved portion 22C (see FIG. 2) that branches off from a branching portion 22B (see FIG. 2) in the first transport path 22A and curves, and leads to the second discharge unit 33. The curved portion 22C is curved at a curvature that allows the document to make a U-turn inside the housing 22.

[0028] In ADF1, the document placed on the document placement section 21 is transported along either a first transport path (hereinafter also referred to as a straight path) that leads to the first discharge section 29 via the first transport path 22A, or a second transport path (hereinafter also referred to as a U-shaped path) that leads to the second discharge section 33 via the second transport path 22D.

[0029] 2, an opening 22E is provided at the bottom of the housing 22. The opening 22E exposes a portion of the second transport path 22D to the outside. In the opening 22E, the second imaging unit 43 (see FIGS. 1 and 2) of the image reading unit 2 reads an image of the document transported by the ADF 1.

[0030] The pickup roller 23 is provided above the document placement unit 21. The pickup roller 23 comes into contact with the surface (top surface) of the uppermost document in the document stack lifted by the lift plate, and transports the document in the transport direction D1.

[0031] The paper feed belt 24 is provided on the first transport path 22A. The paper feed belt 24 comes into contact with the surface of the document transported in the transport direction D1 by the pickup roller 23, and transports the document downstream in the transport direction D1.

[0032] Separation roller 25 is provided below paper feed belt 24 in contact with paper feed belt 24. Of multiple documents transported to the contact position with paper feed belt 24, separation roller 25 separates a document that is in contact with paper feed belt 24 from documents below it.

[0033] The registration rollers 26 are provided on the first transport path 22A downstream in the transport direction D1 from the paper feed belt 24. The registration rollers 26 come into contact with the document transported by the paper feed belt 24 and transport the document downstream in the transport direction D1.

[0034] The switching unit 27 is provided at the branching portion 22B on the first transport path 22A downstream of the registration rollers 26 in the transport direction D1. The switching unit 27 is a guide member that comes into contact with the document transported by the registration rollers 26 and guides the document to either the downstream side of the branching portion 22B on the first transport path 22A or the second transport path 22D. Specifically, the switching unit 27 is provided so that its position can be changed between a first position in which the document is guided to the downstream side of the branching portion 22B on the first transport path 22A, and a second position in which the document is guided to the second transport path 22D. The switching unit 27 changes its position by receiving a driving force supplied from the driving unit 27A shown in FIG. 1. For example, the driving unit 27A is a motor.

[0035] The first discharge roller 28 is provided on the first transport path 22A downstream of the branching portion 22B in the transport direction D1. The first discharge roller 28 comes into contact with the document guided by the switching portion 27 to the downstream side of the branching portion 22B on the first transport path 22A, and discharges the document to the first discharge portion 29. The document discharged by the first discharge roller 28 is stacked in the first discharge portion 29.

[0036] The first transport rollers 30 are provided at the curved portion 22C of the second transport path 22D. The first transport rollers 30 come into contact with the document guided to the second transport path 22D by the switching unit 27, and transport the document downstream in the transport direction D1.

[0037] An opening 22E is formed in the second transport path 22D downstream in the transport direction D1 from the first transport roller 30. In the opening 22E, the image of the document passing through the opening 22E is read by the second imaging unit 43 (see FIGS. 1 and 2) of the image reading unit 2.

[0038] The second transport roller 31 is provided on the second transport path 22D downstream of the opening 22E in the transport direction D1. The second transport roller 31 comes into contact with the document transported by the first transport roller 30, and transports the document downstream in the transport direction D1.

[0039] The second discharge roller 32 is provided on the second conveying path 22D downstream of the second conveying roller 31 in the conveying direction D1. The second discharge roller 32 comes into contact with the document conveyed by the second conveying roller 31 and discharges the document to the second discharge section 33. The document discharged by the second discharge roller 32 is stacked in the second discharge section 33.

[0040] The second detection unit 21B is provided at a detection position P1 (see FIG. 2) on the first transport path 22A closer to the document placement unit 21 than the branching portion 22B, and detects the thickness of a document passing through the detection position P1. The second detection unit 21B is configured, for example, with a transmission-type optical sensor or an ultrasonic sensor. For example, the ultrasonic sensor detects (measures) a voltage value corresponding to the thickness of a document passing through the detection position P1. The ultrasonic sensor has, for example, a transmitter and a receiver arranged opposite each other across the first transport path 22A. The transmitter emits ultrasonic waves toward the first transport path 22A, and the receiver receives the ultrasonic waves emitted from the transmitter. The ultrasonic sensor outputs an electrical signal corresponding to the intensity of the ultrasonic waves received by the receiver. The electrical signal (voltage value) output from the ultrasonic sensor is input to the control unit 7. A determination processing unit 52 of the control unit 7 determines the thickness of the document based on the voltage value obtained from the ultrasonic sensor.

[0041] As shown in FIGS. 1 and 2, the image reading unit 2 includes a document table 41, a first imaging unit 42, a second imaging unit 43, and a third imaging unit 44.

[0042] A document to be read is placed on document table 41. Document table 41 is provided on the upper part of the housing of image forming apparatus 100. ADF 1 is provided so as to be openable and closable relative to document table 41, and also serves as a document cover that supports one side of a document placed on first contact glass 411 of document table 41.

[0043] 2, the document table 41 includes a first contact glass 411, a second contact glass 412, and a guide member 413. A document, whose image is to be read by the second imaging unit 43, is placed on the first contact glass 411. The second contact glass 412 and the guide member 413 face the opening 22E of the housing 22 and form part of the second transport path 22D when the ADF 1 is closed relative to the document table 41. The second contact glass 412 transmits light emitted from the second imaging unit 43 toward the opening 22E and light reflected by the document. The guide member 413 guides the document to the second transport roller 31 downstream of the second contact glass 412 in the transport direction D1.

[0044] The second imaging unit 43 is provided below the first contact glass 411 and the second contact glass 412. The second imaging unit 43 is elongated in the depth direction of the paper in FIG. 2 and is provided movably in the left-right direction of the paper in FIG. 2. The second imaging unit 43, while disposed below the second contact glass 412, reads an image of the front side of a document (an example of the first side of the present invention) conveyed by the ADF 1. Specifically, the second imaging unit 43 includes a CIS (Contact Image Sensor) and a housing that houses the CIS. The second imaging unit 43 outputs an analog signal corresponding to the image read from the front side of the document. The analog signal output from the second imaging unit 43 is converted into a digital signal (image data) by an analog front-end circuit (not shown) and input to the control unit 7.

[0045] The first imaging unit 42 is provided on the first conveying path 22A downstream of the branching portion 22B in the conveying direction D1 and upstream of the first discharge roller 28 in the conveying direction D1. The first imaging unit 42 reads an image of the front surface of the document guided by the switching unit 27 to the downstream side of the branching portion 22B in the first conveying path 22A. Specifically, the first imaging unit 42 is a CIS. The first imaging unit 42 outputs an analog signal corresponding to the image read from the front surface of the document. The analog signal output from the first imaging unit 42 is converted into a digital signal (image data) by the analog front-end circuit and input to the control unit 7.

[0046] The third imaging unit 44 is provided on the first conveying path 22A upstream of the branching portion 22B in the conveying direction D1 and downstream of the registration rollers 26 in the conveying direction D1. The third imaging unit 44 reads an image of the back side of the document conveyed by the registration rollers 26. Specifically, the third imaging unit 44 is a CIS. The third imaging unit 44 outputs an analog signal corresponding to the image read from the back side of the document. The analog signal output from the third imaging unit 44 is converted into a digital signal (image data) by the analog front-end circuit and input to the control unit 7.

[0047] Incidentally, there is known a conventional image reading device that stops conveying the document or switches the conveying path from a U-shaped path to a straight path when it detects that the document has a thickness equal to or greater than a threshold value.

[0048] However, in the above-mentioned image reading device, when a thick document is automatically switched from a U-shaped path to a straight path, the order of the pages of the document discharged after the reading process is completed is reversed, resulting in a problem in which the transport process is performed unintended by the user.

[0049] In contrast to this, in the image forming apparatus 100 according to the embodiment of the present invention, as will be described below, it is possible to carry out a document transport process as intended by the user when reading an image of a thick document.

[0050] [Configuration of control unit 7] Next, the configuration of the control unit 7 will be described in more detail with reference to FIG.

[0051] As shown in FIG. 1, the control unit 7 includes an acquisition processing unit 51, a determination processing unit 52, a transport control unit 53, and a notification processing unit .

[0052] Specifically, a document reading program for causing the CPU 11 to execute a document reading process (see FIGS. 5 and 6) described below is stored in advance in the ROM 12. The control unit 7 executes the document reading program stored in the ROM 12, thereby functioning as an acquisition processing unit 51, a determination processing unit 52, a conveyance control unit 53, and a notification processing unit 54. Here, an apparatus including the ADF 1 and the control unit 7 is an example of a sheet conveying apparatus of the present invention.

[0053] The document reading program may be recorded on a computer-readable recording medium such as a CD, a DVD, or a flash memory, and may be read from the recording medium and stored in a storage device such as the memory unit 6. The acquisition processing unit 51, the determination processing unit 52, the transport control unit 53, and the notification processing unit 54 may be configured by electronic circuits such as an integrated circuit (ASIC).

[0054] The acquisition processing unit 51 acquires transport path information indicating whether the transport path of the document placed on the document placing unit 21 is the first transport path or the second transport path. As described above, the first transport path is the transport path that leads to the first discharge unit 29 via the first transport path 22A, and the second transport path is the transport path that leads to the second discharge unit 33 via the second transport path 22D (see FIG. 2).

[0055] For example, the control unit 7 accepts an operation from the user to select either a straight path (the first transport path) or a U-shaped path (the second transport path) as the transport path for the original documents on a reception screen displayed on the operation display unit 5. For example, the user selects the straight path when he / she wants to scan a thick original document or when he / she wants to scan a stack of original documents containing multiple original documents in a short time. Alternatively, the user selects the U-shaped path when he / she wants to scan a thin original document or when he / she wants the page order of the ejected original document stack to match the page order of the original document stack placed on the original placement unit 21.

[0056] When the user selects the straight path, the acquisition processing unit 51 acquires transport path information indicating that the transport path is the first transport path, and when the user selects the U-shaped path, the acquisition processing unit 51 acquires transport path information indicating that the transport path is the second transport path. Note that the user may select either the first discharge unit 29 or the second discharge unit 33 as the document discharge destination on the reception screen. The user places the document on the document placement unit 21, selects the document transport path and the like on the reception screen, and then issues an instruction to read the image.

[0057] Furthermore, the acquisition processing unit 51 may be omitted from the image forming apparatus 100. In this case, the image forming apparatus 100 sets the conveying path to a straight path or a U-shaped path in advance.

[0058] The determination processing unit 52 determines the thickness of the original. Specifically, the determination processing unit 52 determines whether the thickness of the original passing through the detection position P1 is equal to or greater than a preset threshold. For example, when an original transported from the original placement unit 21 reaches the detection position P1 (see FIG. 2), the second detection unit 21B detects the thickness of the original. The determination processing unit 52 determines whether the thickness of the original is equal to or greater than a threshold based on the detection result (voltage value) obtained from the second detection unit 21B. The threshold is set to, for example, a voltage value. Furthermore, the threshold is set to an upper limit value at which the original can be transported (made a U-turn) on the second transport path without being damaged. The determination processing unit 52 determines the thickness of each original transported.

[0059] In addition, the judgment processing unit 52 may perform the judgment process when the document transport path is set to the second transport path (U-shaped path), and may omit the judgment process when the document transport path is set to the first transport path (straight path).

[0060] The transport control unit 53 transports the document placed on the document placing unit 21 along either the first transport path or the second transport path in accordance with the transport path information acquired by the acquisition processing unit 51. When a document stack including multiple documents is placed on the document placing unit 21, the transport control unit 53 transports each document in the document stack sequentially along either the first transport path or the second transport path. In this way, the transport control unit 53 sets the transport path to either the first transport path or the second transport path in accordance with the transport path information acquired by the acquisition processing unit 51.

[0061] When the document transport path is set to the second transport path (U-shaped path), if the judgment processing unit 52 determines that the document thickness is greater than or equal to a threshold value, the notification processing unit 54 notifies the user of specified information that allows the user to select a document transport method.

[0062] Here, it is assumed that the transport control unit 53 has set the transport path to the second transport path. When the transport path is set to the second transport path, the document placed on the document placement unit 21 is guided by the branching unit 22B to the curved unit 22C and then discharged to the second discharge unit 33 via the second transport path 22D. Also, while the document is being transported along the second transport path, the third imaging unit 44 reads an image of the back side of the document, and the second imaging unit 43 reads an image of the front side of the document. Note that when the image reading unit 2 reads only one side (front side) of the document, that is, when the document reading mode is set in advance to the single-sided reading mode, the reading process of the third imaging unit 44 is omitted.

[0063] Here, when the transport path is set to the second transport path, if the determination processing unit 52 determines that the thickness of the document is equal to or greater than the threshold, the transport control unit 53 stops the transport process of the document. In this case, the document stops upstream of the branching unit 22B on the first transport path 22A. Then, the notification processing unit 54 displays selection information (selection screen) that allows the user to select the transport path of the document.

[0064] 3, the notification processor 54 displays a selection screen (error screen) indicating that a thick document has been detected on the operation display unit 5. In addition, the notification processor 54 displays, on the selection screen, first selection information F1 indicating that only documents having a thickness equal to or greater than a threshold value are to be transported to the first transport path (straight path), second selection information F2 indicating that all documents are to be transported to the first transport path (straight path), and third selection information F3 indicating that the document transport process is to be stopped (cancelled).

[0065] Furthermore, the notification processing unit 54 displays warning information K1 on the selection screen, in association with the first selection information F1, indicating that the page order of the document placed on the document placement unit 21 and the page order of the document discharged to each of the first discharge unit 29 and the second discharge unit 33 will change.

[0066] The first selection information F1, the second selection information F2, and the third selection information F3 each function as a selection button that can be touched by the user. That is, the first selection information F1 functions as a reception unit that receives an instruction from the user to transport only documents having a thickness equal to or greater than a threshold value to the first transport path (straight path). The second selection information F2 functions as a reception unit that receives an instruction from the user to transport all documents to the first transport path (straight path). The third selection information F3 functions as a reception unit that receives an instruction from the user to stop (cancel) the document transport process and reading process. The first selection information F1 includes warning information K1 (see FIG. 3).

[0067] The user selects one of the first selection information F1, the second selection information F2, and the third selection information F3 on the operation display unit 5. The transport control unit 53 executes transport processing according to the selection information selected by the user.

[0068] For example, if the user selects first selection information F1 (see FIG. 3), the transport control unit 53 resumes the document transport process, transporting subsequent documents having a thickness equal to or greater than the threshold to the first transport path (straight path) (solid line in FIG. 4) and transporting documents having a thickness less than the threshold to the second transport path (U-shaped path) (dotted line in FIG. 4). In this case, for documents having a thickness equal to or greater than the threshold, the first imaging unit 42 reads an image of the front side of the document while the document is transported along the first transport path, and for documents having a thickness less than the threshold, the second imaging unit 43 reads an image of the front side of the document while the document is transported along the second transport path. Note that if the document reading mode is set to double-sided reading mode in advance, the third imaging unit 44 reads an image of the back side of each document.

[0069] Furthermore, when the user selects first selection information F1, documents having a thickness equal to or greater than the threshold are discharged to first discharge section 29, and documents having a thickness less than the threshold are discharged to second discharge section 33. This may result in a change in the page order of the documents placed on document placement section 21 and the page order of the documents discharged to first discharge section 29 and second discharge section 33. In this regard, according to the above configuration, warning information K1 is displayed in association with first selection information F1, so the user can understand that the document order will change before the transport process and reading process are resumed.

[0070] Furthermore, for example, if the user selects second selection information F2 (see FIG. 3), the transport control unit 53 resumes the transport process of the original documents and transports all subsequent original documents to the first transport path (straight path) (solid line in FIG. 4). In this case, for all original documents, the first imaging unit 42 reads an image of the front side of the original document while the original document is transported along the first transport path. Note that if the original document reading mode is set to the double-sided reading mode in advance, the third imaging unit 44 reads an image of the back side of each original document.

[0071] Although not shown in the figure, in another embodiment, the notification processing unit 54 may display warning information in the second selection information F2 indicating that when the document transport path is switched from the second transport path to the first transport path, the page order of the sheets placed on the document loading unit 21 and the page order of the document discharged to the first discharge unit 29 will be swapped.

[0072] Furthermore, for example, if the user selects the third selection information F3 (see FIG. 3), the transport control unit 53 stops the transport process of the document. If the user does not want to read a thick document, the user can select the third selection information F3 (cancel button) to stop the document reading process.

[0073] [Document scanning process] 5 and 6, an example of the procedure of the document reading process executed by the control unit 7 in the image forming apparatus 100 and the sheet conveying method of the present invention will be described below. Here, steps S11, S12, etc. represent the numbers of the processing procedures (steps) executed by the control unit 7. The document reading process is executed when an image reading instruction (e.g., a scan instruction) is given on the operation display unit 5.

[0074] Here, it is assumed that the conveying path is set to the second conveying path (U-shaped path). Specifically, the control unit 7 drives the drive unit 27A to set the posture of the switching unit 27 to the second posture that guides the sheet to the second conveying path 22D.

[0075] <Step S11> First, in step S11, the control unit 7 acquires the thickness of the document. Specifically, the control unit 7 acquires the detection result (voltage value) indicating the thickness of the document from the second detection unit 21B. <Step S12>

[0076] In step S12, the control unit 7 determines whether the thickness of the document is equal to or greater than a threshold value. If the thickness of the document is equal to or greater than the threshold value (S12: Yes), the control unit 7 shifts the process to step S13, and if the thickness of the document is less than the threshold value (S12: No), the control unit 7 shifts the process to step S21. The process of step S12 is an example of a determination step of the present invention, and is executed by the determination processing unit 52 of the control unit 7.

[0077] <Step S13> In step S13, the control unit 7 causes the operation display unit 5 to display a selection screen (see FIG. 3) indicating that a document having a thickness equal to or greater than the threshold has been detected.

[0078] In addition, the control unit 7 displays on the selection screen first selection information F1 indicating that only documents having a thickness equal to or greater than a threshold value are to be transported to the first transport path (straight path), second selection information F2 indicating that all documents are to be transported to the first transport path (straight path), and third selection information F3 indicating that the document transport process is to be stopped (cancelled).

[0079] Furthermore, the control unit 7 causes warning information K1, which indicates that the page order of the documents placed on the document placement unit 21 will change from the page order of the documents discharged to the first discharge unit 29 and the second discharge unit 33, to be displayed in association with the first selection information F1 on the selection screen. The process of step S13 is an example of a notification step of the present invention, and is executed by the notification processing unit 54 of the control unit 7.

[0080] <Step S14> In step S14, the control unit 7 determines whether or not the first selection information F1 has been selected. That is, the control unit 7 determines whether or not an instruction to transport only documents having a thickness equal to or greater than a threshold value to the first transport path (straight path) has been received from the user. If the first selection information F1 has been selected (S14: Yes), the control unit 7 shifts the process to step S15. If the first selection information F1 has not been selected (S14: No), the control unit 7 shifts the process to step S21 (see FIG. 6). The process of step S14 is an example of a determination step of the present invention, and is executed by the determination processing unit 52 of the control unit 7.

[0081] <Step S15> In step S15, the control unit 7 switches the transport path from the second transport path to the first transport path.

[0082] For example, the control unit 7 drives the drive unit 27A to set the attitude of the switching unit 27 to the first attitude that guides the document to the downstream side of the branching unit 22B in the first transport path 22A. The process of step S15 is an example of a transport control step of the present invention, and is executed by the transport control unit 53 of the control unit 7.

[0083] <Step S16> In step S16, the control unit 7 executes an image reading process.

[0084] Specifically, the control unit 7 reads an image of the document whose transport process has been stopped. For example, the control unit 7 reads an image of the front side of the document transported on the first transport path by the first imaging unit 42. Note that if the document reading mode is set to a double-sided reading mode in advance, the control unit 7 reads an image of the back side of the document on the first transport path by using the third imaging unit 44.

[0085] <Step S17> In step S17, the control unit 7 determines whether the image reading process has ended. For example, the control unit 7 determines that the image reading process has ended when there is no document on the document placing unit 21. The control unit 7 determines that the image reading process has not ended when there is a document on the document placing unit 21. When the image reading process has ended (S17: Yes), the control unit 7 shifts the process to step S43. When the image reading process has not ended (S17: No), the control unit 7 shifts the process to step S18.

[0086] <Step S18> In step S18, the control unit 7 acquires the thickness of the document conveyed next from the document placement unit 21.

[0087] <Step S19> In step S19, the control unit 7 determines whether the thickness of the document is equal to or greater than a threshold value. If the thickness of the document is equal to or greater than the threshold value (S19: Yes), the control unit 7 proceeds to step S16. If the thickness of the document is less than the threshold value (S19: No), the control unit 7 proceeds to step S20. The process of step S19 is an example of a determination step of the present invention, and is executed by the determination processing unit 52 of the control unit 7.

[0088] <Step S20> In step S20, the control unit 7 switches the transport path from the first transport path to the second transport path.

[0089] For example, the control unit 7 drives the drive unit 27A to set the attitude of the switching unit 27 to the second attitude that guides the document to the second transport path 22D. The process of step S20 is an example of a transport control step of the present invention, and is executed by the transport control unit 53 of the control unit 7. After step S20, the control unit 7 shifts the process to step S16. When returning to step S16, the control unit 7 reads an image of the front side of the document transported on the second transport path with the second imaging unit 43.

[0090] In this way, when the user selects the first selection information F1 (see FIG. 3), the control unit 7 transports documents having a thickness equal to or greater than the threshold (S19: Yes) to the first transport path (straight path) (solid line in FIG. 4), and transports documents having a thickness less than the threshold (S19: No) to the second transport path (U-shaped path) (dotted line in FIG. 4). In this case, for documents having a thickness equal to or greater than the threshold, the first imaging unit 42 reads an image of the front side of the document while the document is transported along the first transport path, and for documents having a thickness less than the threshold, the second imaging unit 43 reads an image of the front side of the document while the document is transported along the second transport path. Note that if the document reading mode is set to the double-sided reading mode, the third imaging unit 44 reads an image of the back side of each document. When the reading process for all documents in the document stack is completed (S17: Yes), the control unit 7 proceeds to step S43.

[0091] <Step S21> In step S21 (see FIG. 6), the control unit 7 determines whether or not the second selection information F2 has been selected. That is, the control unit 7 determines whether or not an instruction to transport all documents to the first transport path (straight path) has been received from the user. If the second selection information F2 has been selected (S21: Yes), the control unit 7 shifts the process to step S22. If the second selection information F2 has not been selected (S21: No), the control unit 7 shifts the process to step S31. The process of step S21 is an example of a determination step of the present invention, and is executed by the determination processing unit 52 of the control unit 7.

[0092] <Step S22> In step S22, the control unit 7 executes an image reading process.

[0093] Specifically, the control unit 7 reads an image of the document whose transport process has been stopped. For example, the control unit 7 reads an image of the front side of the document transported on the first transport path by the first imaging unit 42. Note that if the document reading mode is set to a double-sided reading mode in advance, the control unit 7 reads an image of the back side of the document on the first transport path by using the third imaging unit 44.

[0094] <Step S23> In step S23, the control unit 7 determines whether the image reading process has ended. For example, the control unit 7 determines that the image reading process has ended when there is no document on the document placing unit 21. The control unit 7 determines that the image reading process has not ended when there is a document on the document placing unit 21. When the image reading process has ended (S23: Yes), the control unit 7 shifts the process to step S43 (see FIG. 5). When the image reading process has not ended (S23: No), the control unit 7 shifts the process to step S22.

[0095] In this way, when the user selects second selection information F2 (see FIG. 3), the control unit 7 transports all documents to the first transport path (straight path) (solid line in FIG. 4). In this case, for all documents, the first imaging unit 42 reads an image of the front side of the document while the document is transported along the first transport path. Note that if the document reading mode is set to double-sided reading mode, the third imaging unit 44 reads an image of the back side of each document. When the reading process for all documents in the document stack is completed (S23: Yes), the control unit 7 proceeds to step S43 (see FIG. 5).

[0096] <Step S31> In step S31, the control unit 7 determines whether or not the third selection information F3 (see FIG. 3) has been selected. That is, the control unit 7 determines whether or not an instruction to cancel the transport process and the reading process has been received from the user. If the third selection information F3 has been selected (S31: Yes), the control unit 7 ends the image reading process (see FIG. 5). If the third selection information F3 has not been selected (S31: No), the control unit 7 shifts the process to step S14 (see FIG. 5). The process of step S31 is an example of a determination step of the present invention, and is executed by the determination processing unit 52 of the control unit 7.

[0097] <Step S43> In step S43 (see FIG. 5), the control unit 7 outputs the image data read by the image reading process to the output destination set by the user. As described above, the control unit 7 executes the above-mentioned processes for each document in the document stack.

[0098] As described above, image forming apparatus 100 determines whether the thickness of a document passing through predetermined detection position P1 on the transport path along which the document is transported is equal to or greater than a threshold value. Image forming apparatus 100 transports a document along either a first transport path from document placement unit 21 to first discharge unit 29 via first transport path 22A, or a second transport path from first transport path 22A to second discharge unit 33, which is different from first discharge unit 29, via second transport path 22D including curved portion 22C that branches off from first transport path 22A and curves.

[0099] Furthermore, when the document transport path is set to the second transport path and it is determined that the document thickness is equal to or greater than the threshold, the image forming apparatus 100 notifies the user of predetermined information that allows the user to select a document transport method. Specifically, the image forming apparatus 100 displays, on the operation display unit 5, first selection information F1 indicating that only documents having a thickness equal to or greater than the threshold are to be transported to the first transport path (straight path), second selection information F2 indicating that all documents are to be transported to the first transport path (straight path), and third selection information F3 indicating that the document transport process is to be stopped (cancelled).

[0100] In addition, the image forming device 100 displays warning information K1, which indicates that the page order of the document placed on the document placement section 21 and the page order of the document discharged to each of the first discharge section 29 and the second discharge section 33 will change, in association with the first selection information F1.

[0101] This allows the user to select the desired transport method when a document with a thickness equal to or greater than the threshold is detected. Furthermore, the user can understand in advance that selecting the first selection information F1 will change the page order of the document. Therefore, when scanning an image of a thick document, the document can be transported as intended by the user. Furthermore, because the transport path can be switched depending on the thickness of the document, damage to the document and the transport path can be prevented. [Explanation of symbols]

[0102] 1 ADF 2 Image reading unit 3 Image forming unit 4 Paper feed section 5 Operation display section 6 Memory section 7 Control Unit 21 Document placement area 21A First detection unit 21B Second detection unit 22 Case 22A First conveying path 22B Branch 22C curved section 22D Second transport path 27 Switching section 27A Drive Unit 29 1st discharge section 33 Second discharge section 42 First imaging unit 43 Second imaging unit 44 Third Imaging Unit 51 Acquisition processing unit 52 Judgment processing unit 53 Transport control unit 54 Notification processing section 100 Image forming device

Claims

1. a determination processing unit that determines whether or not the thickness of a sheet passing through a predetermined detection position on a conveying path along which the sheet is conveyed is equal to or greater than a threshold; a conveyance control unit that conveys the sheet along either a first conveyance path from a sheet placement unit on which the sheet is placed to a first discharge unit via a first conveyance path, or a second conveyance path that branches off from the first conveyance path and includes a curved portion that curves to a second discharge unit different from the first discharge unit; a notification processing unit that notifies a user of predetermined information for selecting a sheet transport method when the determination processing unit determines that the sheet thickness is equal to or greater than the threshold value in a case where the sheet transport path is set to the second transport path; and A sheet conveying device comprising:

2. When the determination processing unit determines that the thickness of the sheet is equal to or greater than the threshold value, the conveyance control unit stops the sheet conveyance process, the notification processing unit displays selection information that allows a user to select a sheet transport path; The sheet transport device according to claim 1 .

3. the notification processing unit displays first selection information indicating that only sheets having a thickness equal to or greater than the threshold value are to be conveyed to the first conveying path; When the first selection information is selected by a user, the conveyance control unit resumes the sheet conveyance process, conveys a sheet having a thickness equal to or greater than the threshold value to the first conveyance path, and conveys a sheet having a thickness less than the threshold value to the second conveyance path. The sheet transport device according to claim 2 .

4. The notification processing unit further displays, in association with the first selection information, warning information indicating that the page order of the sheets placed on the sheet placement unit and the page order of the sheets discharged to the first discharge unit and the second discharge unit will change. The sheet transport device according to claim 3 .

5. the notification processing unit displays second selection information indicating that all sheets are to be conveyed to the first conveying path; when the second selection information is selected by a user, the conveyance control unit resumes the sheet conveyance process and conveys all sheets to the first conveyance path.

4. The sheet conveying device according to claim 2 or 3.

6. the notification processing unit displays third selection information indicating that the sheet conveyance process is to be stopped; the conveyance control unit stops the sheet conveyance process when the third selection information is selected by a user. The sheet transport device according to any one of claims 2 to 5.

7. a sheet conveying device according to any one of claims 1 to 6; an image reading unit that reads an image on a sheet conveyed by the sheet conveying device; An image processing device comprising:

8. a determining step of determining whether or not the thickness of a sheet passing through a predetermined detection position on a conveying path along which the sheet is conveyed is equal to or greater than a threshold; a conveyance control step of conveying the sheet along either a first conveyance path from a sheet placement section on which the sheet is placed to a first discharge section via a first conveyance path, or a second conveyance path from the first conveyance path to a second discharge section different from the first discharge section via a second conveyance path including a curved section that branches off from the first conveyance path; a notification step of notifying a user of predetermined information for selecting a sheet transport method when the sheet transport path is set to the second transport path and it is determined in the determination step that the sheet thickness is equal to or greater than the threshold value; A sheet transport method that is performed by a computer.

Images