Document reading device and image forming apparatus

Abstract

To provide a document reading device that can convey a plurality of sizes of documents and can improve productivity, and an image forming apparatus including the same.SOLUTION: A document reading device comprises: a loading unit; a feeding unit that feeds a plurality of documents one by one from the topmost document in a feeding direction; a reading unit that reads the documents; a driving source; and a control unit that can execute a mode for feeding and reading a plurality of documents with different sizes that is loaded and arranged in an ascending order from the document with the smallest width from the top. In the mode, the control unit controls the driving source so that the feeding unit feeds a first document at a first feeding speed, and when the width of the first document is larger than a predetermined width, controls the driving source so that the feeding unit feeds a second document subsequent to the first document at a second feeding speed faster than the first feeding speed.SELECTED DRAWING: Figure 19

Description

Technical Field

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[0003]

[0001] The present invention relates to a document reading device for reading a document and an image forming apparatus including the same.

Background Art

[0002] In recent years, in an image reading device that reads an image while conveying a document, it has been required that documents of various sizes can be mixed and fed. For example, by setting small-sized documents such as receipts and A4-sized documents together on a document tray and feeding them, efficient reading can be performed.

[0003] Conventionally, a document conveyance device including a first document table and a second document table detachably provided on the first document table has been proposed (see Patent Document 1). The second document table has, for example, a second document placement surface of a size on which a business card can be placed and a third document placement surface of a size on which a receipt can be placed. This document conveyance device is fed by the same paper feed roller and retard roller regardless of whether the document is placed on the first document table or on either the second document placement surface or the third document placement surface of the second document table.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, generally, small-sized documents are more likely to skew than large-sized documents, and as a countermeasure, it is known to slow down the document feeding speed. Therefore, when various sizes of documents can be mixed as in the document conveyance device described in Patent Document 1, it is conceivable to feed large-sized documents at a speed corresponding to small-sized documents. However, in this case, productivity decreases.

[0006] Therefore, the present invention aims to provide a document reading device capable of transporting documents of multiple sizes and improving productivity, and an image forming apparatus equipped therewith. [Means for solving the problem]

[0007] The present invention relates to a document reading device comprising: a loading section on which documents are stacked; a feeding section that feeds one document at a time in the feeding direction from the topmost document among a plurality of documents stacked in the loading section; a reading section that reads the documents fed by the feeding section; a drive source that drives the feeding section; and a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the loading section such that documents with smaller widths in the width direction intersecting the feeding direction are placed higher up, are fed by the feeding section and read by the reading section, wherein the control unit controls the drive source so that the feeding section feeds a first document at a first feeding speed, and if the width of the first document is greater than a predetermined width, controls the drive source so that the feeding section feeds a second document following the first document at a second feeding speed faster than the first feeding speed.

[0008] Furthermore, the present invention relates to a document reading device comprising: a loading section on which documents are stacked; a feeding section that feeds documents one by one in the feeding direction from the topmost document among a plurality of documents stacked in the loading section; a reading section that reads the documents fed by the feeding section; a detection section positioned upstream of the feeding section in the feeding direction and detecting the width of the documents fed by the feeding section in the width direction intersecting the feeding direction; a drive source that drives the feeding section; and documents of different sizes stacked in the loading section such that documents with smaller widths are positioned higher up. The device comprises a control unit capable of executing a mode in which multiple documents are fed by the feeding unit and read by the reading unit, wherein the control unit, in the mode, executes a first feeding process in which the feeding unit feeds the documents at a first feeding speed, a detection process in which the detection unit detects the width of the documents, and a second feeding process in which, if the width of the documents detected by the detection process is greater than a predetermined width, the feeding unit feeds the documents at a second feeding speed faster than the first feeding speed. [Effects of the Invention]

[0009] According to the present invention, it is possible to transport documents of multiple sizes and improve productivity. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic diagram showing an image forming apparatus according to the first embodiment. [Figure 2] A schematic diagram showing a document scanning device. [Figure 3] Block diagram of an image forming apparatus. [Figure 4] A schematic diagram showing a modified version of a document reading device equipped with a pressure plate. [Figure 5] A block diagram showing the rollers driven by each motor. [Figure 6] A flowchart illustrating shading control. [Figure 7] A plan view showing the feed attachment. [Figure 8](a) is a perspective view showing a feeding attachment, and (b) is a sectional view showing the feeding attachment. [Figure 9] A plan view showing a feeding attachment attached to a document tray. [Figure 10] A sectional view showing the stacking order of documents. [Figure 11] (a) is a diagram showing an image of a document, and (b) is a diagram showing a reading area. [Figure 12] A schematic diagram showing the gap between the surface glass facing member and the document. ] [Figure 13] (a) is a diagram showing the transmission order of each pixel data, and (b) is a diagram showing the arrangement order of the received pixel data. [Figure 14] A diagram showing a document image after rotational correction. [Figure 15] (a) is a screen diagram for selecting a document reading size, and (b) is a screen diagram for selecting a method for detecting the size of a free-size document. [Figure 16] A table showing the reading speed. [Figure 17] A table showing the feeding speed. [Figure 18] A flowchart showing the control of the entire document reading device. [Figure 19] A flowchart showing the control of the entire document reading device. [Figure 20] A flowchart showing image reading control. [Figure 21] A flowchart showing image reading control. 1] [Figure 22] A flowchart showing image reading control. [Figure 23] A flowchart showing image reading control. [Figure 24] A flowchart showing conveyance processing. [Figure 25] A flowchart showing conveyance processing. [Figure 26] A flowchart showing conveyance processing. 6] [Figure 27] A flowchart showing conveyance processing. [Figure 28] A table showing the management information of the document reading device. [Figure 29]A table showing page management information. [Figure 30] A flowchart showing how to determine the reading size. [Figure 31] A diagram illustrating parallel processing of multiple controls. [Figure 32] (a) is a screen diagram for selecting the document scanning size according to the second embodiment, (b) is a screen diagram for selecting the size detection method for a free-size document, and (c) is a screen diagram showing a message displayed on the operation unit. [Figure 33] A plan view showing the transport path from the document tray to the transport roller pair according to the third embodiment. [Figure 34] A flowchart illustrating the overall control of the document scanning device. [Figure 35] A flowchart illustrating the overall control of the document scanning device. [Figure 36] A flowchart illustrating the overall control of the document scanning device. [Figure 37] A flowchart illustrating image reading control. [Figure 38] A flowchart illustrating image reading control. [Figure 39] A flowchart illustrating image reading control. [Figure 40] A flowchart illustrating image reading control. [Figure 41] A flowchart illustrating image reading control. [Figure 42] A flowchart illustrating the transport process. [Figure 43] A flowchart illustrating the transport process. [Figure 44] A flowchart illustrating the transport process. [Figure 45] A flowchart illustrating the transport process. [Modes for carrying out the invention]

[0011] <First Embodiment> The image reading apparatus and image forming apparatus related to this disclosure will be described below with reference to the drawings. Unless otherwise specifically stated, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments are not intended to limit the scope of application of this technology to those components alone.

[0012] [Outline configuration of an image forming apparatus] First, the schematic configuration of the image forming apparatus 1000 according to this embodiment will be described with reference to Figure 1. As shown in Figure 1, the image forming apparatus 1000 comprises a printer body 500, a document reading device 600, and a controller unit 400 (see Figure 3). The document reading device 600, located above the printer body 500, comprises a reader 200 and an ADF (Auto Document Feeder) 100, as will be described in more detail later, and optically scans the document to read image information. The document is a sheet of paper such as paper and envelopes, plastic film such as overhead projector sheets (OHP), and cloth. The image information converted into an electrical signal by the document reading device 600 is transferred to the controller unit 400 (see Figure 3).

[0013] The printer body 500 includes an image forming unit 540 that forms an image on a sheet, which is a recording medium, and a sheet feeding unit 550 that feeds the sheet to the image forming unit 540. The sheet feeding unit 550 is equipped with cassettes 514 and 515 that can store sheets of different sizes. The sheets stored in cassettes 514 and 515 are fed out by pickup rollers 527 and 528, respectively, and separated one by one by separation roller pairs 529 and 530 and transported. The sheets are then passed sequentially to a plurality of transport roller pairs arranged along the sheet transport path, and transported to a registration roller pair 526.

[0014] The registration roller pair 526 stops the leading edge of the sheet to correct its skewness and resumes transporting the sheet in accordance with the progress of the image formation operation, which is the toner image formation process by the image forming unit 540.

[0015] The image forming unit 540, which forms an image on the sheet, is an electrophotographic image forming unit equipped with a photosensitive drum 511, which is a photoreceptor. The photosensitive drum 511 is rotatable along the sheet transport direction, and a charger 512, an exposure device 510, a developer 513, and a transfer charger 516 are arranged around the photosensitive drum 511. The charger 512 uniformly charges the surface of the photosensitive drum 511, and the exposure device 510 exposes the photosensitive drum 511 via a polygon mirror 510a based on image information input from a document reader 600 or the like, forming an electrostatic latent image on the drum.

[0016] The developer unit 513 contains a two-component developer including toner and a carrier, and develops the electrostatic latent image into a toner image by supplying charged toner to the photosensitive drum 511. The toner image supported on the photosensitive drum 511 is transferred to a sheet conveyed by the registration roller pair 526 by a bias electric field formed by the transfer charger 516. The sheet with the transferred toner image is conveyed toward the fuser unit 517 by the pre-fixer conveyor unit.

[0017] The sheet transported to the fuser unit 517 is held between roller pairs, pressurized, and heated, fixing the image through the melting and solidification of toner. If image output is complete, the sheet with the fixed image is discharged via the discharge roller pair 518 to the discharge tray 519 which protrudes outside the printer body 500. In double-sided printing, when forming an image on the back side of the sheet, the sheet that has passed through the fuser unit 517 is reversed by the inversion unit 139, and transported to the registration roller pair 526 by the double-sided transport unit 140. The sheet, with the image formed again by the image forming unit 540, is then discharged to the discharge tray 519.

[0018] Here, when the sheet is ejected with its image-forming surface facing downwards (face down), the sheet that has passed through the fixing unit 517 is first guided into the inversion path 522 by the switching operation of the guide member 521. After the rear end of the sheet has passed through the guide member 521, the sheet is switched back and ejected to the ejection tray 519 by the ejection roller pair 518. This ejection method is called inverted ejection. This inverted ejection is performed when forming images sequentially from the first page, such as when forming an image on a sheet from a document read by the ADF 100 or when forming an image output from a computer, and the order of the sheets after ejection will be the correct page order.

[0019] Furthermore, since highly rigid sheets such as cardboard fed from the manual feed tray 525 cannot be transported to the reversal path 522, the guide member 521 guides the sheet to the discharge roller pair 518 with the image forming surface facing upwards (face up) without leading it to the reversal path 522.

[0020] Furthermore, when forming images on both sides of the sheet, the guide member 521 guides the sheet to the double-sided transport path 524 via the inversion path 522. The sheet, transported from the double-sided transport path 524 to the registration roller pair 526, has an image formed on the back side (second side) as well, and is then discharged to the discharge tray 519 by the discharge roller pair 518.

[0021] [Document scanning device] Next, the document scanning device 600 will be described in detail. As shown in Figure 2, the document scanning device 600 includes an ADF 100 that feeds documents S (including stacks of documents) loaded on the document tray 30 and discharges them to the discharge tray 10, and a reader 200. The document scanning device 600 also includes a surface reading unit 210 that reads the surface of the documents transported by the ADF 100, and a back-side reading unit 110 that reads the back of the documents transported by the ADF 100. In other words, the ADF 100 constitutes a document transport device that transports documents to the surface reading unit 210 and the back-side reading unit 110. The document tray 30, which serves as the loading section, is provided with a pair of side regulating plates 31 on the document loading surface that are movable in the width direction and contact the edges of the documents in the width direction to regulate the position of the documents in the width direction. Furthermore, the ADF100 is rotatably supported relative to the reader 200 by a hinge (not shown) so that the document glass 209 can be opened.

[0022] The ADF100 has, in order from upstream to downstream in the transport direction, a pickup roller 1 as a feeding section and a separation roller 2 that contacts the separation pad 21. Furthermore, the ADF100 has a pair of pull-out rollers 3, transport rollers 4, 41, and 42, a pair of lead rollers 5, a pair of transport rollers 7, and a pair of discharge rollers 9. The ADF100 also has, in more detail later, a document presence detection sensor 11, a post-separation sensor 12, a pull-out sensor 13, a registration sensor (hereinafter referred to as the register sensor) 14, a lead sensor 15, a discharge sensor 16, etc. Furthermore, as shown in Figure 3, the ADF100 has a feed motor 121, a transport motor 122, a glass motor 123, a back-side light source lamp 103, a transport system sensor 120, a size detection sensor 130, and a back-side reading unit 110. The back-side reading unit 110 includes a CCD sensor 111 and a CCD control unit 112.

[0023] Furthermore, as shown in Figure 2, the ADF100 is equipped with a surface glass facing member 6 at a position opposite the surface reading unit 210, with a surface reading upstream roller 51 positioned upstream in the transport direction and a surface reading downstream roller 52 positioned downstream. The ADF100 is also equipped with a back glass facing member 8 at a position opposite the back reading unit 110, with a back reading upstream roller 53 positioned upstream in the transport direction and a back reading downstream roller 54 positioned downstream.

[0024] On the other hand, the reader 200 is equipped with a document glass 209, a surface reading glass 201, the surface reading unit 210 mentioned above, and the like. Furthermore, as shown in Figure 3, the reader 200 is equipped with a ROM 322, a RAM 323, a paper spacing correction unit 324, an optical motor 326, a light source lamp 203, and a reader sensor 327. In addition, the reader 200 is equipped with a CPU 321, a backup unit 330, an image processing unit 325, and an image memory 329. The image processing unit 325 is equipped with a shading RAM 331, a shading correction circuit 332, a skew detection circuit 333 as a tilt detection means, and a skew correction circuit 334. The surface reading unit 210, which is the reading unit, is equipped with a CCD sensor 211 and a CCD control unit 212.

[0025] Next, the document scanning operation will be explained. The document scanner 600 reads image information from a document using two modes: a scrolling mode in which the document image is scanned while the document loaded in the document tray 30 is transported by the ADF 100, and a fixed mode in which the document placed on the document glass 209 is scanned. The scrolling mode is selected when the document presence detection sensor 11 detects a document loaded in the document tray 30, or when the user explicitly instructs it to be selected using an operation unit (not shown) or the like.

[0026] When the skimming mode is activated, the pickup roller 1 descends and contacts the topmost document on the document tray 30. The document is then transported by the pickup roller 1, and the separation section formed by the separation roller 2 and separation pad 21 applies resistance to the second and subsequent documents, separating them one by one. Simultaneously with the descent of the pickup roller 1, the surface reading unit 210 moves below the surface reading glass to read the transported documents. When a stack of documents is loaded in the document tray 30, the pickup roller 1 feeds one document at a time, starting from the top document in the stack.

[0027] Here, the document feeding speed is limited not only by the material and size of the rollers, but also by the type and size of the document. This is because if a narrow but thick document, such as a business card or credit card, is fed at the same speed as a normal document, the leading edge of the document will press too hard against the separation section (separation nip) formed by the separation roller 2 and the separation pad 21. In this case, when the leading edges of multiple documents press against the separation section simultaneously, the separation effect of the separation pad 21 on the second and subsequent documents will be insufficient, leading to double feeding.

[0028] On the other hand, even with thin documents like receipts, if the feeding speed is the same as for normal documents, the less rigid the document itself is, the more likely it is to tilt due to the balance between the force in the transport direction by the pickup roller 1 and the frictional force with the document directly below it. Also, there is a greater possibility that the leading edge of the document will buckle when it comes into contact with the separation section. Therefore, it is necessary to reduce the feeding speed for narrow documents.

[0029] The leading and trailing ends of the document that have passed through the separation section are detected by the post-separation sensor 12 or the withdrawal sensor 13, which serve as a reference for the raising and lowering timing of the pickup roller 1, as well as the start and stop timing of its drive. In this embodiment, as shown in Figure 5, the feed motor 121, which acts as the drive source, drives the pickup roller 1 and the separation roller 2. The transport motor 122 drives the withdrawal roller pair 3, transport roller pairs 4, 41, 42, 7, lead roller pair 5, front-side reading upstream roller 51, front-side reading downstream roller 52, back-side reading upstream roller 53, back-side reading downstream roller 54, and discharge roller pair 9.

[0030] Then, as shown in Figure 2, when a predetermined time has elapsed since the leading edge of the document was detected by the extraction sensor 13, the feed motor 121 stops, and the rotation of the pickup roller 1 stops. This suppresses the feeding of the next document. Since the separation roller 2 also stops when the feed motor 121 stops, the document is transported for a while by only the extraction roller pair 3 acting as the transport unit. The transport speed of the document by the extraction roller pair 3 driven by the transport motor 122 is set to be faster than the transport speed of the document by the pickup roller 1 and separation roller 2 driven by the feed motor 121. As a result, the transport speed of the document switches to the transport speed of the extraction roller pair 3 when the leading edge of the document reaches the extraction roller pair 3.

[0031] The document being transported is conveyed toward the front reading glass 201 by the withdrawal roller pair 3, transport roller pairs 4, 41, 42, and lead roller pair 5. The front reading upstream roller 51 and the front reading downstream roller 52 are positioned opposite the front reading glass 201 and guide the document passing through the front reading glass 201 so that it does not lift away from the front reading glass 201 between itself and the front glass opposing member 6. The document being transported further is conveyed toward the back reading glass 101 by the front reading upstream roller 51 and the front reading downstream roller 52. The back reading upstream roller 53 and the back reading downstream roller 54 are positioned opposite the back reading glass 101 and guide the document passing through the back reading glass 101 so that it does not lift away from the back reading glass 101 between itself and the back glass opposing member 8. The document that has passed between the back reading glass 101 and the back glass opposing member 8 is then discharged into the discharge tray 10 by the discharge roller pair 9.

[0032] In the case of surface scanning, the image of the document's surface is read by the surface scanning unit 210 via the surface scanning glass 201. The surface of the document passing between the surface scanning glass 201 and the surface scanning glass opposing member 6 is illuminated by light source lamps 203a and 203b. The reflected light is reflected by multiple reflection mirrors 204a, 204b, and 204c, and the CCD sensor 211 reads the surface image of the document line by line. The read image information is transferred to the image memory 329 (see Figure 3).

[0033] In the case of double-sided scanning, the front side is read by the front-side scanning unit 210 as described above, and the image on the back side of the document is read by the back-side scanning unit 110. The back side of the document passing between the back-side scanning glass 101 and the back-side glass opposing member 8 is illuminated by light source lamps 103a and 103b. The reflected light is reflected by multiple reflection mirrors 104a, 104b, and 104c, and the CCD sensor 111 reads the back-side image of the document line by line. The read image information is transferred to the image memory 329 (see Figure 3). Such front-side scanning or double-sided scanning is repeated until the last document has been scanned if there are multiple documents on the document tray 30.

[0034] On the other hand, the fixed reading mode is selected when the device detects a document placed on the document glass 209 or when the user explicitly instructs it to be selected via an operation unit (not shown). In this case, the document on the document glass 209 does not move, and the surface reading unit 210 is moved along the document glass 209 by the drive of the optical motor 326 to scan the document. The image information read by the CCD sensor 211 of the surface reading unit 210 is transferred to the image memory 329 (see Figure 3).

[0035] Alternatively, instead of the ADF100 shown in Figure 2, a pressure plate 230 may be used in the document scanning device, as shown in Figure 4. Such a document scanning device cannot perform a scrolling mode, but it can perform a fixed-position scanning mode. That is, the pressure plate 230 holds the document between itself and the document glass 209 so that the document on the document glass 209 does not move. The document on the document glass 209 is read by the surface scanning unit 210 in the same way as in the fixed-position scanning mode described above.

[0036] [Conveyor control] In the processes of feeding, separating, transporting, reading, and ejecting documents, sensors 12, 13, 14, 15, and 16, installed at various points along the transport path, detect the presence or position of a document along the transport path, and processing is performed according to the detection results. In particular, the lead sensor 15 is used to detect the leading edge of the document being transported, and the start of reading at the front-side reading position is controlled based on the timing of the lead sensor 15 detecting the leading edge of the document and the distance from the lead sensor 15 to the front-side reading position. Similarly, the start of reading at the back-side reading position is controlled based on the timing of the lead sensor 15 detecting the leading edge of the document and the distance from the lead sensor 15 to the back-side reading position.

[0037] During the document feeding and transport operations from the ADF100, the CPU321 periodically monitors the detection signals of the separation sensor 12, the withdrawal sensor 13, the register sensor 14, the read sensor 15, and the ejection sensor 16. If, during the document feeding and transport operations, the detection signals of each sensor continue to indicate the presence or absence of a document for a predetermined period of time or longer, the CPU321 determines that a jam has occurred as an abnormality in document transport. In the following, "present document" refers to the state in which a sensor has detected a document at its detection position, and "absent document" refers to the state in which a sensor has detected a document at its detection position.

[0038] [Details of the control system] Next, the configuration and operation of the control system in the printer 100 will be explained in detail using the block diagram of the image forming apparatus 1000 shown in Figure 3. Since the ADF 100 does not have a CPU, the CPU 321 of the reader 200 actually controls the ADF 100 as a whole.

[0039] The CPU 321 of the reader 200 is connected via a bus line to the ROM 322, which stores the program, and the RAM 323, which is the work area. The CPU 321 controls the transport of documents in the ADF 100 via the output port and input port connected to the ADF 100, according to the control program stored in the ROM 322. The output port is connected to the feed motor 121, the transport motor 122, and the glass motor 123 that moves the back-side reading glass 101. The input port is connected to the document presence detection sensor 11 mentioned above and the transport system sensor 120 used to control the timing for transporting documents. Specifically, the transport system sensor 120 consists of a separation sensor 12, an extraction sensor 13, a register sensor 14, a read sensor 15, and an ejection sensor 16.

[0040] Furthermore, a size detection sensor 130 for acquiring the size of a document on the document tray 30 is connected to the input port. The size detection sensor 130 includes document length detection sensors 17 and 18 that detect different positions of the document on the document tray 30 in the transport direction, and a tray width detection sensor (not shown) that detects the position of the side regulating plate 31 (see Figure 2) in the width direction perpendicular to the transport direction. Also connected to the CPU 321 are a backside light source lamp 103 (including 103a and 103b) for illuminating the back side of the document, and a backside reading unit 110, which in detail is connected to a CCD sensor 111 and a CCD control unit 112 that controls the CCD sensor 111.

[0041] The CPU 321 of the reader 200 controls not only the ADF 100 but also the entire document scanning device 600. The backup unit 330 can back up some of the work data used for control, as well as setting values ​​if there are settings specific to each machine. The optical motor 326 includes a driver circuit for driving the optical drive motor.

[0042] Furthermore, the CPU 321 is connected to a light source lamp 203, a surface reading unit 210 (including a CCD sensor 211 and a CCD control unit 212), and various reader sensors 327. The CPU 321 controls the surface reading unit 210 via an image processing unit 325, which includes a shading RAM 331, a shading correction circuit 332, a skew detection circuit 333, a skew correction circuit 334, etc., and performs image reading processing. The surface reading unit 210 is used not only to read the surface image of a document loaded in the ADF 100, but also to read the image of a document placed on the document glass 209. The various reader sensors 327 include a pressure plate opening / closing detection sensor that detects the opening and closing of the ADF 100 relative to the reader 200, and a size detection sensor for detecting the length of a document placed on the document glass 209. In addition, the paper spacing correction unit 324 corrects the spacing between multiple documents in the transport direction.

[0043] The CPU 321, acting as the control unit, achieves image reading of the desired document by synchronizing the document transport control in the ADF 100 and the image reading processing in the front-side reading unit 210 and the back-side reading unit 110.

[0044] The image signal formed by the CCD sensor 211 of the surface reading unit 210 is converted into digital image data. The converted image data is transferred to the image processing unit 325 via the image data communication line 354, where various image processing operations such as shading and detection and correction of streaks and other unwanted images on the image data are performed, and the image memory 329 is used as a working area for these operations. The image data processed by the image processing unit 325 is sequentially transmitted to the controller unit 400 via the image communication line 353, which includes the image transfer clock signal line. In addition, the leading edge signal, which serves as the reference for the leading edge of the original image data, is time-adjusted by the CPU 321 and notified to the controller unit 400 via the control communication line 352.

[0045] The controller unit 400 controls the entire document reading device 600, including the reader 200 and ADF 100, as well as the entire image forming apparatus 1000. The controller unit 400 includes a control unit 401, a rotational scaling control circuit 402, a correction circuit 403, an image memory 404, an operation unit 405, and an external interface 406.

[0046] Digital image data sent to the controller unit 400 via the image processing unit 325 is image-controlled by the rotation / magnification processing control circuit 402 and then transmitted to the correction circuit 403. The correction circuit 403 then performs color correction processing on the image signal and writes it to the image memory 404. This processing is performed on the image data of the original image area to generate the scanned image of the original. The operation unit 405 includes a display unit such as an LCD panel and physical keys. The operation unit 405 can receive instructions from the user for image scanning operations of the entire system and display scanned images; in other words, it is configured to communicate with the control unit 401 to perform desired displays and inputs. Instructions for image scanning operations include specifying single-sided / double-sided scanning of the original, color / black and white, scanning size, and image quality.

[0047] The External I / F406 is an interface for connecting to an external network, receiving document scanning requests from network computers, transmitting scanned document images, and transmitting obtained document images to network computers. In addition to wired LAN connections, it also has wireless communication capabilities for communication with mobile devices such as smartphones, enabling information mediation between mobile devices and network computers.

[0048] The printer control unit 501 controls the entire printer body 500. Using the results of communication with the control unit 401, the printer control unit 501 receives image output from the image memory 404 and controls the image forming unit 540, as well as issuing instructions to the sheet transport control unit 503 which controls the transport of sheets.

[0049] [Shading control] As shown in Figures 2 and 4, a whiteboard 202 for surface shading is positioned between the surface reading glass 201 and the document glass 209, facing the surface reading unit 210. Also, as shown in Figure 2, a whiteboard 102 for back surface shading is positioned on the back surface reading glass 101. These whiteboards 202 for surface shading and 102 for back surface shading are whiteboards used to create reference data for the white level through shading.

[0050] Specifically, the CPU 321 has the whiteboard 202 read by the front reading unit 210 and the whiteboard 102 read by the back reading unit 110 before reading the original document, and then processes the images to create reference data for both the front and back sides. At this time, the reading brightness in a completely black state with the light source lamps 203a, 203b (or 103a, 103b) turned off becomes the reference data for the black level. Also, the reading brightness in a completely white state with the light source lamps 203a, 203b (or 103a, 103b) turned on becomes the reference data for the white level.

[0051] The reference data is acquired for all read pixels across the main scanning direction. The process of acquiring black level reference data is called black shading, and the process of acquiring white level reference data is called white shading. By normalizing the luminance level obtained during document scanning with the black level reference data obtained by black shading and the white level reference data obtained by white shading, the luminance output during document image scanning can be made appropriate. This process is performed on both the front and back sides of the document.

[0052] The CPU 321 moves the front reading unit 210 to a position facing the whiteboard 202, reads the whiteboard 202, and creates reference data for the front surface. The whiteboard 102 for back surface shading is attached to the back surface reading glass 101, which is movable by the glass motor 123 (see Figure 3). The CPU 321 moves the back surface reading glass 101 so that the whiteboard 102 faces the back surface reading unit 110, reads the whiteboard 102, and creates reference data for the back surface. After reading the whiteboard 102 for back surface shading, the CPU 321 moves the back surface reading glass 101 to retract the whiteboard 102 from the position facing the back surface reading unit 110, enabling document reading.

[0053] Next, the shading control of the surface reading unit 210 will be explained using the flowchart in Figure 6. The shading control of the back surface reading unit 110 is performed in substantially the same manner as the shading control of the surface reading unit 210. First, the CPU 321 moves the surface reading unit 210 directly below the whiteboard 202 and turns on the power of the CCD sensor 211 (S601, S602). Subsequently, the CPU 321 performs black shading by reading the whiteboard 202 with the light source lamps 203a and 203b turned off, and obtains the black level (S603).

[0054] Next, the CPU 321 checks whether the acquired black level is within the desired range (S604). That is, if the black level (brightness) exceeds the predetermined range (S604: No), the CPU 321 determines that the CCD sensor 211 is faulty or the position of the surface reading unit 210 is inappropriate, and turns off the power to the surface reading unit 210 (S612). Then, the CPU 321 returns to the process of step S601 and repeats the above process (S601~S605, S612) (S613: No).

[0055] This is to avoid the device becoming unusable immediately due to a malfunction, even if the surface reading unit 210 is directly below the whiteboard 202 and fails to read the whiteboard 202 due to sudden troubles such as electrical noise or the surface reading unit 210 getting stuck while moving. If the CPU 321 determines that the processing in steps S601 to S605 and S612 has been repeated twice (S613: Yes), it determines that the device is malfunctioning (S614) and terminates the process.

[0056] In step S605, if it is determined that the black level (luminance) is within a predetermined range (S605: Yes), the CPU 321 turns on the light source lamps 203a and 203b (S606). Furthermore, the CPU 321 starts moving the surface reading unit 210 from directly below the whiteboard 202 to the surface reading position shown in Figure 2 (S607). While the surface reading unit 210 is moving, the CPU 321 reads the whiteboard 202 with the light source lamps 203a and 203b lit as white shading and obtains the white level (S608).

[0057] Next, the CPU 321 checks the acquired white level, similar to the black shading process (S609), and determines whether it has finished moving to the surface reading position (S610). If it has finished moving to the surface reading position (S610: Yes), the CPU 321 determines whether the checked white level is normal (S611). If it determines that the white level is normal (S611: Yes), the CPU 321 terminates the series of shading processes while keeping the light source lamps 203a and 203b lit.

[0058] On the other hand, if the white level is determined to be abnormal (S611: No), the CPU 321 turns off the light source lamps 203a and 203b (S615) and turns off the power to the surface reading unit 210 (S612). Then, the CPU 321 returns to the process of step S601 and repeats the above process (S601~S611, S615, S612) (S613: No). If the CPU 321 determines that the process of steps S601~S611, S615, S612 has been repeated twice (S613: Yes), it determines that there is a device failure (S614) and terminates the process.

[0059] [Feeding attachment] As shown in Figure 7, the stack of documents placed on the document tray 30 is held in place by the side restricting plates 31, which hold it in place from both sides. The rear and front side restricting plates 31 are configured to move in conjunction with the width direction WD, which is perpendicular (tolerant) to the feeding direction CD, by a mechanism (not shown) provided inside the document tray 30. That is, when the rear side restricting plate 31 moves to one side in the width direction WD, the front side restricting plate 31 moves to the other side in the width direction WD.

[0060] For the side restrictor plates 31 to clamp the stack of documents from both sides, the documents in the stack must be of the same size. However, in actual use, it is necessary to handle mixed scanning of stacks of documents of multiple sizes. Therefore, the side restrictor plates 31 are set to match the widest document size, and for documents S' that are narrower, the back of the document is aligned with the rear side restrictor plate 31. This suppresses the skewing of the documents when they are loaded into the document tray 30. For this reason, the pickup roller 1 is positioned slightly towards the back (upper side in Figure 7) rather than at the center of the width direction WD of the document tray 30, so that even narrow documents can be fed appropriately when scanning stacks of documents of different sizes. However, the combination of document sizes that can handle mixed scanning cannot be arbitrary. That is, the smallest size document to be mixed must be able to be properly fed by the pickup roller 1 when it is pressed against the rear side restrictor plate 31.

[0061] Furthermore, due to the size constraints of the moving mechanisms on the front and back sides of the side restrictor plate 31, and the fact that the pickup roller 1 is positioned slightly further back to accommodate mixed loading as mentioned above, the range of motion of the side restrictor plate 31 is limited. In this embodiment, the minimum width of a stack of documents that can be held by the side restrictor plate 31 is up to the vertical feed size of A6 according to JIS standards (105.0 mm in width).

[0062] Therefore, in order to enable the scanning of narrow documents such as receipts and business cards, this embodiment provides a document feed attachment 70, as shown in Figures 8(a) and 8(b), that can be attached to and detached from the document tray 30. The document feed attachment 70 has a first auxiliary tray 71 that can hold documents smaller than the smallest document that can be placed on the document tray 30, and a second auxiliary tray 72 that can hold documents larger than the first auxiliary tray 71. The position of a document placed on the first auxiliary tray 71 is restricted in the width direction WD by guides 71A and 71B. The position of a document placed on the second auxiliary tray 72 is restricted in the width direction WD by guides 72A and 72B.

[0063] The first auxiliary tray 71, where document A in Figure 9 is set, accommodates documents with a width of 48 mm to 58 mm, and is intended for business cards and narrow receipts. The second auxiliary tray 72, where document B in Figure 9 is set, accommodates documents with a width of 58 to 91 mm, and is intended for wider receipts and checks. In other words, the first auxiliary tray 71 is a first loading section capable of loading documents with a first width, and the second auxiliary tray 72 is a second loading section capable of loading documents with a second width greater than the first width.

[0064] Furthermore, the document feed attachment 70, which functions as a loading unit, is formed in a roughly U-shape in cross-section. By attaching it to the document tray 30 by covering it from above the side restrictor plate 31, documents can also be placed in the space inside the document feed attachment 70. In this way, by attaching the document feed attachment 70 to the document tray 30, the width of documents that the document reader 600 can feed can be narrowed to 48 mm.

[0065] When multiple documents are placed on the first auxiliary tray 71, the second auxiliary tray 72, and the document tray 30, the configuration shown in Figure 10 is achieved. This configuration allows the documents loaded on the first auxiliary tray 71, the second auxiliary tray 72, and the document tray 30 to be fed sequentially to the pickup roller 1. When executing a document scanning job on the ADF 100, the documents loaded on the first auxiliary tray 71 are fed first. Once the documents on the first auxiliary tray 71 are empty, the documents loaded on the second auxiliary tray 72 are fed next. After all the documents on the second auxiliary tray 72 have been fed, the documents loaded on the document tray 30 are fed last. When this is completed, the document presence detection sensor 11 detects that there are no documents, and the series of scanning jobs is completed.

[0066] [Skewing detection using scanned images] Next, we will explain the detection of skew (tilt) based on the scanned image and its correction control. As will be described in detail later, based on the lead sensor 15 detecting the leading edge of the document, the surface reading unit 210 starts reading the document image from a predetermined distance before the leading edge of the document reaches the reading position on the surface reading glass 201. That is, in order to prevent image loss due to the document being skew (tilted), the ADF 100 starts reading the image earlier than the leading edge of the document detected by the lead sensor 15 reaches the reading position, so that the image is not lost even at the upper limit of the allowable range of skew. For example, if the image of the document is the image shown in Figure 11(a), then as shown in Figure 11(b), an image is obtained that includes not only the document but also the surface glass opposing member 6 as its background.

[0067] Subsequently, the skew detection circuit 333 of the image processing unit 325 extracts the boundary between the document and the surface glass opposing member 6 in the scanned image through image processing. Specifically, when the leading edge of the document reaches the surface glass opposing member 6, the leading edge of the document is not held, so a shadow is created by the gap GP between the surface glass opposing member 6 and the document, as shown in Figure 12. By performing edge extraction processing on this shadow, the intersection point of the leading edge and the side edge of the document can be calculated, and the position, width, and skew angle of the document in the scanned image can be detected.

[0068] [Correction control based on read image] The image read by the surface reading unit 210 is stored in the image memory 329 as an image of the original document, with the original document still skewed. When it is transmitted to the controller unit 400, the skew correction circuit 334 extracts only the original document portion according to the position, width, and skew angle of the original document detected by the skew detection circuit 333. This generates image data of the original document with the skew corrected.

[0069] This correction method will be explained using Figures 13(a) and 13(b). As mentioned above, the width and skew angle of the original document can be detected, so when transmitting the image data of the original document to the controller unit 400, it is sufficient to control the transmission order of each pixel data as shown in Figure 13(a). Figure 13(a) shows the scanned image as is, with each rectangular area representing one pixel. As a result of detecting the shadow of the edges of the original document (dotted lines) in this image, the edges of the original document at the pixel level are located inside the shaded area. The rectangular area enclosed by the four corners of the original document (the intersection of the leading edge and the left edge, the intersection of the leading edge and the right edge, the intersection of the trailing edge and the left edge, and the intersection of the trailing edge and the right edge) is treated as the image within the valid area of ​​the original document.

[0070] Since the line from the intersection of the leading edge of the document to the intersection of the left edge and the right edge of the document corresponds to the leading edge of the document, when sending image data to the controller unit 400, first a Vsync signal, which is a sub-scan reference signal indicating the beginning of a page, is sent. After sending an Hsync signal, which is a signal indicating the beginning of the main scan direction, the image data is sent one pixel at a time sequentially from the left edge of the document, for one line. Once the transfer of the first line of image data is complete, an Hsync signal is sent again, and then the image data for the next line is transferred. In Figure 13(a), the areas 1-1, 1-2, 1-3, ... each represent one pixel transferred to the controller unit 400, and the area mn (m, n are integers) represents the nth pixel from the left edge on the mth line from the beginning. In this example, after sending the 1-1 pixel, the pixel to the right of the 1-1 pixel is either in shadow or has already been transferred, so the pixel directly below this pixel is transferred to the controller unit 400 as the 1-2 pixel. After pixels 1-2, the next pixel to its right is neither in shadow nor has already been transmitted, so it is sent as pixels 1-3.

[0071] The controller unit 400 can reproduce the image from the original document by arranging the received pixels line by line, as shown in Figure 13(b). In this way, by controlling the order in which the image data stored in the image memory 329 is sent to the controller unit 400, skew can be corrected.

[0072] Here, using this image data, the position of the document at the time of scanning can be determined from the intersection of the leading edge and left edge, and the leading edge and right edge, in the main scanning direction, relative to the leading edge position of the document after the rotation of the original image has been corrected. As shown in Figure 14, if the document feeding direction CD is the vertical direction in the figure, the main scanning direction (width direction WD) is the horizontal direction in the figure. Within this, the area enclosed by the solid line is the original image after rotation correction. Also, the upper side of this figure is the leading edge side of the document in the feeding direction CD, and the distance from the edge of the area where scanning was actually performed can be obtained. Note that the surface scanning unit 210 reads across the entire width in the main scanning direction, so that even if the document is skewed, the original image is not cut off in the main scanning direction, and the scanning is performed over a wide area.

[0073] [Switching the feeding speed when handling stacks of documents of mixed sizes] As previously mentioned, when feeding narrow documents, the feeding speed must be reduced. Therefore, when scanning narrow documents with the feeding attachment 70 attached, the paper feeding speed by the feeding motor 121 must be reduced.

[0074] When the operation unit 405 executes a scanning job for a document placed in the ADF 100, there are various settings for specifying the size of the document. For example, as shown in the screen in Figure 15(a), one method is to simply specify the scanning size of the document to a specific size (e.g., A4), or the device determines the scanning size of the entire document stack based on the size of the first document in the stack. Another method for specifying the size of the document is to determine the size of each document as it is being transported, assuming that the stack consists of documents of various standard sizes.

[0075] Furthermore, for stacks of documents that are known not to be of a standard size, there is a free-size mode in which the width and length of each document can be specified or measured individually. Selecting the "Free" icon in Figure 15(a) switches to the screen shown in Figure 15(b). This allows selection from multiple modes within free-size scanning. In this embodiment, the screen shown in Figure 15(b) also includes a mode for using the feed attachment 70. Selecting the "Use Attachment" icon in Figure 15(b) sets the system to the mode for using the feed attachment 70.

[0076] Figure 15(b) shows two types of free-size modes: a fixed free-size mode, which specifies a fixed scanning size in millimeters for all documents in a scanning job, and a mixed free-size mode. In mixed free-size mode, the width and length of each document are measured using the skew detection function described in [Skew Detection by Scanned Image] and the document length detection function, which is calculated by measuring the time from ON to OFF of the sensor in the transport path. Within the mixed free-size mode, there are two types: the standard "mixed free-size mode" which does not use the feed attachment 70, and the "feed attachment usage mode" which uses the feed attachment 70 and includes documents with narrower widths.

[0077] The differences between "Mixed Free Size Mode" and "Feed Attachment Mode" will be explained with specific figures. If the stack of documents contains only documents with a width exceeding 91 mm, there is no need to use the feed attachment 70. In this case, the documents are loaded into the document tray 30 so that the rear end of the documents abuts against the rear side restraint plate 31, and the system is set to "Mixed Free Size Mode". Both "Mixed Free Size Mode" and "Feed Attachment Mode" are modes in which multiple documents of different sizes are loaded so that documents with smaller widths in the width direction WD are placed at the top, and multiple documents are fed and scanned.

[0078] If the stack of documents contains documents with a width of 91 mm or less, use the document feed attachment 70. Documents with a width of 58 mm or less are loaded onto the first auxiliary tray 71 with the rear guide 71A abutting against it, and documents with a width exceeding 58 mm but not exceeding 91 mm are loaded onto the second auxiliary tray 72 with the rear guide 72A abutting against it. If the stack of documents contains documents with a width exceeding 91 mm, they will not fit on the second auxiliary tray 72, so the stack of documents is loaded onto the document tray 30. Then, the position of the side regulating plate 31 is adjusted to match the widest document in the stack, and documents of other widths are loaded with the rear side regulating plate 31 abutting against it. When the documents are loaded in this manner, set the system to "Document Feed Attachment Use Mode".

[0079] When a mode other than "using the document feed attachment" is selected as the document scanning size, the size of the document fed from the document tray 30 is too large to fit in the second auxiliary tray 72 of the document feed attachment 70 (document width exceeds 91 mm). Therefore, according to the correspondence table between document width and document feed speed shown in Figure 17, the fastest possible document feed speed is 590 mm / sec. On the other hand, the scanning speed of the surface scanning unit 210 is determined by the resolution specified during scanning, and the document feed speed is determined within a range that does not exceed the scanning speed. Specifically, the scanning speed for all scanning resolutions specified in the surface scanning unit 210 is determined by the table shown in Figure 16. For example, when scanning in color with a main scan of 300 dpi and a sub-scan of 300 dpi, and when scanning in black and white with a main scan of 600 dpi and a sub-scan of 600 dpi, scanning at the fastest speed of 590 mm / sec is possible. Since reading at 590 mm / sec is not possible with other specified reading resolutions, the feed speed will have to be reduced accordingly to match the reading speed.

[0080] When "Feed Attachment Usage Mode" is selected as the document scanning size, it is assumed that the document is placed not only on the document tray 30 but also on either the first auxiliary tray 71, the second auxiliary tray 72, or both. Therefore, as shown in the table in Figure 17, the feed speed needs to be adjusted according to the width of the document. Here, the feed speed is differentiated according to the width of the document, and the feed speed is assigned according to the width of each of the multiple trays provided by the device. Note that the feed attachment 70 is not equipped with a document presence detection sensor to detect the presence or absence of a document in the first auxiliary tray 71 and the second auxiliary tray 72, in order to allow for easy attachment and detachment from the document tray 30.

[0081] Therefore, as explained in [Skewing Detection by Scanned Image], the width of the document is determined by scanning the image of the document, and the feeding speed is switched according to this determination of the document width. As shown in Figure 10, the documents are fed in the order of the first auxiliary tray 71, the second auxiliary tray 72, and the document tray 30, while as shown in Figure 17, the feeding speed increases as the document width W increases. Therefore, since it is possible to determine from the scanned image of the document that the feeding location has switched and the width of the document being fed has increased, the feeding of that document will remain slow, but the feeding speed for subsequent documents can be increased. This process makes it possible to appropriately increase the feeding speed even in scanning jobs of document bundles with mixed sizes, in a configuration where the upper limit of the feeding speed changes according to the document width.

[0082] [CPU processing flow during document scanning] Next, we will explain the processing performed by CPU321 in the document scanning job using the "document feed attachment mode". As will be described later, CPU321 performs the process of switching the feed speed of the next document according to the scanned image of the document. In this document scanning job, multiple documents are transported into the ADF100 simultaneously, and control is performed to switch the feed speed as needed.

[0083] [Overall control of the document scanning device] Figures 18 and 19 are flowcharts illustrating the overall control of document scanning by the document scanner 600. As shown in Figure 18, the CPU 321 first determines whether or not it has received a request to scan the first page (S1801). If it determines that it has received a request to scan the first page (S1801: Yes), the CPU 321 generates overall management information for the document scanner 600 and page management information for scanning the first page of the document on the RAM 323 (S1802).

[0084] The overall management information for the document scanner 600 includes, as shown in Figure 28, the selection of color / black and white, the specification of the document scanning resolution, the placement position of the document (either on the document glass 209 or the document tray 30), the method for determining the document scanning size, and the scanning speed. Page management information, as shown in Figure 29, is a block of information used to control each individual document, including the page number for identifying the document to be scanned, the selection of color / black and white, and the size of the detected document. The CPU 321 controls document scanning and transport while referring to this page management information.

[0085] Next, the CPU 321 determines whether the method for determining the reading size is "feed attachment usage mode" based on the generated management information (S1803). The user makes settings on the screen displayed on the operation unit 405 shown in Figures 15(a) and 15(b), and the CPU 321 sets the method for determining the reading size in the document scanning job according to the flowchart shown in Figure 30, based on the settings made by the user.

[0086] As shown in Figure 30, the CPU 321 first determines whether the user has specified a scanning size for the document scanning job from the operation unit 405 (S2501). If it is determined that a scanning size has been specified from the operation unit 405 (S2501: Yes), the CPU 321 determines whether the specified scanning size was selected from among several pre-prepared standard sizes (S2502).

[0087] If it is determined that a size has been specified from the standard sizes (S2502:Yes), the CPU321 sets the method for determining the scanning size in the document scanning job to "Specified Standard Size Mode". If it is determined that no size has been specified from the standard sizes (S2502:No), the CPU321 sets the method for determining the scanning size in the document scanning job to "Fixed Free Size Mode".

[0088] In step S2501, if it is determined that the user has not specified the scanning size for the document scanning job from the operation unit 405 (S2501: No), the CPU 321 determines the size of the document at the start of the job or while scanning the document image. The CPU 321 then determines whether the scanning size for the document scanning job is set to the standard size determined at the start of the job (S2503). The case in which the size is set to the standard size determined at the start of the job is when the user selects the "Automatic (Uniform)" icon on the screen shown in Figure 15(a). In other words, the user selects the "Automatic (Uniform)" icon when the sizes of all the documents constituting the document stack are the same and are a standard size.

[0089] In this case (S2503:Yes), the CPU 321 automatically determines the size of the document on the document tray 30 from the standard sizes using the detection results of the size detection sensor 130 when the job starts, and sets it to "Automatic detection standard size mode".

[0090] If it is determined that the document is not of a standard size determined at the start of the job (S2503: No), this occurs when the user selects the "Mixed" icon or the "Free" icon on the screen shown in Figure 15(a). In other words, if it is known in advance that the multiple documents constituting the document bundle consist of multiple standard sizes, such as A4 and A3, the user selects the "Mixed" icon on the screen shown in Figure 15(a) (S2504: Yes). As a result, the CPU 321 sets the method for determining the reading size in the document scanning job to the "Mixed Standard Size Mode," which determines that the size of each document being transported is one of the standard sizes.

[0091] Furthermore, if the multiple documents constituting the document stack are not of a standard size and consist of various sizes, the user selects the "Free" icon on the screen shown in Figure 15(a) (S2504: No). When using the feed attachment 70 (S2505: Yes), the CPU 321 selects the "Use Attachment" icon on the screen shown in Figure 15(b) and sets the method for determining the scan size to the "Use Feed Attachment Mode" described later. When not using the feed attachment 70 (S2505: No), the "Mixed" icon is selected on the screen shown in Figure 15(b), and the CPU 321 sets the method for determining the scan size in the document scanning job to "Mixed Free Size".

[0092] Note that the "Document Feeding Attachment Usage Mode" is set when the width of the smallest document in the document stack is sufficiently smaller than the smallest standard size, A6 portrait feed. The "Mixed Free Size" mode is set when the width of the smallest document in the document stack is equivalent to or significantly larger than A6 portrait feed, and it is not necessary to use document feeding attachment 70.

[0093] Returning to step S1803 in Figure 18, if the method for determining the scan size is "using the feed attachment" (S1803: Yes), the CPU 321 sets the upper limit of the feed speed to 210 mm / sec, the slowest among those shown in Figure 17 (S1805). This is because, when set to "using the feed attachment," the feed attachment 70 is attached to the document tray 30, making it highly likely that a narrow document will be fed, and the feed setting should be adjusted to accommodate the minimum document width of 48 mm. When feeding a narrow document, the document is prone to skewing or buckling at the leading edge, so the feed speed needs to be reduced.

[0094] Conversely, if the method for determining the scanning size in a document scanning job is not "using the document feed attachment mode" (S1803: No), the CPU 321 sets the upper limit of the document feed speed to 590 mm / sec (S1804). This is because, when "using the document feed attachment mode" is not set, the document feed attachment 70 is not attached to the document tray 30, making it highly likely that a document with a certain width will be fed.

[0095] Next, the CPU 321 sets the reading speed based on the relationship between the resolution and the reading color in the reading job, according to the table shown in Figure 16 (S1806). Since the document is transported at the same speed from the pair of extraction rollers 3 to the reading position, the transport speed by the transport motor 122 is also set to be equal to the reading speed.

[0096] Next, the CPU 321 sets the feeding speed, but the feeding speed by the pickup roller 1 and separation roller 2 must be less than or equal to the transport speed (=reading speed) of the pair of extraction rollers 3 driven by the transport motor 122. Therefore, the feeding speed must satisfy the following two upper limits (1) and (2). Feeding speed ≤ Reading speed ···(1) Feeding speed ≤ Upper limit of feeding speed ···(2) Furthermore, in order to shorten the reading time, the feed speed needs to be as fast as possible. Therefore, if the reading speed is less than the upper limit of the feed speed, Feeding speed = Reading speed < Upper limit of feeding speed ···(3) Also, if the reading speed exceeds the upper limit of the feed speed, Feeding speed = Upper limit of feeding speed ≤ Reading speed ···(4) This is the resulting formula.

[0097] For example, consider the case where you want to find the feed speed at the start of a reading job in "feed attachment usage mode" with color reading and a reading resolution of 300 dpi main scan × 600 dpi sub scan. In this case, since it is feed attachment usage mode, the upper limit of the feed speed is 210 mm / sec according to step S11805. Also, according to Figure 16, the reading speed determined from the reading resolution is 340 mm / sec. Therefore, (reading speed) = 340 ≥ (upper limit of feed speed) = 210, which fits into equation (4) above, and a feed speed of 210 mm / sec is obtained.

[0098] In step S1807, once the feeding speed is set, the CPU 321 instructs the ADF 100 to start feeding the document, prepare for scanning, and start scanning (S1808, S1809, S1810). The ADF 100 transports the document to the surface scanning position by carrying the document in the sequence shown in Figures 24 to 26. The CPU 321 of the ADF 100 also performs image scanning of the document in the sequence shown in Figures 20 to 23.

[0099] Therefore, by reading the image of the document, the width of the document is detected by the edge extraction process described above, and the CPU 321 can obtain the document width (S1811: Yes). In other words, the CPU 321 determines the width of the document in the width direction WD based on the image of the document read by the surface reading unit 210. From the obtained document width, the CPU 321 infers from which tray of the feed attachment 70 the document that was transported this time was fed. In the table showing the relationship between document width and feed speed shown in Figure 17, the document width corresponds to the width of the first auxiliary tray 71, the second auxiliary tray 72, and the document tray 30 of the feed attachment 70. For example, if the document width obtained in step S1811 was 55 mm, it is inferred that the document that was transported this time was fed from the first auxiliary tray 71, which corresponds to a document with a width of 48 mm to 58 mm.

[0100] Next, the CPU 321 updates the upper limit of the feed speed according to the obtained document width (S1812). For example, at the start of the job, the upper limit of the feed speed was originally set to 210 mm / sec by step S1805, but consider the case where the document width obtained in step S1811 is greater than the upper limit of the width that can be set in the first auxiliary tray 71 (58 mm). Since this document cannot be set in the first auxiliary tray 71, it can be seen that there are no remaining documents in the first auxiliary tray 71. Therefore, the feed speed when feeding from the second auxiliary tray 72 can be increased to 300 mm / sec according to the table in Figure 17.

[0101] Similarly, once it is determined that the document width obtained in step S1811 is a width that can only be set in the document tray 30, it is also determined that there are no remaining documents in the second auxiliary tray 72. Therefore, since feeding will now be done from the document tray 30, the upper limit of the feeding speed can be increased again to 590 mm / sec.

[0102] In this way, by updating the upper limit of the feed speed according to the document width obtained by image scanning, the CPU 321 sets (updates) the feed speed for the next document scanned (S1813). That is, if documents are set in two or more locations among the first auxiliary tray 71, the second auxiliary tray 72, and the document tray 30, a new document width is obtained when a document is removed from one of the trays and the first document in the next tray is scanned. Then, by updating the upper limit of the feed speed based on the new document width, the feed speed for the next document (the second document in the tray) can be changed to an accelerating direction. This shortens the time from the start of document feeding to the start of extraction by the extraction roller pair 3, thereby improving productivity.

[0103] Next, the CPU 321 waits until the withdrawal sensor 13 detects that there is no document, that is, until the trailing edge of the document passes the position of the withdrawal sensor 13, and then refers to the document presence detection result from the document presence detection sensor 11 at that time (S1814, S1815). If it is determined that there is no next document on the document tray 30 or the document feed attachment 70 (S1815: No), the CPU 321 does not perform a new document feed process and proceeds to step S1818.

[0104] If the CPU 321 determines that the next document is on the document tray 30 or the document feed attachment 70 (S1815: Yes), it generates the next page management information (S1816) and instructs the ADF 100 to start feeding the next document (S1817). The feeding speed at this time reflects the setting result in step S1813.

[0105] Then, when the document reading is complete and the CPU 321 receives a notification that the image reading is complete (S1818: Yes), the CPU 321 checks whether it was determined in step S1815 that there is a next document. If it is determined in step S1815 that there is a next document (S1819: Yes), the process returns to step S1810. If it is determined in step S1815 that there is no next document (S1819: No), the CPU 321 issues termination instructions to the document reading control unit and the transport control unit (S1820, S1821), and stops the transport motor 122 (S1822). Furthermore, the CPU 321 notifies the controller unit 400 that reading has ended (S1823), and the process ends.

[0106] [Parallel processing of multiple controls] The flowchart described so far represents the control content for the entire document reading process. The CPU 321 processes this flowchart, along with the flowcharts for processing in the image reading control unit and transport control unit of the document reader 600, in a time-division multiplexer manner, and executes them almost in parallel. The control related to the image reading control unit is explained in Figures 20 to 23, and the transport processing for each individual document related to the transport control unit is explained in Figures 24 to 27.

[0107] The image reading control unit simultaneously executes two flowcharts during double-sided reading: a flowchart for front-side reading by the front-side reading unit 210 and a flowchart for back-side reading by the back-side reading unit 110. The transport control unit executes the transport process flowchart each time a document feeding instruction is issued, and the transport process ends when the document is ejected. In this way, the CPU 321 executes multiple flowcharts that need to be processed in a time-division manner, and how it processes these multiple flowcharts will be explained below with reference to Figure 31.

[0108] CPU321, for example, uses software such as a multitasking OS to create tasks for the processes described in each flowchart, and executes each task using time-sharing processing. Specifically, CPU321 monitors each task using time-sharing processing, and when a task such as the document transport process or the scanning unit process requires waiting for a predetermined time, it switches to another process (document transport, scanning unit, overall control). This makes it possible to process the necessary processes for double-sided scanning of multiple documents in parallel.

[0109] For example, as shown in Figure 31, the CPU 321 performs four processes in parallel: processing for page A1, processing for page B11, processing for the reading unit, and overall processing. The processing for the reading unit includes reading processing for the surface reading unit 210.

[0110] In the overall processing sequence, there are several waiting processes, such as waiting for the document width to be determined in step S1811 in Figure 10, waiting for the presence or absence of the next document to be determined in step S1814, and waiting for notification that the image reading is complete in step S1818. During this time, the CPU 321 monitors and executes each task in the time-division processing, and switches the task that the CPU 321 executes when a predetermined waiting time for each task has elapsed. Once the predetermined processing for each task is completed, the CPU 321 executes the processing for the next task according to the processing order of the waiting tasks.

[0111] If all other tasks are in a waiting state, the task performing the overall processing waits by repeatedly executing a simple loop (S1811, S1814, S1818), waiting for something to arise that other tasks need to process.

[0112] As an example, as shown in Figure 31, suppose there are processes A-1 / A-2 / A-3 for page A1, processes B-1 / B-2 / B-3 for page B1, and processes C-1 / C-2 for the reading unit. If process A-1 is executed and then the waiting process A-2 is executed, the CPU 321 will execute the overall process because the other pages are also in a waiting state. Then, when the predetermined waiting time for the processing of page B1 is completed, the overall process stops and process B-1 is executed. Similarly, when the waiting process B-3 for page B1 is executed, the execution of the overall process returns, and when the predetermined waiting time for the processing of the reading unit on the surface is completed, it transitions to process C-1. In this way, the CPU 321 executes the transport processing of pages A1 and B1, the processing of the reading unit, and the overall process in parallel.

[0113] [Control related to the reading unit] Next, the processing related to the document reading unit will be explained using the flowcharts in Figures 20 to 23. The processing related to the document reading unit is initiated by the read preparation instruction in step S1809 in Figure 18. As shown in Figure 20, the CPU 321 is not yet ready to read when a read request is received (S1901: Yes). Therefore, based on the management information generated in step S1802, the CPU 321 issues a preparation instruction to the reading unit and changes its state to "reading preparation" (S1903).

[0114] Then, the CPU 321 resets the shading control iteration count to 0 (S1904) and starts moving the surface reading unit 210 directly below the whiteboard 202 (S1905). Normally, the surface reading unit 210 is already located directly below the whiteboard 202, so movement is unnecessary, but the movement process is executed in step S1905 to initialize its position.

[0115] Once the surface reading unit 210 has finished moving (S1906: Yes), the CPU 321 turns on the power to the surface reading unit 210 (S1907) and acquires the black level with the light source lamps 203a and 203b turned off for black shading (S1908). Next, the CPU 321 determines whether the acquired black level is normal or not (S1909). If it is determined that the black level is normal (S1909: Yes), the CPU 321 turns on the light source lamps 203a and 203b for white shading (S1910) and starts moving the surface reading unit 210 toward the surface reading position (S1911).

[0116] Next, the CPU 321 determines whether the surface reading unit 210 has reached the reading area of ​​the whiteboard 202 (S1912). If it is determined that the surface reading unit 210 has reached the reading area of ​​the whiteboard 202 (S1912: Yes), the CPU 321 moves the surface reading unit 210 and reads the whiteboard 202 to obtain the white level (S1913). The CPU 321 checks the obtained white level (S1914) and confirms whether the surface reading unit 210 has reached the reading position (S1915).

[0117] When the surface reading unit 210 reaches the flow reading position (S1915: Yes), the CPU 321 determines whether the acquired white level is normal or not (S1916). If it is determined that the white level is normal (S1916: Yes), the CPU 321 changes the state of the reading unit of the document reader 600 to "readable" (S1917) and returns to step S1901. This allows processing to begin in the readable state.

[0118] On the other hand, for some reason, the level of black sampled with black shading or the level of white sampled with white shading may not be normal. If the level of white is not normal (S1916: No), the CPU 321 turns off the light source lamps 203a and 203b (S1918) and turns off the power to the surface reading unit 210 (S1919). As a result, the CPU 321 resumes the shading process. At this time, the surface reading unit 210 is in the surface reading position, so in S1905 the CPU 321 moves the surface reading unit 210 directly below the white board 202.

[0119] However, considering the possibility that the abnormality is due to a malfunction of the device rather than an accidental sample value, the number of repetitions is checked in step S1920, and the number of repetitions is increased (S1921) before performing shading. If the abnormality persists even after repeating shading twice (S1920: Yes), the process proceeds to step S1955, indicating a device malfunction.

[0120] In step S1901 of Figure 20, if the reading unit of the document reader 600 is in a "readable" state (S1901: No), the CPU 321 determines whether or not it has received a reading completion request, as shown in Figure 22 (S1930). If it has not received a reading completion request (S1930: No), the CPU 321 checks whether or not it has received a reading request in the document transport control (step S2056 in Figure 26, described later) (S1931). If it has not received a reading request (S1931: No), it returns to step S1930.

[0121] When a reading request is received (S1931: Yes), the CPU 321 determines whether the document has reached the reading start timing (S1932). The reading start timing is when the leading edge of the document reaches a position that is close enough to the surface scanning position to ensure sufficient space for detection of the shadow width and minimize the effects of the document's skew. If the document has reached the reading start timing (S1932: Yes), the state of the reading unit of the document reader 600 and the state of the reading unit in the page management information are both set to "reading" (S1933). The CPU 321 then starts storing the document image read by the surface reading unit 210 in the image memory 329 (S1934).

[0122] Then, once a predetermined length has been read from the leading edge of the image, the CPU 321 detects the width of the document along with its position and angle of obliqueness from the image data (S1935: Yes). The width of the document is then notified to the CPU 321 (S1936), and the CPU 321 determines whether or not it has completed reading the requested size (S1937).

[0123] If the reading of the requested size is completed (S1937: Yes), the CPU 321 notifies that the reading of the document is complete (S1938) and determines whether the transfer of the image data stored in the image memory to the controller unit 400 is complete (S1939). If it is determined that the transfer of the image data is complete (S1939: Yes), the CPU 321 sets the status of the reading unit in the page management information to "Transferred" (S1940) and returns the status of the reading unit of the entire document reader 600 to "Readable" (S1941). Then, it returns to step S1930.

[0124] If a reading completion request is received in step S1930 (S1930: Yes), the CPU 321 sets the status of the entire reading unit of the document reader 600 to "reading completion" (S1950). Then, the CPU 321 turns off the light source lamps 203a and 203b (S1951) and turns off the power to the surface reading unit 210 (S1952). After that, the CPU 321 starts moving the surface reading unit 210 directly below the whiteboard 202 (S1953) and determines whether the surface reading unit 210 has finished moving directly below the whiteboard 202 (S1954).

[0125] If the CPU 321 determines that the surface reading unit 210 has finished moving directly below the whiteboard 202 (S1954: Yes), it sets the reading state of the entire document reader 600 to "unreadable" (S1955) and terminates the process.

[0126] [Processing for transporting one page of a document] Next, the document transport process for scanning will be explained using the flowcharts in Figures 24 to 27. This transport process is performed after page management information is generated in step S1802 in Figure 18 or step S1816 in Figure 19.

[0127] First, the CPU 321 uses the document presence detection sensor 11 to detect whether a document is present in the first auxiliary tray 71, the second auxiliary tray 72, or the document tray 30 of the document feed attachment 70 (S2001). If the document presence detection sensor 11 detects the presence of a document (S2001: Yes), the CPU 321 determines whether the document being fed is the first page of a document scanning job (S2002).

[0128] If the document is the first page of the job (S2002:Yes), the CPU 321 starts rotating the transport motor 122 (S2003), and then rotates the feed motor 121 at the specified reading speed (S2005). If the document is the second or subsequent page of the job (S2002:No), the CPU 321 rotates the feed motor 121 at the specified reading speed (S2005) when the distance to the preceding document exceeds a predetermined value (S2004:Yes).

[0129] Here, we will explain how to ensure that the second and subsequent documents in a job maintain an appropriate distance from the preceding document. To prevent collision with the preceding document, the second and subsequent documents in a job are fed only after the trailing edge of the preceding document has passed the pair of extraction rollers 3. More specifically, the document is fed only after a predetermined travel time has elapsed since the preceding document was detected by the extraction sensor 13. This travel time is calculated from the distance from the extraction sensor 13 to the pair of extraction rollers 3 and the transport speed of the preceding document, and is the time it takes for the trailing edge of the preceding document to move from the extraction sensor 13 to the pair of extraction rollers 3.

[0130] In this way, by delaying the start of feeding the next document until the trailing edge of the preceding document has passed through the pair of withdrawal rollers 3, it is possible to prevent the next document being fed from colliding with the preceding document.

[0131] Next, the CPU 321 determines whether the separation sensor 12 has detected the presence of a document (S2006). If the separation sensor 12 has detected the presence of a document (S2006: Yes), the CPU 321 determines whether the document has reached a temporary stopping position (S2008). When the document is in the temporary stopping position, the leading edge of the document is positioned between the separation sensor 12 and the pair of extraction rollers 3 in the transport direction. In this state, the document can be stopped by stopping the feed motor 121.

[0132] If it is determined that the document has reached a temporary stopping position (S2008: Yes), the CPU 321 determines whether or not the document can be read (S2009). The determination of whether or not it can be read is made not only by whether there is an area in the image memory 329 to store the image, but also by whether the state of the reading unit is "readable" in step S1917 in Figure 21. If it is determined at this point that the document can be read (S2009: Yes), the document will not stop at the temporary stopping position, and the document transport will continue, proceeding to step S2013.

[0133] On the other hand, if, for example, there is no free space in the image memory 329 and therefore the document cannot be read, or if the state of the reading unit is not yet "readable" (S2009: No), the CPU 321 stops the feed motor 121 (S2010). As a result, the document is temporarily stopped at the stopping position and waits until the state of the reading unit becomes "readable" (S2011). When the state of the reading unit becomes "readable" (S2011: Yes), the CPU 321 rotates the feed motor 121 and resumes the feeding operation (S2012), and proceeds to step S2013.

[0134] In step S2013, the CPU 321 determines whether the paper has been detected by the paper extraction sensor 13, that is, whether the paper extraction sensor 13 has detected the presence of a paper (S2013). If it is determined that the paper extraction sensor 13 has not detected the presence of a paper (S2013: No), the CPU 321 monitors the paper extraction sensor 13 for the presence of a paper until a predetermined time has elapsed (S2014). If the paper extraction sensor 13 has not detected the presence of a paper even after the predetermined time has elapsed (S2014: No), the CPU 321 stops the transport of the paper, assuming that the transport of the paper was not performed correctly, as shown in Figure 26 (S2063). Specifically, the CPU 321 stops both the feed motor 121 and the transport motor 122 and proceeds to step S2065.

[0135] Furthermore, in step S2013 of Figure 25, if the extraction sensor 13 detects the presence of a document (S2013:Yes), the CPU 321 waits until a predetermined time has elapsed (S2015). Then, once the predetermined time has elapsed (S2015:Yes), when the leading edge of the document is gripped by the extraction roller pair 3, the CPU 321 stops the feed motor 121 (S2016).

[0136] Here, after stopping the feed motor 121 so that the leading edge of the document is transported only by the pair of withdrawal rollers 3, the CPU 321 checks whether the trailing edge of the document being transported has passed the separation sensor 12 in preparation for feeding the next document. This process is executed in parallel with the next document presence detection control (S2050~S2059) performed by the register sensor 14, lead sensor 15, and discharge sensor 16, which are located downstream of the separation sensor 12 in the transport direction. The position of the document on the transport path is detected by the separation sensor 12, register sensor 14, lead sensor 15, and discharge sensor 16.

[0137] Specifically, the CPU 321 determines whether the register sensor 14 has detected the presence of a document (S2050). If the register sensor 14 has not detected the presence of a document (S2050: No), the CPU 321 determines whether a predetermined time has elapsed (S2051). If the predetermined time has not elapsed (S2051: No), the CPU 321 performs the next document presence detection described later in Figure 27 (S2052) and returns to step S2050. If the predetermined time has elapsed (S2051: Yes), the CPU 321 stops document transport by stopping the feed motor 121 and the transport motor 122 (S2063) and proceeds to step S2065.

[0138] If the register sensor 14 detects the presence of a document (S2050: Yes), the CPU 321 determines whether or not the lead sensor 15 has detected the presence of a document (S2053). If the lead sensor 15 does not detect the presence of a document (S2053: No), the CPU 321 determines whether or not a predetermined time has elapsed (S2054). If the predetermined time has not elapsed (S2054: No), the CPU 321 performs the next document presence detection described later in Figure 27 (S2055) and returns to step S2053. If the predetermined time has elapsed (S2054: Yes), the CPU 321 stops document transport by stopping the feed motor 121 and the transport motor 122 (S2063) and proceeds to step S2065.

[0139] If the read sensor 15 detects the presence of a document (S2053: Yes), the CPU 321 instructs the surface reading unit 210 to start reading the surface of the document (S2056). The CPU 321 then determines whether or not the ejection sensor 16 has detected the presence of a document (S2057). If the ejection sensor 16 has not detected the presence of a document (S2057: No), the CPU 321 determines whether or not a predetermined time has elapsed (S2058). If the predetermined time has not elapsed (S2058: No), the CPU 321 performs the next document presence detection described later in Figure 27 (S2059) and returns to step S2057. If the predetermined time has elapsed (S2058: Yes), the CPU 321 stops document transport by stopping the feed motor 121 and the transport motor 122 (S2063) and proceeds to step S2065.

[0140] If the discharge sensor 16 detects the presence of a document (S2057: Yes), the CPU 321, in parallel with detecting the presence or absence of the next document (S2059), determines whether the discharge sensor 16 has detected the absence of a document (S2060). This is to confirm whether the document can be properly discharged into the discharge tray 10. If the discharge sensor 16 does not detect the absence of a document (S2060: No), the CPU 321 determines whether a predetermined time has elapsed (S2061). If the predetermined time has not elapsed (S2061: No), the CPU 321 performs the detection of the presence or absence of the next document, as described later in Figure 27 (S2062), and returns to step S2060. If the predetermined time has elapsed (S2061: Yes), the CPU 321 stops document transport by stopping the feed motor 121 and the transport motor 122 (S2063), and proceeds to step S2065.

[0141] If the ejection sensor 16 detects that there is no document (S2060: Yes), the CPU 321 determines whether the time required for the trailing edge of the document to exit the ejection tray 10 has elapsed (S2064). If it is determined that the time required for the trailing edge of the document to exit the ejection tray 10 has elapsed (S2064: Yes), the CPU 321 deletes the page management information (S2065) and terminates the document transport sequence for one document.

[0142] Figure 27 is a flowchart showing the process related to detecting the presence or absence of the next document (S2052, S2055, S2059, S2062) as shown in Figure 26. As shown in Figure 27, when detecting the presence or absence of the next document is performed, the CPU 321 determines whether or not the presence or absence of a document has already been notified (S2201). This is because there are multiple opportunities to determine the presence or absence of a document during the document transport process for a single document, so it is not necessary to perform the same process multiple times. If the presence or absence of a document has already been notified (S2201: Yes), the process is terminated.

[0143] If the presence or absence of a document has not yet been notified (S2201: No), the CPU 321 determines whether the post-separation sensor 12 has detected the absence of a document (S2202). In other words, the CPU 321 determines whether the post-separation sensor 12 has changed from detecting a document to detecting no document when the trailing edge of the document passes through it.

[0144] If the separated sensor 12 detects that there is no document (S2202: Yes), the CPU 321 checks whether a document remains in the first auxiliary tray 71, the second auxiliary tray 72, or the document tray 30 based on the detection result of the document presence detection sensor 11 (S2203). If it is determined that a document remains in the first auxiliary tray 71, the second auxiliary tray 72, or the document tray 30 (S2203: Yes), the CPU 321 notifies that there is a next document (S2204) and issues the instruction to start feeding as shown in Figure 19 (S1817). On the other hand, if it is determined that there is no document remaining in the first auxiliary tray 71, the second auxiliary tray 72, or the document tray 30 (S2203: No), the CPU 321 notifies that there is no next document (S2205).

[0145] As described above, in this embodiment, in a document scanning job using the document feed attachment, the document width is obtained based on the scanned document image (S1810, S1811 in Figure 19). Then, from the obtained document width, it is estimated which of the first auxiliary tray 71, the second auxiliary tray 72, or the document tray 30 the scanned document was placed on. Furthermore, the feeding speed for the next document is set (updated) according to the estimated tray (S1812, S1813 in Figures 17 and 19).

[0146] In other words, in the feed attachment usage mode, the CPU 321 controls the feed motor 121 so that the pickup roller 1 feeds the first document at a first feed speed. Furthermore, if the width in the width direction WD intersecting the feed direction CD of the first document is greater than a predetermined width, the CPU 321 controls the feed motor 121 so that the pickup roller 1 feeds the second document following the first document at a second feed speed. The second feed speed is faster than the first feed speed.

[0147] Furthermore, in the feed attachment usage mode, the CPU 321 controls the feed motor 121 so that the pickup roller 1 feeds the documents loaded onto the first auxiliary tray 71 at a first feed speed. The CPU 321 also controls the feed motor 121 so that the pickup roller 1 feeds the first document loaded onto the second auxiliary tray 72 at a first feed speed. In addition, the CPU 321 controls the feed motor 121 so that the pickup roller 1 feeds the second and subsequent documents loaded onto the second auxiliary tray 72 at a second feed speed.

[0148] Therefore, in document scanning jobs using the feed attachment 70, productivity can be improved while suppressing document skew and buckling of the leading edge. In addition, documents of multiple sizes can be transported and scanned in a single job.

[0149] <Second Embodiment> Next, a second embodiment of the present invention will be described. The second embodiment has substantially the same configuration as the document reading device 600 of the first embodiment, but the document feeding attachment 70 is not installed. For this reason, the same components as in the first embodiment will not be shown in the illustration, or will be described using the same reference numerals in the illustration.

[0150] In the first embodiment, the document feed attachment 70 was mounted on the document tray 30, and narrow documents were placed on the first auxiliary tray 71 or the second auxiliary tray 72 of the document feed attachment 70. On the other hand, in this embodiment, the document feed attachment 70 is not used, and narrow documents are mixed in with other documents on the document tray 30.

[0151] The screen of the operation unit 405 switches to the screen shown in Figure 32(b) by selecting the “Free” icon in Figure 32(a). In this embodiment, as in the first embodiment, a fixed free size mode is provided. Furthermore, by selecting the “Mixed” icon on the screen shown in Figure 32(b), the mixed free size mode is selected. In addition, by selecting the “Mixed (Advanced)” icon, it becomes possible to scan documents that are too narrow to be held between both ends by the side restrictor plate 31, or document stacks where the narrowest document in the stack is only half the width of the widest document.

[0152] To properly read such a stack of documents, in this embodiment, when the “Mixed (Advanced)” icon in Figure 32(b) is selected, a message like the one shown in Figure 32(c) is displayed on the operation unit 405, which acts as a display unit. For example, the operation unit 405 displays messages such as: 1. Maximum of 10 documents, 2. Place wider documents at the bottom (the narrower the document, the higher it goes), 3. Move documents towards the center of the tray, 4. Position them parallel to the guides.

[0153] This prompts the user to arrange the documents in the stack so that, when the document feed attachment 70 is not attached to the document tray 30, the documents with smaller widths are placed higher up. The user is also prompted to align the stack of documents with the center of the document tray 30 in the width direction (WD). In other words, the user is prompted to arrange the documents so that the center of the documents stacked in the document tray 30 in the width direction (WD) aligns with the center of the pair of side regulating plates 31 in the width direction (WD).

[0154] By following these instructions and loading the document stack onto the document tray 30, the user can scan documents with the same control as in the "document feed attachment usage mode" of the first embodiment, even without using the document feed attachment 70. This improves productivity while suppressing document skew and buckling of the leading edge.

[0155] <Third Embodiment> Next, a third embodiment of the present invention will be described. The third embodiment is configured by adding a first document width detection sensor 81 and a second document width detection sensor 82 to the document reading device 600 of the first embodiment. For this reason, components similar to those in the first embodiment will not be shown in the illustration, or will be described using the same reference numerals in the illustration.

[0156] Figure 33 is a plan view showing the transport path of the document scanner 600B from the document tray 30 to the transport roller pair 4. In the example shown in Figure 33, images are being read from documents A and C loaded on the first auxiliary tray 71 of the feed attachment 70. Document A has reached the registration sensor 14, while document C has not yet been fed by the pickup roller 1.

[0157] In Figure 33, lines P71A and P71B indicate the positions in the width direction WD of the rear guide 71A and front guide 71B, respectively, provided on the first auxiliary tray 71. Lines P72A and P72B indicate the positions in the width direction WD of the rear guide 72A and front guide 72B, respectively, provided on the second auxiliary tray 72. Lines P31A and P31B indicate the abutment positions in the width direction WD of the original document for the rear and front side regulating plates 31, respectively, when the pair of side regulating plates 31 are in their most open state. These lines P31A, P31B, P71A, P71B, P72A, and P72B extend along the feeding direction CD.

[0158] In this embodiment, a first document width detection sensor 81 and a second document width detection sensor 82 are positioned between the separated sensor 12 and the register sensor 14 in the feeding direction CD, respectively, as detection units capable of detecting the presence or absence of a document being transported at each position. The first document width detection sensor 81 is positioned between straight lines P71A and P72A in the width direction WD. The second document width detection sensor 82 is positioned between straight lines P72A and P31A in the width direction WD.

[0159] Therefore, the first document width detection sensor 81 cannot detect documents fed from the first auxiliary tray 71, but can detect documents fed from the second auxiliary tray 72 and the document tray 30. Also, the second document width detection sensor 82 cannot detect documents fed from the second auxiliary tray 72, but can detect documents fed from the document tray 30.

[0160] In this embodiment, when a document is placed in the first auxiliary tray 71 or the second auxiliary tray 72, the document is placed while abutting against the guides 71A and 72A. Therefore, for example, when document A, which was loaded in the first auxiliary tray 71, is properly transported, the first document width detection sensor 81 and the second document width detection sensor 82 cannot detect the document being fed. Thus, if the first document width detection sensor 81 does not detect the document when the leading edge of the document reaches the register sensor 14, it can be inferred that document A was fed from the first auxiliary tray 71.

[0161] Then, it is assumed that document C, which follows document A, is also in the first auxiliary tray 71, and it is fed at a feeding speed appropriate to the width of the document loaded in the first auxiliary tray 71. Furthermore, if the first document width detection sensor 81 detects a document, but the second document width detection sensor 82 does not detect a document, it can be assumed that the fed document was fed from the second auxiliary tray 72. Moreover, if both the first document width detection sensor 81 and the second document width detection sensor 82 detect a document, it can be assumed that the fed document was fed from the document tray 30.

[0162] Thus, in this embodiment, at least three different document widths can be detected by two first document width detection sensors 81 and a second document width detection sensor 82, which are positioned at different locations in the width direction WD. Furthermore, the first document width detection sensor 81 and the second document width detection sensor 82 are positioned upstream of the register sensor 14 and the surface reading unit 210 in the feeding direction CD. For this reason, in the second embodiment, the document width can be detected more quickly than in the first embodiment, which detects the document width based on the scanned document image.

[0163] Furthermore, productivity can be improved by changing the feeding speed of the documents fed by the pickup roller 1 and the separation roller 2 based on the detected document width. In addition, since the feeding speed of a document whose width has been detected can be changed when the leading edge reaches the register sensor 14, the feeding speed of mixed documents can be changed one by one at a faster timing than in the first embodiment, thereby improving productivity.

[0164] [Overall control of the document scanning device] Figures 34 to 36 are flowcharts showing the overall control of document scanning by the document scanning device 600. The process in Figure 34 is basically the same as the process in Figure 18. That is, steps S2901 to S2909 in Figure 34 correspond to steps S1801 to S1809 in Figure 18, so their explanation is omitted.

[0165] When the instruction to prepare the document for scanning is issued in step S2909 in Figure 34, the CPU 321 determines whether or not the document width has been obtained (S2910: Yes), as shown in Figure 35. As described above, when the leading edge of the document fed by the pickup roller 1 and the separation roller 2 reaches the register sensor 14, the document width is detected based on the detection results of the first document width detection sensor 81 and the second document width detection sensor 82.

[0166] If the document width cannot be obtained in step S2910 (S2910: No), the CPU 321 executes the reading instruction flow described later in Figure 37 and returns to step S2910. If the document width can be obtained (S2910: Yes), the CPU 321 executes steps S2912 and S2913. Steps S2912 and S2913 correspond to steps S1812 and S1813 in Figure 19, and update the upper limit of the document feeding speed and change (update) the document feeding speed setting for the next document. In this embodiment, compared to the first embodiment in which the document width is determined from the scanned image of the document, the document width is detected by the first document width detection sensor 81 and the second document width detection sensor 82, so the timing of obtaining the document width is earlier. For this reason, not only the document feeding speed for the next document, but also the document feeding speed of the document whose width has been detected by the first document width detection sensor 81 and the second document width detection sensor 82, and the reading speed set by the transport motor 122 may be changed based on the newly obtained document width. This will allow for increased productivity.

[0167] Next, the CPU 321 sets the read status in the page management information shown in Figure 29, as shown in the first embodiment, to "reading" (S2914), as the document supplied this time is a readable document. Steps S2915, S2917 to S2919 are the same as S1814 to S1817 in Figure 19, so their explanation is omitted.

[0168] During the document feeding process for a single document, steps S2910 and S2915 are in a waiting loop, and at the time when no further document feeding is required (step S2920), the reading instruction flow (S2911, S2916, S2920), described later, is executed. The reading instruction flow issues a reading start instruction to the document that was selected for reading in step S2914, and processes the image after reading is complete.

[0169] As shown in Figure 37, the reading instruction flow first determines in steps S2908 and S919 whether there are any documents that have been instructed to start feeding and in step S2914 whether there are any documents waiting to be read (S3001). If there are no such documents (S3001: No), the process proceeds to step S3005. If there are such documents (S3001: Yes), the CPU 321 determines whether there is enough free space in the image memory 329 to store the scanned image data of the documents (S3002). If there is no free space in the image memory 329 (S3002: No), the process proceeds to step S3005.

[0170] If there is free space in the image memory 329 (S3002: Yes), the CPU 321 reserves free space in the image memory 329 and instructs the reading control unit to start reading the document (S3004). Next, the CPU 321 determines whether there is any image data in the image memory 329 that has already been read or transferred to the controller unit 400 (S3005). If such image data exists (S3005: Yes), the CPU 321 releases the storage area for the image data from the image memory 329 (S3006) and terminates the process.

[0171] Returning to Figure 36, the reading instruction flow (S2920) is executed until all document images have been read (S2921: No). Once all document images have been read (S2921: Yes), steps S2922 to S2925 are executed, similar to steps S1820 to S1823 in Figure 19.

[0172] [Control related to the reading unit] Next, the processing related to the document reading unit will be explained using the flowcharts in Figures 38 to 41. The basic processing related to the document reading unit is the same as the processing described in Figures 20 to 23 of the first embodiment. Steps S3101 to S3135 in the flowcharts shown in Figures 38 and 39 are the same as steps S1901 to S1935 in the flowcharts shown in Figures 20 and 21.

[0173] In step S3135, the CPU 321 determines whether the width of the scanned document has been detected in order to correct the skew of the document image (S3135). In this embodiment, since the document width is obtained from the first document width detection sensor 81 and the second document width detection sensor 82 in step S2910 (see Figure 35), the document width is not obtained from the scanned image. Therefore, if the width of the document is detected (S3135: Yes), the process in step S1936 shown in Figure 22 is not performed, and the process proceeds to step S3136. Steps S3136 to S3155 shown in Figures 40 and 41 are the same as steps S1937 to S1955 shown in Figures 22 and 23.

[0174] [Processing for transporting one page of a document] Next, the transport process for document scanning will be explained using the flowcharts in Figures 42 to 45. Steps S3201 to S3252 shown in Figures 42 to 44 are the same as steps S2001 to S2052 shown in Figures 24 to 26. Note that the detection of the presence or absence of the next document in step S3252 shown in Figure 44 and steps S3261, S3265, and S3268 shown in Figure 45 are the same as those explained in Figure 27, so the explanation will be omitted. As shown in Figure 44, when the register sensor 14 detects the presence of a document (S3250: Yes), the CPU 321 determines whether or not the second document width detection sensor 82 has detected the presence of a document (S3253).

[0175] If the second document width detection sensor 82 detects the presence of a document (S3253: Yes), the CPU 321 determines that the document was fed from the document tray 30 (S3257) and proceeds to step S3258. If the second document width detection sensor 82 does not detect the presence of a document (S3253: No), the CPU 321 determines whether or not the first document width detection sensor 81 detected the presence of a document (S3254). If the first document width detection sensor 81 detects the presence of a document (S3254: Yes), the CPU 321 determines that the document was fed from the second auxiliary tray 72 (S3256) and proceeds to step S3258. If the first document width detection sensor 81 does not detect the presence of a document (S3254: No), the CPU 321 determines that the document was fed from the first auxiliary tray 71 (S3255) and proceeds to step S3258. The CPU 321 then notifies the control unit that writes the determined width of the document (S3258).

[0176] Steps S3259 to S3269 shown in Figure 45 are the same as steps S2050 to S2064 shown in Figure 26. As shown in Figure 45, if it is determined that time has elapsed until the trailing edge of the document comes out of the output tray 10 (S3269: Yes), the CPU 321 determines whether the image data stored in the image memory 329 has been transferred to the controller unit 400 (S3271). If it is determined that the image data has been transferred to the controller unit 400 (S3271: Yes), the CPU 321 deletes the page management information (S3272) and terminates the document transport sequence for one document.

[0177] The reason for deleting the page management information only after confirming that the image data has been transferred to the controller unit 400 is that even after the document has been ejected to the output tray 10, image data that is still waiting to be transferred may remain in the image memory 329.

[0178] As described above, in this embodiment, a first document width detection sensor 81 and a second document width detection sensor 82 capable of detecting the width (size) of the fed document are provided on the document transport path. Then, in a document reading job using the document transport attachment, the document width is acquired based on the detection results of the first document width detection sensor 81 and the second document width detection sensor 82 (S2910, S3253~S3258). Then, from the acquired document width, it is estimated which of the first auxiliary tray 71, the second auxiliary tray 72, or the document tray 30 the scanned document was placed on. Furthermore, the feeding speed for the next document is set (updated) according to the estimated tray (S2913).

[0179] In other words, in the feed attachment usage mode, the CPU 321 performs a first feed process, a detection process, and a second feed process. The first feed process is the process of feeding the document at a first feed speed using the pickup roller 1. The detection process is the process of detecting the width of the document using the first document width detection sensor 81 and the second document width detection sensor 82. The second feed process is the process of feeding the document at a second feed speed faster than the first feed speed using the pickup roller 1 when the width of the document detected by the detection process is greater than a predetermined width.

[0180] Therefore, in document scanning jobs using the feed attachment 70, productivity can be improved while suppressing document skew and buckling of the leading edge. In addition, documents of multiple sizes can be transported and scanned in a single job.

[0181] Furthermore, even in a configuration that does not have a function to obtain the document width from the scanned image, as in the first embodiment, the feeding speed can be appropriately switched according to the width of the document being fed. Moreover, the above second feeding process can further improve productivity compared to the first embodiment.

[0182] <Other embodiments> In all of the configurations described above, the document was fed by the pickup roller 1, but this is not the only option. For example, the document may be fed by a rotatable belt or the like instead of the pickup roller 1.

[0183] Furthermore, in all of the configurations described above, the pickup roller 1 feeds the documents in order from the topmost document loaded in the document tray 30 or the document feed attachment 70, but is not limited to this. For example, the pickup roller 1 may feed the documents in order from the bottommost document supported by the document tray 30 or the document feed attachment 70, in which case the documents supported by the document tray 30 or the document feed attachment 70 will increase in size from the bottom to the top.

[0184] Furthermore, in the third embodiment, the size of the document fed from the document tray 30 or the document feeding attachment 70 was detected by two first document width detection sensors 81 and a second document width detection sensor 82, but this is not limited to this. For example, the size of the document may be detected by a single line sensor that is long in the width direction WD, and the configuration of the sensor for detecting the size of the document is not limited to an optical sensor, but may also be a mechanical sensor using a flag, etc.

[0185] Furthermore, in all of the configurations described above, control related to document transport and reading was performed by the CPU 321 provided in the reader 200, but this is not limited to this. For example, control related to document transport and reading may be performed by the control unit 401 of the controller unit 400, the printer control unit 501 of the printer body 500, etc.

[0186] Furthermore, the second embodiment may be combined with the first or third embodiment.

[0187] Furthermore, although the embodiments described above have been explained using an electrophotographic image forming apparatus, the present invention is not limited to this. For example, the present invention can also be applied to an inkjet image forming apparatus that forms an image on a sheet by ejecting ink liquid from a nozzle.

[0188] The present invention can also be realized by supplying a program that implements one or more of the functions of the above embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0189] Furthermore, the disclosure of this embodiment includes the following configuration examples and method examples. (Composition 1) The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A drive source that drives the feeding unit, The system includes a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the stacking section such that documents with smaller widths in the width direction intersecting the feeding direction are placed higher up, are fed by the feeding section and read by the reading section, In the mode, the control unit controls the drive source so that the feeding unit feeds the first document at a first feeding speed, and if the width of the first document is greater than a predetermined width, the control unit controls the drive source so that the feeding unit feeds the second document following the first document at a second feeding speed faster than the first feeding speed. A document reading device characterized by the following features. (Configuration 2) A loading unit comprising a first loading section capable of loading documents having a first width, and a second loading section capable of loading documents having a second width greater in the width direction than the first width, wherein the loading unit is detachably attached to the loading section. The feeding unit is capable of sequentially feeding the documents loaded in the first and second loading units, such that when the documents loaded in the first loading unit are empty, it feeds the documents loaded in the second loading unit. The document reading device according to configuration 1, characterized by the above. (Composition 3) The control unit controls the drive source in the mode such that the feeding unit feeds the documents loaded in the first loading unit at a first feeding speed, controls the drive source such that the feeding unit feeds the first document in the second loading unit at a first feeding speed, and controls the drive source such that the feeding unit feeds the second and subsequent documents in the second loading unit at a second feeding speed. The document reading device according to configuration 2, characterized in that it is a document reading device. (Composition 4) In the mode described above, the loading section is equipped with a display unit that shows a prompt indicating that the documents to be loaded should be placed in an order such that the documents with smaller widths are placed higher up. The document reading device according to feature 1. (Composition 5) The loading section is equipped with a pair of regulating plates that restrict the position of the documents loaded in the width direction, In the mode, the display unit displays a message prompting the placement of the documents so that the center of the documents in the width direction of the documents placed on the stacking unit aligns with the center of the pair of regulating plates in the width direction. The document reading device according to configuration 4, characterized by the above. (Composition 6) The control unit determines the width of the document based on the image of the document read by the reading unit. A document reading device according to any one of configurations 1 to 5, characterized by the above. (Composition 7) The control unit includes a detection unit that detects the width of the document fed by the feeding unit. A document reading device according to any one of configurations 1 to 5, characterized by the above. (Composition 8) The detection unit is positioned upstream of the reading unit in the feeding direction. The document reading device according to configuration 7, characterized by the features described above. (Composition 9) The transport unit is located downstream of the feeding unit in the aforementioned feeding direction and transports the original document fed by the feeding unit, The document transport speed by the transport unit is faster than the document transport speed by the feeding unit. A document reading device according to any one of configurations 1 to 8, characterized by the above. (Composition 10) The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A detection unit is positioned upstream of the feeding unit in the feeding direction and detects the width of the document fed by the feeding unit in the width direction intersecting the feeding direction, A drive source that drives the feeding unit, The system includes a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the stacking section such that the smaller documents are positioned higher up, are fed by the feeding unit and read by the reading unit, In the mode, the control unit performs a first feeding process in which the feeding unit feeds the document at a first feeding speed, a detection process in which the detection unit detects the width of the document, and a second feeding process in which, if the width of the document detected by the detection process is greater than a predetermined width, the feeding unit feeds the document at a second feeding speed faster than the first feeding speed. A document reading device characterized by the following features. (Composition 11) An image forming unit that forms an image on a recording medium, The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A drive source that drives the feeding unit, The device comprises a stacking section on which multiple documents of different sizes are stacked such that documents with smaller widths in the width direction intersecting the feeding direction are placed higher up, and a control unit capable of executing a mode in which the multiple documents are fed by the feeding section and read by the reading section, In the mode, the control unit controls the drive source so that the feeding unit feeds the first document at a first feeding speed, and if the width of the first document is greater than a predetermined width, the control unit controls the drive source so that the feeding unit feeds the second document following the first document at a second feeding speed faster than the first feeding speed. An image forming apparatus characterized by the following features. (Composition 12) An image forming unit that forms an image on a recording medium, The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A detection unit is positioned upstream of the feeding unit in the feeding direction and detects the width of the document fed by the feeding unit in the width direction intersecting the feeding direction, A drive source that drives the feeding unit, The system includes a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the stacking section such that the smaller documents are positioned higher up, are fed by the feeding unit and read by the reading unit, In the mode, the control unit performs a first feeding process in which the feeding unit feeds the document at a first feeding speed, a detection process in which the detection unit detects the width of the document, and a second feeding process in which, if the width of the document detected by the detection process is greater than a predetermined width, the feeding unit feeds the document at a second feeding speed faster than the first feeding speed. An image forming apparatus characterized by the following features. [Explanation of Symbols]

[0190] 1: Feeding section (pickup roller) / 3: Transport section (pull-out roller pair) / 30: Loading section (document tray) / 70: Loading unit (feeding attachment) / 71: First loading section (first auxiliary tray) / 72: Second loading section (second auxiliary tray) / 81, 82: Detection section (first document width detection sensor, second document width detection sensor) / 121: Drive source (feeding motor) / 210: Reading section (surface reading unit) / 321: Control unit (CPU) / 405: Display section (operation section) / 540: Image forming section / 600: Document reading device / 1000: Image forming device / CD: Feeding direction / WD: Width direction

Claims

1. The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A drive source that drives the feeding unit, The system includes a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the stacking section such that documents with smaller widths in the width direction intersecting the feeding direction are placed higher up, are fed by the feeding section and read by the reading section, In the mode, the control unit controls the drive source so that the feeding unit feeds the first document at a first feeding speed, and if the width of the first document is greater than a predetermined width, the control unit controls the drive source so that the feeding unit feeds the second document following the first document at a second feeding speed faster than the first feeding speed. A document reading device characterized by the following features.

2. A loading unit comprising a first loading section capable of loading documents having a first width, and a second loading section capable of loading documents having a second width greater in the width direction than the first width, wherein the loading unit is detachably attached to the loading section. The feeding unit is capable of sequentially feeding the documents loaded in the first and second loading units, such that when the documents loaded in the first loading unit are empty, it feeds the documents loaded in the second loading unit. The document reading device according to feature 1.

3. The control unit controls the drive source in the mode such that the feeding unit feeds the documents loaded in the first loading unit at a first feeding speed, controls the drive source such that the feeding unit feeds the first document in the second loading unit at a first feeding speed, and controls the drive source such that the feeding unit feeds the second and subsequent documents in the second loading unit at a second feeding speed. The document reading device according to feature 2.

4. In the mode described above, the loading section is equipped with a display unit that shows a prompt indicating that the documents to be loaded should be placed in an order such that the documents with smaller widths are placed higher up. The document reading device according to feature 1.

5. The loading section is equipped with a pair of regulating plates that restrict the position of the documents loaded in the width direction, In the mode, the display unit displays a message prompting the placement of the documents so that the center of the documents in the width direction of the documents placed on the stacking unit aligns with the center of the pair of regulating plates in the width direction. The document reading device according to feature 4.

6. The control unit determines the width of the document based on the image of the document read by the reading unit. The document reading device according to feature 1.

7. The control unit includes a detection unit that detects the width of the document fed by the feeding unit. The document reading device according to feature 1.

8. The detection unit is positioned upstream of the reading unit in the feeding direction. The document reading device according to feature 7.

9. The transport unit is located downstream of the feeding unit in the aforementioned feeding direction and transports the original document fed by the feeding unit, The document transport speed by the transport unit is faster than the document transport speed by the feeding unit. The document reading device according to feature 1.

10. The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A detection unit is positioned upstream of the feeding unit in the feeding direction and detects the width of the document fed by the feeding unit in the width direction intersecting the feeding direction, A drive source that drives the feeding unit, The system includes a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the stacking section such that the smaller documents are positioned higher up, are fed by the feeding unit and read by the reading unit, In the mode, the control unit performs a first feeding process in which the feeding unit feeds the document at a first feeding speed, a detection process in which the detection unit detects the width of the document, and, if the width of the document detected by the detection process is greater than a predetermined width, a second feeding process in which the feeding unit feeds the document at a second feeding speed faster than the first feeding speed. A document reading device characterized by the following features.

11. An image forming unit that forms an image on a recording medium, The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A drive source that drives the feeding unit, The system includes a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the stacking section such that documents with smaller widths in the width direction intersecting the feeding direction are placed higher up, are fed by the feeding section and read by the reading section, In the mode, the control unit controls the drive source so that the feeding unit feeds the first document at a first feeding speed, and if the width of the first document is greater than a predetermined width, the control unit controls the drive source so that the feeding unit feeds the second document following the first document at a second feeding speed faster than the first feeding speed. An image forming apparatus characterized by the following features.

12. An image forming unit that forms an image on a recording medium, The loading section where the manuscripts are stacked, A feeding unit that feeds one document at a time in the feeding direction from the topmost document among the multiple documents loaded in the aforementioned loading unit, A reading unit that reads the document fed by the aforementioned feeding unit, A detection unit is positioned upstream of the feeding unit in the feeding direction and detects the width of the document fed by the feeding unit in the width direction intersecting the feeding direction, A drive source that drives the feeding unit, The system includes a control unit capable of executing a mode in which a plurality of documents of different sizes, stacked in the stacking section such that the smaller documents are positioned higher up, are fed by the feeding unit and read by the reading unit, In the mode, the control unit performs a first feeding process in which the feeding unit feeds the document at a first feeding speed, a detection process in which the detection unit detects the width of the document, and, if the width of the document detected by the detection process is greater than a predetermined width, a second feeding process in which the feeding unit feeds the document at a second feeding speed faster than the first feeding speed. An image forming apparatus characterized by the following features.

Images