Sheet feeding device, image reading device, and image forming device

Abstract

The present invention provides a sheet feeding device, an image reading device, and an image forming device that, despite their simple structure, can position the sheet stopper in a retracted position from its restricted position when not feeding or transporting a sheet. [Solution] The sheet feeding device 300 includes a holder moving unit 305 that moves the roller holder 314 to a lowered position where the feeding roller 311 contacts the sheet G or to an elevated position where it separates from the sheet G, and a sheet stopper 16 that can move between a first position that restricts the feeding of the sheet G to the sheet transport path W3 and a second position that does not restrict it. The device is capable of performing a feeding operation in which the roller holder 314 is moved to the lowered position to feed the sheet G, and a retraction operation in which the feeding operation is stopped and the roller holder 314 is moved to the elevated position. If the retraction operation is performed while the sheet stopper 16 is in the second position, the device is equipped with a holding restricting unit 17 that holds the sheet stopper 16 so that it does not move from the second position.

Description

Technical Field

[0001] The present disclosure relates to a sheet feeding device, an image reading device, and an image forming device (such as a copier, a multifunction peripheral, a printer, and a facsimile device, etc.).

Background Art

[0002] A conventional sheet feeding device (such as the document feeding device described in Patent Document 1) generally includes a sheet placement unit (document placement tray) on which a sheet (document) with an image formed thereon can be placed, a sheet conveyance path through which the sheet is conveyed, and a sheet feeding unit that feeds the sheet placed on the sheet placement unit to the sheet conveyance path. As such a sheet feeding device, for example, the sheet feeding unit includes a feeding roller (nagger roll) that rotates by receiving a rotational driving force from a driving source, a roller holder (swing bracket) that supports the feeding roller, a lifting mechanism that moves the roller holder to a lowered position where the feeding roller abuts on the sheet placed on the sheet placement unit or to a raised position where the feeding roller is separated from the sheet placed on the sheet placement unit, and a sheet stopper (set gate) that is swingable between a regulating position that regulates the feeding of the sheet to the sheet conveyance path and a non-regulating position that does not regulate the feeding of the sheet to the sheet conveyance path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such conventional sheet feeding devices, it may be necessary to position the sheet stopper in a position that restricts its swing from a restricted position to an unrestricted position during sheet feeding operations, while positioning it in a retracted position from the restricted position when not feeding sheets. For example, in a sheet feeding device equipped with an opening / closing member (e.g., an opening / closing cover member) that forms a sheet transport path when closed and opens the sheet transport path when open, and in a sheet feeding unit where the feed roller, roller holder, and sheet stopper are located on the underside of the opening / closing member, if a sheet jams and the opening / closing member is opened or closed without removing the jammed sheet, the sheet stopper will return from the unrestricted position to the restricted position, and the sheet stopper will press down on the sheet from above. This can cause damage to the sheet and / or breakage of the sheet stopper.

[0005] In this regard, the sheet stopper described in Patent Document 1 has a gate portion against which the leading edge of the sheet abuts, and a joint portion that supports the gate portion so that it can be bent in the direction opposite to the direction in which the leading edge of the sheet abuts.

[0006] However, in the sheet stopper described in Patent Document 1, the joint portion is structured to support the gate portion so that it can be bent in the opposite direction to the direction in which the leading edge of the sheet abuts, which complicates the structure.

[0007] Therefore, the present disclosure aims to provide a sheet feeding device, an image reading device, and an image forming device that have a simple structure and can position the sheet stopper in a retracted position from the restricted position when not feeding the sheet. [Means for solving the problem]

[0008] The sheet feeding device relating to this disclosure solves the above problem, A sheet mounting section on which the sheet is placed, A sheet transport path through which the aforementioned sheets are transported, A sheet feeding unit that sends the sheet placed on the sheet placement unit to the sheet transport path, A sheet transport detection unit for detecting the sheet being transported along the sheet transport path, It comprises a control unit and, The aforementioned sheet feeding unit is Located above the aforementioned sheet mounting section, A feed roller that rotates around its axis of rotation by receiving rotational driving force from a power source, A roller holder that pivotally supports the aforementioned feeding roller, The roller holder is moved by a holder movement unit that moves the feed roller to a lowered position where it contacts the sheet placed on the sheet mounting unit, or to an elevated position where it separates from the sheet placed on the sheet mounting unit, The sheet stopper is movable between a first position that restricts the feeding of the sheet placed on the sheet placement section to the sheet transport path and a second position that does not restrict the feeding of the sheet placed on the sheet placement section to the sheet transport path. The control unit is capable of performing a feeding operation in which the roller holder is moved to the lowered position and the sheet placed on the sheet placement section is fed to the sheet transport path by the feeding roller, and, if it is determined based on the detection result of the transport sheet detection unit that the sheet fed by the feeding operation has stopped in the sheet transport path, it is capable of performing a retraction operation in which the feeding operation of the feeding roller is stopped and the roller holder is moved to the raised position. The sheet feeding unit is further characterized in that, when the retraction operation is performed while the sheet stopper is in the second position, it holds the sheet stopper so as not to move from the second position. [Effects of the Invention]

[0009] According to this disclosure, despite its simple structure, it is possible to retract the sheet stopper from its restricted position when the sheet is not being fed. [Brief explanation of the drawing]

[0010] [Figure 1]It is a schematic cross-sectional view seen from the front of an example of an image forming apparatus provided with a document feeder according to the present embodiment. [Figure 2] It is a perspective view showing the document feeder and the image reading device shown in FIG. 1. [Figure 3] It is a cross-sectional view showing the main part of the document feeder and the image reading device shown in FIG. 1. [Figure 4] It is a perspective view showing a state in which an opening / closing member is in an open position in the document feeder shown in FIG. 1. [Figure 5] It is a perspective view showing an enlarged view of a document supply portion on the lower surface of the opening / closing member in the open position. [Figure 6] It is a perspective view showing an enlarged view of a roller holder portion on the lower surface of the opening / closing member in the open position. [Figure 7] It is a perspective view showing a document stopper provided in the document feeding unit. [Figure 8] It is a cross-sectional view of the document stopper viewed in a direction orthogonal to the first swing shaft portion. [Figure 9] It is a perspective view showing an enlarged view of a document feeding portion when the document stopper is in a regulation position (first position) with the roller holder in an ascending position. [Figure 10] It is a cross-sectional view of the document feeding portion when the document stopper is in a regulation position (first position) with the roller holder in an ascending position, cut at a location of a stopper portion in the document stopper. [Figure 11] It is a perspective view showing a state in which the roller holder is in a descending position. [Figure 12] It is a cross-sectional view of a state in which the roller holder is in a descending position, cut at a location of an engaging portion in the document stopper and an engaged portion in the roller holder. [Figure 13] It is a cross-sectional view of a roller holder portion of the document feeder during document feeding operation, cut at a location of an engaging portion in the document stopper and an engaged portion in the roller holder. [Figure 14] It is a cross-sectional view of a state in which the roller holder is in an ascending position when the document is jammed, cut at a location of a stopper portion in the document stopper. [Figure 15]A perspective view showing a state where when the opening / closing member is closed and the document stopper is in the unrestricted position (second position), the roller holder is raised to the raised position and the swinging of the document stopper from the unrestricted position to the restricted position (first position) is restricted. [Figure 16] A cross-sectional view showing a portion of the placed document detection unit in a state where no document is detected. [Figure 17] A cross-sectional view showing a portion of the placed document detection unit in a state where a document is detected. [Figure 18] A schematic block diagram showing the system configuration of the control unit in the document feeding device. [Figure 19] A flowchart showing an example of the flow of the document feeding process of the control unit in the document feeding device. [Figure 20] A flowchart showing the return process when the document stops during document feeding in the first embodiment. [Figure 21] An example of a message displayed on the first display screen of the operation display unit when the document gets jammed. [Figure 22] A flowchart showing an example of the flow of the document feeding process including the return process when the document stops during document feeding in the second embodiment. [Figure 23] An example of a message displayed on the second display screen of the operation display unit when the document gets jammed. [Figure 24] An example of a message displayed on the third display screen of the operation display unit when the document gets jammed.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0012] [Image Forming Apparatus] Figure 1 is a schematic cross-sectional view of an image forming apparatus 100 equipped with an image reading device 200 according to this embodiment, viewed from the front. In the figure, the symbol X indicates the width direction, the symbol Y indicates the left-right direction, and the symbol Z indicates the up-down direction (vertical direction). Here, of the width direction X shown in Figure 1, the side closer to the viewer (relative to the paper) is the front of the image forming apparatus 100, and the side further away (relative to the paper) is the back of the image forming apparatus 100. The symbol H in Figure 1 represents the document feeding direction (transport direction), which is the direction in which the document G is supplied by the document feeder 300 (sheet feeder) described later.

[0013] The image forming apparatus 100 according to this embodiment is a color image forming apparatus that forms multi-color and monochrome images on a sheet of paper P. The image forming apparatus 100 performs image forming processing according to image data read by the image reading device 200 or image data transmitted from an external source. The image forming apparatus 100 may also be a monochrome image forming apparatus.

[0014] First, we will explain the main body 110 of the image forming apparatus 100. The image forming apparatus 100 includes an image forming apparatus body 110 for forming an image on a sheet of paper P. The image forming apparatus body 110 includes an image forming unit 102 and a paper transport unit 103.

[0015] The image forming unit 102 includes an exposure device 1, a developing device 2, a photoreceptor drum 3 that acts as an electrostatic latent image carrier, a cleaning device 4, a charging device 5, a primary transfer device 6, a secondary transfer device 10, and a fixing device 7. The paper transport unit 103 includes a paper feed tray 81 that holds one or more sheets of paper P on which an image is formed, a manual feed tray 82 that holds one or more sheets of paper P on which an image is formed, an output roller 31, and an output tray 14.

[0016] The paper transport unit 103 further includes a paper transport path W1 for transporting sheets of paper P, contained in the paper feed tray 81 or manual feed tray 82, one sheet at a time to the secondary transfer device 10 and the fuser device 7, and then to the discharge tray 14. The paper transport path W1 is equipped with intake rollers 11a, 11b, transport roller 12a, registration roller 13, transfer roller 10a in the secondary transfer device 10, heat roller 71 and pressure roller 72 in the fuser device 7, and discharge roller 31 for transporting the paper P.

[0017] Next, we will briefly explain the image formation process performed in the image forming unit 102. In the image forming unit 102, when performing image formation, the surface of the photoreceptor drum 3, which has been uniformly charged by the charging device 5, is laser-exposed by the exposure device 1 according to the image data (image information), and electrostatic latent images are formed on the photoreceptor drum 3. The electrostatic latent images formed on the photoreceptor drum 3 are developed by the developing device 2 and manifested as toner images. The toner images on the photoreceptor drum 3 are stretched over the drive roller 6a and driven roller 6b in the primary transfer device 6 and intermediately transferred onto the intermediate transfer belt 6c, which rotates in a predetermined rotation direction E. The toner images on the intermediate transfer belt 6c, which rotates in a predetermined rotation direction E, are transported to the secondary transfer device 10, which has a secondary transfer roller 10a. The toner images intermediately transferred onto the intermediate transfer belt 6c are transported from the paper feed tray 81 or the manual feed tray 82 to the transfer nip section, which is the contact point between the intermediate transfer belt 6b and the secondary transfer roller 10a, and are transferred at the transfer nip section. Here, the paper P transported to the transfer nip section is paper P that has been placed in the paper feed tray 81 or manual feed tray 82, drawn one sheet at a time into the paper transport path W1 by the intake roller 11a or 11b, transported via the transport roller 12a, and temporarily stopped by the register roller 13. The register roller 13 then resumes transporting the temporarily stopped paper P toward the transfer nip section at a timing that aligns with the toner image on the intermediate transfer belt 6c. The paper P onto which the toner image has been transferred in the transfer nip section is sent to the fixing nip section, which is the contact point between the heat roller 71 and the pressure roller 72 of the fixing device 7, whose surfaces are controlled to a predetermined temperature. The toner image transferred to the paper P is melted by heat and pressure in the fixing nip section and fixed to the paper P. The paper P with the fixed toner image continues to be transported along the paper transport path W1 and is discharged onto the discharge tray 14 via the discharge roller 31. Here, if image formation is to be performed on the back side of the paper P as well as the front side, the paper P is transported in the reverse direction from the discharge roller 31 to the inverted paper transport path W2. The paper P is then guided back to the registration roller 13 after being inverted via the inverted transport rollers 12b to 12b, with its front and back sides reversed. Then, the paper P is discharged toward the discharge tray 14 after a toner image is formed and fixed on the back side in the same way as on the front side.

[0018] [Image reading device] The image reading device 200 included in the image forming apparatus 100 will be described next. An image reading device 200 for reading an image from a document G (a sheet on which an image has been formed) is provided at the top of the main body 110 of the image forming apparatus. The image reading device 200 includes a document placement table 221 (sheet placement table), which is specifically made of a glass plate on which the document G is placed, and a document reading plate section 222, which is made of a glass plate for reading the document G that is fed by a document feeding device 300 (sheet feeding device), which will be described later.

[0019] The image reading device 200 includes an image reading unit 400 (specifically, an image reading unit) having an image sensor 410 for reading an image of the document G. The image reading unit 400 is located below the document tray 221. The image reading device 200 scans the document G placed on the document tray 221 by moving the image reading unit 400 along the underside of the document tray 221 from one end (left end) to the other end (right end) in the left-right direction Y of the document G. In this way, the image reading device 200 reads the image of the document G placed on the document tray 221 with the image sensor 410.

[0020] The reciprocating movement of the image reading unit 400 in the left-right direction Y relative to the housing 201 is performed by the image reading unit drive unit 420. The image reading unit drive unit 420 has a motor 420a and a drive belt 420b stretched between a drive pulley (not shown) and a driven pulley, which are rotated by a gear provided on the shaft of the motor 420a. A portion of the drive belt 420b is connected to the image reading unit 400, and when the motor 420a is rotated, the drive belt 420b moves via the drive pulley, so that the image reading unit 400 can be moved in the left-right direction Y to read the document G. In addition, the document reading unit 400 can be moved below the document reading plate 222.

[0021] [Document feeder] A document feeder 300 (sheet feeder) is provided above the image reading device 200, that is, above the document placement table 221 and the document reading plate 222.

[0022] Figure 2 is a perspective view showing the document feeder 300 and image reading device 200 shown in Figure 1. Figure 3 is a cross-sectional view showing the main parts of the document feeder 300 and image reading device 200 shown in Figure 1.

[0023] As shown in Figures 2 and 3, the document feeder 300 (sheet feeder) has a document placement section 301 (sheet placement section) on which multiple documents G (sheets G) can be placed.

[0024] The document placement section 301 is capable of holding multiple documents G~G. Therefore, the document placement section 301 has a pair of guide members 302, 302 for aligning the positions of the multiple documents G~G in the width direction X, which is perpendicular to the feeding direction (by the feeding roller 311). The guide members 302 may be provided so as to be movable (slidable) in the width direction X relative to the document placement section 301 to accommodate the sizes of the multiple documents G. In that case, the guide members 302 may be configured to reciprocate in the width direction X with respect to the center of the document G in the width direction X.

[0025] Furthermore, the document feeder 300 includes a document transport path W3 (sheet transport path) that transports the document G1 placed on the document placement section 301 to the document reading plate section 222 of the image reading device 200, a document feeding section 310 (sheet feeding section) that feeds the documents placed on the document placement section 301 one by one to the document transport path W3, a document transport roller 313 that transports the documents G sent by the document feeding section 310 along the document transport path W3, a transported document detection section 130 that detects the documents G being transported by the document transport roller 313, and a document discharge tray 350 on which the documents G read by the document reading plate section 222 are discharged.

[0026] The document feeding unit 310 includes a feeding roller 311 that feeds the document G placed on the document placement unit 301 (or the document G placed on top if multiple documents are placed) toward the document transport path W3, and a separation transport unit 312 that prevents the documents G from being sent toward the document transport path W3 in an overlapping state when multiple documents G are placed on the document placement unit 301.

[0027] The separation and transport unit 312 includes a supply roller 3121 (paper feed roller) and a separation member [separation roller or separation pad (separation pad 3122 in this example)] provided to contact the supply roller 3121. The feed roller 311 feeds the document G placed on the document placement unit 301 toward the contact point between the supply roller 3121 and the separation pad 3122. When the documents G fed by the feed roller 311 are fed stacked vertically, the lower document G comes into contact with the separation pad 3122 at the contact point between the supply roller 3121 and the separation pad 3122, and the upper document G comes into contact with the rotating supply roller 3121 at the contact point between the supply roller 3121 and the separation pad 3122. At this time, the rotational force of the supply roller 3121 is not transmitted to the lower document G because of the document G above it, and it comes to a stop due to the frictional force received from the separation pad 3122. Therefore, only the upper document G receives rotational force from the supply roller 3121 and passes through the contact area between the supply roller 3121 and the separation pad 3122 to be sent to the document transport path W3. In other words, the document feeding unit 310 feeds the multiple documents G placed on the document placement unit 301 one by one to the document transport path W3.

[0028] Here, the document transport path W3 has a U-shape, extending from the document placement section 301 toward the document output tray 350 located below the document placement section 301, and is formed so as to face the document reading plate section 222 at a portion of the lower side of the U-shaped document transport path W3.

[0029] The document transport roller 313 is located downstream of the document feeding unit 310 in the document feeding direction H, within the document transport path W3. In this example, the document transport roller 313 consists of a roller shaft 313a and a plurality of roller sections 313b to 313b provided on the roller shaft 313a at intervals in the direction of the rotation axis (the direction of the rotation axis α of the rotation axis 311a) (width direction X). The document transport roller 313 is positioned to contact an opposing roller 313c, and the document G sent from the document feeding unit 310 is gripped at the contact point between the document transport roller 313 and the opposing roller 313c, and sent toward the document reading plate unit 222. Once the document G reaches the document reading plate unit 222, the image is read by the image sensor 410 of the image reading unit 400, which has been moved below the document reading plate unit 222, and converted into electronic data. The original document G, read by the image sensor 410 of the image reading unit 400, is then transported by the document transporter W3 and discharged into the document output tray 350.

[0030] (Document transport detection unit) Furthermore, a document transport path W3 between the document transport roller 313 and the document reading plate unit 222 is provided with a transported document detection unit 130 (transported sheet detection unit) for detecting the document G being transported from the document transport roller 313.

[0031] The transport document detection unit 130 includes a detection unit 131 that oscillates when it comes into contact with a document G being transported along the document transport path W3, and a transmissive optical sensor 132 having a light-emitting unit and a light-receiving unit that receives light from the light-emitting unit. The detection unit 131 has a pivot shaft 131a that rotates around a pivot axis along the rotation axis α direction (X) of the feed roller 311, a document contact arm 131b provided on the pivot shaft 131a that comes into contact with the document G, and a sensor light-shielding unit 131c provided on the pivot shaft 341a that is detected by the transmissive optical sensor 132 (see Figure 3). In order to detect a document G being transported along the document transport path W3, the detection unit 131 is positioned by its own weight such that a part of the document contact arm 131b obstructs the document transport path W3. In this state, the sensor light-shielding part 131c is positioned to block the detection light path (the space between the light-emitting part and the light-receiving part) of the transmissive optical sensor 132. Therefore, the detected part 131 (transmissive optical sensor 132) outputs a Low output signal because the light-receiving part does not receive light from the light-emitting part. Furthermore, when the document G being transported along the document transport path W3 comes into contact with the document contact arm 131b, the detected part 131 rotates around the pivot axis 131a as the document G moves, and the document contact arm 131b moves to a retracted position that allows the document G to pass. When the document contact arm 131b is in this retracted position, the sensor light-shielding part 131c is positioned not to block the detection light path of the transmissive optical sensor 132. Therefore, while the document contact arm 131b is in contact with the document G being transported, that is, while the document contact arm 131b is in the retracted position, the detection unit 131 (transmissive optical sensor 132) outputs a High output signal. In other words, it is possible to determine whether or not there is a document G in the document transport path W3 depending on whether the output signal is High or Low.

[0032] Here, the transport document detection unit 130 is installed in the section between the document transport roller 313 and the document reading plate unit 222 of the document transport path W3. Therefore, based on the output value of the transmissive optical sensor 132, it is possible to predict the timing at which the document G will reach the document reading plate unit 222. In other words, the transport document detection unit 130 can detect the document G before starting reading at the document reading plate unit 222, thereby enabling reading of the document G at the appropriate timing.

[0033] <About this figure> 1. First Embodiment The document feeder 300 according to this embodiment will now be described in detail. As described above, the document feeder 300 (sheet feeder) comprises a document placement section 301 (sheet placement section) on which multiple documents G (sheets G on which images are formed) can be placed, a document transport path W3 (sheet transport path) on which the documents G are transported, a document feeding section 310 (sheet feeding section) that sends the documents G placed on the document placement section 301 to the document transport path G3, and a transported document detection section 130 (transported sheet detection section) that detects the documents G being transported along the document transport path W3.

[0034] The document feeding unit 310 of this embodiment is positioned above the document placement unit 301 and includes a feeding roller 311 that rotates around a rotation axis α by receiving rotational driving force from a drive source 316, a roller holder 314 that pivotally supports the feeding roller 311, and a mechanism that lowers the roller holder 314 (by rotational driving force from the drive source 316) so that the feeding roller 311 contacts the document G placed on the document placement unit 301 (feeding position) or the feeding roller 311 is in contact with the document placement unit The device includes a holder movement unit 305 that moves the holder to an elevated position that separates it from the document G placed on the document G (or the document placement unit 301 itself if there is no document G), and a document stopper 16 (sheet stopper) that can move between a first position (restricting position) that restricts the feeding of the document G placed on the document placement unit 301 to the document transport path W3, and a second position (unrestricting position) that does not restrict the feeding of the document G placed on the document placement unit 301 to the document transport path W3.

[0035] Furthermore, the document feeder 300 of this disclosure includes an opening / closing member 303 that can move between an open position that opens a portion of the upper part of the document transport path W3 and a closed position that forms the document transport path W3. The opening / closing member 303 is provided with a document feeding unit 310 and a placed document detection unit 340 (placement sheet detection unit) that detects whether or not a document G is placed on the document placement unit 301.

[0036] Figure 4 is a perspective view showing the document feeder 300 shown in Figure 1 with the opening / closing member 303 in the open position.

[0037] As shown in Figure 4, the opening / closing member 303 is rotatably supported on the main body 300a of the document feeder 300a around a pivot axis along the width direction X, and is provided with a plurality of document guide ribs 3031 to 3031 that form part of the document transport path W3 when in the closed position.

[0038] Figure 5 is a magnified perspective view showing the document feeding section 310 located on the lower surface of the opening / closing member 303 in the open position. Figure 6 is a magnified perspective view showing the roller holder 314 located on the lower surface of the opening / closing member 303 in the open position.

[0039] Figure 7 is a perspective view of the document stopper 16 of the document feeding unit 310, viewed from an oblique angle. Figure 9 is a perspective view showing an enlarged view of the document feeding unit 310 in the state where the opening / closing member 303 is in the closed position, the roller holder 314 is in the raised position, and the document stopper 16 is in the restricting position. Figure 10 is a side view of the document feeding unit 310 in the state shown in Figure 9 (where the opening / closing member 303 is in the closed position, the roller holder 314 is in the raised position, and the document stopper 16 is in the restricting position), and is a cross-sectional view cut at the stopper portion of the document stopper 16. Figure 11 is a perspective view showing the state where the opening / closing member 303 is in the closed position and the roller holder 314 is in the lowered position. Figure 12 is a side view of the state shown in Figure 11 (with the opening / closing member 303 in the closed position and the roller holder 314 in the lowered position), and is a cross-sectional view taken at the engagement portion 161a of the document stopper 16 and the engaged portion 314a of the roller holder 314.

[0040] Figure 13 is a side view of the roller holder 314 during document feeding, with the opening / closing member 303 in the closed position. It is a cross-sectional view taken at the engagement portion 161a of the document stopper 16 and the engaged portion 314a of the roller holder 314.

[0041] Figure 14 is a side view of the state in which the roller holder 314 has moved to the raised position when the document G stops (gets jammed) while being fed into the document transport path W3, with the opening / closing member 303 in the closed position. It is a cross-sectional view taken at the stopper portion 162a of the document stopper 16. Figure 15 is a perspective view showing the state in Figure 14 (the state in which the opening / closing member 303 is in the closed position, and the roller holder 314 has moved to the raised position when the document G stops while being fed into the document transport path W3). Note that, for the sake of clarity, the opening / closing member 303 in Figures 10 to 15 is partially omitted in the explanation.

[0042] [Roller holder] The document feeding unit 310 is located above the document placement unit 301 and includes a feeding roller 311 (pickup roller) that rotates in response to rotational driving force from a drive source 316 (see Figure 4), and a roller holder 314 (holding member) that pivotally supports the feeding roller 311.

[0043] The feed roller 311 has a rotating shaft 311a and is supported by a roller holder 314 so as to rotate around the rotation axis α of the rotating shaft 311a. (See Figure 6)

[0044] [Holder movement part] The document feeding unit 310 has a holder moving unit 305 (lifting mechanism) that moves the roller holder 314 to a lowered position (feeding position) where the feeding roller 311 contacts the document G placed on the document placement unit 301, or to an elevated position where the feeding roller 311 is separated from the document G placed on the document placement unit 301.

[0045] The holder movement unit 305 has a drive rotating shaft 3121a that rotates by receiving rotational driving force from the drive source 316, and a torque limiter 3121c. (See Figure 4)

[0046] The drive shaft 3121a is mounted on the opening / closing member 303 so as to be rotatable around a rotation axis parallel to the rotation axis α of the feed roller 311. The torque limiter 3121c is mounted between the drive shaft 3121a and the roller holder 314. In other words, the roller holder 314 is supported so as to be able to swing around the drive shaft 3121a via the torque limiter 3121c (torque limiter for lifting and lowering the roller holder). That is, the roller holder 314 is attached to the drive shaft 3121a via the torque limiter 3121c and is mounted so as to swing around the swing axis β2, which is the rotation axis of the drive shaft 3121a. This swing mechanism will be explained in detail.

[0047] The torque limiter 3121c has the characteristic of not allowing free rotation until a predetermined load is applied, but allowing free rotation once the predetermined load is exceeded.

[0048] As shown in Figure 10, the roller holder 314, which is in the raised position (separated position), rotates (moves) in the lowered position via the torque limiter 3121c because the drive shaft 3121a rotates in the forward rotation direction Ra when the drive source 316 rotates in the first direction, which is the first direction. The feed roller 311 then moves to a position where it contacts the document G placed on the document placement section 301. When the feed roller 311 contacts the document G, the roller holder 314, which is trying to rotate via the torque limiter 3121c, receives a reaction force from the document G via the feed roller 311. When this load due to the reaction force exceeds a predetermined value, the torque limiter 3121c slips, and the roller holder 314 stops in the lowered position as shown in Figure 12. In other words, the feed roller 311 contacts the document G with a predetermined contact pressure while the drive shaft 3121c continues to rotate. Here, the drive shaft 3121a and the feed roller 311 are connected by a timing belt 315c (see Figures 5 and 6). Therefore, when the drive shaft 3121a rotates in the forward direction Ra, the feed roller 311 also rotates in the forward direction Ra around the rotation axis α. As a result, when the roller holder 314 is moved to the lowered position by the holder movement unit 305, the rotating feed roller 311 sends the document G toward the document transport path W3. In other words, when the roller holder 314 contacts the document G on the document placement unit 301 with respect to the rotation of the drive shaft 3121a in the forward direction Ra, the oscillation of the roller holder 314 is restricted, and when the load acting on the torque limiter 3121c exceeds a predetermined load, the drive shaft 3121a can be rotated relative to the roller holder 314. Therefore, the feed roller 311 can be rotated via the timing belt 315c, and the original document G can be fed in the original document feeding direction H toward the original document transport path W3. Here, the drive rotation shaft 3121a is provided with a supply roller 3121, and as mentioned above, the supply roller 3121 is in contact with the separation member 312, so the original document G fed from the feed roller 311 is sent one by one to the original document transport path W3 by passing between the supply roller 3121 and the separation pad 3122.

[0049] On the other hand, when the drive source 316 rotates in the second direction, which is opposite to the first direction, and the drive rotation shaft 3121a rotates in the reverse rotation direction Rb, the roller holder 314 in the contact position shown in Figure 12 swings (moves) to the raised position (separated position) via the torque limiter 3121c. In other words, it becomes separated from the document G or the document placement section 301. Note that this swinging (movement) of the roller holder 310 from the lowered position to the raised position may be performed by controlling the drive source 316 to rotate it by a predetermined angle in the reverse rotation direction Rb and then stopping the drive source 316, or by controlling the drive source 316 to rotate the drive rotation shaft 3121a in the reverse rotation direction Rb, and with the roller holder 314 in contact with the opening / closing member 303 and the rotation of the roller holder 314 restricted, the torque limiter 3121c may be allowed to spin freely and then stopped.

[0050] As described above, the holder movement unit 305 can lower the roller holder 314 (feeding roller 311) by rotating the drive rotation shaft 3121a in the forward rotation direction Ra, while raising the roller holder 314 (feeding roller 311) by rotating the drive rotation shaft 3121a in the reverse rotation direction Rb.

[0051] As shown in Figures 5 and 6, the timing belt 315c that transmits rotational force from the drive shaft 3121a to the feed roller 311 is an endless belt and is wrapped around the drive timing pulley 315a provided on the drive shaft 3121 and the driven timing pulley 315b provided on the rotation shaft 311a of the feed roller 311. As a result, when the drive shaft 3121a of the feed roller 3121 is rotated in the forward rotation direction Ra, the rotation shaft 311a of the feed roller 311 can be rotated in the forward rotation direction Ra, which is the document feeding direction H, via the drive timing pulley 315a, the timing belt 315c, and the driven timing pulley 315b.

[0052] As will be explained in more detail later, the roller holder 314 is provided with an engaged portion 314a (projection) that protrudes from the roller holder 314 in the direction of the rotation axis α of the feed roller 311.

[0053] [Manuscript Stopper] The document feeding unit 310 further includes a document stopper 16 that restricts the movement of the document G placed on the document placement unit 301 in the document feeding direction H. Figure 7 is a perspective view of the document stopper 16 from diagonally above. Figure 8 is a cross-sectional view of the document stopper 16.

[0054] As shown in Figures 7 and 8, the document stopper 16 of this embodiment has a first pivoting shaft portion 160, a stopper portion 162a that contacts the document G placed on the document placement portion 301, and an engaging portion 161a that can engage with the engaged portion 314a (projection) of the roller holder 314 described above.

[0055] The engaging portion 161a of the document stopper 16 is provided on one end and the other end of the first oscillating shaft portion 160, respectively, and the stopper portion 162a is provided on the shaft body 160a, which is the main body of the first oscillating shaft portion 160. In this way, the engaging portion 161a and the stopper portion 162a are fixed to the first oscillating shaft portion 160 at different positions in the circumferential direction.

[0056] The document stopper 16 further comprises a first arm portion 161 and a second arm portion 162. The first arm portion 161 is fixed to one end and the other end of the first pivot shaft portion 160, and the second arm portion 162 is fixed to the shaft portion body 160a. The first arm portion 161 and the second arm portion 162 are provided at different positions around the first pivot axis β, which is the rotation axis of the shaft portion. Furthermore, the first arm 161 and the second arm 162 are provided on the same side, specifically on the downstream side in the document feeding direction H, with respect to a virtual vertical line γ that intersects the document feeding direction H of the document G and passes through the first pivot axis β1, which is the centerline of the first pivot shaft portion 160. The engaging portion 161a and the stopper portion 162a are provided at the tip of the first arm portion 161 and the tip of the second arm portion 162, respectively. The engaging portion 161a is an engaging projection that protrudes from the tip of the first arm portion 161 on the side opposite to the shaft portion body 160a, with a first engaging portion 161a1 provided at the upstream end of the engaging projection in the document feeding direction H, and a second engaging portion 161a2 provided at the downstream end in the document feeding direction H. The stopper portion 162a is formed at the tip of the second arm portion 162 so as to extend on the side opposite to the engaging portion 161a, and the portion formed to extend from the tip of the second arm portion 162 has a flat portion that extends in the direction of the first pivot axis β1.

[0057] Thus, the document stopper 16 has an engaging portion 161a, a stopper portion 162a that contacts the document G placed on the document placement portion 301, and a first oscillating shaft portion 160 that rotates around a first oscillating axis β1 along the rotation axis α of the feed roller 311. The engaging portion 161a and the stopper portion 162b are provided at different circumferential positions of the first oscillating shaft portion 160, and the stopper portion 162b has a flat portion that contacts one end of a plurality of documents G placed on the document placement portion 301 and aligns the end positions of the plurality of documents G.

[0058] Furthermore, the document stopper 16 has a first arm portion 161 extending radially from the first pivot shaft portion 160 and a second arm portion 162 extending radially from the circumferential surface of the first pivot shaft portion 160 where the first arm portion 161 is not provided. The engaging portion 161a is an engaging projection provided at the tip of the first arm portion 161 so as to protrude toward the roller holder 314. The planar portion of the stopper portion 162a is provided so as to extend from the tip of the second arm portion 162 toward the opposite side of the engaging portion 161a in a direction intersecting the extension direction of the second arm portion 162. When the document stopper 16 is in the restricting position (first position), the first arm portion 161 and the second arm portion 162 are located downstream in the document feeding direction with respect to a virtual vertical line passing through the first pivot axis β1. Therefore, the center of gravity of the document stopper 16 is located downstream of the virtual vertical line γ in the document feeding direction H. As a result, a force acts on the document stopper 16, causing it to rotate counterclockwise around the first oscillation axis β1 from the position of the document stopper 16 shown in Figure 8. The effects of this configuration will be described later.

[0059] As shown in Figures 4 to 6, the first pivot shaft portion 160 of the document stopper 16 (having the above configuration) is supported on a plurality of document guide ribs 3031 to 3031 (or a portion thereof) of the opening / closing member 303 so as to be rotatable. Here, the document stopper 16 and the roller holder 314 are provided (on the opening / closing member 303) adjacent to each other in the direction of the rotation axis α of the feed roller 311, and the first pivot axis β1, which is the axial direction of the first pivot shaft portion 160 of the document stopper 16, is provided (on the opening / closing member 303) so as to be parallel to the rotation axis α of the feed roller 311. In this way, the first pivot shaft portion 160 of the document stopper 16 is provided on the opening / closing member 303 so as to be able to pivot around the first pivot axis β1 along the direction (X) of the rotation axis α of the feed roller 311.

[0060] As described above, the opening / closing member 303 has a plurality of document guide ribs 3031 that extend along the document feeding direction H of the document G and form a part of the document transport path W3, the document stopper 16 is supported between the plurality of document guide ribs 3031 so as to be able to swing around a first pivot axis β, and the aforementioned roller holder 314 is provided on the document guide rib 3031 so as to be able to swing around a second pivot axis β2 along the rotation axis α of the feed roller 311.

[0061] As described above, the first pivoting shaft portion 160 of the document stopper 16 is pivotably supported by the opening / closing member 303. As will be explained in more detail later, when the opening / closing member 303 is in the closed position and the roller holder 314 is in the lowered position, the stopper portion 162a can rotate and move (oscillate) between a restricting position (first position) that restricts the movement (supply) of the document G placed on the document placement portion 301 to the document transport path W3, and an unrestricted position (second position) that does not restrict the movement (supply) of the document G placed on the document placement portion 301 to the document transport path W3.

[0062] Furthermore, as shown in Figures 4 to 6, the document stoppers 16 are provided on the opening / closing member 303 on both outer sides in the direction of the rotation axis (X) of the roller holder 314. In other words, two document stoppers 16 are arranged on the opening / closing member 303 so as to be symmetrical with respect to the roller holder 314, with reference to a reference line along the vertical direction Z when viewed from one side in the left-right direction Y. As mentioned above, the engaging portions 161a of the document stoppers 16 are provided on one end and the other end of the first pivoting shaft portion 160, respectively. Therefore, the document stoppers 16, 16 arranged on either side of the roller holder 314 in the direction of the rotation axis α of the feed roller 311 will have engaging portions 161a, 161a facing the roller holder 314. This makes it possible to use a common part for the pair of document stoppers 16, 16.

[0063] [Retention Regulation Department] As described above, the document stopper 16 is configured to swing between a restricting position (first position) that restricts the movement of the document to the document transport path W3 and an unrestricted position (second position) that does not restrict the movement of the document to the document transport path W3, and is provided on the opening / closing member 303. However, the document feeding unit 310 in this embodiment further has a holding restricting unit 17 that holds the position of the document stopper 16, i.e., the restricting position or the unrestricted position, and restricts its swinging. The holding restricting unit 17 includes an engaged portion 314a provided on the roller holder 314 and an engaged portion 161a provided on the document stopper 16. Next, the operation of the holding restriction unit 17 will be described.

[0064] [Regulation position (1st position)] Figure 9 is an enlarged perspective view of the document feeding unit 310 when the roller holder 314 is in the raised position and the document stopper 16 is in the restricting position. Figure 10 is a cross-sectional view of the document feeding unit 310 in the state shown in Figure 9, i.e., when the roller holder 314 is in the raised position and the document stopper 16 is in the restricting position, cut at the stopper portion 162a of the document stopper 16.

[0065] As shown in Figures 9 and 10, when the roller holder 314 is in the raised position and the document stopper 16 is in the restricted position, even if the document stopper 16 attempts to rotate around the first pivot axis β1, the engaging portion 161a (specifically the second engaging portion 161a1) of the document stopper 16 engages (comes into contact with) the engaged portion 314a of the roller holder, thereby restricting the swing of the stopper portion 162a downstream in the document feeding direction H. Furthermore, the document guide rib 3031 of the opening / closing member 303 that supports the document stopper 16 is provided with a rotation-restricting portion 3032 that restricts the rotation of the document stopper 16. In other words, the rotation-restricting portion 3032 is provided on the document guide rib 3031 that restricts the swing of the stopper portion 162a of the document stopper 16 in the restricted position upstream in the document feeding direction H. Therefore, even if the document stopper 16 attempts to rotate around the first pivot axis β1, the rotation-stopping part 3032 contacts the engaging part 161a (specifically the second engaging part 121a2), thereby restricting the stopper part 162a from swinging upstream in the document feeding direction H. In other words, the rotation of the engaging part 161a is restricted by the engaged part 314a of the roller holder 314, which is in the raised position, and the rotation-stopping part 3032, thus restricting its movement from the restricted position. That is, it is held in the restricted position. This state in which the roller holder 314 is in the raised position and the document stopper 16 is restricted from moving from the restricted position by the restricting holding part 17, i.e., held in the restricted position, is called the feeding preparation state.

[0066] In this feeding preparation state, where the document stopper 16 is held in the restricted position by the holding restriction unit 17, the document G on the document placement unit 301 comes into contact with the document stopper 16, restricting the movement of the document G in the document feeding direction H. This allows multiple documents G to be placed on the document placement unit 301 with their edges aligned. In other words, since multiple documents G are placed on the document placement unit 301 with their positions aligned (the feeding direction of the feed roller 311 is aligned for multiple documents G), the feeding conditions by the feed roller 311 are stabilized, and the occurrence of transport defects can be suppressed.

[0067] [Non-regulated position (2nd position)] Next, the operation of the document stopper 16 when the roller holder 314 is in the lowered position will be described.

[0068] Figure 11 is an enlarged perspective view of the document feeding unit 310 when the roller holder 314 is in the lowered position and the document stopper 16 is in the restricting position. Figure 12 is a cross-sectional view of the document feeding unit 310 in the state shown in Figure 11, i.e., when the roller holder 314 is in the lowered position and the document stopper 16 is in the restricting position, cut at the stopper portion 162a of the document stopper 16.

[0069] As shown in Figures 11 and 12, when the roller holder 314 moves to the lowered position by the holder movement unit 305, the engaged portion 314a provided on the roller holder 314 also moves downward and moves to a position where it does not engage with the engaged portion 161a (it is not on the movement path of the engaged portion 161a). Therefore, the document stopper 16 in the restricting position can rotate in the direction of Rc about the first pivot axis β1. When the roller holder 314 is in the lowered position, the feed roller 311 that has come into contact with the document G placed on the document placement unit 301 feeds the document G in the document feeding direction H, and the fed document G pushes up the stopper portion 162a, causing the document stopper 16 to rotate to an unrestricted position where it does not restrict the passage of the document G. Figure 13 is a diagram illustrating this state, and is a cross-sectional view showing the state in which the document G being fed pushes up the stopper portion 162a and the document stopper 16 is in the unrestricted position. As shown in Figure 13, since the engaged portion 314a is located below the engaging portion 161a, the document stopper 16 can move to the unrestricted position without its rotation being restricted by the engaged portion 314a.

[0070] As described above, the document stopper 16 and the roller holder 314 are provided adjacent to each other in the direction of the rotation axis α of the feed roller 311, and the holding restricting portion 17 includes an engaged portion 314a provided on the roller holder 314 and an engaging portion 161a provided on the document stopper 16 that can engage with the engaged portion 314a, and the engaged portion 314a is an engaged projection that protrudes from the roller holder 314 toward the document stopper 16, and when the roller holder 314 is in the lowered position it is in a position that does not engage with the engaging portion 161a, and when the roller holder 314 is in the raised position it is in a position that engages with the engaging portion 161a.

[0071] With the roller holder 314 in the lowered position, the documents G fed from the feed roller 311 are separated one by one as they pass through the contact area between the supply roller 3121 and the separation pad 3122, as described above, and fed to the document transport path W3. The documents G fed to the document transport path W3 are then sent toward the document reading plate section 222 by the document transport roller 313, which rotates under the rotational driving force of the drive source 316, and are read by the image sensor 410 of the document reading device 400. The read documents G are then discharged into the document discharge tray 350.

[0072] Next, we will explain the operation of the holding restriction unit 17 when a document G being transported along the document transport path W3 stops midway for some reason without being ejected to the document output tray 350, a so-called jam.

[0073] [Operation of the retention control unit during jamming (retraction operation)] As mentioned above, a transported document detection unit 130 (transported sheet detection unit) is provided between the document transport roller 313 and the document reading plate unit 222 of the document transport path G3. Therefore, if the transported document detection unit 130 outputs an output signal High for a predetermined time or if the output signal does not become High even after a predetermined time has elapsed since the feed roller 313 started feeding the document G, it can be determined that the document G has stopped in the document transport path W3. In such cases, the rotation of the drive source 316, which was rotating in the first direction, is stopped, and then a retraction operation (retraction process) is performed in which the drive source 316 is rotated in the second direction opposite to the first direction to move the roller holder 314 to the raised position (separated position).

[0074] Figures 14 and 15 show the state in which this retraction operation is performed when the document stopper 16 is in the unrestricted position, that is, when the stationary document G is pushing up the stopper portion 162a. Figure 14 is a cross-sectional view of the document supply unit 310, cut at the stopper portion 162a of the document stopper 16, with the document stopper 16 in the unrestricted position and the roller holder 314 in the raised position. Figure 15 is a magnified perspective view of the document supply unit 310, similar to Figure 14, that is, with the document stopper 16 in the unrestricted position and the roller holder 314 in the raised position.

[0075] As shown in Figures 14 and 15, when the document stopper 16 is in the unrestricted position and the roller holder 314 is in the raised position, even if the document stopper 16 attempts to rotate around the first oscillation axis β1, the engaging portion 161a of the document stopper 16 engages (comes into contact with) the engaged portion 314a of the roller holder, thereby restricting the stopper portion 162a from swinging upstream in the document feeding direction H. In other words, the document stopper 16 is held in the unrestricted position by the restricting holding portion 17. Therefore, even if the document G that has stopped in the document transport path W3 is pulled out by the end on the document placement portion 301 side, the rotation of the stopper portion 162a prevents damage to the pulled-out document G.

[0076] [Drive transmission unit and biasing member] The document feeder 300 according to this embodiment has a drive transmission unit 304 that transmits the rotational driving force of the drive source 316 to the drive rotating shaft 3121a. The drive transmission unit 304 includes a drive gear 304a that is connected to a gear train or the like on the rotating shaft of the drive source 316 provided on the document feeder body 300a and rotates when the drive source 316 rotates, and a rotating shaft gear 304b provided on the end of the drive rotating shaft 3121a opposite to the side on which the supply roller 3121 is provided.

[0077] As described above, the drive rotating shaft 3121a is pivotally supported by the opening / closing member 303 (more specifically, by a bearing (not shown) provided on the document guide rib 3131), and the rotating shaft gear 304b is configured to mesh with the drive gear 304a when the opening / closing member 303 is in the closed position, and to be separated from the drive gear 304a when the opening / closing member 303 is in the open position. Therefore, when the opening / closing member 303 is in the closed position, the drive rotating shaft 3121a can rotate in either direction, Ra, which moves the roller holder 314 to the lowered position, or Rb, which moves the roller holder 314 to the raised position, by receiving rotational driving force from the drive source 316. However, when the opening / closing member 303 is in the open position, the rotating shaft gear 304b is not meshed with the drive gear 304a and can rotate freely. Therefore, even when the roller holder 314 is in the raised position due to the retraction operation, when the opening / closing member 303 is opened, the roller holder 314 moves by its own weight to the lowered position, where the engaged portion 314a provided on the roller holder 314 does not engage with the engaged portion 161a of the document stopper 16. To address this, the document feeder 300 of this embodiment is provided with a biasing member 330 (in this example, a coil spring) that applies a biasing force to rotate the roller holder 314 toward the raised position.

[0078] The biasing member 330 has one end that is locked to a locking portion 303a (locking portion 1) provided between the document guide ribs 3031 of the opening / closing member 303, and the other end that is locked to a locking portion 314b (locking portion 2) provided on the roller holder 314. The biasing force of the biasing member 330 is sufficient to hold the roller holder 314 in the raised position when the opening / closing member 303 is in the open position, that is, when the rotating shaft gear 304b is separated from the drive gear 304a and not meshing. It does not have enough force to prevent the roller holder 314 from moving to the lowered position when the opening / closing member 303 is in the closed position and rotational driving force is transmitted from the drive source 316. Furthermore, it does not have enough force to move the roller holder 314 to the raised position when the opening / closing member 303 is in the closed position and the roller holder 314 is in the lowered position.

[0079] With this configuration, if the document G stops for some reason during feeding and a retraction operation is performed, even if the opening / closing member 303 is moved to the open position to remove the stopped document G, and then the opening / closing member 303 is accidentally returned to the closed position before removing the document G, the document stopper 16 is held in the unrestricted position, thus preventing damage to the document G remaining on the document placement section 301.

[0080] Furthermore, when the opening / closing member 303 is in the closed position, a torque limiter may be provided between the rotating shaft gear 304b and the drive rotating shaft 3121a to facilitate the removal of the document G that has stopped on the document placement section 301 during feeding. In this way, the document G can be removed without opening the opening / closing member 303. Even in this case, since the document stopper 16 is held in the retracted position, damage to the removed document by the document stopper 16 is prevented.

[0081] Furthermore, as will be described in more detail later, there is a clutch device (not shown) between the drive source 316 and the drive gear 304a. By controlling the clutch device, it is possible to switch between a state where rotational driving force is transmitted from the rotating drive source 316 to the drive gear 304a and a state where it is not. This makes it possible to create a state where the document transport roller 313 is rotating due to the rotational driving force from the drive source 316, but the feed roller 311 is stopped.

[0082] [Document Detection Unit] The document feeder 300 of this embodiment further includes a document detection unit 340 (document sheet detection unit) that detects whether or not a document G is placed on the document placement unit 301.

[0083] Figures 16 and 17 are cross-sectional views of the document detection state of the document detection unit 340, viewed from the side. Figure 16 shows the state in which no document G is placed on the document placement unit 301, and Figure 17 shows the state in which document G is placed on the document placement unit 301.

[0084] As shown in Figures 4, 16, and 17, the document detection unit 340 is provided on the opening / closing member 303 so as to be located above the document placement unit 301.

[0085] The document detection unit 340 includes a detection unit 341 whose position changes depending on the presence or absence of a document G, and a transmissive optical sensor 342 in which a light-emitting unit (not shown) and a light-receiving unit that receives light from the light-emitting unit are arranged with a predetermined gap between them. The detection unit 341 has a pivot shaft 341a that rotates around a pivot axis along the rotation axis α (X) of the feed roller 311, a document contact arm 341b provided so as to protrude radially from one end of the pivot shaft 341a and in contact with the document G placed on the document placement unit 301, and a sensor light-shielding unit 341c provided so as to protrude radially from the other end of the pivot shaft 341a and is detected by the transmissive optical sensor 342. Here, "rotation" means that the target member rotates 360 degrees or more, and "rotation" means that the target member rotates less than 360 degrees.

[0086] As shown in Figure 16, when the document G is not placed on the document placement unit 301, the document contact arm 341b rotates around the pivot axis 341 due to its own weight, and the document contact arm 341b comes into contact with the wall portion 301b of the recess 301a provided at the bottom of the document placement unit 301 and stops. In this state, the sensor light shielding portion 341c provided on the document contact unit 341 is positioned so as not to obstruct the detection light path formed in the gap between the light-emitting portion and the light-receiving portion of the transmissive optical sensor 342. Therefore, the transmissive optical sensor 342 outputs an output signal High when the light-receiving portion receives light from the light-emitting portion. When a document G is placed on the document placement section 301 from this state so that its leading edge contacts the stopper section 162a of the document stopper 16, the document contact arm 341b contacts the leading edge of the placed document G, as shown in Figure 17, causing the detection section 341 to rotate around the pivot axis 341a. In this state, the sensor light shielding section 341c is in a position to shield the detection light path of the transmissive optical sensor 342. Therefore, the transmissive optical sensor 342 outputs a Low output signal because the light receiving section cannot receive light from the light emitting section.

[0087] As described above, the document detection unit 340 outputs a High output signal when no document G is placed on the document placement unit 301, and outputs a Low output signal when document G is placed on the document placement unit 301. In other words, it is possible to determine whether or not there is a document G on the document placement unit 301 based on whether the output signal is High or Low.

[0088] [Termination action (feed preparation state)] In this embodiment, the document feeder 300 stops the drive source 316 when, during the document feeding operation of the document feeding unit 310, the transport document detection unit 130 detects an output signal Low, indicating that it has not detected a document G, and a predetermined time has elapsed since then, and the placed document detection unit 340 detects that there is no document G. At this time, since there is no document G in the document placement unit 301, the document stopper 16 rotates around the first pivot axis β1 by its own weight, as described above, and the second engaging portion 161a2 of the engaging portion 161a comes into contact with the rotation stopper portion 3032 provided on the opening / closing member 303, stopping it. In other words, the document stopper 16 is in the restricted position. Once in this state, the drive source 316 is rotated in the second direction to move the roller holder 314 to the raised position, the engaged portion 314a of the roller holder 314 engages (comes into contact with) the first engaged portion 161a1 of the engaging portion 161a, and the document stopper 16 is held in the regulating position, creating a feeding preparation state, before the document feeding operation of the document G is terminated. In other words, the document feeding operation of the document G is terminated after the document G is in a state where it can be placed on the document placement section 301.

[0089] [Operation display unit and control unit] The image reading device 200 having the document feeder 300 according to this embodiment further comprises an operation display unit 120 (operation panel) and a control unit 15.

[0090] The operation display unit 120, although not shown, is located in front of the image reading unit 200 of the image forming apparatus body 110 (on the front side of the image forming apparatus 100) in the width direction X. The operation display unit 120 displays various information based on display information (display data) sent from the control unit 15. The operation display unit 120 also includes an operation unit that receives operations from the user (operator), and the control unit 15 can cause the image reading unit 200 and the document feeder 300 to perform predetermined operations based on the operations (operation information) received by the operation unit.

[0091] (Control Unit) This section describes the control unit 15 that controls the document feeder 300 and the document reader 200.

[0092] Figure 18 is a schematic block diagram showing the system configuration of the control unit 15 and the document feeder 300 and image reader 200 controlled by the control unit 15.

[0093] The image reading unit drive unit 420 of the image reading device 200 is connected to the output system of the control unit 15 and is driven based on a drive signal from the control unit 15. The image sensor 410 of the image reading device 200 is connected to both the output system and the input system of the control unit 15, and reading is initiated based on a drive signal from the control unit 15, and the image signal read by the image sensor 410 is received.

[0094] The drive source 316 of the document feeder 300 is connected to the output system of the control unit 15 and is driven based on the drive signal from the control unit 15. The document detection unit 340 (transmissive optical sensor 342) of the document feeder 300 is connected to the input system of the control unit 15 and transmits different output signals to the control unit 15 depending on whether or not a document G is placed on the document placement unit 301. The transport document detection unit 130 (transmissive optical sensor 132) provided in the document transport path W3 of the document feeder 300 is connected to the input system of the control unit 15 and transmits different output signals to the control unit 15 depending on whether or not it has detected a document G.

[0095] The operation display unit 120 is connected to the output system of the control unit 15 and receives display information from the control unit 15. In other words, the operation display unit 120 can receive and display display information from the control unit 15. Also, the operation display unit 120 is connected to the input system of the control unit 15 and transmits user input operations as operation information to the control unit 15. As a result, the control unit 15 can recognize the user's operation information and execute processing corresponding to the operation information.

[0096] The control unit 15 comprises a processing unit 15a consisting of a microcomputer such as a CPU, and a storage unit 15b including non-volatile memory such as ROM and volatile memory such as RAM. The control unit 15 controls the operation (processing) of various components by having the processing unit 15a load a control program pre-stored in the ROM of the storage unit 15b onto the RAM of the storage unit 15b and execute it.

[0097] The processing unit 15a includes a plurality of operation control processing units performed by the loaded control program. The processing unit 15a includes a read processing unit 15c, a jam processing unit 15d, and a preparation processing unit 15e.

[0098] The reading processing unit 15c can, for example, drive the image reading unit drive unit 420 to scan the image reading unit 400 in the left-right direction Y, and perform a first reading process in which the document G placed on the document placement table 221 is read by the image sensor 410 and converted into electronic data, or drive the document supply unit 310 and the document transport roller 313 with the drive source 316 to transport the document G placed on the document placement unit 301 to the document reading plate unit 222, read by the image sensor 410 and converted into electronic data, and selectively perform one of these processes based on the operation information received by the operation display unit 120.

[0099] During the second reading process, the jam processing unit 15d can determine whether the document G being transported along the document transport path W3 is jammed (paper jammed) based on the output signal from the document transport detection unit 130. If it determines that the document G is jammed, the jam processing unit 15d performs a retraction operation to move the roller holder 314 to the raised position.

[0100] After the jam processing unit 15d has performed the retraction process, the preparation processing unit 15e performs a preparatory operation (preparation process) to move the roller holder 314 from the raised position to the lowered position, and then move it back to the raised position, based on the operation information received by the document detection unit 340 or the operation display unit 120.

[0101] Furthermore, the control unit 15 can determine whether or not the document G is placed on the document placement unit 301 based on the output signal from the document placement detection unit 340. Therefore, if the document placement detection unit 340 has not detected the document G, the second reading process by the reading processing unit 15c will not be executed even if the operator operates the operation display unit 120.

[0102] (Control flow) This section describes the flow in which the control unit 15 performs the second reading process, which is the process of reading the document G using the document feeder 300.

[0103] Figure 19 is a flowchart showing the flow of the second reading process performed by the control unit 15. Figure 20 is a flowchart showing the recovery operation (recovery process) performed by the control unit 15 after the document G stops and is moved away during the second reading process. Figure 21 is an example of post-processing information (first display screen D1) that prompts the user to remove the document G when the document G is moved away, and is displayed on the operation display unit 120.

[0104] When the control unit 15 receives operation information from the operation display unit 120 to perform the second reading process, it starts the execution of the second reading process and performs step S1.

[0105] In step S1, the drive source 316 is rotated in a predetermined first direction, which is the first rotational direction. Then the process moves on to the next step S2.

[0106] In step S2, the clutch device is operated to transmit the rotational force of the drive source 316 to the holder moving section 305 (clutch engagement), moving the roller holder 314 to the lowered position and bringing the feed roller 311 into contact with the document G placed on the document placement section 301. At the same time as sending the document G to the document transport path W3, the first timer, which is the first timer, starts counting, and the process proceeds to the next step S3.

[0107] In step S3, the transport document detection unit 310 determines whether or not it has output an output signal High. If it determines that it has not detected an output signal High, the process proceeds to step S4; if it has detected an output signal High, the process proceeds to step S6. Next, the flow after step S4 will be explained first, and steps S6 and beyond will be explained later.

[0108] In step S4, it is determined whether the first timer has reached a predetermined time, which is the first threshold. If the first threshold has not been reached, the process returns to step S3; if the first threshold has been reached, the process proceeds to step S5.

[0109] In step S5, even though the value of the first timer has reached the first threshold, the transport document output signal is not high, meaning that the document G that has started to be fed has not reached the transport document detection unit 130. Therefore, a retraction operation is performed, and post-processing information (see Figure 21) prompting the display operation unit 120 to remove the document G that is stopped in the document transport path W3 is displayed, and then the second reading process is terminated. As mentioned above, the retraction operation is an operation in which the drive source 316 is stopped, then rotated in the second rotation direction opposite to the first rotation direction to move the roller holder 314 to the raised position, and then stopped. As a result, if the document stopper 16 was in the second position (unrestricted position) due to the stopped document G, the document stopper 16 will be held in the second position by the holding restriction unit 17. In other words, the engaging portion 161a of the document stopper 16 is engaged with the engaged portion 314a of the roller holder 314 at the second engagement position P2 (the state in which it is engaged at the second engagement position P2). Therefore, even when opening or closing the opening / closing member 303, it is possible to prevent damage to the document G which is stopped by the document stopper 16. Then, the value of the jam detection flag, which is a flag to confirm that the retraction operation has been performed and a flag to determine that a jam has occurred, is set to 1.

[0110] Next, returning to step S3, we will describe step S6, which is performed when the transport document detection unit 310 outputs an output signal High.

[0111] In step S6, the image sensor 410 of the image reading device 200 starts reading the original document G, the second timer starts counting, and then the process proceeds to the next step S7.

[0112] In step S7, it is determined whether the value of the first timer has reached the second threshold, and a first delay process is performed to wait until it reaches that threshold. Here, the second threshold is the time when the trailing edge of the document G separates from the feed roller 311. Therefore, step S7 is a time-waiting process. When the value of the first timer reaches the second threshold, the process proceeds to the next step S8.

[0113] In step S8, the clutch device is disengaged (clutch disengaged) to stop the rotation of the feed roller 311, preventing the next document G from being fed into the document transport path W3. Then the first timer is cleared and the process proceeds to the next step S9.

[0114] In step S9, it is determined whether the value of the second timer has reached the third threshold, and a second delay process is performed to wait until it reaches that threshold. Here, the third threshold is the time from when the trailing edge of the document G passes the transport document detection unit 130 until it passes the document reading plate unit 222. Therefore, step S9 is also a time-waiting process. When the value of the second timer reaches the third threshold, the process proceeds to the next step S10.

[0115] In step S10, since the trailing edge of the document G has passed the document reading plate section 222, the image sensor 410 of the image reading device 200 finishes reading the document G. Then, the process proceeds to the next step S11.

[0116] In step S11, it is determined whether the transport document detection unit 130 is outputting an output signal Low. If the output signal is not Low, it is determined that the document G is stopped, so the process proceeds to step S5 described above and the retraction operation is performed. If the output signal is LOW, the process proceeds to step S12.

[0117] In step S12, it is determined whether the document detection unit 340 is outputting an output signal Low. If the output signal is not Low, there is a document G on the document placement unit 301, so the process returns to step S2 and starts reading the next document G. If the output signal is Low, the process proceeds to step S13.

[0118] In step S13, the clutch is engaged and the drive source 316 is rotated in the second direction and stopped, thereby performing a finishing operation that moves the roller holder 314 to the raised position. This sets the document stopper 16 to the first position (restriction position) and ends the second reading process. In other words, the second reading process ends with the engaging portion 161a of the document stopper 16 engaged with the engaged portion 314a of the roller holder 314 at the first engagement position P1.

[0119] Next, using Figure 20, we will explain the recovery operation performed by the control unit 15 after the post-processing information is displayed on the operation display unit 120 in step S5.

[0120] After displaying post-processing information on the operation display unit 120 in step S5, that is, while the jam detection flag value is 1, the control unit 15 determines in step S14 whether the document detection unit 340 is outputting an output signal Low. If an output signal Low is detected, the control unit proceeds to the next step S15; otherwise, it does not proceed to the next step S15 and enters a standby state.

[0121] In step S15, the control unit 15 rotates the drive source 316 in a first direction and engages the clutch, causing the holder moving unit 305 to move the roller holder 314 to the lowered position. It then holds the lowered position for a predetermined time, causing the document stopper 16 to move to the first position (restricted position) by its own weight. After that, the drive source 316 is rotated in a second direction, causing the holder moving unit 305 to move the roller holder 314 to the raised position, and the holding restriction unit 17 holds the document stopper 16 in the first position. The jam detection flag is then set to 0 to confirm that there is no jam. In this way, step S15 performs a recovery operation to hold the document stopper 16 in the first position, and then ends the recovery operation after preparing the system for the second reading process. In other words, the drive source 316 is rotated in a predetermined first direction, and the drive rotation shaft 3121a is rotated in a predetermined forward rotation direction Ra for a first time to move the roller holder 314 to the lowered position. Then, the drive source 316 is rotated in a second direction opposite to the first direction, and the drive rotation shaft 3121a is rotated in the reverse rotation direction Rb for a predetermined second time to move the roller holder 314 to the raised position and complete the return operation.

[0122] As described above, the document feeder 300 of this embodiment comprises a document placement section (sheet placement section) 301 on which a document G (sheet G) is placed, a document transport path (sheet transport path) W3 on which the document G is transported, a document feeding section (sheet feeding section) 310 that sends the document G placed on the document placement section 301 to the document transport path W3, a transported document detection section (transported sheet detection section) 130 that detects the document G being transported along the document transport path W3, and a control unit 15.

[0123] The document feeding unit 310 is located above the document placement unit 301 and includes a feeding roller 311 that rotates around a rotation axis α by receiving rotational driving force from a drive source 316, a roller holder 314 that pivotally supports the feeding roller 311, and a holder moving unit 305 that moves the roller holder 314 to a lowered position where the feeding roller 311 contacts the document G placed on the document placement unit 301, or to an elevated position where the feeding roller 311 is separated from the document G placed on the document placement unit 301. The system includes a document stopper (sheet stopper) 16 that is movable (swingable) between a first position that restricts the feeding of the document G placed on the document placement section 301 to the document transport path W3 (when the roller holder 314 is in the lowered position) and a second position that does not restrict the feeding of the document G placed on the document placement section 301 to the document transport path W3.

[0124] The control unit 15 can perform a feeding operation in which it moves the roller holder 314 to the lowered position and feeds the document G placed on the document placement unit 301 to the document transport path W3 using the feeding roller 311, and a retraction operation in which it stops the feeding operation of the feeding roller 311 and moves the roller holder 314 to the raised position if it is determined based on the detection result of the transport document detection unit 130 that the document G fed by the feeding operation has stopped in the document transport path W3.

[0125] The document feeding unit 310 further includes a holding restriction unit 17 that holds the document stopper 16 in place from the second position (where it is in a state where it is not restricted by the stopped document G) if a retraction operation is performed while the document stopper 16 is in the second position (where it is in a state where it is in the second position).

[0126] Therefore, even if the document G stops for some reason while being transported along the document transport path W3, and the document stopper 16 is in contact with the stopped document G and in the second position when the retraction operation is performed, the holding regulating unit 17 will hold the document stopper 16 in the second position. This prevents the document G from being damaged by the document stopper 16 even if the stopped document G is pulled out.

[0127] Furthermore, the document feeder 300 of this embodiment is An opening / closing member 303 (having a document guide rib 3031) is movable between an open position that opens a portion of the upper part of the document transport path W3 and a closed position that forms the document transport path W3, The system further includes a drive force transmission unit 304 that transmits rotational driving force from the drive source 316 to the feed roller 311 and the holder moving unit 305 when the opening / closing member 303 is in the closed position, and does not transmit rotational driving force from the drive source 316 to the feed roller 311 and the holder moving unit 305 when the opening / closing member 303 is in the open position. The holder movement unit 305 is capable of moving the roller holder 314 to a lowered or raised position by rotational driving force from the drive source 316 when the opening / closing member 303 is in the closed position. The document feeding unit 310 further includes a biasing member 330 provided on the opening / closing member 303, which applies a biasing force to the roller holder 314 so that the roller holder 314 maintains its raised position even when the opening / closing member 303 is moved to the open position while the roller holder 314 is in the raised position.

[0128] With this configuration, even if the opening / closing member 303 is opened after the retraction operation in which the document stopper 16 is held in the second position by the holding regulating unit 17, the document stopper 16 will remain in the second position. Therefore, even if the user forgets to remove the document G remaining on the document placement unit 301 and moves the opening / closing member 303 to the closed position, the document stopper 16 will not damage the document G.

[0129] The document stopper 16 is configured to be in a first position by its own weight when the roller holder 314 is in the lowered position and there is no document G on the document placement section 301. The document feeder 300 of this embodiment further includes a placed document detection unit 340 that detects whether or not a document G is placed on the document placement section 301. Therefore, during the document feeding operation, the control unit 15 stops the document feeding operation after it is determined that there is no more document G on the document placement section 301 based on the detection result of the placed document detection unit 340, and performs a preparatory operation to move the roller holder 314 from the lowered position to the raised position from the state in which the document stopper 16 is in the first position by its own weight to prepare for feeding. In the feeding preparation state, the document stopper 16 is held by the holding restriction unit 17 so as not to move from the first position.

[0130] In this feeding preparation state, the document stopper 16 is held in place by the holding restriction unit 17 so as not to move from the first position. Therefore, when performing the next second reading process, the document G to be placed on the document placement unit 301 can be brought into contact with the stopper portion 162a of the document stopper 16 and aligned.

[0131] The document feeder 300 of this embodiment further includes an operation display unit 120 that informs the operator of information. If the document G stops for any reason while being transported along the document transport path W3 and a retraction operation is performed, the control unit 15 sets the value of the jam detection flag to 1 and then displays post-processing information (see Figure 21) on the operation display unit 120 prompting the operator to remove the document G remaining on the document transport path W3 and the document placement unit 301. After the post-processing information is displayed on the operation display unit 120 (i.e., while the jam detection flag is 1), if the detection result of the placed document detection unit 340 determines that the document G is not on the document placement unit 301, the control unit 15 moves the roller holder 314 to the lowered position so that the document stopper 16 is in the first position (by its own weight), then moves the roller holder 314 to the raised position so that the document stopper 16 is held in the first position by the holding restriction unit 17, and performs a return operation, and the jam detection flag is changed to 0.

[0132] Therefore, even if the document G stops for any reason while being transported along the document transport path W3 and a retraction operation is performed, the control unit 15 can automatically perform a recovery operation based on the detection result of the placed document detection unit 340, and the document stopper 16 can be returned to the first position, which is the regulated position. In other words, preparations are made for the second reading process to be performed.

[0133] Here, the engagement portion 161a of the document stopper 16 includes a first engagement portion 161a1 located on the upstream side in the document feeding direction H and a second engagement portion 161a2 located on the downstream side in the document feeding direction H. When the document is in a feeding preparation state, the first engagement portion 161a1 engages with the engaged portion 314a, and the retraction operation is performed. When the document stopper 16 is held in the second position by the holding restricting portion 17, the second engagement portion 161a2 engages with the engaged portion 314a.

[0134] Since the engaging portion 161a has a first engaging portion 161a1 and a second engaging portion 161a2, the restrictive holding portion 17 can hold the document stopper 16 in the first or second position when the roller holder 314 moves to the raised position.

[0135] 2. Second Embodiment Here, we will describe an example of control by the control unit 15 of the document feeder 300, which differs from that of the first embodiment. The only difference from the first embodiment is the recovery operation when the document G stops during the second reading process.

[0136] Figure 22 shows the control flow of the second reading process in the second embodiment. Figures 23 and 24 are examples of post-processing information (second display screen D2, third display screen D3) that prompts the removal of the original document G when a retraction operation is performed in the flow shown in Figure 22.

[0137] In the second embodiment, the difference from the first embodiment is the process P enclosed by the dashed line in Figure 22, that is, the process from step S16 to step S18. The other processes are the same as in the first embodiment, so the explanation of the other steps is omitted here.

[0138] The process from step S16 to step S18 is a processing flow related to the recovery process from a state in which the document G has stopped (retracted state) in the document transport path W3 during the second scanning process. In step S16, which is performed after the control unit 15 determines that the document G has stopped in the document transport path W3 and executes step S5, the operation display unit 120 displays a jam release operation as shown in Figure 23. Since the operation display unit 120 of the second embodiment is a touch panel, when the OK button displayed on the screen is pressed, the same recovery operation as performed in the first embodiment is performed, and the operation display unit 120 displays an operation screen for resuming the feeding of the document G as shown in Figure 24.

[0139] In other words, the document feeder 300 according to the second embodiment further comprises an operation display unit 120 capable of displaying information and accepting predetermined operations from the user (operator), that is, a display unit that displays information and an operation unit that accepts predetermined operations. The control unit 15 displays post-processing information on the display unit (see Figure 23) indicating a predetermined operation to remove the document G remaining in the document transport path W3 and the document placement unit 301 after the retraction operation is performed in step S5. When the operation unit accepts the predetermined operation displayed in the post-processing information, it moves the roller holder 314 to the lowered position so that the document stopper 16 is in the first position, and then moves the roller holder 314 to the raised position so that the document stopper 16 is held in the first position by the holding restriction unit 17. After the return operation is performed, it displays information on the display operation unit 120 instructing the resumption of document feeding (see Figure 24).

[0140] This recovery operation may be performed only after the document detection unit 340 determines that there is no document G on the document placement unit 301.

[0141] In this way, the operation display unit 120 displays post-processing information indicating the operation to remove the document G that has stopped in the document transport path W3, and by performing recovery processing based on the operation information received from the user, it becomes possible to easily restart the document G even if it has stopped in the document transport path W3.

[0142] This disclosure is not limited to the embodiments described above, and can be implemented in a variety of other ways. Therefore, these embodiments are merely illustrative in all respects and should not be constrained. The scope of this disclosure is defined by the claims and is not restricted by the text of the specification. Furthermore, any variations or modifications falling within the equivalent scope of the claims are all within the scope of this disclosure. [Explanation of symbols]

[0143] 15 Control Unit 16. Document stopper (sheet stopper) 160 First oscillating shaft 161 First Arm Section 161a Engagement part 161a1 First engaging part 161a2 Second engaging part 162 Second Arm Section 162a Stopper part 17 Retention Regulation Section 100 Image forming apparatus 120 Operation and display unit (operation unit and display unit) 130 Document transport detection unit (transport sheet detection unit) 200 Image reading device 300 Document feeder (sheet feeder) 300a Document feeder unit (sheet feeder unit) 301 Manuscript Placement Section (Sheet Placement Section) 302 Guide member 303 Opening / closing member 3031 Manuscript Guide Rib 3032 Stopper section 304 Drive transmission section 304a Drive gear 304b Rotating shaft gear 305 Holder movement section (lifting mechanism) 310 Document feeding unit (sheet feeding unit) 311 Feeding roller 311a Rotation axis 311b Second one-way clutch 312 Separation and transport section 3121 Supply Roller 3121a Drive Rotating Shaft 3121b First one-way clutch 3121c Torque Limiter 3122 Separation Pad 313 Document transport roller 314 Roller Holder 3141 Roller holder body 314a Engaged part (engaged protrusion) 314b Locking part 315 Supply drive transmission mechanism 316 Power source 320 Document transport system 330 Biasing member 340 Document detection unit (sheet detection unit) 341 Detected part 342 Transmissive Optical Sensor D1 1st display screen D2 2nd display screen D3 Third Display Screen G. Original document (sheet with image formed on it) H Original feeding direction P1 1st engagement position P2 2nd engagement position Ra (forward rotation direction) Rb reverse rotation direction Rc oscillation direction W3 Document transport path (sheet transport path) X Width direction Y left / right direction Z vertical direction α rotation axis β1 First oscillation axis β2 Second oscillation axis γ Virtual vertical line

Claims

1. A sheet mounting section on which the sheet is placed, A sheet transport path through which the aforementioned sheets are transported, A sheet feeding unit that sends the sheet placed on the sheet placement unit to the sheet transport path, A sheet transport detection unit for detecting the sheet being transported along the sheet transport path, It comprises a control unit and, The aforementioned sheet feeding unit is Located above the aforementioned sheet mounting section, A feed roller that rotates around its axis of rotation by receiving rotational driving force from a power source, A roller holder that pivotally supports the aforementioned feeding roller, The roller holder is moved by a holder movement unit that moves the feed roller to a lowered position where it contacts the sheet placed on the sheet mounting unit, or to an elevated position where it separates from the sheet placed on the sheet mounting unit, The sheet stopper is movable between a first position that restricts the feeding of the sheet placed on the sheet placement section to the sheet transport path and a second position that does not restrict the feeding of the sheet placed on the sheet placement section to the sheet transport path. The control unit is capable of performing a feeding operation in which the roller holder is moved to the lowered position and the sheet placed on the sheet placement section is fed to the sheet transport path by the feeding roller, and, if it is determined based on the detection result of the transport sheet detection unit that the sheet fed by the feeding operation has stopped in the sheet transport path, it is capable of performing a retraction operation in which the feeding operation of the feeding roller is stopped and the roller holder is moved to the raised position. The sheet feeding device is characterized in that the sheet feeding unit further includes a holding regulating unit that holds the sheet stopper so as not to move from the second position when the retraction operation is performed while the sheet stopper is in the second position.

2. A sheet feeding device according to claim 1, The system further includes an opening / closing member that can move between an open position that opens a portion of the upper part of the sheet transport path and a closed position that forms the sheet transport path. The holder movement unit is capable of moving the roller holder to the lowered position or the raised position by rotational driving force from the drive source when the opening / closing member is in the closed position. The sheet feeding device is characterized in that the sheet feeding section further comprises a biasing member provided on the opening / closing member, which applies a biasing force to the roller holder such that the roller holder maintains the raised position even when the opening / closing member is moved to the open position while the roller holder is in the raised position.

3. A sheet feeding device according to claim 2, The sheet feeding device is characterized in that the sheet stopper is positioned in the first position by its own weight when the roller holder is in the lowered position and there is no sheet in the sheet mounting section.

4. A sheet feeding device according to claim 3, The sheet placement section further includes a sheet placement detection unit that detects whether or not the sheet is placed on it. The control unit, during the feeding operation, stops the feeding operation after it is determined that there are no more sheets in the sheet storage area based on the detection result of the sheet storage unit, and performs a preparatory operation to move the roller holder from the state in which the sheet stopper is in the first position to the raised position to prepare for feeding. A sheet feeding device characterized in that, in the feeding preparation state, the sheet stopper is held by the holding restricting unit so as not to move from the first position.

5. A sheet feeding device according to claim 4, It is further equipped with a display unit that informs the operator of information, When the retraction operation is performed, the control unit displays post-processing information on the display unit prompting the removal of the sheet remaining in the sheet transport path and the sheet placement section. A sheet feeding device characterized in that, after the post-processing information is displayed on the display unit, if it is determined that the sheet is not present on the sheet placement unit based on the detection result of the sheet placement unit, the roller holder is moved to the lowered position so that the sheet stopper is in the first position, and then the roller holder is moved to the raised position so that the sheet stopper is held in the first position by the holding regulating unit, thereby performing a return operation.

6. A sheet feeding device according to claim 5, It further includes an operating unit that accepts predetermined operations from the operator, When the retraction operation is performed, the control unit displays post-processing information on the display unit indicating a predetermined operation to remove the sheet remaining in the sheet transport path and the sheet placement section. A sheet feeding device characterized in that, when the operating unit receives a predetermined operation displayed in the post-processing information, it moves the roller holder to the lowered position so that the sheet stopper is in the first position, then moves the roller holder to the raised position, and performs a return operation so that the sheet stopper is held in the first position by the holding restricting unit.

7. A sheet feeding device according to claim 2, The sheet stopper and the roller holder are provided adjacent to each other in the direction of the rotation axis of the feed roller. The aforementioned holding regulating unit is The engaged portion provided on the roller holder, The sheet stopper includes an engaging portion that can engage with the engaged portion, The engaged portion is an engaged projection that protrudes from the roller holder toward the sheet stopper, A sheet feeding device characterized in that, when the roller holder is in the lowered position, it is positioned not to engage with the engaging portion, and when the roller holder is in the raised position, it is positioned to engage with the engaging portion.

8. A sheet feeding device according to claim 7, The sheet stopper has an engaging portion, a stopper portion that contacts the sheet placed on the sheet mounting portion, and a first oscillating shaft portion that rotates around a first oscillating axis along the rotation axis direction of the feeding roller. The engaging portion and the stopper portion are provided at different positions in the circumferential direction of the first pivot shaft portion. The sheet feeding device is characterized in that the stopper portion has a flat portion that contacts one end of a plurality of sheets placed on the sheet placement portion and aligns the end positions of the plurality of sheets.

9. A sheet feeding device according to claim 8, The seat stopper has a first arm portion extending radially from the first pivot shaft portion, and a second arm portion extending radially from the circumferential surface of the first pivot shaft portion where the first arm portion is not provided. The engagement portion is an engagement projection provided at the tip of the first arm portion so as to protrude toward the roller holder side. The planar portion is provided so as to extend from the tip of the second arm portion in a direction intersecting the extension direction of the second arm portion, and on the opposite side from the engaging portion. A sheet feeding device characterized in that, when the document stopper is in the first position, the first arm and the second arm are positioned downstream in the sheet feeding direction with respect to a virtual vertical line passing through the first pivot axis.

10. A sheet feeding device according to claim 9, The engagement portion includes a first engagement portion located on the upstream side in the feeding direction and a second engagement portion located on the downstream side in the feeding direction. A sheet feeding device characterized in that, when in the feeding preparation state, the first engaging portion engages with the engaged portion, the retraction operation is performed, and when the sheet stopper is held in the second position by the holding restricting portion, the second engaging portion engages with the engaged portion.

11. A sheet feeding device according to claim 8, The opening and closing member has a plurality of guide ribs extending along the sheet feeding direction that form the sheet transport path, The seat stopper is supported between the plurality of guide ribs so as to be able to swing around the first pivot axis, The sheet feeding device is characterized in that the roller holder is provided on the guide rib so as to be able to swing about a second pivot axis along the rotation axis direction of the feeding roller.

12. A sheet feeding device according to claim 11, A sheet feeding device characterized in that the guide rib is provided with a rotation-retaining portion that restricts the stopper portion of the sheet stopper in the first position from swinging upstream in the sheet feeding direction.

13. A sheet feeding device according to either claim 1 or claim 2, An image reading device characterized in that an image reading unit is provided at a position facing the sheet transport path of the sheet feeding device.

14. An image forming apparatus characterized by comprising the image reading device described in claim 13.

Images