Document transport device, image forming apparatus

Abstract

To provide a document transport device and an image forming apparatus capable of preventing the document from being fed out with the pickup roller tilted. [Solution] The ADF includes a roller holder 27 that rotatably supports the pickup roller and is rotatably mounted around the rotation axis of the paper feed roller; a cover portion that is openable and closable relative to the document guide portion; a pair of walls that face each other in the axial direction of the rotation axis, sandwiching the cover portion; a hook portion 33 that is provided at one end of the cover portion in the axial direction so as to be able to move back and forth along the axial direction, and which retracts toward the cover portion when the cover portion is closed by contacting the upper surface of the wall portion and engaging with the upper surface; and an interlocking portion 36 that rotates the roller holder 27 in conjunction with the movement of the hook portion 33.

Description

Technical Field

[0001] The present invention relates to a document conveyance device and an image forming apparatus.

Background Art

[0002] An image forming apparatus including a document conveyance device for conveying a document is known (see, for example, Patent Document 1).

[0003] This type of document conveyance device includes a pickup roller, a paper feed roller, a document guide unit, a cover unit, and a gear. The pickup roller feeds out a document placed on a document placement unit such as a document tray. The paper feed roller is provided downstream of the pickup roller in the feeding direction of the document by the pickup roller and conveys the document. The document guide unit contacts the lower surface of the document conveyed by the paper feed roller and guides the document. The cover unit rotatably supports the pickup roller and the paper feed roller, and is provided to be openable and closable about an axis on the downstream side of the paper feed roller in the feeding direction. The gear is provided at a first end in the width direction of the document in the cover unit, and forms a transmission path of a rotational driving force from a motor to the paper feed roller and the pickup roller when the cover unit is closed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in the aforementioned document transport device, if the cover is not completely closed, the second end of the cover, opposite to the first end, may lift up. In this case, the pickup roller tilts in a way that allows rotational driving force to be transmitted to the pickup roller via the gear. When the document is fed out while the pickup roller is tilted, problems such as paper jams may occur.

[0006] The object of the present invention is to provide a document transport device and an image forming apparatus that can prevent documents from being fed out with the pickup roller tilted. [Means for solving the problem]

[0007] A document transport device according to one aspect of the present invention comprises a document placement section, a pickup roller, a paper feed roller, a roller holder, a document guide section, a cover section, a pair of wall sections, a hook section, a motor, a gear, and an interlocking section. A document is placed on the document placement section. The pickup roller contacts the upper surface of the document placed on the document placement section and feeds the document. The paper feed roller is provided downstream of the pickup roller in the direction of document feeding by the pickup roller and transports the document. The roller holder rotatably supports the pickup roller and is provided to rotate between a contact position where the pickup roller contacts the document and a separation position where the pickup roller is separated from the document, around the rotation axis of the paper feed roller. The document guide section contacts the lower surface of the document downstream of the paper feed roller in the feeding direction and guides the document. The cover portion rotatably supports the paper feed roller and is rotatably provided so as to be between a closed position that covers the document guide portion and an open position that exposes the document guide portion to the outside, on an axis downstream of the paper feed roller in the feeding direction. The pair of wall portions face each other in the axial direction of the rotation axis, sandwiching the cover portion. The hook portion is provided so as to be able to move back and forth along the axial direction at each of the first and second ends of the cover portion in the axial direction, and when the cover portion is rotated to the closed position, it retracts toward the cover portion by contacting the upper surface of the wall portion and engages with the upper surface. The motor rotates the pickup roller and the paper feed roller. The gear is provided at the first end and forms a transmission path for rotational driving force from the motor to the paper feed roller and the pickup roller when the hook portion at the first end engages with the upper surface of the wall portion. The interlocking portion is provided in the cover portion and rotates the roller holder in conjunction with the movement of the hook portion at the second end.

[0008] An image forming apparatus according to another aspect of the present invention comprises the document transport device, an image reading unit, and an image forming unit. The image reading unit reads an image of the document transported by the document transport device. The image forming unit forms the image of the document read by the image reading unit onto a sheet. [Effects of the Invention]

[0009] According to the present invention, it is possible to prevent the document from being fed out while the pickup roller is tilted. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a cross-sectional view showing the configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] Figure 2 is a perspective view showing the configuration of the ADF and image reading unit of an image forming apparatus according to an embodiment of the present invention. [Figure 3] Figure 3 is a cross-sectional view showing the configuration of the ADF of an image forming apparatus according to an embodiment of the present invention. [Figure 4] Figure 4 is a cross-sectional view showing the configuration of the ADF of an image forming apparatus according to an embodiment of the present invention. [Figure 5] Figure 5 is a plan view showing the configuration of a pickup roller, a paper feed roller, and a roller holder in an image forming apparatus according to an embodiment of the present invention. [Figure 6] Figure 6 is a plan view showing the configuration of the ADF of an image forming apparatus according to an embodiment of the present invention. [Figure 7] Figure 7 is a side view showing the cover portion of an image forming apparatus according to an embodiment of the present invention in an open state. [Figure 8] Figure 8 is a cross-sectional view taken along the line VIII-VIII in Figure 6. [Figure 9] Figure 9 shows a state in which one side of the cover portion of the image forming apparatus according to an embodiment of the present invention is floating. [Figure 10] Figure 10 shows the configuration of the roller holder and interlocking part of an image forming apparatus according to an embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing the configuration of an interlocking part of an image forming apparatus according to an embodiment of the present invention. [Figure 12] FIG. 12 is a diagram showing the configuration of a roller holder and an interlocking part of an image forming apparatus according to an embodiment of the present invention. [Figure 13] FIG. 13 is a cross-sectional view showing a roller holder and an interlocking part when a front hook portion is engaged with an upper surface portion in an image forming apparatus according to an embodiment of the present invention. [Figure 14] FIG. 14 is a cross-sectional view showing a roller holder and an interlocking part when a front hook portion is not engaged with an upper surface portion in an image forming apparatus according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following embodiments are an example of embodying the present invention and do not limit the technical scope of the present invention.

[0012] [Configuration of Image Forming Apparatus 100] First, the configuration of an image forming apparatus 100 according to an embodiment of the present invention will be described while referring to FIG. 1.

[0013] For convenience of explanation, in an installation state (the state shown in FIG. 1) where the image forming apparatus 100 can be used, the vertical direction is defined as the up-down direction D1. Also, the front-rear direction D2 is defined with the front side (front surface) of the image forming apparatus 100 shown in FIG. 1 as the front (front face). Further, the left-right direction D3 is defined based on the front of the image forming apparatus 100 in the installation state.

[0014] The image forming apparatus 100 is a multifunction device having a plurality of functions such as a scan function for reading an image from a document, a print function for forming an image based on image data, a fax function, and a copy function. Note that the image forming apparatus 100 may be a copy machine.

[0015] As shown in FIG. 1, the image forming apparatus 100 includes an ADF (Auto Document Feeder) 1, an image reading unit 2, an image forming unit 3, and a paper feeding unit 4.

[0016] The ADF 1 conveys the document whose image is to be read by the image reading unit 2. The ADF 1 is an example of the document conveying apparatus of the present invention.

[0017] The image reading unit 2 can read the image of the document. Specifically, the image reading unit 2 can read the image of the document by a CCD (Charge Coupled Device) method. As shown in FIG. 1, the image reading unit 2 includes a document table 11, a reading unit 12, a mirror 13, a mirror 14, an optical lens 15, and a CCD 16.

[0018] The document table 11 is the upper surface portion of a box-shaped housing that houses each component of the image reading unit 2. The document table 11 includes a contact glass on which the document is placed.

[0019] The reading unit 12 is provided below the contact glass of the document table 11. The reading unit 12 is configured to be movable along the sub-scanning direction in the same direction as the lateral direction D3 by a moving mechanism (not shown) having a driving unit such as a stepping motor. As shown in FIG. 1, the reading unit 12 includes a light source 12A and a mirror 12B. [[ID=​​​​​​Mirror 13 reflects the light reflected by mirror 12B of the reading unit 12 to mirror 14. Mirror 14 reflects the light reflected by mirror 13 to optical lens 15. Optical lens 15 focuses the light reflected by mirror 14 and directs it into the CCD 16.

[0022] The CCD16 is an image sensor having a plurality of photoelectric conversion elements arranged along the main scanning direction. The CCD16 outputs an electrical signal corresponding to the amount of light received. In the image reading unit 2, light emitted from the light source 12A and reflected by the document is incident on the CCD16 via mirrors 12B, 13, 14, and optical lens 15. As a result, the CCD16 outputs an analog electrical signal corresponding to the image of the document. The analog electrical signal output from the CCD16 is converted into a digital electrical signal (image data) by an AFE (analog front-end) circuit (not shown) and input to a control unit (not shown). The image data output from the image reading unit 2 is used for image formation by the image forming unit 3, etc.

[0023] The image reading unit 2 may also read the image of the document using the CIS (Contact Image Sensor) method.

[0024] The image forming unit 3 forms an image on the sheet based on the image data. Specifically, the image forming unit 3 forms the image on the sheet using an electrophotographic method. For example, the image forming unit 3 includes a photosensitive drum, a charging roller, a light scanning device, a developing device, a transfer roller, a cleaning device, a fixing device, and a sheet ejection unit. The image forming unit 3 may also form the image on the sheet using other image forming methods, such as an inkjet method.

[0025] The paper feeding unit 4 supplies sheets to the image forming unit 3. The paper feeding unit 4 includes a paper feeding cassette and a plurality of transport rollers.

[0026] [ADF1 Configuration] Next, the configuration of the image forming apparatus 100 according to an embodiment of the present invention will be described with reference to Figures 1 to 8. Here, Figure 2 is a perspective view of the ADF1 in a closed state relative to the document table 11, as seen from the rear side of the image forming apparatus 100. Figure 3 is a cross-sectional view showing the internal configuration of the storage section 21 of the ADF1, showing the state in which the pickup roller 25 is positioned at a distance from the document. Figure 4 is a cross-sectional view showing the internal configuration of the storage section 21 of the ADF1, showing the state in which the pickup roller 25 is positioned at a contact position in contact with the document.

[0027] As shown in Figure 1, the ADF1 is provided above the document tray 11 of the image reading unit 2. The ADF1 is also provided so as to be able to open and close relative to the document tray 11 of the image reading unit 2. Specifically, the ADF1 is rotatably supported by a pair of hinges provided at the rear end of the document tray 11. This allows the ADF1 to change its orientation between a closed position that covers the document tray 11 (see Figures 1 and 2) and an open position that exposes the document tray 11 (not shown).

[0028] As shown in Figures 1 and 2, the ADF1 comprises a storage section 21, a bottom section 22, an output tray 23, a document tray 24, a pickup roller 25, a paper feed roller 26, a roller holder 27, a document guide section 28, a cover section 29, multiple transport rollers 30, a front wall section 31, and a rear wall section 32. The ADF1 also comprises a hook section 33, a motor 34, and an input gear 35, as shown in Figures 5, 6, and 8.

[0029] The storage section 21 is formed in a roughly rectangular parallelepiped shape, with dimensions in the front-to-back direction D2 being approximately the same as the document glass 11, and dimensions in the left-to-right direction D3 being smaller than the document glass 11 (see Figure 2). The storage section 21 is positioned above the area of ​​the document glass 11, including the left end, when the ADF 1 is closed to the document glass 11 (see Figures 1 and 2). The storage section 21 houses the pickup roller 25, the paper feed roller 26, and the multiple transport rollers 30 used for transporting documents. A document loading port 21A (see Figure 1) is formed on the right side of the storage section 21 through which documents are loaded. Below the document loading port 21A on the right side of the storage section 21, a document discharge port 21B (see Figure 1) is formed through which documents are discharged. Inside the storage section 21, a document transport path 21C (see Figure 1) is formed, leading from the document loading port 21A to the document discharge port 21B. The document transport path 21C comprises an upper transport path extending in the left-right direction D3, a lower transport path extending in the left-right direction D3 below the upper transport path, and a return section connecting the left end of the upper transport path and the left end of the lower transport path.

[0030] The bottom portion 22 is formed as a flat plate extending to the right from the bottom of the right side of the storage portion 21 (see Figure 2). Together with the bottom surface of the storage portion 21, the bottom portion 22 forms a cover surface that covers the document glass 11 of the image reading unit 2. This cover surface is also the bottom surface of the ADF 1. When the ADF 1 is closed to the document glass 11, the bottom portion 22 is positioned above the area of ​​the document glass 11 that includes the right end (see Figures 1 and 2).

[0031] As shown in Figure 1, the output tray 23 is formed on the upper part of the bottom portion 22. Documents transported by the ADF 1 are discharged into the output tray 23.

[0032] As shown in Figure 1, the document tray 24 is provided above the output tray 23 and opposite the output tray 23. The document tray 24 is provided so as to extend to the right from below the document loading port 21A and above the document output port 21B of the storage unit 21. Documents transported by the ADF 1 are placed on the document tray 24. The document tray 24 is formed in a flat plate shape having a loading surface on which documents are placed. The document tray 24 is positioned so as to be inclined downward toward the document loading port 21A so that documents placed on the loading surface are guided toward the document loading port 21A. The position of documents placed on the loading surface in the front-to-back direction D2 is adjusted by a pair of side cursors provided on the document tray 24. The document tray 24 is an example of a document loading unit of the present invention.

[0033] As shown in Figure 1, the pickup roller 25 is located above the document input opening 21A. The pickup roller 25 contacts the top surface of the uppermost document among the multiple documents placed on the document tray 24, and feeds that document into the document transport path 21C.

[0034] As shown in Figure 1, the paper feed roller 26 is located downstream of the pickup roller 25 in the document feeding direction D4 (see Figure 1). The paper feed roller 26 transports the documents fed by the pickup roller 25 to the back of the document transport path 21C.

[0035] The roller holder 27 rotatably supports the pickup roller 25. The roller holder 27 is also rotatably mounted around the rotation axis 26A of the paper feed roller 26 (see Figure 4) so ​​as to be able to move between a contact position where the pickup roller 25 contacts the document (see Figure 4) and a separation position where the pickup roller 25 moves away from the document (see Figure 3). As shown in Figure 5, the rotation axis 26A is an axis that extends in the front-rear direction D2.

[0036] As shown in Figure 5, the roller holder 27 comprises an upper surface portion 27A, a pair of bearing portions 27B, a pair of shaft holes 27C, and an opening 27D. The upper surface portion 27A forms the upper surface of the roller holder 27. The upper surface portion 27A is formed in a flat plate shape. The pair of bearing portions 27B are provided below the upper surface portion 27A, facing each other in the front-rear direction D2. The pair of bearing portions 27B rotatably support the pickup roller 25. The pair of shaft holes 27C are provided below the upper surface portion 27A, facing each other in the front-rear direction D2. The pair of shaft holes 27C are also provided to the left of the pair of bearing portions 27B. The rotating shaft 26A of the paper feed roller 26 is inserted through the pair of shaft holes 27C. The roller holder 27 is rotatably supported in the rotation direction D5 shown in Figure 3 by the rotating shaft 26A inserted through the pair of shaft holes 27C. The opening 27D is rectangular in shape on the upper surface 27A. The opening 27D is located between a pair of bearing portions 27B and a pair of shaft hole portions 27C in the left-right direction D3.

[0037] The document guide section 28 contacts the lower surface of the document downstream of the paper feed roller 26 in the feeding direction D4 and guides the document. The document guide section 28 forms the lower portion of the upper transport path of the document transport path 21C.

[0038] The cover portion 29 rotatably supports the rotation shaft 26A (see Figure 5) of the paper feed roller 26. The cover portion 29 is rotatably provided around the pivot shaft 29C (see Figure 1) between a closed position that covers the document guide portion 28 (see Figure 1) and an open position that exposes the document guide portion 28 to the outside (see Figure 7). As shown in Figure 1, the pivot shaft 29C is provided at the left end of the housing portion 21. For example, the pivot shaft 29C is provided in the cover portion 29. The housing portion 21 also includes a bearing portion that rotatably supports the pivot shaft 29C. The cover portion 29 rotates in the rotation direction D6 shown in Figure 6 because the pivot shaft 29C is rotatably supported by the bearing portion of the housing portion 21. The pivot shaft 29C may also be provided in the housing portion 21. In this case, the cover portion 29 only needs to have a shaft hole through which the pivot shaft 29C is inserted. Furthermore, the pivot shaft 29C only needs to be located downstream of the paper feed roller 26 in the feeding direction D4.

[0039] Multiple transport rollers 30 are arranged at intervals from each other along the document transport path 21C. Each transport roller 30 transports the document fed out by the pickup roller 25 toward the document output port 21B.

[0040] The front wall portion 31 is erected along the front end of the upper surface of the bottom portion 22 (see Figure 2). The front wall portion 31 forms the front side surface of the housing portion 21.

[0041] The rear wall portion 32 is erected along the rear end of the upper surface of the bottom portion 22 (see Figure 2). The rear wall portion 32 forms the rear side surface of the housing portion 21. Also, as shown in Figure 2, the rear wall portion 32 extends to the right from the housing portion 21.

[0042] As shown in Figure 2, the front wall portion 31 and the rear wall portion 32 face each other across the cover portion 29 in the axial direction of the rotation axis 26A (the same direction as the front-rear direction D2). As shown in Figure 2, when the cover portion 29 is in the closed position, it forms the upper surface of the housing portion 21 together with the upper surface portion 31A that forms the upper surface of the front wall portion 31 and the upper surface portion 32A that forms the upper surface of the rear wall portion 32. The front wall portion 31 and the rear wall portion 32 are examples of a pair of wall portions of the present invention.

[0043] The hook portion 33 is provided so as to be able to move back and forth along the front-rear direction D2 at each of the front end portion 29A (see Figure 6) (an example of a second end portion in this disclosure) and the rear end portion 29B (see Figure 6) (an example of a first end portion in this disclosure) of the cover portion 29 in the front-rear direction D2. When the cover portion 29 is rotated to the closed position, the hook portion 33 retracts toward the cover portion 29 by contact with the upper surface portion of either the front wall portion 31 or the rear wall portion 32 and engages with the said upper surface portion.

[0044] As shown in Figure 8, the upper surface portion 31A of the front wall portion 31 is provided with an engaged portion 31B that engages with the hook portion 33 of the front end portion 29A. The engaged portion 31B is formed in a flat plate shape that slopes downward toward the cover portion 29. Similarly, the upper surface portion 32A of the rear wall portion 32 is provided with an engaged portion 32B (see Figure 9) that engages with the hook portion 33 of the rear end portion 29B. The engaged portion 32B is formed in a flat plate shape that slopes downward toward the cover portion 29.

[0045] The hook portion 33 of the front end 29A comprises a flat plate-shaped portion formed perpendicular to the front-rear direction D2, and a protruding portion that projects in a V-shape toward the front wall portion 31 from the flat plate-shaped portion (see Figures 8 and 10). The hook portion 33 of the front end 29A is supported by the cover portion 29 so as to be able to move back and forth along the front-rear direction D2.

[0046] As shown in Figure 8, a coil spring 33A and a spring support portion 33B are provided at the front end 29A of the cover portion 29. The coil spring 33A biases the hook portion 33 toward the front wall portion 31. The coil spring 33A is elongated in the front-rear direction D2, and its front end is in contact with the flat plate-shaped portion of the hook portion 33. The spring support portion 33B supports the rear end of the coil spring 33A.

[0047] When the cover portion 29 is rotated from the open position to the closed position by the user of the image forming apparatus 100, the protruding portion of the hook portion 33 of the front end portion 29A and the engaged portion 31B of the front wall portion 31 come into contact before the cover portion 29 reaches the closed position, and the hook portion 33 is pressed towards the cover portion 29. As a result, the hook portion 33 of the front end portion 29A retracts in the retraction direction D7 (see Figure 8) against the biasing force of the coil spring 33A. When the cover portion 29 reaches the closed position, the protruding tip of the protruding portion of the hook portion 33 of the front end portion 29A moves beyond the lower end of the engaged portion 31B and to its underside. As a result, the hook portion 33 advances slightly in the advance direction D8 until the flat plate portion and the lower end of the engaged portion 31B come into contact, and then slides under the engaged portion 31B. In other words, the hook portion 33 and the engaged portion 31B become engaged. The rotation of the cover portion 29 is restricted when the hook portion 33 and the engaged portion 31B engage.

[0048] When the cover portion 29 is rotated from the closed position to the open position by the user of the image forming apparatus 100, the protruding portion of the hook portion 33 of the front end portion 29A comes into contact with the engaged portion 31B of the front wall portion 31, and the hook portion 33 is pressed towards the cover portion 29. As a result, the hook portion 33 of the front end portion 29A retracts in the retraction direction D7 (see Figure 8) against the biasing force of the coil spring 33A. When the protruding tip of the protruding portion of the hook portion 33 of the front end portion 29A moves over the lower end of the engaged portion 31B and above it, the hook portion 33 of the front end portion 29A advances in the advance direction D8 (see Figure 8) due to the biasing force of the coil spring 33A. As a result, the engagement between the hook portion 33 and the engaged portion 31B is released.

[0049] Note that the configuration of the hook portion 33 and its surrounding area at the rear end 29B is the same as that of the front end 29A, so its explanation will be omitted.

[0050] As shown in Figure 6, the motor 34 is located below the upper surface 32A of the rear wall 32. The motor 34 rotates the pickup roller 25 and the paper feed roller 26.

[0051] The input gear 35 is provided at the rear end 29B of the cover portion 29 (see Figure 6). When the hook portion 33 of the rear end 29B of the input gear 35 engages with the upper surface portion 32A of the rear wall portion 32, it forms a transmission path for rotational driving force from the motor 34 to the pickup roller 25 and the paper feed roller 26. The input gear 35 is an example of a gear of the present invention.

[0052] As shown in Figure 6, the rotating shaft 26A of the paper feed roller 26 extends to the rear end 29B of the cover portion 29. As shown in Figures 5 and 6, the input gear 35 is provided at the rear end of the rotating shaft 26A.

[0053] As shown in Figure 6, an output gear 34A is provided on the drive shaft of the motor 34. The motor 34 and the output gear 34A are positioned below the input gear 35 so that they can mesh with the input gear 35 when the hook portion 33 of the rear end 29B engages with the upper surface portion 32A of the rear wall portion 32.

[0054] When the hook portion 33 of the rear end portion 29B engages with the upper surface portion 32A of the rear wall portion 32, the input gear 35 and the output gear 34A mesh. This creates a transmission path for rotational driving force from the motor 34 to the rotation shaft 26A of the paper feed roller 26 via the output gear 34A and the input gear 35. The rotational driving force transmitted to the paper feed roller 26 is transmitted to the pickup roller 25 via a driving force transmission member such as a belt provided between the paper feed roller 26 and the pickup roller 25.

[0055] Incidentally, in conventional document transport devices, if the cover portion 29 is not closed completely, the front end portion 29A of the cover portion 29 may lift up (see Figure 9). In this case, the pickup roller 25 tilts in a way that allows rotational driving force to be transmitted to the pickup roller 25 via the input gear 35 (see Figure 9). When a document is fed out with the pickup roller 25 tilted, problems such as paper jams may occur.

[0056] In contrast, the image forming apparatus 100 according to an embodiment of the present invention can suppress the feeding of the original document while the pickup roller 25 is tilted, as will be explained below.

[0057] Specifically, the cover portion 29 includes the interlocking portion 36 shown in Figure 10.

[0058] [Configuration of the interlocking unit 36] Next, the configuration of the interlocking unit 36 ​​will be explained with reference to Figures 10 to 14. Here, Figure 10 is a view of the interlocking unit 36 ​​from the upper right side when the roller holder 27 is not lifted. Figure 11 is a view of the interlocking unit 36 ​​from the upper right side. Figure 12 is a view of the interlocking unit 36 ​​from the lower right side when the roller holder 27 is lifted.

[0059] The interlocking unit 36 ​​is provided on the cover unit 29 and rotates the roller holder 27 in conjunction with the movement of the hook unit 33 at the front end 29A of the cover unit 29.

[0060] Specifically, the interlocking unit 36 ​​rotates the roller holder 27 from the separated position (see Figure 3) to the contact position (see Figure 4) in response to the retraction of the hook portion 33 of the front end 29A in the retraction direction D7 as the cover portion 29 rotates from the open position to the closed position. Also, the interlocking unit 36 ​​rotates the roller holder 27 from the contact position (see Figure 4) to the separated position (see Figure 3) in response to the advancement of the hook portion 33 of the front end 29A in the advancement direction D8 as the cover portion 29 rotates from the closed position to the open position.

[0061] As shown in Figure 11, the interlocking part 36 comprises an extension part 36A, a support part 36B, and an inclined surface forming part 36C. The extension part 36A extends in the retraction direction D7 from the hook part 33 of the front end 29A. The support part 36B supports the inclined surface forming part 36C below the upper end of the extension part 36A. The support part 36B comprises a first support part extending downward from the extension tip of the extension part 36A, and a second support part extending in the retraction direction D7 from the lower end of the first support part. The inclined surface forming part 36C forms an inclined surface 36D (see Figure 11). The inclined surface 36D lifts the roller holder 27 from below in conjunction with the extension of the hook part 33 of the front end 29A toward the front wall part 31. Specifically, the inclined surface 36D is formed to incline upward toward the retraction direction D7. The inclined surface forming portion 36C is formed to protrude upward from the second support portion of the support portion 36B.

[0062] The interlocking part 36 is provided to move back and forth integrally with the hook part 33 of the front end 29A. For example, the hook part 33 of the front end 29A and the interlocking part 36 are integrally formed using synthetic resin or the like.

[0063] The inclined surface forming portion 36C of the interlocking portion 36 is inserted from below into the opening 27D of the roller holder 27 when the hook portion 33 of the front end portion 29A is engaged with the engaged portion 31B of the front wall portion 31 (see Figures 10 and 13). In this state, the interlocking portion 36 does not lift the roller holder 27. Therefore, the pickup roller 25 is positioned at the contact position (see Figure 4).

[0064] When the cover portion 29 is opened (rotated from the closed position to the open position), the engagement between the hook portion 33 of the front end portion 29A and the engaged portion 31B of the front wall portion 31 is released, and the hook portion 33 advances in the advance direction D8. As a result, the inclined surface forming portion 36C of the interlocking portion 36 inserted into the opening 27D of the roller holder 27 moves toward the advance direction D8 in conjunction with the hook portion 33. Therefore, the inclined surface 36D comes into contact with the edge of the opening 27D, and the roller holder 27 is pushed up along the inclined surface 36D. In other words, the interlocking portion 36 lifts the roller holder 27 (see Figures 12 and 14). Consequently, the pickup roller 25 moves from the contact position (see Figure 4) to the separated position (see Figure 3).

[0065] When the cover portion 29 is closed (rotated from the open position to the closed position), the hook portion 33 of the front end portion 29A and the engaged portion 31B of the front wall portion 31 engage, and the hook portion 33 retracts in the retraction direction D7. As a result, the inclined surface forming portion 36C of the interlocking portion 36 moves in conjunction with the hook portion 33 toward the retraction direction D7, and the inclined surface forming portion 36C is inserted into the opening 27D of the roller holder 27. Therefore, the lifted state of the roller holder 27 by the interlocking portion 36 is released (see Figures 10 and 13). Consequently, the pickup roller 25 moves from the separated position (see Figure 3) to the contact position (see Figure 4).

[0066] Here, even when the cover portion 29 is closed, as shown in Figure 9, if the hook portion 33 of the front end portion 29A is not engaged with the engaged portion 31B of the front wall portion 31, the inclined surface forming portion 36C of the interlocking portion 36 will not move toward the retraction direction D7. Therefore, the lifted state of the roller holder 27 by the interlocking portion 36 is not released. In other words, the feeding of the document by the pickup roller 25 while the front end portion 29A of the cover portion 29 is lifted is avoided.

[0067] Thus, the image forming apparatus 100 is equipped with an interlocking unit 36 ​​that rotates the roller holder 27 in conjunction with the movement of the hook portion 33 at the front end 29A of the cover portion 29. This makes it possible to prevent the original document from being fed out with the pickup roller 25 tilted.

[0068] Furthermore, the interlocking section 36 of the image forming apparatus 100 is equipped with an inclined surface 36D that lifts the roller holder 27 from below in conjunction with the extension of the hook section 33 of the front end 29A toward the front wall section 31. This makes it possible to rotate the roller holder 27 with a simple configuration.

[0069] Furthermore, the interlocking unit 36 ​​of the image forming apparatus 100 is provided to move back and forth integrally with the hook portion 33 of the front end portion 29A. This simplifies the configuration of the interlocking unit 36.

[0070] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0071] <Note 1> A document holder is provided to rotatably support the pickup roller and rotate around the rotation axis of the paper feed roller so as to be able to move between a contact position where the pickup roller contacts the document and a separation position where the pickup roller moves away from the document. A document guide section is provided downstream of the paper feed roller in the direction of feeding so as to be able to move the document and rotate around the rotation axis of the paper feed roller so as to be able to move between a contact position where the pickup roller contacts the document and a separation position where the pickup roller moves away from the document. A document guide section is provided downstream of the paper feed roller in the direction of feeding so as to be able to move the document guide section and rotate around the axis downstream of the paper feed roller in the direction of feeding so as to be able to move the document guide section to the outside. A document transport device comprising: a cover portion rotatably provided between an open position to expose the cover; a pair of wall portions facing each other in the axial direction of the rotation shaft, sandwiching the cover portion; a hook portion provided at each of the first and second ends of the cover portion in the axial direction, so as to be able to move back and forth along the axial direction, and which retracts toward the cover portion side by contact with the upper surface of the wall portion when the cover portion is rotated to the closed position and engages with the upper surface of the wall portion; a motor for rotating the pickup roller and the paper feed roller; a gear provided at the first end, which forms a transmission path for rotational driving force from the motor to the paper feed roller and the pickup roller when the hook portion at the first end engages with the upper surface of the wall portion; and an interlocking portion provided in the cover portion, which rotates the roller holder in conjunction with the movement of the hook portion at the second end.

[0072] <Note 2> The document transport device according to Appendix 1, wherein the interlocking part has an inclined surface that lifts the roller holder from below in conjunction with the extension of the hook part of the second end toward the wall.

[0073] <Note 3> The document transport device according to Appendix 1 or 2, wherein the interlocking part is provided to be able to move back and forth integrally with the hook part at the second end.

[0074] <Note 4> An image forming apparatus comprising: a document transport device as described in any of Appendix 1 to 3; an image reading unit for reading an image of the document transported by the document transport device; and an image forming unit for forming an image of the document read by the image reading unit onto a sheet. [Explanation of symbols]

[0075] 1 ADF 2 Image reading unit 3 Image forming unit 4 Paper feed section 11. Manuscript stand 12 Reading Units 13 Mirror 14 Mirror 15 Optical Lenses 16 CCD 21 Storage Unit 22 Bottom part 23 Discharge tray 24 Document tray 25 Pickup Roller 26 Paper feed roller 26A Rotating shaft 27 Roller holder 27A Top part 27B Bearing section 27C Shaft hole 27D opening 28 Manuscript Guidelines Section 29 Cover section 29A Front end 29B Rear end 29C Rotary shaft 30 Conveyor Rollers 31 Front wall 31A Top part 31B Engaged part 32 Rear wall 32A Top part 32B Engaged part 33 Hook section 33A Coil Spring 33B Spring support section 34 motors 34A Output Gear 35 Input Gear 36 Interlocking section 36A Extension 36B Support part 36C Inclined surface forming part 36D sloped surface 100 Image forming apparatus

Claims

1. The manuscript placement section where the manuscript is placed, A pickup roller that contacts the upper surface of the document placed on the document placement section and feeds out the document, A paper feed roller is provided downstream of the pickup roller in the direction in which the document is fed out by the pickup roller, and is used to transport the document. A roller holder is provided that rotatably supports the pickup roller and is rotatable between a contact position in which the pickup roller contacts the document and a separation position in which the pickup roller is separated from the document, with respect to the rotation axis of the paper feed roller. A document guide unit that contacts the lower surface of the document and guides the document downstream of the paper feed roller in the feeding direction, A cover portion is provided that rotatably supports the paper feed roller and is rotatable between a closed position that covers the document guide portion and an open position that exposes the document guide portion to the outside, with respect to the axis downstream of the paper feed roller in the feeding direction. A pair of wall portions facing each other in the axial direction of the rotating shaft, with the cover portion in between, A hook portion is provided at each of the first and second ends in the axial direction of the cover portion so as to be able to move back and forth along the axial direction, and when the cover portion is rotated to the closed position, the hook portion is retracted toward the cover portion by contact with the upper surface of the wall portion and engages with the upper surface, A motor that rotates the pickup roller and the paper feed roller, A gear provided at the first end, which, when the hook portion of the first end engages with the upper surface portion of the wall, forms a transmission path for rotational driving force from the motor to the paper feed roller and the pickup roller, The cover portion is provided with an interlocking part that rotates the roller holder in conjunction with the movement of the hook portion at the second end, A document transport device equipped with the following features.

2. The interlocking part has an inclined surface that lifts the roller holder from below in conjunction with the extension of the hook portion of the second end toward the wall. The document transport device according to claim 1.

3. The interlocking part is provided so as to be able to move back and forth integrally with the hook part at the second end. The document transport device according to claim 1 or 2.

4. A document transport device according to claim 1 or 2, An image reading unit that reads the image of the document being transported by the document transport device, An image forming unit that forms an image of the original document read by the image reading unit onto a sheet, An image forming apparatus equipped with the following features.

Images