JP6254725B2 - Sheet conveying apparatus, image reading apparatus, and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet, an image reading apparatus including the sheet conveying apparatus, and an image forming apparatus including the image reading apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine or a printer that forms an image on a sheet is provided with an image reading apparatus that reads an image of a document in the apparatus main body, and the image read by the image reading apparatus is copied. In this case, the image reading apparatus includes a sheet conveying device that conveys a document (Patent Document 1). In the conventional sheet conveying apparatus, one of the pair of rollers can be detached by opening a cover member that holds a roller separate from the exterior cover, and the rollers can be replaced. Yes.

JP 2009-1113940 A

  However, when a roller as a rotating body is mounted, the roller may not be mounted properly. In this case, there is a problem that the roller cannot be rotated normally and the sheet cannot be conveyed.

  For example, when mounting a roller, it can be considered that the roller is moved in a predetermined direction and mounted on a support means for supporting the roller. In this case, the roller may not be securely attached to the support means.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet conveying apparatus capable of preventing a mounting defect of a rotating body, an image reading apparatus including the sheet conveying apparatus, and an image forming apparatus including the image reading apparatus.

  The sheet conveying apparatus according to the present invention includes a first rotating body, a second rotating body capable of holding and conveying a sheet between the first rotating body, and the first rotating body fitted in a predetermined direction. The first rotating body can be mounted at a predetermined position that supports the first rotating body and moves in the predetermined direction, so that the first rotating body mounted at the predetermined position is moved to the second position. A rotating body supporting means that can move to a conveying position where the sheet can be conveyed between the rotating body and the rotating body supporting means when the first rotating body is attached to the rotating body supporting means. Restriction means for restricting movement of the rotating body support means in the predetermined direction so that the first rotating body is fitted into the predetermined position before reaching the transport position. It is said.

  An image reading apparatus according to the present invention includes the above-described sheet conveying device and an image reading unit that reads a document conveyed by the sheet conveying device.

  An image forming apparatus according to the present invention includes the above-described image reading apparatus and an image forming unit that forms an image on a sheet based on image information of the image reading apparatus.

  The sheet conveying apparatus of the present invention can prevent the mounting failure of the rotating body.

  The image reading apparatus of the present invention can prevent the rotating body from being mounted incorrectly.

  The image forming apparatus of the present invention can prevent the mounting failure of the rotating body.

2 is a schematic cross-sectional view along the sheet conveying direction of the image forming apparatus according to the embodiment of the present disclosure. FIG. 3 is an enlarged view of a main part of an automatic document feeder, and a cross-sectional view taken along a document conveyance direction. FIG. 3 is a view showing a state in which an open / close cover of an automatic document feeder is opened from the closed state of FIG. 2. FIG. 4 is a perspective view of a separation unit of an automatic document feeder. FIG. 6 is a view when a document guide path is opened by an opening / closing cover. FIG. 2A is a perspective view of a retard roller unit having a retard roller and its periphery. (B) is RR arrow sectional drawing of (A). FIG. 6 is a perspective view of a retard roller unit having a retard roller and its periphery when a document guide path is opened by an opening / closing cover. It is a perspective view of a retard roller unit. FIG. 7 is a view of a retard roller holder when the retard roller unit in FIGS. 5 and 6 is removed, and the surroundings thereof. (A) is a perspective view when a retard roller holder is in an exchange position. (B) is a perspective view of the support groove of a retard roller holder. It is a figure of a conveyance guide when the retard roller holder in FIG. 8 is removed. (A) is a perspective view. (B) is a perspective view of a blocking rib. It is a figure which shows the position of the handle of a retard roller. (A) is a figure when a handle exists in a conveyance position. (B) is a view when the handle is in the exchange position. It is a figure for demonstrating engagement operation | movement with the protrusion of a retard roller holder, and a prevention rib when an opening / closing cover is closed. It is a figure when a handle is in an exchange position. It is a figure when the handle seen from the opposite direction of FIG. 12 exists in an exchange position.

  Hereinafter, an image reading apparatus according to an embodiment of the present invention and an image forming apparatus including the image reading apparatus in an apparatus body will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of the image forming apparatus 100 according to the embodiment of the present invention along the sheet conveyance direction. The image forming apparatus 100 includes an apparatus main body 400 of the image forming apparatus 100 and an image reading apparatus 300 provided on the upper part of the apparatus main body 400.

  Pickup rollers 420 and 421 in the apparatus main body 400 send out the sheets P stored in the cassettes 404 and 405 from the cassettes 404 and 405. The conveyance roller pair 422 feeds the sheet fed from the cassette between the photosensitive drum 402 and the transfer unit 406.

  On the other hand, the laser scanner 401 irradiates the photosensitive drum 402 whose surface is charged by the charger 423 with a laser, and forms a latent image on the photosensitive drum 402 based on image information obtained by reading an original with the image reading device 300. To do. The latent image is developed with toner by the toner developing device 403 to become a toner image. The transfer unit 406 transfers the toner image on the photoconductive drum 402 to a sheet fed between the photoconductive drum 402 and the transfer unit 406, and sends the sheet to the fixing unit 407 with the photoconductive drum 402. The fixing device 407 fixes the toner image on the sheet by heating the sheet. Finally, the discharge roller pair 408 discharges the sheet to the tray 424.

  When forming images on both sides of the sheet, the sheet sent from the fixing device 407 is sent to the reverse path 412 by the guidance of the switching members 409, 417, and 413 and the conveyance of the conveyance roller pair 411. Thereafter, the sheet is fed from the reverse path 412 to the return path 410 by the reverse rotation of the conveying roller pair 411 and the guidance of the switching member 413. During this time, the sheet is conveyed in a switchback and turned upside down. The sheet is guided through a return path 410 and is sent again between the photosensitive drum 402 and the transfer unit 406 to form a toner image on the other surface. The sheet is fixed with the toner image in the fixing device 407 and is finally discharged to the tray 424.

  The charger 423, the photosensitive drum 402, the toner developing unit 403, the transfer unit 406, and the like constitute an image forming unit 430.

  The image reading apparatus 300 includes an image reading unit 1 that reads an image of a document, and an automatic document transport unit 2 that is provided above the image reading unit 1 and serves as a sheet transport device that feeds the document to the image reading unit 1. Yes. The automatic document feeder 2 is provided in the image reading unit 1 so as to be freely opened and closed.

  In FIG. 1, the image reading unit 1 includes a fixed reading glass 301, a flow reading glass 101, a scooping member 322, and the like at a portion facing the automatic document conveying unit 2. The image reading unit 1 includes a scanning unit 302, a signal processing unit 503, a motor 308 and a belt 312 that move the scanning unit 302 in the sub-scanning directions H and E, and a control that controls the image reading device 300. Part 510 and the like.

  FIG. 2 is an enlarged view of a main part of the automatic document feeder 2, and is a cross-sectional view taken along the document conveyance direction. FIG. 3 is a view showing a state where the opening / closing cover 22 of the automatic document feeder 2 is opened from the closed state of FIG. FIG. 4 is a perspective view of the separation unit 7 of the automatic document feeder 2.

  First, the flow reading operation by the image reading apparatus 300 will be described.

  1, 2, and 3, the pickup roller 4 of the automatic document conveyance unit 2 includes a separation conveyance roller 5 and a retard roller that are in contact with each other and separate and convey the document D placed on the document tray 3 by the user. 6 is fed into the separation part 7 having 6. The separation unit 7 conveys the document to the registration roller pair 8. However, there are cases where a plurality of originals overlapped from the pickup roller 4 are conveyed to the separation unit 7. In this case, the separation unit 7 prevents the overlapped originals from being conveyed by the retard roller 6, and conveys only one uppermost original by the separation conveyance roller 5.

  The registration roller pair 8 receives the leading edge of the document sent from the separation unit 7, corrects the skew of the document, and conveys it between the flow reading glass 101 and the white roller 10 according to the reading timing. The reading timing is determined by detecting the leading edge of the document sent from the separation unit 7 by the registration sensor 9. When the reading timing is determined, the image of the document is read in advance by the scanning unit 302 waiting under the flow reading glass 101. Then, the read roller pair 11, 12 conveys the original and passes it over the flow reading glass 101, and finally, the original discharge roller pair 13 discharges the original to the discharge original tray 14. A document guide path 31 is formed from the pickup roller 4 to the document discharge roller pair 13, and the document is conveyed by guidance of the document guide path 31.

  When images are formed on both sides of the document, the document discharge roller pair 13 does not discharge the document to the discharge document tray 14 and transports it to the trailing edge of the document. The document is conveyed to the switchback path 32 by the guidance of the member 33. As a result, the document is turned upside down (inverted) while being transported by the switchback, transported through the document guide path 31, and transported to the document discharge roller pair 13. During this time, the scanning unit 302 reads an image on the other side of the document.

  Since the document is turned upside down by the previous switchback conveyance, if the document is discharged as it is to the discharged document tray 14, the page order of the document will be out of order. For this reason, the document may be discharged back to the discharged document tray 14 after being conveyed switchback again. At this time, the scanning unit 302 does not read the original image.

  As described above, a method of reading an image by passing a document over the stopped scanning unit 302 is referred to as “streaming reading”.

  Next, a fixed reading operation by the image reading apparatus 300 will be described.

  The user lifts the front side of the automatic document feeder 2, opens the upper surface of the fixed reading glass 301, places a document on the upper surface, and returns the automatic document feeder 2 to its original position. As a result, the automatic document feeder 2 presses the document against the fixed reading glass 301 so that the document does not float from the fixed reading glass 301. Thereafter, the scanning unit 302 reads the image of the document while moving in the sub-scanning direction H. After scanning the document image, the scanning unit 302 moves in the sub-scanning direction E and returns to a standby position (not shown).

  As described above, the method of fixing the document and moving the scanning unit 302 and reading the document is referred to as “fixed reading”.

  The image reading apparatus 300 converts image information read by flow reading or fixed reading of an original into optical information by a signal processing unit 503, and transmits it to the laser scanner 401. The apparatus main body 400 of the image forming apparatus 100 copies the image of the document on the sheet based on the image information received by the laser scanner 401 as described above.

  The image forming apparatus 100 can also receive image information from other image forming apparatuses 100, external devices such as a facsimile machine and a personal computer by a laser scanner 401 and form an image on a sheet.

  Incidentally, the automatic document feeder 2 may be subjected to internal maintenance. Also, the document guide path 31 may be jammed or the retard roller 6 may be replaced. Therefore, as shown in FIG. 3, the opening / closing cover 22 is opened in the upstream portion 31A of the document guide path 31 so that maintenance, removal of the jammed document, replacement of the retard roller 6 and the like can be performed. It has been opened by. The opening / closing cover 22 opens and closes the upstream portion 31 </ b> A of the document guide path 31 by a rotation support shaft 23 provided in the apparatus main body 2 </ b> A of the automatic document feeder 2. An upstream portion 31A of the document guide path 31 as a transport path is formed by a lower guide portion 31Aa and an upper guide portion 31Ab that can approach and separate from each other.

  As shown in FIG. 3, the opening / closing cover 22 is formed with an upper guide portion 31Ab. The open / close cover 22 is provided with a pickup roller 4, a separation / conveying roller 5, one roller of the registration roller pair 8, and the like protruding from the guide surface of the upper guide portion 31 Ab. As shown in FIG. 3, when the document guide path 31 is opened by the opening / closing cover 22, the document jammed in the document guide path 31 can be removed.

  Next, a structure in which maintenance inside the automatic document feeder 2 and replacement of the retard roller 6 can be performed will be described. FIG. 4 is a perspective view of the separation unit 7. The separation unit 7 in the present embodiment includes a separation conveyance roller 5 as a second rotating body that separates and conveys the document D placed on the document tray 3 and a retard roller 6 as the first rotation body. Have. The pickup roller 4 and the retard roller 6 are rotatable, can hold and convey a document, and can separately convey a document.

  5 and 6 are perspective views of the retard roller unit 15 having the retard roller 6 and its periphery when the document guide path 31 is opened by the opening / closing cover 22. FIG. 7 is a perspective view of the retard roller unit 15. FIG. 8 is a perspective view of the retard roller holder 19 and its periphery when the retard roller unit 15 in FIGS. 5 and 6 is removed. FIG. 9 is a perspective view of the conveyance guide 21 when the retard roller holder 19 in FIG. 8 is removed.

  First, a description will be given of a portion 2B (FIG. 2) for receiving a document provided with a pickup roller 4, a retard roller 6 and the like in the automatic document feeder 2. The document receiving portion 2B of the automatic document feeder 2 includes a pickup roller 4, an entrance portion of the document guide path 31, a separation unit 7, a retard roller unit 15, a retard roller holder 19, a compression coil spring 20, A conveyance guide 21 and the like are provided.

  In FIG. 7, the retard roller 6 is unitized as a retard roller unit 15 together with the torque limiter 17 and is easily replaced. The retard roller unit 15 includes a retard roller 6, a retard roller shaft 16 that rotatably supports the retard roller 6, a torque limiter 17 provided on the retard roller shaft 16, and a handle fixed to one end of the retard roller shaft 16. 18. The torque limiter 17 is formed in a double cylindrical shape (not shown), the outer cylinder is connected to the retard roller 6, the inner cylinder is fixed to the retard roller shaft 16, and a predetermined rotational load is applied to the retard roller 6. Torque is applied. The handle 18 is a portion that is gripped by the user when the retard roller unit 15 is handled, such as during replacement, and is provided to facilitate the handling of the retard roller unit 15.

  2 and 3, the conveyance guide 21 is provided so as to be rotatable with respect to the rotation shaft 13 a of one roller of the document discharge roller pair 13. 5, 8, and 9, the conveyance guide 21 is formed with a pair of bearing recesses 213 that rotatably support the pair of support shafts 192 of the retard roller holder 19.

  5, 6, and 8, the retard roller holder 19 includes a pair of support shafts 192 that are rotatably supported by a pair of bearing recesses 213 of the transport guide 21. It can be rotated in the directions of arrows C and V intersecting the upper surface 21a. A retard roller unit 15 is detachably attached to the retard roller holder 19 (detachable). For this reason, as shown in FIG. 8, the retard roller holder 19 is formed with a support hole 194 for supporting the retard roller shaft 16 and a U-shaped support groove 195.

  As shown in FIGS. 2 and 3, a compression coil spring 20 is provided between the conveyance guide 21 and the retard roller holder 19. As shown in FIG. 9, a seat 20 a into which the compression coil spring 20 is fitted projects from the conveyance guide 21. The compression coil spring 20 can press the retard roller holder 19 in the direction of arrow F that separates the retard roller holder 19 from the transport guide 21, and presses the retard roller 6 against the separation transport roller 5. A leaf spring or the like may be used instead of the compression coil spring 20. The retard roller holder 19 is pushed up by the compression coil spring 20 when the open / close cover 22 is opened as shown in FIG. 3, and as shown in FIG. It is received by the lower surface 211b of 211a. The amount by which the compression coil spring 20 pushes up the retard roller holder 19 is regulated by the hook member 211.

  Next, a procedure for mounting the retard roller unit 15 to the retard roller holder 19 when the retard roller 6 is replaced will be described.

  When the retard roller unit 15 is mounted, one end portion 16a (FIG. 7) of the retard roller shaft 16 of the retard roller unit 15 is inserted into the support hole 194 of the retard roller holder 19 shown in FIG. 8, and the retard roller shaft is inserted into the support groove 195. 16 middle part 16b is pushed in. As shown in FIG. 7, a rib 181 that can be elastically deformed is formed on the handle 18 of the retard roller unit 15. The rib 181 is formed to extend in parallel with the retard roller shaft 16 from the end portion of the retard roller shaft 16 toward the torque limiter 17 side. The rib 181 is formed with an inclined surface 181b, a tip surface 181c, and a side end surface 181d. The inclined surface 181b is formed to be inclined in the rotational direction of the retard roller 6 from the side end surface 181d. On the other hand, as shown in FIG. 8A, the retard roller holder 19 is provided with a tongue piece 193 extending toward the support groove 195, with which the rib 181 abuts. A slope 193 a is formed above the tip of the tongue piece 193. Further, on the side surface of the retard roller holder 19, an inclined surface 19a inclined outward and a side wall 19b following the inclined surface 19a are formed.

  When the retard roller unit 15 is mounted, the retard roller unit 15 is pressed toward the retard roller holder 19 (predetermined direction). Then, first, the front end surface 181 c of the rib 181 contacts the inclined surface 19 a of the retard roller holder 19, and the inclined surface 181 b of the rib 181 contacts the inclined surface 193 a of the retard roller holder 19. Then, as shown in FIG. 5A, the rib 181 is elastically deformed in the arrow M direction while being pushed in the arrow K direction. Thereafter, the rib 181 is still pressed, passes through the slopes 19a and 193a, is located on the lower surface 193b of the tongue piece 193, returns to its original shape by elasticity, and enters the lower surface 193b of the tongue piece 193, Lifting up is prevented by the tongue piece 193.

  The retard roller unit 15 is attached to the retard roller holder 19 as described above. However, when the user attaches the retard roller unit 15 to the retard roller holder 19, the retard roller unit 15 may not be securely attached to the retard roller holder 19 in some cases.

  First, the operation of the protrusion 191 and the blocking rib 212 when the retard roller unit 15 is mounted on the retard roller holder 19 and the open / close cover 22 is closed will be described.

  The opening / closing cover 22 as the opening / closing means is closed, and the retard roller unit 15 is pressed toward the retard roller holder 19. A protrusion 191 that protrudes laterally on the side of the retard roller holder 19 is below the lower slope 212c of the blocking rib 212 that functions as an elastically deformable restricting means that protrudes upward on the conveyance guide 21. Dive in.

  As shown in FIG. 8A, the protrusion 191 is provided in the vicinity of the support groove 195 in a direction along the groove of the support groove 195. And as shown to FIG. 8 (B), the protrusion 191 is formed with the lower side slope 191a and the upper side slope 191b. The lower slope 191a is steeper than the upper slope 191b. As shown in FIG. 9, a protrusion 212 a is also formed on the blocking rib 212. The protrusion 212 a is formed at a position facing the protrusion 191 of the retard roller holder 19. The protrusion 212a is formed with an upper slope 212b and a lower slope 212c. The upper slope 212b is steeper than the lower slope 212c.

  Next, the state of the protrusion 191 of the retard roller holder 19 and the blocking rib 212 when the opening / closing cover 22 is closed will be described in detail with reference to FIG. FIG. 11 is a schematic cross-sectional view of the vicinity of the protrusion 191 when the opening / closing cover 22 is closed in the order of (A) to (D).

  While the opening / closing cover 22 is closed, as shown in FIG. 11A, first, the lower slope 191a of the protrusion 191 of the retard roller holder 19 contacts the upper slope 212b of the blocking rib 212. Thereafter, as shown in FIGS. 11B and 11C, the protrusion 191 of the retard roller holder 19 is pushed down while coming into contact with the protrusion 212 a of the blocking rib 212 as the opening / closing cover 22 is closed. When the open / close cover 22 is completely closed, the protrusion 191 enters below the lower slope 212c as shown in (D). At this time, the retard roller 6 is in contact with the separation / conveyance roller 5 and is in a state where the document D fed by the pickup roller 4 can be separated and conveyed (moves to the conveyance position).

  Next, the operation when the open / close cover 22 is closed when the retard roller unit 15 is not securely attached to the retard roller holder 19 will be described.

  Even when the opening / closing cover 22 is closed in a state where the retard roller unit 15 is not securely attached, the opening / closing cover 22 is closed, whereby the retard roller unit 15 is pressed against the retard roller holder 19 side.

  When the retard roller unit 15 is pressed toward the retard roller holder 19, the lower slope 191 a of the protrusion 191 of the retard roller holder 19 is the upper slope of the blocking rib 212 of the conveyance guide 21 as shown in FIG. 212b abuts. Here, since the slope of the lower slope 191a and the upper slope 212b is steep, the protrusion 191 is difficult to enter below the protrusion 212a. A compression coil spring 20 is provided between the conveyance guide 21 and the retard roller holder 19. Therefore, if the retard roller unit 15 is not strongly pressed against the engagement load between the lower slope 191a and the upper slope 212b and the elasticity of the compression coil spring 20, the retard roller holder 19 has the protrusion 191. It cannot enter below the lower slope 212c.

  Here, when the opening / closing cover 22 is closed, the retard roller 6 of the retard roller unit 15 is pressed by the separation conveying roller 5 provided on the opening / closing cover 22 side.

  As the protrusion 191 of the retard roller holder 19 enters below the lower inclined surface 212c of the blocking rib 212, the retard roller unit 15 is strongly pressed in a predetermined direction as the opening / closing cover 22 is closed. Then, before the protrusion 191 of the retard roller holder 19 enters the lower side of the protrusion 212 a of the blocking rib 212 (before reaching the conveyance position), the rib 181 of the retard roller unit 15 is attached to the tongue of the retard roller holder 19. It enters the lower surface 193b of the piece 193 (it is fitted in a predetermined position). Therefore, even when the retard roller unit 15 is not securely attached to the retard roller holder 19, the retard roller unit 15 can be reliably attached to the retard roller holder 19 by closing the opening / closing cover 22. The blocking rib 212 is more difficult to bend than the rib 181.

  At this time, the separation conveying roller 5 presses the retard roller 6, so that the rib 181 passes through the inclined surfaces 19 a and 193 a and enters the lower surface 193 b of the tongue piece 193, and the retard roller unit 193 lifts the retard roller unit 15. Is prevented.

  When the opening / closing cover 22 is rotated in the direction of arrow B and the document guide path 31 is closed (closing the opening / closing cover 22), the separation conveying roller 5 presses the retard roller 6. Then, the separation conveying roller 5 compresses the compression coil spring 20 via the retard roller 6, the retard roller unit 15, and the retard roller holder 19. As a result, the retard roller 6 is pressed against the separation / conveying roller 5 by the reaction force of the compression coil spring 20, and separates the multi-fed original when the original is conveyed in an overlapping manner, and the separation / conveying roller 5 separates the original. One sheet can be conveyed.

  Further, when performing maintenance in the automatic document feeder 2, as shown in FIG. 3, the opening / closing cover 22 is opened in the direction of arrow A (opening operation), and the conveyance guide 21 is rotated on the rotation shaft 13a of the document discharge roller pair 13. May open in the direction of arrow C. At this time, the retard roller unit 15 mounted on the retard roller holder 19 also rotates in the direction of arrow C together with the transport guide 21. However, in the retard roller unit 15, the rib 181 enters the lower surface 193 b of the tongue piece 193. For this reason, the retard roller unit 15 is prevented from falling off by the rib 181 of the handle 18, and rotates in the direction of arrow C integrally with the conveyance guide 21.

  Therefore, the rib 181 and the tongue piece 193 prevent the retard roller 6 from dropping from the retard roller holder 19 as the rotating body support means.

  Further, when the retard roller 6 is replaced, the automatic document feeder 2 makes it easy for the user to grip the handle 18 of the retard roller unit 15 so that the retard roller 6 can be replaced easily.

  Next, a structure that can easily replace the retard roller 6 will be described. In FIG. 2, the open / close cover 22 is locked to the apparatus main body 2A by a lock mechanism (not shown) when the document guide path 31 is closed. The separation conveying roller 5 provided on the opening / closing cover 22 presses the retard roller 6. On the other hand, the retard roller 6 receives the pressing force of the compression coil spring 20 via the retard roller unit 15 and the retard roller holder 19. For this reason, the separation conveyance roller 5 pushes the retard roller 6, the retard roller unit 15, and the retard roller holder 19 against the compression coil spring 20 into the conveyance guide 21 in the direction of arrow V in FIG. 3. Become. As a result, as shown in FIG. 10A, the upper surface 19c of the retard roller holder 19 and the upper surface 21a of the conveyance guide 21 are flush with each other to form a part of the upstream portion 31A of the document guide path 31. Will be. At this time, the retard roller 6 protrudes from the upper surface 19 c of the retard roller holder 19 in order to convey the document with the separation and conveyance roller 5. However, the handle 18 of the retard roller unit 15 does not protrude from the upper surface 19 c of the retard roller holder 19. When the retard roller holder 19 is pushed into the transport guide 21, the upper surface 19 c of the retard roller holder 19 and the upper surface 21 a of the transport guide 21 form a part of the lower guide portion 31 Aa of the document guide path 31. Forming.

  Thus, the handle 18 does not protrude from the upper surface 19 c of the upper surface 21 a of the conveyance guide 21, and the retard roller 6 and the retard roller unit 15 when the retard roller 6 protrudes from the upper surface 19 c of the upper surface 21 a of the conveyance guide 21. The position is defined as a transfer position (transfer position).

  When the opening / closing cover 22 is rotated in the direction of arrow A in FIG. 3 to open the document guide path 31, the separation conveying roller 5 provided on the opening / closing cover 22 is separated from the retard roller 6. Then, the retard roller unit 15 is pressed against the compression coil spring 20 integrally with the retard roller holder 19 in the direction of arrow C in FIG. 3, and as shown in FIGS. 10B, 12 and 13, the retard roller holder Protrudes upward from the upper surface 21a of the conveyance guide 21. Accordingly, the retard roller unit also protrudes above the upper surface 21 a of the conveyance guide 21. At this time, the positions of the retard roller 6, the retard roller unit 15, and the retard roller holder 19 are defined as an exchange position (exchange position).

  As shown in FIGS. 5B and 8, the retard roller holder 19 when it is in the exchange position is pushed up in the direction of arrow F by the compression coil spring 20 to hook the catching member 211 of the conveyance guide 21. It is received by the lower surface 211b of 211a. Note that the position of the retard roller holder 19 when the retard roller holder 19 is at the transport position is a position indicated by a broken line in FIG. Therefore, the retard roller 6, the retard roller unit 15, and the retard roller holder 19 are moved up and down by a distance L between the transport position and the exchange position.

  When the retard roller 6 is located at the replacement position, the handle 18 and the rib 181 of the retard roller holder 19 protrude above the upper surface 21a of the conveyance guide 21, so that the user can easily grasp the handle 18. As a result, the user can easily remove the retard roller unit 15 from the retard roller holder 19 and easily replace the retard roller 6.

  Note that the retard roller unit 15 and the retard roller holder 19 move up and down integrally between the transport position and the exchange position, so that there is no change in their relative positions. For this reason, even if the retard roller holder 19 is in the replacement position, the retard roller unit 15 does not protrude above the retard roller holder 19 and protrudes above the upper surface 21 a of the conveyance guide 21.

  As described above, the automatic document feeder 2 is configured such that the rib 181 protrudes from the upper surface 21 a of the conveyance guide 21 by the compression coil spring 20, so that the user can easily grasp the rib 181 and the retard roller 6. Exchange can be performed easily. Further, the automatic document feeder 2 does not need to use a conventionally used cover, and the retard roller 6 can be easily replaced and the structure can be simplified.

  Further, since the image reading apparatus 300 includes the automatic document feeder 2 having a simple structure, the configuration can be simplified.

  Furthermore, since the image forming apparatus 100 includes the image reading apparatus 300 having a simple structure, the configuration can be simplified.

1: Image reading unit, 2: Automatic document conveyance unit (sheet conveyance device), 2A: Device body of automatic document conveyance unit, 2B: Document receiving portion, 4: Pickup roller, 5: Separation conveyance roller (second rotation) Body), 6: retard roller (first rotating body), 7: separation unit, 15: retard roller unit, 16: retard roller shaft, 18: handle, 181: rib, 19: retard roller holder (rotating body support means) ), 19c: upper surface of the retard roller holder, 191: protrusion, 193: tongue, 20: compression coil spring, 21: transport guide, 21a: upper surface of transport guide, 212: blocking rib (regulating means), 22: opening and closing Cover (opening / closing means), 31: document guide path (conveyance path), 31A: upstream part, 31Aa: lower guide part, 31Ab: upper guide part, 100: image forming apparatus, 300: image Reader, P: sheet, D: document.

Claims (13)

A first rotating body;
A second rotating body capable of sandwiching and conveying a sheet with the first rotating body;
By fitting the first rotating body in a predetermined direction, the first rotating body can be mounted at a predetermined position that supports the first rotating body, and when the first rotating body moves in the predetermined direction, it is mounted at the predetermined position. Rotator support means capable of moving to a transport position where the first rotator can transport a sheet to and from the second rotator;
When the first rotating body is mounted on the rotating body support means, the first rotating body is fitted into the predetermined position before the rotating body support means reaches the transport position. Regulation means for regulating movement of the rotating body support means in the predetermined direction,
A sheet conveying apparatus. Biasing means for biasing the rotating body support means to move in a direction against the predetermined direction;
The restricting means restricts the movement of the rotating body supporting means in the predetermined direction against the urging of the urging means;
The sheet conveying apparatus according to claim 1. The rotating body support means moves to an exchange position where the amount of protrusion in the take-out direction of the first rotating body is larger than the transport position when the first rotating body is attached or detached.
The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. The rotator support means moves to an exchange position where the amount of protrusion in the take-out direction of the first rotator is larger than the transport position when the first rotator is attached and detached.
The urging means urges the rotating body support means in a direction to move from the transport position to the exchange position.
The sheet conveying apparatus according to claim 2. An opening / closing means for enabling the second rotating body to approach and separate from the first rotating body;
The restricting means restricts the movement of the rotating body support means in the predetermined direction when the opening / closing means is closed;
The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. The second rotating body is capable of pressing the first rotating body toward the rotating body support means with the closing operation of the opening / closing means, and the first rotating body with the opening operation of the opening / closing means. Spaced apart from the rotating body,
The sheet conveying apparatus according to claim 5. The first rotating body is attached to the rotating body support means in accordance with the closing operation of the opening / closing means.
The sheet conveying apparatus according to claim 5 or 6. The opening / closing means forms a transport path along which the sheet is transported with a closing operation.
The sheet conveying apparatus according to claim 5, wherein the sheet conveying apparatus is a sheet conveying apparatus. Gripping means that is gripped when taking out the first rotating body from the rotating body support means,
The rotating body support means detachably engages and holds the first rotating body,
The gripping means releases the engagement holding in accordance with a gripping operation, and enables the first rotating body to be detached from the rotating body support means.
The sheet conveying apparatus according to claim 5, wherein the sheet conveying apparatus is a sheet conveying apparatus. The gripping means prevents the first rotating body from falling off the rotating body support means when the rotating body support means moves;
The sheet conveying apparatus according to claim 9. It further comprises a stacking means capable of stacking a plurality of sheets,
The first rotating body is a separating member capable of separating and conveying the sheets stacked on the stacking unit one by one by rotating together with the second rotating body.
The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. A sheet conveying device according to any one of claims 1 to 11,
An image reading unit for reading a document conveyed by the sheet conveying device,
An image reading apparatus. An image reading apparatus according to claim 12,
An image forming unit that forms an image on a sheet according to image information of the image reading device,
An image forming apparatus.

Images