JP2008162771A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means preventing the closure of an upstream outer guide when an ejecting part outer guide is not closed, in an image forming apparatus in which the ejecting part outer guide forming the outer surface of an ejecting part of a carrying passage and the upstream outer guide forming the outer surface of the upstream of the ejecting part can be opened and closed outside the apparatus. <P>SOLUTION: In the image forming apparatus 1, a closure prevention lever 27 preventing the closure of the upstream outer guide 19 is rotatably journaled to an ejecting part inner guide 24 forming the inner surface of the ejecting part of a main carrying passage Rs. A lever stopper 28 restricting the rotation of the lever 27 is disposed so that it is set at a lock position L prohibiting the rotation of the closure prevention lever 27 when the ejecting part outer guide 23 is opened, and set at an unlock position K allowing the rotation of the closure prevention lever 27 when the ejecting part outer guide 23 is closed. On the other hand, the upstream outer guide 19 is provided with a lever pressing projection 50 pressing and rotating the closure prevention lever 27 accompanied by closing operation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, a discharge portion outer guide that forms the outer surface of the discharge portion of the conveyance path and an upstream portion outer guide that forms an outer surface on the upstream side of the discharge portion are provided to be openable and closable to the outside of the apparatus, respectively. The present invention relates to an image forming apparatus.

  Printers, copiers, facsimiles, and the like are equipped with image forming apparatuses that form images such as characters and graphics on recording paper based on image data read from a document or image data received by facsimile. FIG. 16 is a schematic longitudinal sectional view showing a configuration of an image forming apparatus 70 according to a conventional example (see Patent Document 1). In the image forming apparatus 70, a light image based on the image information is exposed from the exposure device 73 on the surface of the photosensitive drum 72 charged by the charger 71 to form a latent image, and toner is supplied from the developing device 74. As a result, the latent image is converted into a toner image. On the other hand, with the start of the image forming operation, the recording paper P set in the paper feed cassette 75 is sequentially fed into the conveyance path 76 and pressed against the photosensitive drum 72 so that the toner image is transferred to the recording paper P. Is done. Thereafter, the recording paper P is further conveyed downstream along the conveying path 76, and heat and pressure are applied by the fixing device 77, whereby the toner image is fixed on the recording paper P. The recording paper P is discharged from a discharge port 78 located at the downstream end of the conveyance path 76 and is stacked on a paper discharge tray 79.

  The image forming apparatus 70 is configured to be able to remove the jammed recording paper P by exposing the inside of the conveying path 76 when the recording paper P is jammed inside the conveying path 76. In other words, the transport path 76 is formed by a pair of guides facing each other at a predetermined interval. Of the pair of guides, an outer guide that forms the outer surface of the transport path 76 can be opened and closed in the apparatus outer direction. Is provided. Specifically, as shown in FIG. 16, a discharge portion outer guide 80 that forms the outer surface of the transport path 76 in the vicinity of the discharge port 78 is provided so as to be openable and closable outside the apparatus with a hinge 81 as a fulcrum. An upstream side outer guide 82 that forms the outer surface of the transport path on the upstream side is also provided so as to be openable and closable outside the apparatus with the hinge 83 as a fulcrum. Accordingly, it is possible to expose the inside of the conveyance path 76 by opening the discharge portion outer guide 80 and the upstream portion outer guide 82 according to the position where the recording paper P is jammed.

  In this image forming apparatus 70, after removing the jammed recording paper P from the conveyance path 76, when the image forming operation is started with the discharge portion outer guide 80 and the upstream portion outer guide 82 being opened, Recording paper jam occurs at the location. As means for avoiding such a situation, an open / close detection sensor (not shown) for detecting the opening / closing of the discharge portion outer guide 80 and the upstream portion outer guide 82 is provided. A method of notifying the user to close the discharge portion outer guide 80 and the upstream portion outer guide 82 by displaying an error in an operation portion (not shown) without starting the image forming operation until the closing of the upstream portion outer guide 82 is detected. There is. However, if the opening / closing detection sensors are separately installed in the discharge portion outer guide 80 and the upstream portion outer guide 82, the cost increases and it is not preferable from the viewpoint of reducing the size and weight of the apparatus.

  Therefore, in the image forming apparatus 70, when both the discharge portion outer side guide 80 and the upstream portion outer side guide 82 are opened, the order to be closed is displayed on the operation portion to allow the user to recognize it, but is finally closed. An open / close detection sensor is provided for detecting the open / close of only the outer guide. According to such a configuration, when the closing of the outer guide to be closed last is detected, it is determined that both the discharge portion outer guide 80 and the upstream portion outer guide 82 are closed, and the image forming operation is started. Therefore, the number of open / close detection sensors can be minimized.

JP 2006-301414 A

  However, in the conventional image forming apparatus 70, the order of closing the discharge portion outer guide 80 and the upstream portion outer guide 82 is displayed on the operation portion, but even if it is not in that order, there is no restriction in terms of the structure. It is possible to close the guide 80 and the upstream outer guide 82. Therefore, for example, even if a user who has overlooked the display section of the operation section closes the discharge section outer guide 80 and the upstream section outer guide 82 in an order different from the displayed order, the one that should be closed last is closed. Then, even if the other remains open, it is determined that both are closed. As a result, there is a problem that a recording paper jam occurs at a position where the image forming operation is started and the outer guide is opened.

  The present invention has been made in view of such problems, and includes a discharge unit outer guide that forms the outer surface of the discharge unit of the conveyance path, and an upstream unit outer guide that forms an outer surface upstream of the discharge unit. However, in the image forming apparatus provided so as to be openable and closable to the outside of the apparatus, means for making the upstream side outer guide impossible to close unless the discharger outer side guide is closed is provided.

  The image forming apparatus according to claim 1, for achieving the above object, includes a discharge unit outer guide that forms an outer surface of a discharge unit in a recording sheet conveyance path from a paper feed cassette to a discharge tray, and the recording sheet conveyance path. In the image forming apparatus in which an upstream outer guide that forms an outer surface on the upstream side of the discharge portion in the image forming apparatus is provided so as to be openable and closable to the outside of the device, The closing prevention lever for suppressing the closing of the upstream outer guide is pivotally supported at a position proximal to the center of gravity so as to be rotatable, and the lever for restricting the rotation of the closing prevention lever. A lock that allows the stopper to rotate when the discharger outer side guide is closed, and a stopper that allows the rotation of the closing prevention lever when the discharger outer side guide is closed. While provided so as to be positioned respectively in removal position, the upstream portion outside the guide, in which the with the closing operation by pressing the closure inhibiting lever lever pressing projection for rotating is provided.

  According to a second aspect of the present invention, the image forming apparatus further includes an opening / closing detection sensor that detects the closing prevention lever when the upstream outer guide is closed.

  4. The image forming apparatus according to claim 3, wherein the lever stopper is pivotally supported by the discharger inner guide at a position closer to the tip than the center of gravity, and the upstream outer guide is closed when the upstream outer guide is closed. When the upstream outer guide is released, it is released from the pressing force of the upstream outer guide and rotated by its own weight to move to the locked position. It is.

  According to the image forming apparatus of the present invention, in a state in which the discharge unit outer guide is closed, the lever stopper is positioned at the unlocking position, so that the upstream unit outer guide can be closed. In the opened state, the lever stopper is positioned at the lock position, so that the upstream portion outer guide cannot be closed. Thus, since the upstream portion outer guide cannot be closed unless the discharge portion outer guide is closed, the image forming operation is not started with only the discharge portion outer guide being opened. It is possible to prevent the recording paper from being jammed.

  Further, according to the image forming apparatus of the present invention, it is possible to detect the opening / closing of both the upstream outer guide and the discharge outer guide only by the opening / closing detection sensor that detects the opening / closing of the upstream outer guide. Compared with the case where the open / close detection sensor for detecting the open / close of the device is installed separately and independently, the cost can be reduced and the device can be reduced in size and weight.

  Further, according to the image forming apparatus of the present invention, the lever stopper moves from the unlocked position to the locked position by its own weight when released from the pressing force of the upstream outer guide, so that the lever stopper is driven. There is no need to provide a complicated mechanism, and the cost can be reduced and the apparatus can be reduced in size and weight.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. This image forming apparatus is a copy / facsimile multifunction peripheral having a document copying function, a facsimile communication function, an Internet facsimile communication function, and the like. FIG. 1 is a schematic longitudinal sectional view showing a configuration of an image forming apparatus 1 according to the present embodiment. The image forming apparatus 1 includes a main transport path Rs from the paper feed cassette 2 through the photosensitive drum 3 to the paper discharge tray 4, and an inversion that communicates the upstream branch position 5 and the downstream branch position 6 of the main transport path Rs. There are three conveyance paths, a conveyance path Rh, and a manual conveyance path Rt that allows the manual feed tray 7 and the upstream branch position 5 to communicate with each other.

  As shown in FIG. 1, the image forming apparatus 1 includes a paper feed cassette 2 for storing recording paper P, a photosensitive drum 3 disposed on the main transport path Rs and having a photosensitive layer formed on the surface thereof, A charging unit 8 that charges the surface of the photosensitive drum 3, an exposure unit 9 that irradiates light on the surface of the photosensitive drum 3, a developing unit 10 that supplies toner to the surface of the photosensitive drum 3, and the photosensitive drum 3. The transfer roller 11, the cleaning unit 12 for cleaning the surface of the photosensitive drum 3, the fixing unit 13 for heating and pressurizing the recording paper P transported through the main transport path Rs, and the most downstream portion of the main transport path Rs. A reversing / discharging unit 14 that feeds the recording paper P to the reversing conveyance path Rh or discharges it to the paper discharge tray 4, a pair of conveying rollers 15 that are appropriately arranged in the reversing conveyance path Rh, and conveys the recording paper P, and the recording paper P By hand A manual feed tray 7 for setting when is made comprises a.

  When single-sided printing is performed by the image forming apparatus 1 configured as described above, when the image forming operation is started, the surface of the photosensitive drum 3 is uniformly charged by the charging unit 8 and light is irradiated from the exposure unit 9. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 3, and a toner image is formed by supplying toner from the developing unit 10 to the electrostatic latent image. On the other hand, with the start of the image forming operation, the recording paper P stored in the paper feed cassette 2 is taken out by the pickup roller 16 and fed into the main transport path Rs. The recording paper P is conveyed downstream through the main conveyance path Rs, and is pressed against the photosensitive drum 3 by the transfer roller 11, whereby the toner image on the photosensitive drum 3 is transferred. Further, the recording paper P is transported downstream through the main transport path Rs, and the toner image is fixed on the recording paper P by being heated and pressurized by the fixing unit 13. Thereafter, the recording paper P is discharged to the paper discharge tray 4 by a pair of discharge rollers 17 provided in the reversing / discharge unit 14. On the other hand, after the toner image is transferred, the surface of the photosensitive drum 3 is charged again by the charging unit 8 after the toner or paper dust remaining on the surface is removed by the cleaning unit 12.

  On the other hand, when performing double-sided printing, firstly, single-sided printing is performed as described above, and the recording paper P for which single-sided printing has been completed is transported downstream of the main transport path Rs beyond the downstream branch position 6. . When this recording paper P reaches the discharge roller 17, the discharge roller 17 stops rotating with the recording paper P nipped, and the branching claw 18 provided at the downstream branch position 6 opens the reverse conveyance path Rh. After switching to the state to be performed, the discharge roller 17 starts reverse rotation, whereby the recording paper P is switched back and sent to the reverse conveyance path Rh. The recording paper P fed into the reverse conveyance path Rh is conveyed toward the upstream branch position 5 by the conveyance roller 15 with the printed first surface facing the inside of the apparatus. Then, the recording paper P passes through the upstream branch position 5 and is re-supplied to the main transport path Rs with the second surface facing the photosensitive drum 3. Thereafter, the recording paper P is printed on the second surface in the same manner as the first surface printing, and is discharged to the paper discharge tray 4 by the reversing / discharging unit 14.

  By the way, the image forming apparatus 1 is configured to remove the jammed recording paper P by exposing the inside when the recording paper jam occurs in each of the transport paths Rs, Rh, and Rt. Specifically, as shown in FIG. 1, in the upstream portion of the main transport path Rs, the upstream portion outer guide 19 that forms the outer surface thereof is a jam access cover that forms the outer surface of the downstream portion of the reverse transport path Rh. The jam access cover 20 is provided so as to be rotatable with respect to the apparatus main body 22 with a pivot pin 21 at the lower end thereof as a fulcrum. As a result, when a recording paper jam occurs in the upstream part of the main transport path Rs or the downstream part of the reverse transport path Rh, as shown in FIG. 2, the jam access cover 20 is rotated and opened to the outside of the apparatus. By doing so, it is possible to expose the inside of the main transport path Rs and the reverse transport path Rh.

  Further, the reversing / discharging unit 14 provided in the discharge portion which is the most downstream portion of the main transport path Rs has a discharge portion outer guide 23 which forms the outer surface of the downstream portion of the main transport path Rs as shown in FIG. And a discharge portion inner guide 24 that forms the inner surface of the downstream portion. The discharge portion inner guide 24 is fixed to the apparatus main body 22, while the discharge portion outer guide 23 is provided in the vicinity of the discharge roller 17. The pivot pin 25 is provided as a fulcrum so as to be rotatable with respect to the discharge portion inner guide 24. In addition, as shown in FIG. 1, when both the discharge portion outer guide 23 and the jam access cover 20 are closed, a pressing piece (not shown) protruding in the horizontal direction from the top portion of the jam access cover 20 is a discharge portion outer guide. It is configured to abut against the upper surface of the sheet 23 so as not to be opened, and the discharge section outer side guide 23 cannot be opened unless the jam access cover 20 is opened. Therefore, when a recording paper jam occurs in the downstream part of the main transport path Rs or the upstream part of the reverse transport path Rh, as shown in FIG. 3, the jam access cover 20 is first rotated to open to the outside of the apparatus. After that, the inside of the main transport path Rs and the reverse transport path Rh can be exposed by rotating the discharge section outer guide 23 to open to the outside of the apparatus.

  4 is an exploded perspective view showing the reversing / discharging unit 14 as seen from the back side of the apparatus, that is, from the back side of the paper in FIG. As described above, the reversal / discharge unit 14 includes the discharge portion inner guide 24 that forms the inner surface of the main transport path Rs and the discharge portion outer guide 23 that forms the outer surface, and a discharge port between the two. 26 is formed. Here, on the side surface 24 a of the discharge portion inner guide 24, a closing suppression lever 27 for suppressing the closing of the jam access cover 20 integrated with the upstream portion outer guide 19 and the operation of the closing suppression lever 27 are restricted. A lever stopper 28 is attached to each of them.

  As shown in FIG. 4, a lever pin 29 is provided on the side surface 24 a of the discharge portion inner guide 24 so as to serve as a rotation support shaft of the closing prevention lever 27. It is installed. In addition, a stopper pin 31 that serves as a pivot for the lever stopper 28 protrudes obliquely below the lever pin 29, and adjacent to the stopper pin 31, the lever stopper 28 rotates. A long hole 32 for regulating the moving range is formed in a substantially arc shape.

  5 and 6 are schematic perspective views showing the configuration of the lever stopper 28. FIG. 5 is a view seen from the front side, and FIG. 6 is a view seen from the back side. The lever stopper 28 is formed by screwing a weight screw 34 into a stopper main body 33 made of resin or the like. The stopper main body 33 is a flat plate member formed so as to be gradually narrowed from the proximal end side toward the distal end side, a base portion 36 having a pin insertion hole 35 formed in the center portion, and a surface of the base portion 36. An eccentric weight portion 37 projecting from the pin insertion hole 35 toward the proximal end, a lever contact portion 38 projecting from the pin insertion hole 35 toward the distal end side, and a base portion A flange portion 39 projecting so as to communicate with the pin insertion hole 35 on the back surface of 36, and a rotation range regulating pin 40 projecting on the rear surface side of the base portion 36 from the pin insertion hole 35. Is integrally molded.

  The eccentric weight portion 37 functions as a weight for shifting the position of the center of gravity of the lever stopper 28 from the position of the pin insertion hole 35 that is the center of rotation to the base end side. As shown in FIG. 5, the eccentric weight portion 37 is formed with a notch 41 on the side of the pin insertion hole 35 to avoid interference with the stopper pin 31. In addition, the weight screw 34 screwed into the stopper main body 33 is for shifting the center of gravity of the lever stopper 28 to the base end side more reliably in combination with the eccentric weight portion 37. As shown in FIG. 6, the weight screw 34 is screwed from the position on the back surface of the base portion 36 on the base end side with respect to the pin insertion hole 35, and reaches the eccentric weight portion 37 located on the back side. When the center of gravity of the lever stopper 28 can be sufficiently shifted to the proximal end side only by the eccentric weight portion 37, the weight screw 34 is not necessarily provided.

  The lever abutting portion 38 is for preventing the rotation of the lever abutting portion 38 by abutting against the closing prevention lever 27. As shown in FIG. 5, the lever abutting portion 38 has a substantially cylindrical shape, and a lock release position holding piece 42 protrudes obliquely upward from the peripheral edge portion thereof. The shape of the lever abutting portion 38 is not limited to a cylindrical shape, and can be appropriately changed in design. Further, the flange portion 39 is for positioning the lever stopper 28 with respect to the side surface 24 a of the discharge portion inner guide 24. As shown in FIG. 6, the flange portion 39 has a substantially cylindrical shape, and its inner diameter is slightly larger than the diameter of the pin insertion hole 35. The rotation range restriction pin 40 is for restricting the rotation range of the lever stopper 28 within a predetermined range. As shown in FIG. 6, the rotation range regulating pin 40 has a substantially cylindrical shape, and its length is obtained by adding the thickness dimension of the side surface 24 a of the discharge section inner guide 24 to the height dimension of the flange section 39. It is formed longer than the size.

  As shown in FIG. 4, the lever stopper 28 configured as described above allows the stopper pin 31 to be inserted into the pin insertion hole 35 from the back side, and the rotation range regulating pin 40 is inserted into the elongated hole. By being inserted through 32, it is attached to the side surface 24 a of the discharge portion inner guide 24. At this time, the lever stopper 28 is positioned in a state where the end surface of the flange portion 39 is in contact with the side surface 24a of the discharge portion inner guide 24 so that the lever stopper 28 is lifted from the side surface 24a of the discharge portion inner guide 24 by the height of the flange portion 39. In addition, the wobbling is prevented and stable attachment to the discharge portion inner guide 24 becomes possible. Further, as described above, the length of the rotation range regulating pin 40 is set to be longer than the height of the flange 39 plus the thickness of the side surface 24a of the discharge portion inner guide 24. In the state where the stopper 28 is positioned, as shown in FIG. 7, the rotation range restriction pin 40 is inserted through the long hole 32 and protrudes into the discharge portion inner guide 24. In this way, the lever stopper 28 is attached to the side surface 24a of the discharge portion inner guide 24 so as to be rotatable about the stopper pin 31 as a fulcrum. It is the range which moves between the upper end of 32, and a lower end.

  8 and 9 are schematic perspective views showing the configuration of the closing prevention lever 27, FIG. 8 is a view seen from the front side, and FIG. 9 is a view seen from the back side. The closing prevention lever 27 is a long member made of resin or the like, and includes a pin insertion protrusion 43 projecting from a base end portion on the back side thereof, and a stopper contact formed by extending the upper surface to the back side. The contact rib 44 and the detection protrusion 45 that protrudes to the front side at an angle of approximately 90 ° from the tip of the contact rib 44 are provided. The pin insertion protrusion 43 is for inserting the lever pin 29 protruding from the discharge portion inner guide 24, and has a substantially cylindrical shape as shown in FIG. The stopper abutting rib 44 is for abutting the lever abutting portion 38 of the lever stopper 28 and extends slightly forward from the tip of the pin insertion projection 43. Further, the detection protrusion 45 is for detecting the closing suppression lever 27 by an opening / closing detection sensor described later.

  As shown in FIG. 4, the closing prevention lever 27 configured in this way is provided with a lever pin 29 from the back side with respect to the pin insertion protrusion 43 from the outside of the lever stopper 28 attached to the discharge portion inner guide 24. Is inserted into the side surface 24a of the discharge portion inner guide 24. At this time, the closing prevention lever 27 is configured such that the end surface of the pin insertion protrusion 43 abuts on the side surface 24a of the discharge portion inner guide 24, whereby the side surface of the discharge portion inner guide 24 is equal to the height of the pin insertion protrusion 43. In addition to being positioned in a floating state from 24a, wobbling is prevented and stable attachment to the discharge portion inner guide 24 becomes possible. Then, as shown in FIG. 4, the fixing screw 46 is screwed into the screw hole 30 of the lever pin 29 from the front side of the closing prevention lever 27 through the pin insertion protrusion 43. A flange 47 having a diameter larger than the inner diameter of the pin insertion protrusion 43 is provided on the head of the fixing screw 46. Accordingly, the closing prevention lever 27 is attached to the side surface 24a of the discharge portion inner guide 24 so as to be rotatable about the lever pin 29 as a fulcrum and not to be detached from the lever pin 29. As shown in FIG. 10, the stopper pin 31 protruded through the lever stopper 28, as shown in FIG. 11, from the position where the front end of the closing prevention lever 27 contacts the wall surface 48 of the discharge portion inner guide 24. In addition, the position is between the position where the stopper abutment rib 44 (not shown in FIG. 11) of the closure prevention lever 27 abuts. Further, since the closing prevention lever 27 is fixed so as not to be detached from the lever pin 29, the lever stopper 28 positioned inside thereof is also fixed so as not to be detached from the stopper pin 31.

  Hereinafter, the operations of the closing prevention lever 27 and the lever stopper 28 accompanying the opening / closing operations of the discharge portion outer guide 23 and the upstream portion outer guide 19 will be described with reference to FIGS. First, FIG. 10 is a view showing a state where both the discharge portion outer guide 23 constituting the reversing / discharge unit 14 and the jam access cover 20 integrated with the upstream portion outer guide 19 (not shown) are closed. is there. In this state, as shown in FIG. 7, the pressing piece 49 protruding from the discharge portion outer guide 23 presses the rotation range restriction pin 40 protruding into the discharge portion inner guide 24 to The lever stopper 28 is located at the unlocking position K as shown in FIG. As a result, the closing prevention lever 27 is in a state where it can freely rotate about the lever pin 29 without being restricted by the lever stopper 28. Then, as shown in FIG. 10, the closing prevention lever 27 is pressed by a lever pressing protrusion 50 that protrudes in the horizontal direction from the jam access cover 20, so that the tip portion thereof is a wall surface 48 of the discharge portion inner guide 24. Is held at a position in contact with. At this time, as shown in FIG. 14, the stopper abutment rib 44 of the closing prevention lever 27 abuts on the unlocking position holding piece 42 protruding from the lever stopper 28, so that the lever stopper 28 is unlocked. It is held more securely at the position K. Here, as shown in FIG. 10, an opening / closing detection sensor 51 for detecting the closing prevention lever 27 is provided in the apparatus main body 22 (not shown) in the vicinity of the reversing / discharging unit 14. The open / close detection sensor 51 is a so-called transmissive optical sensor, and emits a detection signal to a control unit (not shown) when the closing suppression lever 27 is detected. In the state shown in FIG. 10, the open / close detection sensor 51 detects the detection protrusion 45 of the closing suppression lever 27, and the control unit that receives the detection signal closes both the discharge portion outer guide 23 and the jam access cover 20. In other words, the image forming apparatus 1 is controlled so that the image forming operation can be started.

  Next, FIG. 11 is a view showing a state where only the jam access cover 20 is opened from the state shown in FIG. When the jam access cover 20 is opened, the lever pressing projection 50 is separated from the closing prevention lever 27, and the closing prevention lever 27 is released from the pressing force of the jam access cover 20. Here, as described above, since the closing prevention lever 27 is in a freely rotatable state without being restricted by the lever stopper 28, the closing prevention lever 27 released from the pressing force lowers the tip side by its own weight. That is, it rotates clockwise from the state of FIG. 10 and stops at the position where the stopper abutment rib 44 abuts against the stopper pin 31 as shown in FIGS. As a result, the open / close detection sensor 51 does not detect the closing suppression lever 27, and the control unit determines that at least the jam access cover 20 is open, and cannot control the image forming apparatus 1 to start the image forming operation. In addition to the stop state, an error message for notifying the user of the fact is displayed on an operation unit (not shown). As described above, the structure is such that the discharge unit outer guide 23 cannot be opened unless the jam access cover 20 is first opened. Therefore, only the discharge unit outer guide 23 remains closed with the jam access cover 20 closed. It will never be released.

  Next, FIG. 12 is a view showing a state in which the discharge portion outer guide 23 is further opened from the state shown in FIG. When the discharge unit outer guide 23 is opened, as shown in FIG. 7, the pressing piece 49 is separated from the rotation range regulating pin 40, and the lever stopper 28 is released from the pressing force of the discharge unit outer guide 23. Here, as described above, since the lever stopper 28 is pivotably attached with the stopper pin 31 as a fulcrum, the lever stopper 28 released from the pressing force is lowered by its own weight. That is, it rotates counterclockwise from the state of FIG. 11 and stops at the position where the rotation range restricting pin 40 reaches the upper end of the long hole 32, that is, the lock position L, as shown in FIG. At this time, the lever contact portion 38 of the lever stopper 28 enters from the outside of the rotation range of the stopper contact rib 44 of the closing prevention lever 27 into the rotation range. As a result, the closing prevention lever 27 is in a locked state in which the lever abutting portion 38 of the lever stopper 28 abuts on the inner side surface of the stopper abutting rib 44 and the stopper pin 31 abuts on the outer side surface so that it cannot rotate. It becomes. Even in this state, since the open / close detection sensor 51 does not detect the closing suppression lever 27, the image forming apparatus 1 remains stopped, and an error message is still displayed on the operation unit.

  Next, FIG. 13 is a diagram illustrating a state where the jam access cover 20 is to be closed from the state illustrated in FIG. 12 while the discharge portion outer guide 23 is opened. As the jam access cover 20 is closed, the lever pressing projection 50 comes into contact with the proximal end portion of the closing prevention lever 27, and a pressing force is applied in a direction to rotate counterclockwise. However, as described above, the closing prevention lever 27 is in a locked state in which it cannot be rotated due to the restriction by the lever stopper 28, and therefore does not rotate even if it receives a pressing force from the lever pressing protrusion 50. The jam access cover 20 cannot be closed any further. Even in this state, since the open / close detection sensor 51 does not detect the closing suppression lever 27, the image forming apparatus 1 remains stopped, and an error message is still displayed on the operation unit.

  On the other hand, when the discharge portion outer guide 23 is closed with the jam access cover 20 opened from the state shown in FIG. 12, the pressing piece 49 projecting from the discharge portion outer guide 23 as shown in FIG. Then, the rotation range regulating pin 40 protruding into the inside of the discharge portion inner guide 24 is pressed and moved from the upper end to the lower end of the long hole 32. As a result, the lever stopper 28 rotates counterclockwise from the lock position L shown in FIG. 15 to the lock release position K shown in FIG. At this time, the lever abutting portion 38 of the lever stopper 28 is out of the rotation range of the stopper abutting rib 44 of the closing restraining lever 27, and the discharge portion outer side guide 23 is completely closed, whereby the state shown in FIG. Return to. As a result, the closing prevention lever 27 can be rotated counterclockwise and the locked state is released. Even in this state, since the open / close detection sensor 51 does not detect the closing suppression lever 27, the image forming apparatus 1 remains stopped, and an error message is still displayed on the operation unit.

  When the jam access cover 20 is closed after the discharge portion outer guide 23 is completely closed, the lever pressing projection 50 comes into contact with the proximal end portion of the closing prevention lever 27 and rotates counterclockwise. Apply pressure in the direction. Here, as described above, since the closing prevention lever 27 is in the unlocked state, it receives the pressing force from the lever pressing protrusion 50 and rotates counterclockwise to completely close the jam access cover 20. As a result, the state shown in FIG. 10 is restored. Thus, the open / close detection sensor 51 detects the closing suppression lever 27, and the control unit that has received the detection signal determines that both the discharge portion outer guide 23 and the upstream portion outer guide 19 are closed, and the image forming apparatus. 1 is controlled so that an image forming operation can be started.

  As described above, in the image forming apparatus 1, the discharge portion outer guide 23 that forms the outer surface of the discharge portion and the upstream portion outer guide 19 that forms the outer surface on the upstream side of the discharge portion are located outside the apparatus. In each of the configurations provided so as to be openable and closable, since the upstream portion outer guide 19 cannot be closed unless the discharge portion outer guide 23 is closed, the image forming operation is performed with only the discharge portion outer guide 23 being opened. Is not started, and it is possible to prevent the recording paper from being jammed. In addition, since it is possible to detect the opening / closing of both the upstream portion outer guide 19 and the discharge portion outer guide 23 by installing only one opening / closing detection sensor 51 for detecting the opening / closing of the upstream portion outer guide 19, Compared with the case where the open / close detection sensor 51 for detecting the above is separately installed independently, the cost can be reduced and the apparatus can be reduced in size and weight.

  The present image forming apparatus is configured to include three transport paths, ie, a main transport path, a reverse transport path, and a manual transport path. However, the present invention is not limited to this. For example, the transport path can be configured by only the main transport path. It is. The image forming apparatus is not limited to a copy / facsimile multifunction peripheral, and can be configured as, for example, a copy-only machine having only a copy function or a facsimile-only machine having only a facsimile communication function.

1 is a schematic longitudinal sectional view showing a configuration of an image forming apparatus 1 according to an embodiment of the present invention. The schematic longitudinal cross-sectional view which shows the state which open | released the jam access cover 20. FIG. The schematic longitudinal cross-sectional view which shows the state which open | released both the jam access cover 20 and the discharge part outer side guide 23. FIG. The disassembled perspective view which shows the state which looked at the inversion / discharge unit 14 from the apparatus back side. The schematic perspective view which looked at the lever stopper 28 from the front side. The schematic perspective view which looked at the lever stopper 28 from the back side. The schematic perspective view which looked at the inversion and discharge | emission unit 14 of the state which open | released the discharge part outer side guide 23 from the inner side. The schematic perspective view which looked at the closing prevention lever 27 from the front side. The schematic perspective view which looked at the closing prevention lever 27 from the back side. The figure which shows the state in which both the discharge part outer side guide 23 and the jam access cover 20 were closed. The figure which shows the state which open | released only the jam access cover 20 from the state of FIG. The figure which shows the state which open | released the discharge part outer side guide 23 from the state of FIG. The figure which shows the state which tried to close the jam access cover 20 with the discharge part outer side guide 23 open | released from the state of FIG. Explanatory drawing for demonstrating the lock release state of the closure suppression lever 27. FIG. Explanatory drawing for demonstrating the locked state of the closure suppression lever 27. FIG. FIG. 6 is a schematic longitudinal sectional view showing a configuration of an image forming apparatus 70 according to a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper feed cassette 4 Paper discharge tray 19 Upstream outer side guide 23 Ejection part outer side guide 24 Ejection part inner side guide 27 Closure prevention lever 28 Lever stopper 50 Lever pressing protrusion 51 Opening / closing detection sensor K Unlocking position L Locking position Rs Main transport path

Claims (3)

A discharge portion outer guide that forms an outer surface of the discharge portion in the recording paper conveyance path from the paper feed cassette to the discharge tray, and an upstream portion outer guide that forms an outer surface upstream of the discharge portion in the recording paper conveyance path. In the image forming apparatus provided to be openable and closable to the outside of the apparatus,
A closing restraining lever for restraining the closing of the upstream portion outer guide is pivotally supported on the discharging portion inner side guide forming the inner side surface of the discharging portion so that the position on the base end side of the center of gravity can be rotated. The lever stopper for restricting the rotation of the closing prevention lever is in a lock position that prohibits the turning of the closing prevention lever when the discharge portion outer guide is opened, and the closing prevention is performed when the discharge portion outer guide is closed. While being provided to be located at the unlock position that allows the lever to rotate,
The image forming apparatus according to claim 1, wherein the upstream outer guide is provided with a lever pressing protrusion that presses and rotates the closing prevention lever in accordance with the closing operation.   The image forming apparatus according to claim 1, further comprising an open / close detection sensor configured to detect the closing suppression lever when the upstream portion outer guide is closed.   The lever stopper is pivotally supported by the discharge portion inner guide so that the position closer to the tip than the center of gravity is pivotally supported. When the upstream portion outer guide is closed, the lever stopper is pressed by the upstream portion outer guide, thereby releasing the lock position. 3. While being held at the same time, when the upstream outer guide is released, the upstream outer guide is released from the pressing force of the upstream outer guide and rotated by its own weight to move to the locked position. The image forming apparatus described.

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