Image forming device

Abstract

To provide an image forming apparatus that can prevent a sheet ejected along a first ejection path from being curled with high reliability.SOLUTION: An image forming apparatus 1 comprises a housing 9, an image forming unit 3, a conveying unit 26 and a cover 100 that is movable to a closing position and an opening position. The image forming apparatus 1 further comprises: an ejection guide 50 that is movable to a first position where it is accommodated inside the housing 9, and a second position where it projects toward downstream in an ejection direction DE1 from the inside of the housing 9 and can be brought into contact with a sheet SH conveyed by the conveying unit 26 from above; and a connection part 60 that connects the cover 100 and the ejection guide 50 to each other, the connection part 60 moving the ejection guide 50 from the second position to the first position in conjunction with the movement of the cover 100 from the opening position to the closing position, and moving the ejection guide 50 from the first position to the second position in conjunction with the movement of the cover 100 from the closing position to the opening position.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] An example of a conventional image forming apparatus is disclosed in Patent Document 1. This image forming apparatus includes an apparatus main body, an image forming unit, a first discharge roller, and a guide member.

[0003] The apparatus body has an opening. The image forming unit is located within the apparatus body and forms an image on a sheet passing through the apparatus body.

[0004] The first discharge rollers have a drive roller and a driven roller, and convey the sheet that has passed through the image forming unit along a face-up discharge path that discharges the sheet in the discharge direction with the image-formed side facing up, or along a face-down discharge path that guides the sheet above the face-up discharge path and discharges it.

[0005] The discharge direction of the first discharge roller is a direction that slopes upward toward the left side of the paper in FIGS. 1 and 2 of Patent Document 1.

[0006] The guide member is movable between a closed position where it closes the opening and an open position where it moves downstream and downward in the discharge direction from the closed position to open the opening. The closed position of the guide member is a position where the sheet that has passed through the image forming unit heads toward the face-down discharge path. The open position of the guide member is a position where the sheet that has passed through the image forming unit heads toward the face-up discharge path. When in the open position, the guide member supports the sheet that is discharged through the opening along the face-up discharge path.

[0007] The image forming apparatus further includes a support member and a torsion spring. The support member is movable between a first position and a second position. The torsion spring biases the support member to move from the first position to the second position.

[0008] When the guide member swings from the open position to the closed position, the protrusion of the guide member pushes the swing lever of the support member, causing the support member to move to the first position against the biasing force of the torsion spring and be housed within the device body.

[0009] On the other hand, when the guide member swings from the closed position to the open position, the stiffening member is biased by the torsion spring and moves to the second position. This causes the stiffening member to protrude downstream in the discharge direction from within the device body and to be able to abut from above against the sheet being conveyed by the first discharge roller. When in the second position, the stiffening member abuts from above against the sheet being discharged along the face-up discharge path, thereby preventing the sheet from curling. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 5477024 Summary of the Invention [Problem to be solved by the invention]

[0011] However, in the conventional image forming apparatus, when the sheet discharged along the face-up discharge path is cardboard or the like, the sheet tends to be highly rigid. If the highly rigid sheet pushes back the stiffening member in the second position with a force stronger than the biasing force of the torsion spring, the stiffening member may move away from the sheet. As a result, this image forming apparatus has a problem in that it is difficult to reliably prevent the sheet discharged along the face-up discharge path from curling.

[0012] The present invention has been made in consideration of the above-described conventional situation, and aims to provide an image forming apparatus that can reliably prevent a sheet discharged along a first discharge path from curling. [Means for solving the problem]

[0013] The image forming apparatus of the present invention comprises: a housing having an opening; an image forming unit located within the housing, the image forming unit forming an image on a sheet passing through the image forming unit; a conveying unit that conveys the sheet that has passed through the image forming unit along a first discharge path that discharges the sheet in a discharge direction with the image-formed surface facing upward, or along a second discharge path that guides the sheet above the first discharge path and discharges it; a cover that is movable to a closed position that closes the opening, where the sheet that has passed through the image forming unit heads toward the second discharge path, and an open position that moves downstream and downward in the discharge direction from the closed position to open the opening, where the sheet that has passed through the image forming unit heads toward the first discharge path, and where the open position supports the sheet that is discharged via the opening along the first discharge path; An image forming apparatus comprising: a discharge guide that is movable between a first position housed within the housing and a second position that protrudes from within the housing toward the downstream side in the discharge direction and can come into contact from above with the sheet being conveyed by the conveying unit; The device further includes a connecting portion that connects the cover and the ejection guide, the connecting portion moving the ejection guide from the second position to the first position in conjunction with the movement of the cover from the open position to the closed position, and the connecting portion moving the ejection guide from the first position to the second position in conjunction with the movement of the cover from the closed position to the open position.

[0014] In the image forming apparatus of the present invention, when the connecting portion moves the discharge guide to the second position in conjunction with the movement of the cover from the closed position to the open position, the discharge guide abuts from above against the sheet being discharged along the first discharge path, thereby preventing the sheet from curling.

[0015] Here, if the sheet discharged along the first discharge path is cardboard or the like, the sheet tends to have high rigidity, and such a rigid sheet may try to push back against the discharge guide at the second position.

[0016] Even in such a case, a large force corresponding to the weight of the cover acts on the discharge guide via the connecting portion, so the discharge guide is held in the second position with high reliability. As a result, even if the highly rigid sheet tries to push back the discharge guide in the second position, the image forming apparatus can reliably prevent the discharge guide from moving away from the sheet.

[0017] Therefore, the image forming apparatus of the present invention can reliably prevent the sheet discharged along the first discharge path from curling. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a schematic cross-sectional view of the image forming apparatus according to the first embodiment, showing a state in which the cover is in the closed position, the discharge guide is in the first position, and the post-fixing guide is in the guide position. [Figure 2] FIG. 2 is a schematic partial cross-sectional view of the image forming apparatus of the first embodiment, showing a state in which the cover is in the open position, the discharge guide is in the second position, and the post-fixing guide is in the guide position. [Figure 3] FIG. 2 is a partial perspective view of the image forming apparatus of the first embodiment, showing a state in which the cover is in the open position, the discharge guide is in the second position, and the post-fixing guide is in the guide position. [Figure 4] FIG. [Figure 5] 10 is a schematic partial cross-sectional view of the image forming apparatus according to the first embodiment, illustrating the operation of a connecting portion that moves the discharge guide to a second position in conjunction with the movement of the cover to the open position. FIG. [Figure 6] 6 is a schematic partial cross-sectional view similar to FIG. 5, illustrating the operation of the connecting portion that moves the discharge guide to the first position in conjunction with the movement of the cover to the closed position. FIG. [Figure 7]4 is a partial perspective view similar to FIG. 3, illustrating a state in which the cover is in the open position, the discharge guide is in the second position, and the post-fixing guide is in the separated position. FIG. [Figure 8] This is a schematic partial cross-sectional view similar to Figure 5, illustrating the relative relationship between the post-fixing guide and the connecting portion when the cover is in the open position, the discharge guide is in the second position, and the post-fixing guide is in the separated position. [Figure 9] FIG. 10 is a rear view of the image forming apparatus according to the second embodiment. [Figure 10] FIG. 10 is a schematic partial cross-sectional view of an image forming apparatus according to a second embodiment, showing a state in which the first and second covers are in the open position, the discharge guide is in the second position, and the post-fixing guide is in the guide position. [Figure 11] FIG. 10 is a partial perspective view showing a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, first and second embodiments of the present invention will be described with reference to the drawings.

[0020] Example 1 1, an image forming apparatus 1 according to a first embodiment is a specific example of the image forming apparatus of the present invention. The image forming apparatus 1 is a laser printer that forms an image on a sheet SH by electrophotography.

[0021] 1, the side of the housing 9 of the image forming apparatus 1 where the manual feed tray 10 is located is defined as the front of the image forming apparatus 1, the side of the housing 9 where the cover 100 is located is defined as the rear of the image forming apparatus 1, and the side of the housing 9 where the discharge tray 9T is located is defined as the upper side of the image forming apparatus 1. The directions shown in each of the figures from FIG. 2 onwards are shown corresponding to FIG. 1.

[0022] <General configuration of image forming apparatus> 1, the image forming apparatus 1 includes a housing 9, an image forming unit 3, a sheet tray 9C, a feeding unit 20, a manual feed tray 10, a manual feed unit 25, a post-fixing conveying roller pair 26, a cover 100, a discharge assisting roller pair 28, and a discharge roller pair 29. The post-fixing conveying roller pair 26 is an example of the "conveying unit" of the present invention.

[0023] The housing 9 is roughly box-shaped, and the image forming unit 3 is located inside it. The image forming unit 3 is a direct transfer color electrophotographic unit. The image forming unit 3 has a process cartridge 4, a transfer belt 6, a scanner unit 8, a fixing unit 7, and the like, which are well-known components, and forms an image on the upward surface of the sheet SH that passes through it.

[0024] The process cartridge 4 corresponds to four toner colors (black, yellow, magenta, and cyan), and is a collection of four cartridges arranged in series in the front-to-rear direction. The process cartridge 4 has four photoconductors 5 corresponding to the four toner colors, as well as a developing roller, a charger, a toner storage unit, etc. (not shown). A transfer belt 6 faces each photoconductor 5 from below.

[0025] The scanner unit 8 has a laser light source, a polygon mirror, an fθ lens, a reflecting mirror, etc. The scanner unit 8 irradiates each photosensitive member 5 in the process cartridge 4 with a laser beam from above.

[0026] The fixing unit 7 is located behind the process cartridge 4. The fixing unit 7 has a heating roller 7A and a pressure roller 7B. The heating roller 7A is an example of the "heating member" in the present invention. The pressure roller 7B is an example of the "pressure member" in the present invention.

[0027] The nip position between the heating roller 7A and the pressure roller 7B is located above the conveying surface 6A of the transfer belt 6 that faces the photosensitive members 5.

[0028] The fixing unit 7 heats and presses the sheet SH that has passed below the process cartridge 4 with a heating roller 7A and a pressure roller 7B.

[0029] The housing 9 has a discharge tray 9T on its upper surface. The discharge tray 9T supports the sheet SH on which the image has been formed.

[0030] The housing 9 detachably accommodates a sheet tray 9C at its bottom. The sheet tray 9C accommodates stacked sheets SH before images are formed by the image forming unit 3. The sheets SH are paper, overhead projector sheets, etc.

[0031] The feeding section 20 has a feeding roller 21, a separation roller 22, a separation pad 22A, a first conveying roller pair 23, and a second conveying roller pair 24, which are arranged along the feeding path PF1.

[0032] The feeding path PF1 is a path that travels upward and forward from the front end of the sheet tray 9C, then makes a U-turn, travels backward, and reaches the image forming unit 3.

[0033] The supply roller 21 feeds the sheets SH stored in the sheet tray 9C to the feeding path PF1. When a plurality of sheets SH are stacked on top of each other after being fed by the supply roller 21, the separation roller 22 and the separation pad 22A separate the sheets one by one.

[0034] The first conveying roller pair 23 and the second conveying roller pair 24 nip the sheets SH separated one by one by the separation roller 22 and the separation pad 22A and convey them toward the image forming unit 3.

[0035] The front side of the housing 9 supports a manual feed tray 10 in a swingable manner. The manual feed tray 10 is movable between an upright position where it stands and forms part of the front surface of the housing 9, as shown by the solid line in Fig. 1, and a manual feed position where it protrudes forward from the middle of the front surface of the housing 9 in the up-down direction, as shown by the two-dot chain line in Fig. 1.

[0036] When in the manual feed position, the manual feed tray 10 supports sheets SH that a user manually feeds to the image forming unit 3 to form an image on. The sheets SH that the manual feed tray 10 can support include paper, overhead projector sheets, cardboard, envelopes, etc.

[0037] The manual feed section 25 is located in front of the second conveying roller pair 24. The manual feed section 25 cooperates with the second conveying roller pair 24 to convey the sheets SH supported on the manual feed tray 10 at the manual feed position one by one toward the image forming section 3.

[0038] The post-fixing conveying roller pair 26 is located behind the fixing unit 7. The post-fixing conveying roller pair 26 has a drive roller 26A and a pinch roller 26P. The nip position between the drive roller 26A and the pinch roller 26P is located above the nip position between the heating roller 7A and the pressure roller 7B.

[0039] The post-fixing conveying roller pair 26 conveys the sheet SH that has passed through the fixing device 7 of the image forming unit 3 along the first discharge path P1 shown in FIG. 2 or the second discharge path P2 shown in FIG.

[0040] 2, the first discharge path P1 is a path along which the sheet SH, which has passed through the fixing device 7 of the image forming unit 3 and is conveyed by the post-fixing conveying roller pair 26, is discharged in a discharge direction DE1 to a position behind the rear surface of the housing 9 with the surface on which the image is formed facing upward. The discharge direction DE1 is a direction in which the sheet moves backward along the front-to-rear direction.

[0041] As shown in FIG. 1, the second discharge path P2 is a path that guides the sheet SH, which has passed through the fixing device 7 of the image forming unit 3 and is transported by the post-fixing transport roller pair 26, above the first discharge path P1, and makes a U-turn so that the side on which the image is formed faces downward and discharges the sheet onto the discharge tray 9T.

[0042] 1 to 3, the housing 9 has an opening 9H on its rear surface. The opening 9H is a substantially rectangular opening that opens most of the upper half of the rear surface of the housing 9.

[0043] As shown in FIG. 2, opening 9H allows sheet SH to pass through when the sheet SH passes through the fixing device 7 of the image forming unit 3 and is transported by the post-fixing transport roller pair 26 and is discharged to a position behind the rear surface of the housing 9.

[0044] As shown in FIGS. 1 to 3, the housing 9 supports the cover 100 so that it can swing about an opening / closing axis X100. The opening / closing axis X100 extends in the width direction of the housing 9 near the lower edge of the opening 9H. The width direction is a direction perpendicular to the discharge direction DE1 and the up-down direction. The rotation axis of the photosensitive member 5 extends parallel to the width direction.

[0045] The cover 100 can be moved by swinging around the opening / closing axis X100 between a closed position in which the opening 9H is closed, as shown in FIG. 1, and an open position in which the cover 100 moves downstream and downward in the discharge direction DE1 from the closed position to open the opening 9H, as shown in FIGS. 2 and 3.

[0046] 3, in this embodiment, the cover 100 is a resin molded product manufactured by injection molding of a thermoplastic resin or the like. The cover 100 has a flat cover body 101 and a plurality of ribs 109 each protruding from the cover body 101. The ribs 109 are aligned in the width direction at intervals.

[0047] 1, when the cover 100 is in the closed position, the cover body 101 extends in the vertical and width directions to close the opening 9H. In this state, each rib 109 protrudes forward from the surface of the cover body 101 facing the inside of the housing 9 and extends in the vertical direction. Also, in this state, a tip edge 109A of each rib 109, which is located on the opposite side from the cover body 101 and extends in the vertical direction, is curved so that its middle portion is shifted rearward relative to the ends located above and below.

[0048] The closed position of the cover 100 is a position where the sheet SH, which has passed through the fuser 7 of the image forming unit 3 and is conveyed by the post-fixing conveying roller pair 26, heads toward the second discharge path P2. The leading edge 109A of each rib 109 extends along the second discharge path P2 when the cover 100 is in the closed position, and guides the sheet SH, which is conveyed by the post-fixing conveying roller pair 26, along the second discharge path P2. In other words, the leading edge of the sheet SH conveyed by the post-fixing conveying roller pair 26 is guided by each rib 109 of the cover 100, faces upward, and then is redirected to face forward, whereby the sheet SH is discharged onto the discharge tray 9T.

[0049] 2, the open position of the cover 100 is a position where the sheet SH, which has passed through the fuser 7 of the image forming unit 3 and is conveyed by the post-fixing conveying roller pair 26, heads toward the first discharge path P1. When the cover 100 is in the open position, the leading edge 109A of each rib 109 supports the sheet SH, which is discharged along the first discharge path P1 through the opening 9H. That is, when the cover 100 is in the open position, the ribs 109 protrude upward and are aligned in the width direction, and the leading edge 109A of each rib 109 is positioned below the nip point of the post-fixing conveying roller pair 26 and a discharge guide 50 (described later) and downstream in the discharge direction DE1.

[0050] When a user attempts to form an image on a sheet SH that is difficult to transport along the second discharge path P2, such as a highly rigid cardboard or an envelope, the user selects so-called straight discharge, in which the sheet SH is supported on the manual feed tray 10 in the manual feed position and fed to the image forming unit 3 while the cover 100 is in the open position, and the sheet SH that has passed through the image forming unit 3 is discharged along the first discharge path P1.

[0051] The discharge auxiliary roller pair 28 is located above the post-fixing conveying roller pair 26. The discharge roller pair 29 is located forward of the discharge auxiliary roller pair 28 and above the rear end of the discharge tray 9T. The discharge auxiliary roller pair 28 nips the sheet SH conveyed along the second discharge path P2 and conveys it toward the discharge roller pair 29, and the discharge roller pair 29 nips the sheet SH and discharges it onto the discharge tray 9T.

[0052] <Discharge guide and connecting part> The nip position between the heating roller 7A and the pressure roller 7B is located above the conveying surface 6A of the transfer belt 6 that faces each photosensitive element 5. The nip position between the drive roller 26A and the pinch roller 26P is located above the nip position between the heating roller 7A and the pressure roller 7B.

[0053] 2, when the sheet SH is nipped between the heating roller 7A and the pressure roller 7B of the fixing unit 7 and the driving roller 26A and the pinch roller 26P of the post-fixing conveying roller pair 26 and is discharged along the first discharge path P1, the discharged sheet SH may curl upward unless some measures are taken. The sheet SH is particularly prone to curling when it is made of cardboard, an envelope, or the like, which is prone to bending.

[0054] In order to prevent such curling of the sheet SH, the image forming apparatus 1 further includes a discharge guide 50 shown in FIGS. 1 to 8, and a connecting portion 60 shown in FIGS.

[0055] 4, the discharge guide 50 has a base 51, a pair of rotation shafts 52, a pair of passive portions 53, and a plurality of guide protrusions 54. In this embodiment, the discharge guide 50 is a resin molded product manufactured by injection molding of a thermoplastic resin or the like.

[0056] The base 51 extends in a rod-like shape in the width direction. The pair of rotation shafts 52 are cylinders that protrude outward in the width direction from one end and the other end of the base 51 in the width direction. The pair of rotation shafts 52 are centered on a rotation axis X50 that extends in the width direction.

[0057] The pair of passive parts 53 protrude radially outward from one end and the other end of the base 51 in the width direction about the rotation axis X50. The passive part 53 located on one side in the width direction and the passive part 53 located on the other side in the width direction have the same configuration but on opposite sides. The pair of passive parts 53 have connecting holes 53H at their tips.

[0058] The guide protrusions 54 protrude radially outward from the base 51 about the rotation axis X50 and are spaced apart from one another in the width direction. Each guide protrusion 54 has a tapered shape that narrows toward its tip.

[0059] 3, the pair of rotation shafts 52 are rotatably supported by frame members located on one side and the other side in the width direction within the housing 9. As shown in FIG. 1, the rotation axis X50 is located slightly rearward and upward from the outer peripheral surface of the drive roller 26A of the post-fixing conveying roller pair 26.

[0060] The discharge guide 50 is movable between a first position shown in FIGS. 1 and 6 and a second position shown in FIGS. 2, 3, 5, 7 and 8 by rotating about a rotation axis X50.

[0061] As shown in FIGS. 1 and 6, the first position of the ejection guide 50 is a position where the ejection guide 50 is housed in the housing 9 and where the guide protrusions 54 are retracted so as not to intersect with the second ejection path P2.

[0062] 2, 3, and 5, the second position of the discharge guide 50 is a position where the discharge guide 50 protrudes downstream in the discharge direction DE1 from within the housing 9 and where each guide protrusion 54 can abut from above against the sheet SH being conveyed by the post-fixing conveying roller pair 26. In addition, the second position of the discharge guide 50 is a position where each guide protrusion 54 intersects with the second discharge path P2.

[0063] 3, the connecting portion 60 has two pairs of first link arms 61 and second link arms 62. The pair of first link arms 61 and second link arms 62 located on one side in the width direction and the pair of first link arms 61 and second link arms 62 located on the other side in the width direction have the same configuration but on opposite sides. For this reason, the following description will be given of the pair of first link arms 61 and second link arms 62 located on one side in the width direction, and a description of the pair of first link arms 61 and second link arms 62 located on the other side in the width direction will be omitted.

[0064] In this embodiment, the first link arm 61 and the second link arm 62 are each a resin molded product manufactured by injection molding of a thermoplastic resin or the like.

[0065] The first link arm 61 has a C-shaped cross section and extends linearly in the vertical direction. As shown in Figures 5 and 6, the first link arm 61 has a base wall 61A, a pair of side walls 61B and 61C, and a connecting shaft 61S.

[0066] The base wall 61A has a slot 61H extending in the vertical direction. The pair of side walls 61B, 61C protrude inward in the width direction from both side edges of the base wall 61 and extend in the vertical direction.

[0067] A tip 61E of the first link arm 61 is the lower end of the base wall 61 and is spaced downward from the second link arm 62. The connecting shaft 61S is a cylinder that protrudes outward in the width direction from the tip 61E.

[0068] The cover 100 has a plate-like piece 102 that protrudes from a cover body 101, and the plate-like piece 102 has a round hole through which the connecting shaft 61S is fitted.

[0069] That is, the connecting portion 60 is rotatably connected to the cover 100 at a tip 61E of the first link arm 61 that is spaced apart from the second link arm 62.

[0070] The second link arm 62 has an L-shape in a side view, and includes a linear motion portion 62A, a retaining portion 62B, and a transmission portion 62C.

[0071] The linear movement portion 62A has a rectangular cross section and extends linearly in the vertical direction. The linear movement portion 62A is guided by the base wall 61A and side walls 61B and 61C of the first link arm 61, and slides vertically relative to the first link arm 61.

[0072] The retaining portion 62B protrudes outward in the width direction from the linear moving portion 62A and passes through the elongated hole 61H of the first link arm 61. The tip of the retaining portion 62B that extends beyond the elongated hole 61H is larger than the inner width of the elongated hole 61H, thereby preventing the linear moving portion 62A from coming off the first link arm 61.

[0073] That is, the first link arm 61 and the second link arm 62 are connected to each other so as to be slidable in a linear direction.

[0074] The transmission part 62C is connected to the upper end of the linear motion part 62A and protrudes forward. The tip 62E of the second link arm 62 is the front end of the transmission part 62C and is spaced upward and forward from the first link arm 61. The transmission part 62C has a connecting shaft (not shown) that protrudes inward in the width direction from the tip 62E.

[0075] In the discharge guide 50, a connecting shaft (not shown) of the transmission part 62C is inserted into the connecting hole 53H of the passive part 53 shown in Fig. 4. As a result, the passive part 53 of the discharge guide 50 and the transmission part 62C of the second link arm 62 are rotatably connected at a connection point CP1, as shown in Figs.

[0076] That is, the connecting portion 60 is rotatably connected to the discharge guide 50 at the tip 62E of the second link arm 62 that is spaced apart from the first link arm 61. The connecting portion 60 is connected to the discharge guide 50 at a position that is radially different from the rotation axis X50 of the discharge guide 50.

[0077] The connecting portion 60 connects the cover 100 and the discharge guide 50 by the first link arm 61 and the second link arm 62 configured as described above.

[0078] When the cover 100 moves from the open position shown in FIG. 5 to the closed position shown in FIG. 6, the first link arm 61 at the connecting portion 60 moves upward and forward while remaining in a position extending in the vertical direction.

[0079] As a result, the linear moving portion 62A of the second link arm 62 slides downward relative to the first link arm 61, and most of the linear moving portion 62A overlaps with the first link arm 61. The transmission portion 62C of the second link arm 62 moves upward and forward, pushing the passive portion 53 of the ejection guide 50 upward and forward. As a result, the ejection guide 50 moves to the first position.

[0080] That is, the connecting portion 60 moves the ejection guide 50 from the second position to the first position in conjunction with the movement of the cover 100 from the open position shown in FIG. 5 to the closed position shown in FIG.

[0081] When viewed along the width direction, a portion of the connecting portion 60, i.e., the linear portion 62A of the first link arm 61 and the second link arm 62, overlaps with each rib 109 when the cover 100 is in the closed position shown in Figure 6.

[0082] On the other hand, when the cover 100 moves from the closed position shown in FIG. 6 to the open position shown in FIG. 5, the first link arm 61 at the connecting portion 60 moves downward and rearward while remaining in a position extending in the vertical direction.

[0083] As a result, the linear motion portion 62A of the second link arm 62 slides upward relative to the first link arm 61, and the upper portion of the linear motion portion 62A protrudes upward beyond the first link arm 61. The transmission portion 62C of the second link arm 62 moves downward and rearward, pulling the passive portion 53 of the ejection guide 50 downward and rearward. As a result, the ejection guide 50 moves to the second position.

[0084] That is, the connecting portion 60 moves the discharge guide 50 from the first position to the second position in conjunction with the movement of the cover 100 from the closed position to the open position.

[0085] <Post-fixing guide, post-fixing guide operating member, and envelope mode operating member> The image forming apparatus 1 further includes a post-fixing guide 70 shown in Figures 1 to 3 and 5 to 8, a pair of post-fixing guide operating members 77 shown in Figures 3 and 5 to 8, and a pair of envelope mode operating members 78 shown in Figures 3 and 7.

[0086] The post-fixing guide operating member 77 and the envelope mode operating member 78 are examples of the "operating member" of the present invention.

[0087] 3, the pair of envelope mode operation members 78 are located inside in the width direction relative to the pair of post-fixing guide operation members 77. The first link arm 61 and the second link arm 62 of the connecting portion 60 are located inside in the width direction relative to the pair of post-fixing guide operation members 77 and the pair of envelope mode operation members 78.

[0088] The post-fixing guide 70 can move between a guide position shown in Figures 1 to 3, 5 and 6 and a separated position shown in Figures 7 and 8 by swinging about a swing axis X70. The swing axis X70 extends in the width direction below the pinch roller 26P of the post-fixing conveying roller pair 26.

[0089] The post-fixing guide 70 rotatably supports the pinch roller 26P of the post-fixing conveying roller pair 26.

[0090] As shown in Figures 1 and 2, when the post-fixing guide 70 is in the guide position, it abuts the drive roller 26A and pinch roller 26P of the post-fixing conveying roller pair 26, and guides the sheet SH that has passed through the fixing device 7 toward the post-fixing conveying roller pair 26 using the guide surface 70G.

[0091] On the other hand, as shown in Figures 7 and 8, when the post-fixing guide 70 is in the separated position, it moves away from the guide position downstream and downward in the discharge direction DE1, separating the drive roller 26A and pinch roller 26P of the post-fixing conveying roller pair 26.

[0092] 3 and 5, the pair of post-fixing guide operation members 77 are connected to one end and the other end in the width direction of the post-fixing guide 70. The pair of post-fixing guide operation members 77 are lever-shaped and protrude rearward at a position above the post-fixing guide 70 which is in the guiding position.

[0093] With the cover 100 in the open position, the user can move the post-fixing guide 70 between the guiding position and the separated position by operating the pair of post-fixing guide operating members 77. This operation is mainly performed to remove a sheet SH that is jammed around the fixing unit 7.

[0094] As shown in Figures 5 and 8, when the cover 100 is in the open position, the first link arm 61 and the second link arm 62 of the connecting portion 60 move downstream and upward in the discharge direction DE1 relative to the post-fixing guide 70, which moves between the guiding position and the separated position.

[0095] 3, the pair of envelope mode operating members 78 are located outside and above the passive portion 53 of the discharge guide 50 in the width direction. Although not shown, the pair of envelope mode operating members 78 can weaken the biasing force of the biasing member that biases one of the heating roller 7A and the pressure roller 7B in the fixing unit 7 toward the other of the heating roller 7A and the pressure roller 7B via a well-known link mechanism.

[0096] With the cover 100 in the open position, the user can operate the pair of envelope mode operating members 78 to weaken the pressure applied when the heating roller 7A and pressure roller 7B of the fixing unit 7 nip the sheet SH. This operation is mainly performed to form an image on the sheet SH, which is an envelope or the like.

[0097] <Image formation operation> The image forming unit 3 forms an image on a sheet SH fed from the sheet tray 9C or the manual feed tray 10 in the following manner. That is, the surface of each photoconductor 5 is uniformly positively charged by a charger as it rotates, and then exposed to high-speed scanning of a laser beam emitted from the scanner unit 8. As a result, an electrostatic latent image corresponding to the image to be formed on the sheet SH is formed on the surface of each photoconductor 5.

[0098] Next, toner is supplied from the toner storage unit to the surface of each photoconductor 5 in accordance with the electrostatic latent image, and a toner image is formed. Then, as the sheet SH passes through the image forming unit 3, the upward surface of the sheet SH faces the photoconductor 5. The toner image carried on the surface of each photoconductor 5 is transferred to the upward surface of the sheet SH. The fixing unit 7 fixes the toner image transferred by the heating roller 7A and the pressure roller 7B onto the sheet SH.

[0099] 1, when the cover 100 is in the closed position, the post-fixing conveying roller pair 26 conveys the sheet SH that has passed through the fixing device 7 of the image forming unit 3 along the second discharge path P2. The discharge auxiliary roller pair 28 and the discharge roller pair 29 nip the sheet SH and discharge it onto the discharge tray 9T.

[0100] At this time, the discharge guide 50 in the first position is housed within the housing 9, and each guide protrusion 54 is retracted so as not to intersect with the second discharge path P2, so that the sheet SH discharged along the second discharge path P2 is less likely to be obstructed.

[0101] 2, when the cover 100 is in the open position, the post-fixing conveying roller pair 26 discharges the sheet SH that has passed through the fuser 7 of the image forming unit 3 along the first discharge path P1 and through the opening 9H in the discharge direction DE1. Note that not only the sheet SH on which an image has been formed by the image forming unit 3, but also, for example, a sheet sandwiched between laminating films may be conveyed to the fuser 7 without image formation, and the sheet may be pressed and laminated by the heating roller 7A and the pressure roller 7B and discharged in the discharge direction DE1 along the first discharge path P1 and through the opening 9H.

[0102] At this time, the discharge guide 50 in the second position protrudes from within the housing 9 toward downstream in the discharge direction DE1, and each guide protrusion 54 abuts from above on the sheet SH being conveyed by the post-fixing conveying roller pair 26, thereby preventing the sheet SH from curling upward. Even if the sheet SH tries to push back each guide protrusion 54 of the discharge guide 50, a large force corresponding to the weight of the cover 100 acts on the discharge guide 50 via the connecting portion 60, so that the discharge guide 50 is reliably held in the second position. In particular, when a sheet SH such as a highly rigid envelope, cardboard, or the laminated sheet described above is being discharged, the contact between the discharge guide 50 and the sheet SH can prevent the sheet SH from curling.

[0103] When the sheet SH is discharged to a position behind the rear surface of the housing 9, the tip edges 109A of the ribs 109 of the cover 100 support the sheet SH.

[0104] <Action and effect> In the image forming apparatus 1 of Example 1, the first link arm 61 and the second link arm 62 of the connecting portion 60 move the discharge guide 50 to the second position in conjunction with the movement of the cover 100 from the closed position shown in Figure 6 to the open position shown in Figure 5.

[0105] As a result, as shown in FIG. 2, the guide protrusions 54 of the discharge guide 50 come into contact from above with the sheet SH discharged along the first discharge path P1, thereby preventing the sheet SH from curling upward.

[0106] Here, when the sheet SH discharged along the first discharge path P1 is cardboard or the like, the sheet SH tends to have high rigidity. In addition, the sheet SH with high rigidity may try to push back the guide protrusions 54 of the discharge guide 50 that is in the second position.

[0107] Even in such a case, a large force corresponding to the weight of the cover 100 acts on the discharge guide 50 via the first link arm 61 and the second link arm 62 of the connecting portion 60, so the discharge guide 50 is held in the second position with high reliability. As a result, the image forming apparatus 1 can highly reliably prevent the discharge guide 50 from moving away from the sheet SH even if the highly rigid sheet SH tries to push back the guide protrusions 54 of the discharge guide 50 in the second position.

[0108] Therefore, the image forming apparatus 1 of the first embodiment can highly reliably prevent the sheet SH discharged along the first discharge path P1 from curling.

[0109] Furthermore, in the conventional image forming apparatus described above, when the stiffening member moves to the first position, the restoring force stored in the torsion spring causes creep deformation of the members located around the torsion spring, but the image forming apparatus 1 of the first embodiment does not have such a problem.

[0110] 5 and 6, in the image forming apparatus 1, the discharge guide 50 is movable between a first position and a second position by rotating about a rotation axis X50. The transmission portion 62C of the second link arm 62 of the connecting portion 60 is connected to the passive portion 53 of the discharge guide 50 at a position on the discharge guide 50 that is radially different from the rotation axis X50, i.e., at a connecting point CP1. This configuration makes it easy to simplify the configuration that allows the discharge guide 50 to move between the first position and the second position.

[0111] Furthermore, in this image forming apparatus 1, the guide protrusions 54 of the discharge guide 50 intersect with the second discharge path P2 when in the second position shown in Fig. 2, but retract so as not to intersect with the second discharge path P2 when in the first position shown in Fig. 1. With this configuration, the guide protrusions 54 of the discharge guide 50 in the second position can prevent the sheet SH that has passed through the image forming unit 3 from accidentally entering the second discharge path P2. Furthermore, the guide protrusions 54 of the discharge guide 50 in the first position are less likely to obstruct the sheet SH being discharged along the second discharge path P2.

[0112] 5 and 6, in the image forming apparatus 1, the first link arm 61 and the linearly moving portion 62A of the second link arm 62 are connected to each other so as to be slidable in a linear direction. The first link arm 61 is rotatably connected to the plate-like piece 102 of the cover main body 101 of the cover 100 at a tip 61E separated from the second link arm 62. The transmission portion 62C of the second link arm 62 is rotatably connected to the passive portion 53 of the discharge guide 50 at a tip 62E separated from the first link arm 61. This configuration improves the design flexibility of the movement range of the cover 100 when it moves between the closed position and the open position, and the movement range of the discharge guide 50 when it moves between the first position and the second position.

[0113] 3, the cover 100 of the image forming apparatus 1 has a cover main body 101 and a plurality of ribs 109. As shown in FIG. 6, when viewed in the width direction, a portion of the connecting portion 60, i.e., the linear motion portion 62A of the first link arm 61 and the second link arm 62, overlaps with each rib 109 when the cover 100 is in the closed position. This configuration makes it easy to reduce the space occupied by the connecting portion 60 when the cover 100 is in the closed position, thereby preventing the device from becoming too large.

[0114] 5 and 8, in this image forming apparatus 1, the first link arm 61 and the second link arm 62 of the connecting portion 60 are located downstream and upward in the discharge direction DE1 relative to the post-fixing guide 70, which moves between the guiding position and the separated position, when the cover 100 is in the open position. With this configuration, the connecting portion 60 is unlikely to get in the way when the user moves the post-fixing guide 70 to the separated position shown in FIG. 8 to remove a sheet SH that has become jammed around the fixing unit 7.

[0115] 3, in this image forming apparatus 1, the first link arm 61 and the second link arm 62 of the connecting portion 60 are positioned inside in the width direction relative to the post-fixing guide operation member 77 and the envelope mode operation member 78. With this configuration, when the user operates the post-fixing guide operation member 77 and the envelope mode operation member 78 with the cover 100 in the open position, the connecting portion 60 and the discharge guide 50 in the second position are unlikely to get in the way.

[0116] Example 2 As shown in FIGS. 9 and 10, the image forming apparatus of the second embodiment employs a cover 200 and a connecting portion 260 instead of the cover 100 and the connecting portion 60 of the image forming apparatus 1 of the first embodiment.

[0117] Other configurations of the second embodiment are the same as those of the first embodiment. Therefore, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted or simplified.

[0118] In the second embodiment, the cover 200 has a first cover 210 and a second cover 220. The first cover 210 and the second cover 220 are obtained by dividing the cover 100 according to the first embodiment into two parts.

[0119] 9, the first cover 210 is formed by the upper end portion and one end and the other end portion in the width direction of the cover 100 according to Example 1, and the second cover 220 is formed by the other portions of the cover 100 according to Example 1. The second cover 220 is located inside the first cover 210 in the width direction.

[0120] The first cover 210 and the second cover 220 each swing around an opening / closing axis X200, so that the cover 200 can move between a closed position where the opening 9H is closed, as shown in Fig. 9, and an open position where the cover 200 moves downstream and downward in the discharge direction DE1 from the closed position to open the opening 9H, as shown in Fig. 10. The opening / closing axis X200 coincides with the opening / closing axis X100 according to the first embodiment.

[0121] As shown in FIG. 10, when the second cover 220 is in the open position, it is located downstream and below the first cover 210 in the discharge direction DE1, and supports the sheet SH discharged along the first discharge path P1.

[0122] The connecting portion 260 is a single link arm that extends in a rod shape. The first cover 210 is connected to one end of the connecting portion 260 at a connecting point CP2. The other end of the connecting portion 260 is connected to the passive portion 53 of the discharge guide 50 at a connecting point CP3.

[0123] When the cover 200 moves from the closed position to the open position, the connecting portion 260 moves the discharge guide 50 in conjunction with the movement of the first cover 210 from the first position shown by the dotted line in Figure 10 to the second position shown by the solid line in Figure 10.

[0124] On the other hand, when the cover 200 moves from the open position to the closed position, the connecting portion 260 moves the discharge guide 50 in conjunction with the movement of the first cover 210 from the second position shown by the solid line in Figure 10 to the first position shown by the dotted line in Figure 10.

[0125] In the image forming apparatus of Example 2 having such a configuration, a large force corresponding to the weight of the first cover 210 acts on the discharge guide 50 via the connecting portion 260, and thus, similar to the image forming apparatus 1 of Example 1, curling of the sheet SH discharged along the first discharge path P1 can be suppressed with high reliability.

[0126] The present invention has been described above in accordance with Examples 1 and 2, but it goes without saying that the present invention is not limited to the above Examples 1 and 2, and can be modified and applied as appropriate within the scope of the invention.

[0127] (Variation) In the modified example shown in Figure 11, elastic deformation pieces 59 are formed on a frame member that supports a pair of pivot shafts 52 of the discharge guide 50 within the housing 9, and convex portions 58 are formed on the surface facing outward in the width direction of the passive portion 53 of the discharge guide 50.

[0128] When the ejection guide 50 moves to the second position, the elastically deforming pieces 59 move over the protrusions 58 while elastically deforming, thereby exerting a holding force that holds the ejection guide 50 at the second position.

[0129] This modification also makes it possible to highly reliably prevent the sheet SH discharged along the first discharge path P1 from curling.

[0130] In the first and second embodiments, the image forming apparatus of the present invention is embodied as the image forming apparatus 1, but the present invention is not limited to this configuration. For example, the configuration of the present invention may be applied to an image forming apparatus in a multifunction peripheral equipped with an image reading device above the image forming apparatus.

[0131] In the first and second embodiments, the ejection guide 50 is movable between the first and second positions by rotating about the rotation axis X50, but the present invention is not limited to this configuration. For example, the ejection guide may be movable between the first and second positions by a combined movement in which the ejection guide slides while rotating.

[0132] In Examples 1 and 2, the guide protrusions 54 of the discharge guide 50 in the first position are retracted so as not to intersect with the second discharge path P2, but the present invention is not limited to this configuration. For example, the discharge guide may guide the sheet along the second discharge path P2 when in the first position.

[0133] In the first and second embodiments, the post-fixing conveying roller pair 26 located downstream of the fixing unit 7 in the conveying direction serves as a conveying unit to convey the sheet SH so that it is discharged along the first discharge path P1, but the present invention is not limited to this configuration. For example, the present invention also includes a configuration in which the post-fixing conveying roller pair 26 is not present between the fixing unit 7 and the cover 100, and the heating roller 7A and pressure roller 7B of the fixing unit 7 function as a conveying unit to convey the sheet SH along the first discharge path P1 by the rotation of the heating roller 7A and pressure roller 7B and discharge the sheet SH directly onto the cover 100 in the open position.

[0134] In the first embodiment, the connecting portion 60 is formed by two link arms, and in the second embodiment, the connecting portion 260 is formed by one link arm, but the present invention is not limited to this configuration. For example, the connecting portion may be formed by combining three or more link arms. [Explanation of symbols]

[0135] 1...image forming apparatus, 9H...opening, 9...casing 3...Image forming unit, SH...Sheet, DE1...Discharge direction P1: First discharge path, P2: Second discharge path 26...Transport unit (pair of post-fixing transport rollers), 100, 200...Cover 50...Discharge guide, 60, 260...Connecting part, X50...Pivot axis 61...first link arm, 62...second link arm 61E...the tip of the first link arm spaced apart from the second link arm 62E...Tip of second link arm separated from first link arm 101... cover body, 109... plural ribs, 5... photosensitive element 7A...heating member (heating roller), 7B...pressure member (pressure roller) 7...Fuser unit, 70...Post-fuser guide 77, 78...Operation members (77...Post-fixing guide operation member, 78...Envelope mode operation member)

Claims

1. a housing having an opening; an image forming unit located within the housing, the image forming unit forming an image on a sheet passing through the image forming unit; a conveying unit that conveys the sheet that has passed through the image forming unit along a first discharge path that discharges the sheet in a discharge direction with the image-formed surface facing upward, or along a second discharge path that guides the sheet above the first discharge path and discharges the sheet; a cover that is movable to a closed position that closes the opening, where the sheet that has passed through the image forming unit heads toward the second discharge path, and an open position that moves downstream and downward in the discharge direction from the closed position to open the opening, where the sheet that has passed through the image forming unit heads toward the first discharge path, and where the cover supports the sheet that is discharged through the opening along the first discharge path; An image forming apparatus comprising: a discharge guide that is movable between a first position accommodated in the housing and a second position that protrudes from the housing toward the downstream side in the discharge direction and can contact from above the sheet being conveyed by the conveyance unit; a connecting portion that connects the cover and the ejection guide, the connecting portion moving the ejection guide from the second position to the first position in conjunction with movement of the cover from the open position to the closed position, and moving the ejection guide from the first position to the second position in conjunction with movement of the cover from the closed position to the open position, the image forming unit includes a photoreceptor on which a toner image to be transferred to a sheet is formed, and a fixing device that fixes the transferred toner image to the sheet by a heating member and a pressure member; a post-fixing guide movable between a guide position for guiding the sheet that has passed through the fixing unit and a separated position that is spaced downstream and downward in the discharge direction from the guide position; An image forming apparatus characterized in that, when the cover is in the open position, the connecting portion escapes downstream and upward in the discharge direction relative to the post-fixing guide, which moves between the guide position and the separated position.

2. A housing having an opening; an image forming unit located within the housing, the image forming unit forming an image on a sheet passing through the image forming unit; a conveying unit that conveys the sheet that has passed through the image forming unit along a first discharge path that discharges the sheet in a discharge direction with the image-formed surface facing upward, or along a second discharge path that guides the sheet above the first discharge path and discharges the sheet; a cover that is movable to a closed position that closes the opening, where the sheet that has passed through the image forming unit heads toward the second discharge path, and an open position that moves downstream and downward in the discharge direction from the closed position to open the opening, where the sheet that has passed through the image forming unit heads toward the first discharge path, and where the cover supports the sheet that is discharged through the opening along the first discharge path; An image forming apparatus comprising: a discharge guide that is movable between a first position accommodated in the housing and a second position that protrudes from the housing toward the downstream side in the discharge direction and can contact from above the sheet being conveyed by the conveyance unit; a connecting portion that connects the cover and the ejection guide, the connecting portion moving the ejection guide from the second position to the first position in conjunction with movement of the cover from the open position to the closed position, and moving the ejection guide from the first position to the second position in conjunction with movement of the cover from the closed position to the open position; an operating member for manually operating components of the image forming unit when the cover is in the open position; Furthermore, The image forming apparatus is characterized in that the connecting portion is located inside the operation member in a width direction perpendicular to the ejection direction and the up-down direction.

3. the ejection guide is movable between the first position and the second position by rotating at least about a rotation axis; 3. The image forming apparatus according to claim 1, wherein the connecting portion is connected to the ejection guide at a position different in a radial direction of rotation from the rotation axis of the ejection guide.

4. 3. The image forming apparatus according to claim 1, wherein the ejection guide intersects with the second ejection path when in the second position, and retracts so as not to intersect with the second ejection path when in the first position.

5. the connecting portion has a first link arm and a second link arm that are connected to each other so as to be slidable in a linear direction, the connecting portion is rotatably connected to the cover at a tip of the first link arm that is spaced apart from the second link arm, 3. The image forming apparatus according to claim 1, wherein the connecting portion is rotatably connected to the discharge guide at a tip of the second link arm that is spaced apart from the first link arm.

6. The cover includes a flat cover body and a plurality of ribs each protruding from the cover body and extending along the second discharge path when the cover is in the closed position; 3. The image forming apparatus according to claim 1, wherein when viewed in a width direction perpendicular to the ejection direction and the up-down direction, a part of the connecting portion overlaps each of the ribs when the cover is in the closed position.

Images