JP2023151997A - Image forming apparatus - Google Patents

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, a re-conveying unit 30, a cover 100 and a flapper 50. The image forming apparatus 1 further comprises a connection part 60 that connects the cover 100 and the flapper 50 to each other, the connection part 60 moving the flapper 50 from a first position to a second position in conjunction with the movement of the cover 100 from a closing position to an opening position, and moving the flapper 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. At the second position, the flapper 50 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.SELECTED DRAWING: Figure 5

Description

The present invention relates to an image forming apparatus.

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.

The device body has an opening. The image forming unit is located within the apparatus main body and forms an image on a sheet passing therethrough.

The first discharge roller has a drive roller and a driven roller. The first ejection roller guides the sheet that has passed through the image forming unit to a face-up ejection path that ejects the sheet in the ejection direction with the surface on which the image is formed facing upward, or to an area above the face-up ejection path. Convey along the face-down discharge route.

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

The guide member is movable between a closed position where the opening is closed and an open position where the guide member is moved 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. The guide member, in the open position, supports the sheet being discharged through the opening along the face-up discharge path.

The image forming apparatus further includes a stiffening member and a torsion spring. The waist member is movable between a first position and a second position. The torsion spring biases the waist member to move from the first position to the second position.

When the guide member swings from the open position to the closed position, the protrusion of the guide member pushes the swinging lever of the buckle member, and the buckle member moves to the first position against the biasing force of the torsion spring, thereby closing the device. It is housed inside the main body.

On the other hand, when the guide member swings from the closed position to the open position, the waist member is biased by the torsion spring and moves to the second position. Thereby, the stiffening member protrudes from the apparatus main body toward the downstream in the discharge direction, and can come into contact with the sheet conveyed by the first discharge roller from above. The stiffening member in the second position suppresses curling of the sheet by coming into contact with the sheet discharged along the face-up discharge path from above.

Patent No. 5477024

However, in the conventional image forming apparatus described above, when the sheet discharged along the face-up discharge path is made of cardboard or the like, the rigidity of the sheet tends to be high. There is a possibility that the seat, which has high rigidity, pushes back the seat support member in the second position with a force stronger than the biasing force of the torsion spring, causing the seat support member to escape from the seat. As a result, this image forming apparatus has a problem in that it is difficult to reliably suppress curling of sheets discharged along the face-up discharge path.

The present invention has been made in view of the above-mentioned conventional situation, and an object of the present invention is to provide an image forming apparatus that can highly reliably suppress curling of sheets discharged along a first discharge path. .

An image forming apparatus of the present invention includes a housing having an opening;
an image forming unit located within the housing, the image forming unit forming an image on a passing sheet;
A first ejection path that ejects the sheet that has passed through the image forming section in the ejection direction with the surface on which the image is formed facing upward; or a second ejection path that guides and ejects the sheet above the first ejection path. a conveying section for conveying along the discharge route;
The re-conveying unit transports the sheet, which has been switched back so that the rear end of the sheet being conveyed along the second discharging route becomes the leading edge, along a re-conveying route branched from the second discharging route. the re-conveying section conveying the switched-back sheet to the image forming section so that an image is formed on a surface opposite to the surface on which the image is formed;
a closed position in which the opening is closed, and the sheet that has passed through the image forming section is directed toward the second discharge path; and a closed position in which the sheet moves downstream and downward in the discharge direction from the closed position to the an open position in which the opening is opened, the sheet passing through the image forming unit heading toward the first discharge path, the sheet being discharged along the first discharge path via the opening; a cover movable to the open position supporting the seat;
With the cover in the closed position, a first posture is adopted in which the sheet that has passed through the image forming section is guided to the second ejection path, and a sheet that has been switched back in the middle of the second ejection path is transferred to the re-conveyance path. a flapper in a first position that can be displaced into a second position;
An image forming apparatus comprising:
a connecting portion connecting the cover and the flapper, the connecting portion moving the flapper from the first position to the second position in conjunction with the movement of the cover from the closed position to the open position; further comprising the connecting portion that moves the flapper from the second position to the first position in conjunction with the movement of the cover from the open position to the closed position,
The flapper is characterized in that, in the second position, the flapper protrudes from within the housing toward the downstream side in the discharge direction and can come into contact with the sheet conveyed by the conveyance section from above.

In the image forming apparatus of the present invention, when the connecting portion moves the flapper to the second position in conjunction with the movement of the cover from the closed position to the open position, the flapper moves the sheet to be discharged along the first discharge path. By contacting the sheet from above, the sheet is prevented from curling. In other words, the flapper also serves as a discharge guide.

Here, when the sheet discharged along the first discharge path is made of cardboard or the like, the rigidity of the sheet tends to be high. Then, the highly rigid sheet may try to push back the flapper in the second position.

Even in such a case, a large force corresponding to the weight of the cover acts on the flapper via the connecting portion, so that the flapper is held in the second position with high reliability. Thereby, this image forming apparatus can highly reliably prevent the flapper from escaping from the sheet even if the highly rigid sheet tries to push back the flapper at the second position.

Therefore, the image forming apparatus of the present invention can highly reliably suppress curling of the sheet discharged along the first discharge path.

FIG. 2 is a schematic cross-sectional view of the image forming apparatus of the embodiment, showing a state in which the first and second covers are in the closed position, the third cover is in the storage position, and the flapper is in the first position. FIG. 2 is a schematic partial cross-sectional view of the image forming apparatus of the embodiment, showing a state in which the first and second covers are in the open position, the third cover is in the unfolded position, and the flapper is in the second position. FIG. 3 is a rear view of the image forming apparatus according to the embodiment, showing a state in which the first and second covers are in the closed position and the third cover is in the storage position. FIG. 2 is a partial perspective view of the image forming apparatus according to the embodiment, showing a state in which the first and second covers are in the open position, the third cover is in the unfolded position, and the flapper is in the second position. FIG. 3 is a schematic partial cross-sectional view of the image forming apparatus of the embodiment, and is a diagram illustrating the operation of the connecting portion that moves the flapper to the second position in conjunction with the movement of the first and second covers to the open position. FIG. 6 is a schematic partial cross-sectional view similar to FIG. 5, and is a diagram illustrating the operation of the connecting portion that moves the flapper to the first position in conjunction with the movement of the first and second covers to the closed position, in which the flapper is moved to the first position; It is a figure which shows the state displaced to the 1st attitude|position by being biased by the torsion coil spring. FIG. 7 is a schematic partial cross-sectional view similar to FIG. 6, showing a state in which the flapper in the first position has been displaced to the second posture against the biasing force of the torsion coil spring.

Embodiments embodying the present invention will be described below with reference to the drawings.

(Example)
As shown in FIG. 1, an image forming apparatus 1 according to the embodiment is an example of a specific embodiment 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 using an electrophotographic method.

In FIG. 1, the side of the housing 9 of the image forming apparatus 1 where the manual tray 10 is located is defined as the front of the image forming apparatus 1, and the side of the housing 9 where the cover 100 is located is defined as the rear of the image forming apparatus 1. However, 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. Each direction shown in each figure after FIG. 2 is displayed corresponding to FIG. 1.

<Schematic configuration of image forming apparatus>
As shown in FIG. 1, the image forming apparatus 1 includes a housing 9, an image forming section 3, a sheet tray 9C, a feeding section 20, a manual tray 10, a manual feeding section 25, a pair of post-fixing conveyance rollers 26, and a cover 100. , a pair of ejection auxiliary rollers 28, a pair of ejection rollers 29, and a re-conveying section 30. The post-fixing conveyance roller pair 26 is an example of the "conveyance section" of the present invention.

The casing 9 is approximately box-shaped, and the image forming section 3 is located inside the casing 9. The image forming section 3 is of a direct transfer color electrophotographic type. The image forming section 3 includes a process cartridge 4, a transfer belt 6, a scanner section 8, a fixing device 7, and the like, and forms an image on the upwardly facing surface of the sheet SH passing through.

The process cartridge 4 corresponds to toner of four colors, black, yellow, magenta, and cyan, and is an assembly of four cartridges arranged in series in the front-rear direction. The process cartridge 4 includes four photoreceptors 5 corresponding to each color of toner, a developing roller (not shown), a charger, a toner storage section, and the like. The transfer belt 6 faces each photoreceptor 5 from below.

The scanner unit 8 includes a laser light source, a polygon mirror, an fθ lens, a reflecting mirror, and the like. The scanner unit 8 irradiates each photoreceptor 5 in the process cartridge 4 with a laser beam from above.

The fixing device 7 is located at the rear of the process cartridge 4. The fixing device 7 includes a heating roller 7A and a pressure roller 7B. The heating roller 7A is an example of the "heating member" of the present invention. The pressure roller 7B is an example of the "pressure member" of the present invention.

The nip position of the heating roller 7A and the pressure roller 7B is located above the conveying surface 6A of the transfer belt 6 that faces each photoreceptor 5.

The fixing device 7 heats and presses the sheet SH that has passed below the process cartridge 4 using a heating roller 7A and a pressure roller 7B.

The housing 9 has a discharge tray 9T on its upper surface. The discharge tray 9T supports the sheet SH on which image formation has been completed.

The housing 9 removably accommodates a sheet tray 9C at its bottom. The sheet tray 9C stores sheets SH on which images are not formed by the image forming section 3 in a stacked state. The sheet SH is paper, an OHP sheet, or the like.

The feeding section 20 includes a feeding roller 21, a separating roller 22, a separating pad 22A, a first pair of conveying rollers 23, and a second pair of conveying rollers 24, which are arranged along the feeding path PF1.

The feeding path PF1 is a path that proceeds upward and forward from the front end of the sheet tray 9C, then makes a U turn, and proceeds backward to reach the image forming section 3.

The supply roller 21 sends out the sheet SH stored in the sheet tray 9C to the feeding path PF1. The separation roller 22 and the separation pad 22A separate the sheets SH sent out by the supply roller 21 one by one when a plurality of sheets SH are overlapped.

The first conveyance roller pair 23 and the second conveyance 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 section 3.

The housing 9 swingably supports a manual tray 10 on its front side. The manual feed tray 10 has an upright position where it stands up and constitutes a part of the front surface of the housing 9, as shown by the solid line in FIG. It can be moved to a manual insertion position where it projects forward from the middle part of the direction.

The manual feed tray 10 supports a sheet SH, which the user manually feeds onto which the image forming section 3 intends to form an image, in a state where the manual feed tray 10 is in the manual feed position. Sheets SH that can be supported by the manual feed tray 10 include paper, OHP sheets, etc., as well as cardboard, envelopes, and the like.

The manual feeding section 25 is located ahead of the second conveyance roller pair 24. The manual feed section 25 cooperates with the second transport roller pair 24 to transport the sheets SH supported by the manual feed tray 10 at the manual feed position toward the image forming section 3 one by one.

The post-fixing conveyance roller pair 26 is located behind the fixing device 7. The post-fixing transport roller pair 26 includes 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.

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

As shown in FIG. 2, the first discharge path P1 is arranged so that the sheet SH, which passes through the fixing device 7 of the image forming section 3 and is conveyed by the pair of conveying rollers 26 after fixing, has an image-formed surface facing upward. This is a path for discharging the paper in the discharging direction DE1 to a position behind the back surface of the casing 9. The ejection direction DE1 is a direction in which the ejector moves backward along the front-rear direction.

As shown in FIG. 1, the second discharge path P2 guides the sheet SH, which passes through the fixing device 7 of the image forming section 3 and is conveyed by the post-fixing conveyance roller pair 26, above the first discharge path P1. , and a path in which the paper is made a U-turn so that the surface on which the image is formed faces downward, and is discharged onto the discharge tray 9T.

As shown in FIGS. 1 to 4, the housing 9 has an opening 9H on its back surface. The opening 9H is a substantially rectangular opening that opens most of the upper half of the back surface of the housing 9.

As shown in FIG. 2, the opening 9H allows the sheet SH, which passes through the fixing device 7 of the image forming section 3 and is conveyed by the pair of conveying rollers 26 after fixing, to be discharged to a position behind the back surface of the housing 9. Sometimes it is possible to pass the sheet SH.

As shown in FIGS. 1 to 4, the cover 100 includes a first cover 110 and a second cover 120. The housing 9 supports a first cover 110 and a second cover 120 so as to be swingable around 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 vertical direction. The rotation axis of the photoreceptor 5 extends parallel to the width direction.

When the first cover 110 and the second cover 120 respectively swing around the opening/closing axis X100, the cover 100 can be moved between a closed position where the opening 9H is closed, as shown in FIGS. 1 and 3, and a closed position where the opening 9H is closed, as shown in FIGS. 4, it is movable from the closed position to the open position where it moves downstream and downward in the discharge direction DE1 to open the opening 9H.

As shown in FIG. 3, when the first cover 110 is in the closed position, the first cover 110 has an upper portion along the upper edge of the opening 9H and a pair of side edges located on one and the other side in the width direction of the opening 9H. and a lateral portion.

Further, the first cover 110 has a notch 110C. The cutout 110C is a region surrounded by the upper portion and the pair of side portions of the first cover 110.

The second cover 120 is located inside the first cover 110 in the width direction. With the first cover 110 and the second cover 120 in the closed position, the second cover 120 fits into the notch 110C of the first cover 110 and closes the opening 9H together with the first cover 110.

As shown in FIGS. 2 and 4, when the first cover 110 and the second cover 120 are in the open position, the second cover 120 is located downstream and below the first cover 110 in the discharge direction DE1. There is.

As shown in FIG. 4, in this embodiment, the first cover 110 and the second cover 120 are each resin molded products manufactured by injection molding of thermoplastic resin or the like.

The second cover 120 has a flat cover body 121 and a plurality of ribs 129 that respectively protrude from the cover body 121. The ribs 129 are arranged in the width direction at intervals from each other.

As shown in FIG. 1, when the second cover 120 is in the closed position, the cover main body 121 extends in the vertical direction and the width direction to close the opening 9H together with the first cover 110. In this state, each rib 129 protrudes forward from the surface of the cover body 121 facing inside the housing 9 and extends in the vertical direction. In this state, the tip edge 129A of each rib 129, which is located on the opposite side of the cover main body 121 and extends in the vertical direction, is arranged such that the middle part thereof is shifted rearward with respect to the end parts located above and below. It's curved.

The closed position of the first cover 110 and the second cover 120 is a position where the sheet SH, which passes through the fixing device 7 of the image forming section 3 and is conveyed by the post-fixing conveyance roller pair 26, heads toward the second discharge path P2.

The leading edge 129A of each rib 129 extends along the second discharge path P2 when the second cover 120 is in the closed position, and guides the sheet SH conveyed by the post-fixing conveyance roller pair 26 along the second discharge path P2. I will guide you. That is, the sheet SH conveyed by the post-fixing conveyance roller pair 26 is guided by each rib 129 of the second cover 120 and turned upward so that the sheet SH is directed forward. It is discharged onto 9T.

As shown in FIG. 2, the open position of the first cover 110 and the second cover 120 means that the sheet SH, which passes through the fixing device 7 of the image forming section 3 and is conveyed by the pair of conveying rollers 26 after fixing, is placed on the first discharge path. This is the position facing P1.

In the open position, the first cover 110 allows the sheet SH discharged along the first discharge path P1 via the opening 9H to pass through the notch 110C. In the open position, the second cover 120 supports the sheet SH discharged along the first discharge path P1 via the opening 9H by the tip edge 129A of each rib 129. That is, when the second cover 120 is in the open position, each rib 129 projects upward and is lined up in the width direction, and the leading edge 129A of each rib 129 is located at the nip point of the post-fixing conveyance roller pair 26, and , is located below the flapper 50 that has moved to the second position and downstream in the discharge direction DE1, as will be described later.

When a user attempts to form an image on a sheet SH that is difficult to transport along the second ejection path P2, for example, a highly rigid cardboard, an envelope, etc., with the first cover 110 and the second cover 120 in the open position, The sheet SH is supported by the manual feed tray 10 at the manual feed position and fed to the image forming section 3, and the sheet SH that has passed through the image forming section 3 is ejected along the first ejection path P1, so-called straight sheet ejection. You will have to choose.

As shown in FIGS. 1 to 4, the second cover 120 has a third cover 130. As shown in FIGS. The third cover 130 is a flat plate member extending along the outer surface of the cover body 121. The second cover 120 slidably supports the third cover 130 by a pair of slide guides 120G located at one end and the other end of the cover body 121 in the width direction.

By reciprocating in the radial direction of the opening/closing axis X100 along the outer surface of the cover main body 121, the third cover 130 can be moved between the storage position shown in FIGS. 1 and 3 and the deployed position shown in FIGS. 2 and 4. It is movable.

As shown in FIGS. 1 and 3, the third cover 130 overlaps the cover body 121 of the second cover 120 in the storage position. On the other hand, as shown in FIGS. 2 and 4, when the third cover 130 is in the unfolded position, it protrudes rearward from the cover body 121 and opens the sheet SH to be discharged along the first discharge path P1. The second cover 120 is supported together with the second cover 120 in the position.

The discharge auxiliary roller pair 28 is located above the post-fixing conveyance roller pair 26. The ejection roller pair 29 is located forward of the ejection auxiliary roller pair 28 and above the rear end of the ejection tray 9T.

The ejection auxiliary roller pair 28 and the ejection roller pair 29 are controlled by a control section (not shown) to rotate forward and reverse.

When the pair of discharge auxiliary rollers 28 and the pair of discharge rollers 29 rotate forward, the pair of discharge auxiliary rollers 28 nip the sheet SH conveyed along the second discharge path P2 and convey it toward the pair of discharge rollers 29; The discharge roller pair 29 nips the sheet SH and discharges it onto the discharge tray 9T.

The pair of discharge auxiliary rollers 28 and the pair of discharge rollers 29 are controlled by a control unit (not shown) while rotating forward and discharging the sheet SH onto the discharge tray 9T, and are switched from forward rotation to reverse rotation, thereby performing the second discharge. The sheet SH that is being conveyed along the path P2 is switched back so that its trailing edge becomes the leading edge. Then, the pair of discharge auxiliary rollers 28 and the pair of discharge rollers 29 continue to rotate in reverse for a predetermined period of time, thereby conveying the switched back sheet SH toward the reconveying path P3.

The re-conveying path P3 is a path that branches from the second ejecting path P2 and re-conveys the sheet SH, which has been switched back by the reverse rotation of the ejecting auxiliary roller pair 28 and the ejecting roller pair 29, to the image forming section 3.

More specifically, the re-conveyance path P3 branches from a position below the pair of ejection auxiliary rollers 28 in the second ejection path P2 and extends downward, and then extends above the sheet tray 9C and below the transfer belt 6. This is a path in which the transport rollers advance forward, further make an upward U-turn, and merge at a position in front of the second transport roller pair 24 in the feeding path PF1.

The re-conveying unit 30 includes a pair of re-conveying rollers 31, 32, and 33 arranged along the re-conveying path P3. The re-conveying roller pairs 31, 32, and 33 convey the sheet SH, which has switched back and entered the re-conveying path P3 in the middle of the second discharge path P2, along the re-conveying path P3. Then, the re-conveyance unit 30 conveys the switched-back sheet SH to the image forming unit 3 so that an image is formed on the opposite side to the side on which the image was formed.

<Flapper, connecting part, support part, and torsion coil spring>
In the image forming apparatus 1, when the sheet SH that is being transported along the second ejection path P2 is switched back, if no countermeasure is taken, the switched back sheet SH will be mistakenly transferred to the transport roller pair after fixing. There is a possibility that a problem may occur in which the carrier moves toward 26 and becomes unable to enter the retransport route P3.

Further, in the image forming apparatus 1, 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, which faces each photoreceptor 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.

Therefore, as shown in FIG. 2, the sheet SH is nipped by the heating roller 7A and pressure roller 7B of the fixing device 7, and the drive roller 26A and pinch roller 26P of the post-fixing conveyance roller pair 26, and the sheet SH is first ejected. If no measures are taken when the sheet SH is discharged along the path P1, there is a risk that the discharged sheet SH may curl upward. In particular, when the sheet SH is made of cardboard, an envelope, or the like that tends to bend easily, it tends to curl.

In order to suppress these problems, the image forming apparatus 1 includes a flapper 50 shown in FIGS. 1, 2, and 4 to 7, a connecting portion 60 shown in FIGS. It further includes a support portion 70 and a torsion coil spring 59 shown in FIGS. 5 to 7.

As shown in FIGS. 3 and 4, there are a pair of connecting portions 60 on one side and the other side in the width direction of the housing 9, and they have the same configuration and are opposite-handed. Therefore, the connecting portion 60 on one side in the width direction will be described as shown in FIGS. 5 to 7, and the description of the connecting portion 60 on the other side in the width direction will be omitted.

There are also a pair of support parts 70 on one side and the other side in the width direction of the housing 9, and they have the same configuration with opposite hands, so the support part 70 located on one side in the width direction is shown in FIGS. 4 to 7. The explanation will be given as shown in FIG.

There are also a pair of torsion coil springs 59 on one side and the other side in the width direction of the housing 9, and they have the same configuration with opposite hands, so the torsion coil spring 59 located on one side in the width direction is shown in the figure. The torsion coil spring 59 on the other side in the width direction will be explained as shown in FIGS. 5 to 7, and the explanation will be omitted.

As shown in FIGS. 4 and 5, the flapper 50 includes a flapper main body 51, a rotation shaft 56, and a supported shaft 57. In this embodiment, the flapper 50 is a resin molded product manufactured by injection molding of thermoplastic resin or the like.

A pair of rotating shafts 56 and supported shafts 57 are provided at one end and the other end in the width direction of the flapper body 51, respectively, and since they have the same configuration with opposite hands, they are placed on one side in the width direction. The rotation shaft 56 and the supported shaft 57 located on the other side in the width direction will be illustrated and explained in FIGS. 4 to 7, and the explanation of the rotation shaft 56 and the supported shaft 57 on the other side in the width direction will be omitted.

As shown in FIGS. 4 and 5, the flapper main body 51 extends flat in the width direction and has a first surface 50A and a second surface 50B facing oppositely to each other. The first surface 50A and the second surface 50B are each a curved surface substantially composed of a plurality of ribs that protrude from the flapper main body 51 and are spaced from each other and lined up in the width direction.

The rotation shaft 56 is a cylindrical column that protrudes outward in the width direction from the side end surface of the flapper body 51 in the width direction.

The supported shaft 57 is a cylinder that protrudes outward in the width direction from a position spaced apart from the rotation shaft 56 on the side end surface of the flapper main body 51 in the width direction.

As shown in FIGS. 3 and 4, the first cover 110 has a pair of connecting pieces 116 on its outer surface. The pair of connecting pieces 116 are located outside the notch 110C in the width direction and on the upper end side of the first cover 110.

As shown in FIGS. 4 and 5, the connecting portion 60 is one link arm that is bent into a substantially "L" shape when viewed from the side. As shown in FIGS. 5 to 7, the connecting piece 116 of the first cover 110 and one end of the connecting portion 60 are connected at a connecting point CP1.

The other end of the connecting portion 60 is located forward and below the one end of the connecting portion 60, and is also located forward of the first cover 110. The other end of the connecting portion 60 and the rotation shaft 56 of the flapper 50 are connected at a connecting point CP2.

That is, the connecting portion 60 connects the first cover 110 and the flapper 50.

As shown in FIGS. 4 and 5, the support portions 70 are part of the frame members located on one and the other side in the width direction within the housing 9, and protrude rearward. The support portion 70 has a long hole 70H. The elongated hole 70H extends in the front-rear direction along the discharge direction DE1.

As shown in FIGS. 5 to 7, the support portion 70 supports the supported shaft 57 of the flapper 50 so as to be rotatable and slidable in the front-rear direction through the elongated hole 70H.

The torsion coil spring 59 has a coil portion 59C, and one end portion 59A and the other end portion 59B each extending from the coil portion 59C.

The rotation shaft 56 of the flapper 50 is inserted into the coil portion 59C. The one end portion 59A is locked to the flapper body 51 at an intermediate position between the rotating shaft 56 and the supported shaft 57. The other end portion 59B projects upward and rearward from the coil portion 59C.

As shown in FIG. 5, when the first cover 110 and the second cover 120 are in the open position, there is nothing to lock the other end 59B.

When the first cover 110 and the second cover 120 move from the open position shown in FIG. 5 to the closed position shown in FIG. The connecting point CP2 between the connecting portion 60 and the rotating shaft 56 of the flapper 50 moves upstream and downward in the ejection direction DE1, and the rotating shaft 56 of the flapper 50 is moved downward from the supported shaft 57. move it to. As a result, the flapper 50 is rotated around the rotation axis with the first surface 50A facing forward and the second surface 50B facing backward at a position closer to the first cover 110 and the second cover 120 than the first surface 50A. It can be rotated around 56.

At this time, the other end 59B of the torsion coil spring 59 comes into contact with the surface of the second cover 120 facing inside the casing 9 while it is moving to the closed position, and is pushed forward. As a result, as shown in FIG. 6, the torsion coil spring 59 stores a restoring force and urges the flapper 50 to slide the supported shaft 57 forward within the elongated hole 70H.

In this state, the flapper 50 is pushed by the sheet SH transported by the post-fixing transport roller pair 26, and as shown in FIG. Rotate so that it slides backward within the elongated hole 70H.

The position of the flapper 50 shown in FIGS. 1, 6, and 7 is the first position.

The posture of the flapper 50 shown by the two-dot chain line in FIG. 1 and the posture of the flapper 50 shown in FIG. This is the first posture that leads to the second discharge path P2.

The posture of the flapper 50 shown by the solid line in FIG. 1 and the posture of the flapper 50 shown in FIG. 6 are second postures for guiding the sheet SH that has been switched back in the middle of the second discharge path P2 to the re-conveying path P3.

That is, the flapper 50 is in the first position where it can be displaced between the first attitude and the second attitude with the first cover 110 and the second cover 120 in the closed position.

The first surface 50A contacts the sheet SH that is conveyed in the first position and the first attitude of the flapper 50. The second surface 50B comes into contact with the sheet SH that is conveyed through the re-conveying path P3 in the second posture at the first position of the flapper 50.

When the first cover 110 is in the closed position, the connection point CP1 between the connection part 60 and the first cover 110 is located above the flapper 50 in the first position.

When the first cover 110 and the second cover 120 move from the closed position shown in FIG. 6 to the open position shown in FIG. 5, the connecting portion 60 rotates upward around the connecting point CP1 in conjunction with the movement of the first cover 110. The connecting point CP2 between the connecting portion 60 and the rotation shaft 56 of the flapper 50 moves downstream and upward in the discharge direction DE1, and while lifting the rotation shaft 56 of the flapper 50, pulls it downstream in the discharge direction DE1. And the supported shaft 57 is slid downstream in the ejection direction DE1 within the elongated hole 70H.

As a result, the flapper 50 moves to the second position, as shown in FIGS. 2, 4, and 5. When the flapper 50 is in the second position, the first surface 50A faces downward and protrudes from the inside of the casing 9 toward the downstream in the discharge direction DE1. As shown in FIG. 2, the first surface 50A of the flapper 50 can contact the sheet SH conveyed by the post-fixing conveyance roller pair 26 from above.

In this way, the connecting portion 60 moves the flapper 50 from the first position to the second position in conjunction with the movement of the first cover 110 when the first cover 110 and the second cover 120 move from the closed position to the open position. On the other hand, when the first cover 110 and the second cover 120 move from the open position to the closed position, the flapper 50 is moved from the second position to the first position in conjunction with the movement of the first cover 110. ing.

<Image forming operation>
The image forming section 3 forms an image on the sheet SH fed from the sheet tray 9C or the manual feed tray 10 in the following manner. That is, the surface of each photoreceptor 5 is uniformly positively charged by a charger as it rotates, and then exposed by high-speed scanning with a laser beam irradiated from the scanner section 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 photoreceptor 5.

Next, toner is supplied from the toner storage portion to the surface of each photoreceptor 5 in correspondence with the electrostatic latent image, thereby forming a toner image. Then, when the sheet SH passes through the image forming section 3, the upwardly facing surface of the sheet SH faces the photoreceptor 5. Then, the toner image carried on the surface of each photoreceptor 5 is transferred to the upwardly facing surface of the sheet SH. The fixing device 7 fixes the toner image transferred by the heating roller 7A and the pressure roller 7B onto the sheet SH.

As shown in FIG. 1, when the first cover 110 and the second cover 120 are in the closed position and an image is to be formed on only one side of the sheet SH, the post-fixing conveyance roller pair 26 is connected to the fixing unit of the image forming section 3. The sheet SH that has passed through 7 is conveyed along the second discharge path P2. At this time, the flapper 50 in the first position is pushed by the leading end of the sheet SH being conveyed and is displaced to the first attitude, and the first surface 50A comes into contact with the sheet SH. The pair of ejection auxiliary rollers 28 and the pair of ejection rollers 29 rotate forward, nip the sheet SH, and eject it onto the ejection tray 9T.

When the first cover 110 and the second cover 120 are in the closed position and images are to be formed on both sides of the sheet SH, the post-fixing conveyance roller pair 26 moves the sheet SH with an image formed on one side to the second discharge path. Convey along P2. At this time, the flapper 50 in the first position is pushed by the leading end of the sheet SH being conveyed and is displaced to the first attitude, and the first surface 50A comes into contact with the sheet SH. The pair of ejection auxiliary rollers 28 and the pair of ejection rollers 29 rotate forward, nip the sheet SH, and convey it to the middle of the second ejection path P2.

A control unit (not shown) reversely rotates the pair of ejection auxiliary rollers 28 and the pair of ejection rollers 29 at the timing when the rear end of the sheet SH is separated from the flapper 50 and the flapper 50 is displaced to the second position, thereby achieving the second ejection. The sheet SH that is being conveyed along the path P2 is switched back so that its trailing edge becomes the leading edge.

Then, the pair of discharge auxiliary rollers 28 and the pair of discharge rollers 29 continue to rotate in reverse for a predetermined period of time, thereby conveying the switched back sheet SH toward the reconveying path P3. The re-conveyance unit 30 conveys the switched-back sheet SH to the image forming unit 3 so that an image is formed on the opposite side to the side on which the image was formed. The post-fixing transport roller pair 26, the ejection auxiliary roller pair 28, and the ejection roller pair 29 transport the sheet SH, on which images are formed on both sides, along the second ejection path P2, and eject it to the ejection tray 9T.

As shown in FIG. 2, when the first cover 110 and the second cover 120 are in the open position, the post-fixing conveyance roller pair 26 moves the sheet SH that has passed through the fixing device 7 of the image forming section 3 to the first discharge path. The liquid is discharged along P1 through the opening 9H in the discharge direction DE1. The first cover 110 in the open position allows the sheet SH to pass through the notch 110C. Note that not only the sheet SH on which an image has been formed by the image forming section 3, but also a sheet sandwiched between laminate films, for example, is conveyed to the fixing device 7 without image formation, and is transferred to the fixing device 7 by the heating roller 7A and the pressure roller. The sheet crimped and laminated by the sheet 7B may be discharged in the discharge direction DE1 via the opening 9H along the first discharge path P1.

At this time, the flapper 50 in the second position protrudes from inside the housing 9 toward the downstream in the discharge direction DE1, and the first surface 50A contacts the sheet SH conveyed by the post-fixing conveyance roller pair 26 from above. This suppresses the sheet SH from curling upward.

Even if the sheet SH tries to push back the flapper 50, the flapper 50 is held in the second position with high reliability because a large force corresponding to the weight of the first cover 110 acts through the connecting portion 60. . In particular, when a sheet SH such as a highly rigid envelope, cardboard, or the above-mentioned laminated sheet is discharged, the flapper 50 in the second position comes into contact with the sheet SH. Curling can be suppressed.

Then, when the discharged sheet SH is discharged to a position behind the back surface of the casing 9, the second cover 120 supports the sheet SH by the tip edge 129A of each rib 129.

<Effect>
In the image forming apparatus 1 of the embodiment, the connecting portion 60 is linked to the movement of the first cover 110 when the first cover 110 and the second cover 120 move from the closed position shown in FIG. 6 to the open position shown in FIG. to move the flapper 50 to the second position.

As a result, as shown in FIG. 2, the flapper 50 prevents the sheet SH from curling upward due to the first surface 50A coming into contact with the sheet SH discharged along the first discharge path P1 from above. suppress. In other words, the flapper 50 also serves as a discharge guide.

Here, when the sheet SH discharged along the first discharge path P1 is made of cardboard or the like, the rigidity of the sheet SH tends to be high. Then, the highly rigid sheet SH may try to push back the flapper 50 in the second position.

Even in such a case, since a large force corresponding to the weight of the first cover 110 acts on the flapper 50 via the connecting portion 60, the flapper 50 is held in the second position with high reliability. Thereby, the image forming apparatus 1 can highly reliably prevent the flapper 50 from escaping from the sheet SH even if the sheet SH, which has high rigidity, tries to push back the flapper 50 in the second position.

Therefore, the image forming apparatus 1 of the embodiment can highly reliably suppress curling of the sheet SH discharged along the first discharge path P1.

Further, in this image forming apparatus 1, an increase in the number of parts and an increase in size can be suppressed compared to a configuration in which an ejection guide is provided separately from the flapper 50 and the connecting portion 60 connects the cover 100 and the ejection guide. .

Further, as shown in FIGS. 4 and 5, in this image forming apparatus 1, the cover 100 is divided into two members having different functions, that is, the first cover 110 and the second cover 120, so that the flapper 50 is The degree of freedom in designing the range of movement when the first cover 110 moves between the closed position and the second position, the degree of freedom in designing the range of movement when the first cover 110 moves between the closed position and the open position, and the degree of freedom when the second cover 120 moves between the closed position and the closed position. and the degree of freedom in designing the movement range when moving to the open position.

Furthermore, in this image forming apparatus 1, as shown in FIGS. 5 to 7, the connecting portion 60 is connected to the rotating shaft 56 of the flapper 50, and the supporting portion 70 is configured to rotate the supported shaft 57 through the elongated hole 70H. It is supported in a slidable and slidable manner. When the first cover 110 is in the closed position shown in FIGS. 6 and 7, the flapper 50 in the first position rotates around the rotation shaft 56, and the supported shaft 57 slides in the elongated hole 70H. By doing so, it is displaced into the first attitude and the second attitude. When the first cover 110 moves to the open position shown in FIG. The flapper 50 moves to the second position by sliding downstream in the discharge direction DE1. With this configuration, the flapper 50 in the first position can be smoothly displaced between the first attitude and the second attitude.

Further, in this image forming apparatus 1, as shown in FIG. 6, when the first cover 110 is in the closed position, the connection point CP1 between the connection part 60 and the first cover 110 is connected to the flapper 50 in the first position. It is located above. With this configuration, when the flapper 50 interlocked with the movement of the first cover 110 moves to the second position, the posture protruding toward the downstream in the discharge direction DE1 can be easily brought to a horizontal position, so that the flapper 50 can be moved to the first position. Strong contact with the sheet SH discharged along the discharge path P1 can be suppressed.

Furthermore, in this image forming apparatus 1, as shown in FIG. and a second surface 50B that comes into contact with the sheet SH being conveyed through the re-conveying path P3. As shown in FIG. 2, the flapper 50 in the second position projects with the first surface 50A facing downward. With this configuration, the flapper 50 in the second position can smoothly contact the sheet SH discharged along the first discharge path P1 by the first surface 50A.

Furthermore, as shown in FIGS. 2 and 4, this image forming apparatus 1 can expand the area for supporting the sheet SH discharged along the first discharge path P1 by the third cover 130 moved to the unfolded position. .

Further, in this image forming apparatus 1, the second cover 120 supports the third cover 130 so as to be slidable between the storage position and the unfolded position by the slide guide 120G. With this configuration, the user can easily move the third cover 130 between the storage position and the deployed position.

Although the present invention has been described above based on examples, it goes without saying that the present invention is not limited to the above-mentioned examples, and can be applied with appropriate modifications without departing from the spirit thereof.

In the embodiment, 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 including an image reading device above the image forming apparatus.

In the embodiment, the connecting portion 60 is one member, but the present invention is not limited to this configuration. For example, the connecting portion may have a connecting configuration of a plurality of members.

In the embodiment, the cover 100 has the first cover 110 and the second cover 120, and the connecting part 60 moves the flapper 50 in conjunction with the movement of the first cover 110, but the present invention is not limited to this configuration. Not done. For example, the cover may be a single member, and the connecting portion may move the flapper in conjunction with movement of the cover.

In the embodiment, the second ejection path P2 is a path that proceeds in an upward U-turn and ejects the sheet SH to the ejection tray 9T with the image-formed side facing down. is not limited. For example, the second ejection path may be a path in which the sheet is cranked upward and ejected with the image-formed side facing up.

In the embodiment, the third cover 130 slides between the storage position and the deployed position, but the present invention is not limited to this configuration. For example, the third cover may rotate between a storage position and a deployed position.

In the embodiment, the post-fixing conveyance roller pair 26 located downstream of the fixing device 7 in the conveyance direction functions as a conveyance unit and conveys the sheet SH so that it is discharged along the first discharge path P1. It is not limited to the configuration. For example, there is no post-fixing conveyance roller pair 26 between the fixing device 7 and the first cover 110 and second cover 120, and the heating roller 7A and pressure roller 7B of the fixing device 7 function as a conveying section, The present invention also includes a configuration in which the sheet SH is conveyed along the first discharge path P1 by rotation of the roller 7A and the pressure roller 7B, and the sheet SH is directly discharged onto the second cover 120 in the open position.

DESCRIPTION OF SYMBOLS 1... Image forming apparatus, 9H... Opening, 9... Housing 3... Image forming part, SH... Sheet, DE1... Discharge direction P1... First discharge path, P2... Second discharge path 26... Conveyance part (post-fixing conveyance roller versus)
P3... Re-conveyance path, 30... Re-conveyance section, 100... Cover 50... Flapper, 60... Connecting section, 110... First cover 120... Second cover, 57... Supported shaft, 56... Rotating shaft, 70H... Length Hole 70...Support part, CP2...Connection point between the connection part and the rotation axis of the flapper CP1...Connection point between the connection part and the first cover 50A...First surface of the flapper, 50B...Second surface of the flapper 130...No. 3 Cover, 5... Photoreceptor, 7A... Heating member (heating roller)
7B...Pressure member (pressure roller), 7...Fuser

Claims (8)

a casing having an opening;
an image forming unit located within the housing, the image forming unit forming an image on a passing sheet;
A first ejection path that ejects the sheet that has passed through the image forming section in the ejection direction with the surface on which the image is formed facing upward; or a second ejection path that guides and ejects the sheet above the first ejection path. a conveying section for conveying along the discharge route;
The re-conveying unit transports the sheet, which has been switched back so that the rear end of the sheet being conveyed along the second discharging route becomes the leading edge, along a re-conveying route branched from the second discharging route. the re-conveying section conveying the switched-back sheet to the image forming section so that an image is formed on a surface opposite to the surface on which the image is formed;
a closed position in which the opening is closed, and the sheet that has passed through the image forming section is directed toward the second discharge path; and a closed position in which the sheet moves downstream and downward in the discharge direction from the closed position to the an open position in which the opening is opened, the sheet passing through the image forming unit heading toward the first discharge path, the sheet being discharged along the first discharge path via the opening; a cover movable to the open position supporting the seat;
With the cover in the closed position, a first posture is adopted in which the sheet that has passed through the image forming section is guided to the second ejection path, and a sheet that has been switched back in the middle of the second ejection path is transferred to the re-conveyance path. a flapper in a first position that can be displaced into a second position;
An image forming apparatus comprising:
a connecting portion connecting the cover and the flapper, the connecting portion moving the flapper from the first position to the second position in conjunction with the movement of the cover from the closed position to the open position; further comprising the connecting portion that moves the flapper from the second position to the first position in conjunction with the movement of the cover from the open position to the closed position,
The flapper may protrude from within the casing toward the downstream side in the discharge direction and can come into contact with the sheet conveyed by the conveyance unit from above while in the second position. Forming device. The cover includes a first cover that connects to the connecting portion;
a second cover located inside the first cover in a width direction perpendicular to the discharge direction and the vertical direction, the second cover being located downstream of the first cover in the discharge direction when in the open position; The image forming apparatus according to claim 1, further comprising: the second cover located below and supporting the sheet discharged along the first discharge path. The flapper includes a supported shaft protruding outward in the width direction;
a rotating shaft that projects outward in the width direction at a position spaced downward from the supported shaft when the flapper is in the first position;
further comprising a support part that rotatably and slidably supports the supported shaft by an elongated hole extending along the discharge direction,
The connecting portion connects with the rotation shaft of the flapper,
When the first cover is in the closed position, the flapper in the first position rotates around the rotation axis, and the supported shaft slides in the elongated hole, so that the flapper in the first position Displaced between the first posture and the second posture,
When the first cover moves to the open position, the connection point between the connecting portion and the rotation shaft of the flapper moves downstream in the ejection direction, and the supported shaft moves toward the ejection direction within the elongated hole. The image forming apparatus according to claim 2, wherein the flapper moves to the second position by sliding in the downstream direction. 4. The image forming apparatus according to claim 2, wherein when the first cover is in the closed position, a connecting point between the connecting portion and the first cover is located above a flapper in the first position. Device. The flapper has a first surface that contacts the sheet being conveyed in the first attitude at the first position, and a first surface that is closer to the cover than the first surface and is conveyed along the re-conveying path in the second attitude. a second surface that comes into contact with the sheet;
4. The image forming apparatus according to claim 2, wherein the flapper in the second position protrudes with the first surface facing downward. The second cover is movable between a storage position overlapping the second cover and an unfolded position in which the sheet discharged along the first discharge path is supported together with the second cover in the open position. The image forming apparatus according to claim 2 or 3, comprising three covers. 7. The image forming apparatus according to claim 6, wherein the second cover supports the third cover so as to be slidable between the storage position and the unfolded position. The image forming section includes a photoreceptor on which a toner image is formed to be transferred to a sheet;
a fixing device that fixes the toner image transferred by the heating member and the pressure member on the sheet;
The image forming apparatus according to any one of claims 1 to 3, comprising:

Images