JP7331665B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

Conventionally, a discharge tray to which a sheet conveyed through the discharge path is discharged, a re-conveyance path to which a double-sided printed sheet is switched back, and a sheet discharged from the discharge path toward the discharge tray, An image forming apparatus is known that includes a stack lever that presses the sheet toward the discharge tray.

In such an image forming apparatus, the sheets conveyed from the re-conveying path contact and push out the sheets stacked on the discharge tray, which may deteriorate the alignment of the stacked sheets. In particular, when the number of sheets stacked on the discharge tray increases, the contact point of the sheet conveyed from the re-conveyance path to the sheet on the discharge tray becomes closer to the re-conveyance path, and the sheets on which the conveyed sheets are stacked become closer to the re-conveyance path. The extrusion distance becomes longer, and there is a possibility that the deterioration of the alignment of the sheets is increased.

Therefore, in Japanese Patent Application Laid-Open No. 2002-200000, the sheet conveyed from the re-conveying path is guided by the upper surface of the stack lever positioned below the sheet, thereby preventing the sheet from coming into contact with the sheets stacked on the discharge tray. A configuration is disclosed that suppresses this and enables smooth re-conveyance of the sheet.

JP 2016-190696 A

However, in the configuration described in Japanese Patent Application Laid-Open No. 2002-200012, the upper portion of the stack lever is opened, so the sheet transported from the re-transport path is transported in an unintended direction, such as a direction away from the stack lever. , there was a risk that it could not be re-transported smoothly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. By providing a guide member forming a part of the re-conveying path above the stack lever, the posture of the sheet conveyed on the re-conveying path can be changed. allow it to stabilize. In addition, since the distance between the stack lever and the guide member changes according to the number of sheets stacked on the output tray, the number of sheets transported from the re-transport path increases as the number of sheets stacked on the output tray increases. The sheets stacked on the discharge tray come into contact with a portion far from the re-conveyance path, so that the stackability of the sheets can be improved.

An image forming apparatus that solves the above problems has the following features.

That is, the image forming apparatus includes a discharge tray, a discharge path through which the sheet discharged to the discharge tray passes, a re-conveyance path through which the double-sided printed sheet is switched back, and a path from the discharge path to the discharge tray. a rotatable stacking lever that abuts on the sheet discharged by pressing and presses the sheet toward the discharge tray; a guide member extending downstream in the sheet discharge direction and capable of guiding the sheet conveyed through the re-conveying path between itself and the stack lever.

As a result, the posture of the sheet conveyed through the re-conveying path can be stabilized. In addition, the interval between the stack lever and the guide member changes depending on the rotation angle of the stack lever. Since the contact point of the sheet on the ejection tray can be set far away from the re-conveyance path, the alignment of the sheets stacked on the ejection tray can be improved.

Further, the downstream end portion of the guide member in the discharge direction has a first guide surface that guides the sheet conveyed on the re-conveyance path toward the discharge tray.

As a result, it is possible to prevent the user from touching the seat to be switched back.

Also, the first guide surface is located at a position facing the downstream end of the stack lever in the ejection direction.

As a result, the sheet guided toward the discharge tray by the first guide surface can be prevented from moving too far toward the discharge tray, and the alignment of the sheets stacked on the discharge tray can be improved.

Further, the first guide surface has a curved shape that approaches the discharge tray downstream in the discharge direction.

Accordingly, regardless of the contact position of the sheet conveyed on the re-conveying path with the first guide surface, the contact angle of the sheet with respect to the first guide surface can be reduced, and the occurrence of bending of the sheet can be suppressed. .

Further, the stack lever is positioned between a first position where movement toward the first guide surface is restricted and a second position which is a position further away from the first guide surface than the first position. and the upper end of the stack lever at the first position is positioned at the same position in the vertical direction as or below the lower end of the first guide surface.

As a result, the degree of pressing by the stack lever against the sheet guided to the discharge tray side by the first guide surface is not excessively increased, and the sheet can be prevented from being curled.

Moreover, it has a second guide surface forming a lower surface of the re-conveying path, and the lower end of the first guide surface is located below the downstream end of the second guide surface in the discharge direction.

Accordingly, the sheet conveyed through the re-conveying path can be effectively guided toward the discharge tray by the first guide surface.

Further, the guide member can be switched between a covering state covering the upper side of the stack lever and an open state opening the upper side of the stack lever.

Accordingly, by switching to the guide member open state, it is possible to improve the jam processing performance of the sheet conveyed through the re-conveying path.

According to the present invention, it is possible to stabilize the posture of the sheet conveyed through the re-conveying path. In addition, it is possible to improve the alignment of the sheets stacked on the discharge tray.

1 is a schematic side sectional view showing an image forming apparatus; FIG. 1 is a perspective view showing an image forming apparatus; FIG. FIG. 10 is a side cross-sectional view showing the vicinity of the discharge section of the image forming apparatus with the stack lever at the second position; FIG. 3 is a side cross-sectional view showing the vicinity of the discharge section of the image forming apparatus with the stack lever at the first position; 2 is a side cross-sectional view showing the vicinity of a discharge section of the image forming apparatus with the guide member removed from the apparatus main body; FIG. 1 is a side cross-sectional view showing an image forming apparatus in which a guide member is rotatably attached to an apparatus main body; FIG.

Next, a mode for carrying out the present invention will be described with reference to the accompanying drawings.

[Overall Configuration of Image Forming Apparatus]
An image forming apparatus 1 shown in FIGS. 1 and 2 is an embodiment of the image forming apparatus according to the present invention, and includes an apparatus main body 2, a paper feeding unit 3, an image forming unit 5, a discharge unit 7, and a A transport unit 8 and a motor 9 are provided.

In the following description, the right side in FIG. 1 is defined as the front side of the image forming apparatus 1, the left side in FIG. The back side of the paper is defined as the right side of the image forming apparatus 1 . Further, the upper side and the lower side in FIG. 1 are defined as the upper side and the lower side of the image forming apparatus 1, respectively.

The apparatus main body 2 accommodates a paper feeding section 3, an image forming section 5, a discharging section 7, a re-conveying section 8, a motor 9, and the like. As shown in FIGS. 1 and 2, the device body 2 has a front cover 20, a rear cover 21, a left side cover 22, a right side cover 23, a top cover 24, and a guide member 25. As shown in FIGS. The upper surface cover 24 and the guide member 25 are positioned at the upper end of the apparatus main body 2 and constitute the upper surface of the apparatus main body 2 . The guide member 25 is arranged at the rear portion of the top cover 24 .

The front surface of the device main body 2 has an opening 2a, and the front cover 20 is rotatable between a closed position for closing the opening 2a and an open position for opening the opening 2a.

The paper feeding unit 3 is arranged in the lower part of the apparatus main body 2 and can convey the sheet S supported by the sheet cassette 30 to the image forming unit 5 . The image forming unit 5 is arranged downstream of the sheet feeding unit 3 in the conveying direction of the sheet S, and can form an image on the sheet S conveyed from the sheet feeding unit 3 . The discharge unit 7 is arranged downstream of the image forming unit 5 in the conveying direction of the sheet S, and can discharge the sheet S on which an image has been formed by the image forming unit 5 to the outside of the image forming apparatus 1 .

The image forming apparatus 1 has a conveying path L<b>1 for the sheet S from the paper feeding section 3 to the discharging section 7 via the image forming section 5 . The sheet feeding unit 3 includes a sheet cassette 30 that supports sheets S, a sheet feeding mechanism 32 , a transport roller pair 33 , and a registration roller pair 34 .

The paper feed mechanism 32 includes a paper feed roller 32a and a separation roller 32b. The paper feed roller 32a is a roller for feeding the sheet S supported by the sheet cassette 30 toward the separation roller 32b. The separation roller 32b is arranged downstream of the sheet feeding roller 32a in the sheet S conveying direction.

Sheets S fed toward the separation roller 32b by the paper feed roller 32a are separated one by one between the separation roller 32b and a separation pad (not shown). The sheets S separated one by one are conveyed toward the conveying roller pair 33 along the conveying path L1.

The conveying roller pair 33 is a roller that applies a conveying force to the sheet S, and is arranged downstream of the sheet feeding mechanism 32 in the sheet S conveying direction. The sheet S conveyed from the paper feeding mechanism 32 toward the pair of conveying rollers 33 is conveyed by the pair of conveying rollers 33 toward the pair of registration rollers 34 along the conveying path L1.

The registration roller pair 34 is arranged downstream of the transport roller pair 33 in the sheet S transport direction. The registration roller pair 34 corrects the posture of the sheet S by temporarily stopping the movement of the leading edge of the sheet S being conveyed. After that, the registration roller pair 34 conveys the sheet S toward the transfer position of the image forming section 5 at a predetermined timing.

The image forming unit 5 is arranged above the sheet cassette 30, and includes a process cartridge 50 for transferring an image onto the surface of the sheet S conveyed from the paper feeding unit 3, and the surface of the photosensitive drum 54 of the process cartridge 50. An exposure unit 56 for exposure and a fixing unit 60 for fixing an image transferred to the sheet S by the process cartridge 50 are provided.

The process cartridge 50 includes a developer containing chamber 51, a supply roller 52, a developing roller 53, a photosensitive drum 54, a transfer roller 55, and the like. The exposure unit 56 includes a laser diode, a polygon mirror, a lens, a reflecting mirror, and the like. The surface of the photosensitive drum 54 is exposed.

The developer containing chamber 51 contains toner as a developer. The toner stored in the developer storage chamber 51 is sent to the supply roller 52 while being stirred by a stirring member (not shown). The supply roller 52 further supplies the toner sent from the developer storage chamber 51 to the development roller 53 .

The developing roller 53 is arranged in close contact with the supply roller 52, and carries toner supplied from the supply roller 52 and charged by a slide contact member (not shown). A developing bias is applied to the developing roller 53 by bias applying means (not shown).

The photosensitive drum 54 is arranged adjacent to the developing roller 53 . The surface of the photosensitive drum 54 is uniformly positively charged by a charger (not shown) and then exposed by the exposure unit 56 . The exposed portion of the photoreceptor drum 54 has a lower potential than other portions, and an electrostatic latent image based on the image data is formed on the photoreceptor drum 54 . Then, positively charged toner is supplied from the developing roller 53 to the surface of the photosensitive drum 54 on which the electrostatic latent image is formed, so that the electrostatic latent image is visualized and becomes a developer image. .

The transfer roller 55 is arranged to face the photosensitive drum 54, and is applied with a negative transfer bias by a bias applying means (not shown). In a state where a transfer bias is applied to the surface of the transfer roller 55, the sheet S is nipped and conveyed between the photosensitive drum 54 on which the developer image is formed and the transfer roller 55 (transfer position). , the developer image formed on the surface of the photosensitive drum 54 is transferred to the surface of the sheet S. As shown in FIG.

The fixing section 60 has a heating roller 61 and a pressure roller 62 . The heating roller 61 is rotationally driven by the driving force from the motor 9 and is heated by supplying power from a power source (not shown). The pressure roller 62 is arranged to face the heating roller 61 and is in close contact with the heating roller 61 and is driven to rotate. When the sheet S to which the developer image has been transferred is conveyed to the fixing section 60, the sheet S is conveyed while being nipped between the heating roller 61 and the pressure roller 62, and the developer image is fixed on the sheet S. .

The discharge section 7 has a first intermediate discharge roller pair 70 , a second intermediate discharge roller pair 71 , a discharge roller pair 72 and a discharge tray 73 . The first intermediate discharge roller pair 70 and the second intermediate discharge roller pair 71 are arranged downstream of the image forming section 5 in the sheet S conveying direction. The first intermediate discharge roller pair 70 and the second intermediate discharge roller pair 71 further convey the sheet S conveyed from the fixing section 60 toward the discharge roller pair 72 .

The discharge roller pair 72 is configured to further convey the sheet S conveyed by the first intermediate discharge roller pair 70 and the second intermediate discharge roller pair 71 and discharge the sheet S to the outside of the apparatus main body 2 . The discharge tray 73 is formed on the upper surface cover 24 , and the sheet S discharged to the outside of the apparatus main body 2 by the discharge roller pair 72 is supported by the discharge tray 73 .

The sheet S discharged from the apparatus main body 2 to the discharge tray 73 by the discharge roller pair 72 branches from the conveying path L1 at the branch portion 10 located between the first intermediate discharge roller pair 70 and the second intermediate discharge roller pair 71. It is transported along the discharge route L11. The discharge path L11 is a path through which the sheet S discharged to the discharge tray 73 passes.

The image forming apparatus 1 has a rotatable stack lever 75 that contacts the sheet S discharged toward the discharge tray 73 from the discharge path L<b>11 by the discharge roller pair 72 and presses the sheet S toward the discharge tray 73 . are doing. A plurality of stack levers 75 are provided along the left-right direction. In the present embodiment, the stack levers 75 are provided at three locations on the discharge tray 73, ie, the left and right ends and the left and right central portion.

[Retransport route]
The image forming apparatus 1 has a re-conveying path L<b>2 for conveying the sheet S conveyed downstream from the image forming section 5 in the conveying direction toward the image forming section 5 again. In the image forming apparatus 1, for example, when double-sided printing is performed on the sheet S, the sheet S conveyed downstream in the conveying direction from the image forming section 5 is conveyed again toward the image forming section 5 along the re-conveying path L2. be done. The reconveyance route L2 has a first route L21 and a second route L22.

The first path L21 is positioned behind the image forming section 5, and when double-sided printing is performed on the sheet S, the sheet S conveyed from the image forming section 5 is switched back and the front and back of the sheet S are switched. It is a route for A part of the first path L21 is configured by the guide member 25 of the apparatus main body 2 .

The first path L21 branches off from the conveying path L1 at a branching portion 10 between the first intermediate ejection roller pair 70 and the second intermediate ejection roller pair 71 . The first path L21 extends upward from the branch portion 10 and then bends forward. The end of the first path L21 opposite to the branch 10 side is an open opening 13 . When the sheet S introduced into the first path L21 is conveyed from the branch portion 10 side toward the opening portion 13 side, the portion that does not fit within the first path L21 is pushed outside the apparatus main body 2 from the opening portion 13. configured to extend.

The second path L22 branches from the transport path L1 at a branching portion 10, and joins the transport path L1 at a junction 11 between the transport roller pair 33 and the registration roller pair 34 in the transport path L1. The second path L<b>22 extends downward from the branch portion 10 , bends forward, and then bends upward to reach the junction portion 11 . The second path L22 is connected to the first path L21 at the branch portion 10, so that the sheet S switched back on the first path L21 can be introduced into the second path L22.

A switchback roller pair 74 is provided on the first path L21. The switchback roller pair 74 is configured to be able to switch the rotation direction, and the rotation direction (forward rotation direction) when introducing the sheet S to the first path L21 and the rotation direction (normal rotation direction) when the sheet S is introduced from the first path L21 to the second path L22. It is configured to be drivable in the rotating direction (reversing direction) when conveying to. The sheet S conveyed to the second path L22 is conveyed toward the image forming section 5 by the second re-conveying roller pair 36 and the first re-conveying roller pair 35 provided on the second path L22.

In the image forming apparatus 1, the sheet S on which an image is formed on one surface by the image forming section 5 disposed in the middle of the transport path L1 is image-formed through the first path L21 and the second path L22 of the re-transport path L2. It is possible to convey the sheet S again to the unit 5 and form an image on the other side of the sheet S, that is, perform double-sided printing.

[Switchback mechanism]
As shown in FIG. 1 , the image forming apparatus 1 has a flapper 12 arranged in the branch section 10 . The flapper 12 is a member that switches the conveying direction of the sheet S conveyed from the conveying path L1 between the discharge path L11 and the re-conveying path L2 at the branch portion 10, and is provided swingably with respect to the apparatus main body 2. there is

When guiding the sheet S conveyed from the fixing unit 60 to the discharge tray 73 along the discharge path L11, the flapper 12 is positioned at the discharge position (indicated by the solid line in FIG. 1) at which the opening 10a leading to the re-conveyance path L2 is closed. position). Further, when guiding the sheet S conveyed from the fixing section 60 to the re-conveying path L2, the flapper 12 swings to the re-conveying position (the position indicated by the two-dot chain line in FIG. 1) ahead of the discharge position. The opening 10a is opened and the discharge path L11 leading to the discharge tray 73 is closed.

When the flapper 12 is at the re-conveying position, the sheet S sent from the conveying path L1 to the opening 10a is conveyed obliquely backward and upward, and introduced into the first path L21 of the re-conveying path L2. The sheet S introduced into the first path L21 is inherited by the switchback roller pair 74, and is conveyed to the first path L21 side until the full length of the sheet S along the conveying direction passes through the opening 10a. .

After the full length of the sheet S has passed through the opening 10a, the rotation direction of the switchback roller pair 74 is reversed, and the sheet S is conveyed from the first path L21 toward the second path L22. At this time, the flapper 12 is swung from the re-conveying position to the discharging position to close the opening 10a. Next, the sheet S is handed over from the switchback roller pair 74 to the second re-conveying roller pair 36 and the first re-conveying roller pair 35, and conveyed along the second route L22. Reintroduced into L1.

[Stack Lever]
As shown in FIGS. 3 and 4, the stack lever 75 is configured to be vertically rotatable about a rotating shaft portion 75a at the rear end. , is in the lower second position (the position shown in FIG. 3) by its own weight. In this state, the tip 75 b of the stack lever 75 is not in contact with the discharge tray 73 and is spaced upward from the discharge tray 73 . A tip portion 75b of the stack lever 75 is a downstream end portion of the stack lever 75 in the ejection direction, and is located downstream of the rotating shaft portion 75a in the ejection direction.

Further, when the sheet S is discharged to the discharge tray 73 and stacked on the discharge tray 73 , the upper surface of the stacked sheet S abuts the leading end portion 75 b of the stack lever 75 . A tip portion 75b of the stack lever 75 is pushed up by coming into contact with the upper surface of the sheet S, and the stack lever 75 moves upward from the second position. When the discharge tray 73 is fully loaded with sheets S, the stack lever 75 moves to the first position (the position indicated by the solid line in FIG. 4) where the leading end portion 75b is positioned higher than the second position. do.

The stack lever 75 is restricted from further upward rotation when it is in the first position. Specifically, the stack lever 75 has an engaging portion 75c behind the pivot shaft portion 75a, and the device main body 2 has an engaged portion 27 to which the engaging portion 75c engages. Then, when the stack lever 75 moves to the first position, the locking portion 75c is locked to the locked portion 27, and the stack lever 75 is restricted from rotating upward any further.

The first position of the stack lever 75 is the upper end position of the vertical movement range of the stack lever 75 , and the second position of the stack lever 75 is the lower end position of the vertical movement range of the stack lever 75 . That is, the stack lever 75 is configured to be movable between the first position and the second position in the vertical direction.

When the upper surface of the sheets S stacked on the discharge tray 73 contacts the leading end 75b of the stack lever 75 and the stack lever 75 moves above the second position, the sheets S on the discharge tray 73 are not stacked. The weight of the lever 75 presses it toward the discharge tray 73 .

[Guide member]
As shown in FIGS. 3 and 4, the guide member 25 is attached to the upper end portion of the apparatus main body 2 . The guide member 25 is positioned above the stack lever 75 and covers the stack lever 75 from above. The guide member 25 extends downstream of the stack lever 75 in the discharge direction of the sheet S above the stack lever 75 . In other words, the downstream end of the guide member 25 is located downstream of the stack lever 75 in the sheet discharge direction.

The first route L21 of the reconveyance route L2 has a route L21a extending upward from the branching portion 10 and a route L21b extending forward by bending from the upper end of the route L21a. The guide member 25 has an upper path surface 25a forming the upper surface of the route L21b and a lower route surface 25c forming the lower surface of the route L21b. That is, the path L21b is defined by the upper path surface 25a and the lower path surface 25c. The lower route surface 25c is an example of a second guide surface forming the lower surface of the re-conveyance route.

The opening 13 of the first path L21 is located at the downstream end of the path L21b in the discharge direction. A tip portion 75b of the stack lever 75 is positioned downstream in the ejection direction of the opening 13 of the first path L21.

A downstream end portion of the guide member 25 in the discharge direction has a first guide surface 25 b capable of guiding the sheet S conveyed along the first path L<b>21 between itself and the stack lever 75 . The first guide surface 25b is located downstream of the upper path surface 25a in the ejection direction, and is arranged at a position facing the tip portion 75b of the stack lever 75. As shown in FIG. The first guide surface 25b is configured to guide the sheet S conveyed along the first path L21 toward the discharge tray 73 side.

As described above, in the image forming apparatus 1, the sheet S conveyed downstream in the ejection direction along the first path L21 can be guided between the stack lever 75 and the first guide surface 25b of the guide member 25. are doing. Therefore, it is possible to prevent the sheet S from being conveyed in an unintended direction, such as when the guide member 25 is not provided and the upper portion of the stack lever 75 is open. It is possible to stabilize the posture of the seat S, which is placed on the ground.

In particular, since the first guide surface 25b of the guide member 25 is configured to guide the sheet S conveyed along the first path L21 toward the discharge tray 73 side, the first guide surface 25b of the guide member 25 guides the first path L21 downstream in the discharge direction. The sheet S conveyed toward the output tray 73 is not excessively conveyed forward while floating upward from the discharge tray 73, and it is possible to prevent the user from touching the sheet S that is switched back. .

Further, since the first guide surface 25 b is arranged at a position facing the tip portion 75 b of the stack lever 75 , the sheet S guided toward the discharge tray 73 by the first guide surface 25 b It contacts the portion 75b and can be prevented from moving too far toward the discharge tray 73 side.

When the sheet S guided by the first guide surface 25b moves too far toward the discharge tray 73, the angle of contact with the sheet S stacked on the discharge tray 73 becomes too large. may be pushed forward.

However, in the image forming apparatus 1 , the sheet S guided by the first guide surface 25 b abuts against the tip portion 75 b of the stack lever 75 and is prevented from moving too far toward the discharge tray 73 . It is possible to improve the alignment of the sheets S stacked on the discharge tray 73 without an excessively large contact angle with the sheets S stacked thereon.

In this case, the distance between the stack lever 75 and the first guide surface 25b of the guide member 25 changes depending on the rotation angle of the stack lever 75. The distance D from the first guide surface 25b is reduced. For example, when the sheet S is stacked on the discharge tray 73, the distance D1 (see FIG. 3) between the stack lever 75 and the first guide surface 25b when the sheet S is not stacked on the discharge tray 73 is longer than the distance D1 (see FIG. 3). The distance D2 (see FIG. 4) between the stack lever 75 and the first guide surface 25b is smaller.

Therefore, when the sheet S is stacked on the discharge tray 73, the contact point with the sheet S on the discharge tray 73 when the sheet S to be switched back is conveyed downstream in the discharge direction is set far from the first path L21. It is possible to position them apart from each other, so that the alignment of the sheets S stacked on the discharge tray 73 can be improved.

The first guide surface 25b has a curved shape that approaches the discharge tray 73 downstream in the discharge direction and is recessed upward, so that the first guide surface 25b guides the sheet S conveyed along the first path L21 to the discharge tray 73. It is configured to guide toward the side.

As a result, regardless of the contact position of the sheet S conveyed on the first path L21 with the first guide surface 25b, the contact angle of the sheet S with respect to the first guide surface 25b can be reduced, and the sheet S can be folded. It is possible to suppress the occurrence of

However, the first guide surface 25b may have a shape other than the curved shape as long as it approaches the discharge tray 73 downstream in the discharge direction. For example, the first guide surface 25b may be an inclined surface that approaches the discharge tray 73 downstream in the discharge direction. Thus, if the first guide surface 25b has a shape that approaches the discharge tray 73 toward the discharge direction downstream, the sheet S conveyed along the first path L21 can be guided toward the discharge tray 73 side.

When the stack lever 75 is at the first position, the tip 75b of the stack lever 75 is close to the first guide surface 25b, and when the stack lever 75 is at the second position, the tip of the stack lever 75 75b is located farther from the first guide surface 25b than when the stack lever 75 is at the first position.

The vertical position T1 of the upper end of the stack lever 75 at the first position is the same as or lower than the vertical position T2 of the lower end of the first guide surface 25b. In other words, the upper end of the stack lever 75 at the first position is located at the same vertical position as or below the lower end of the first guide surface 25b. As shown in FIG. 4, in this embodiment, the position T1 of the upper end of the stack lever 75 at the first position is located below the position T2 of the lower end of the first guide surface 25b.

Here, if the position T1 of the upper end of the stack lever 75 at the first position is positioned above the position T2 of the lower end of the first guide surface 25b, the first guide surface 25b guides the stack lever 75 toward the discharge tray 73 side. The degree of pressing by the stack lever 75 against the sheet S on which the sheet S is placed is too large, and the sheet S may be bent.

However, in the image forming apparatus 1, the position T1 of the upper end of the stack lever 75 at the first position is at the same position as or lower than the position T2 of the lower end of the first guide surface 25b. The degree of pressing by the stack lever 75 against the sheet S guided to the tray 73 side is not excessively increased, and it is possible to suppress the sheet S from being bent.

Further, as shown in FIG. 3, the downstream end of the lower path surface 25c in the ejection direction is located at a position T3 in the vertical direction, and the position T2 of the lower end of the first guide surface 25b is located at the position T3 of the lower path surface 25c. located below. That is, the lower end of the first guide surface 25b is positioned closer to the discharge tray 73 than the downstream end of the lower path surface 25c. Therefore, it is possible to effectively guide the sheet S conveyed downstream in the discharge direction on the first path L21 toward the discharge tray 73 by the first guide surface 25b.

The guide member 25 is detachably attached to the upper end of the apparatus main body 2, and is attached to the apparatus main body 2 to cover the stack lever 75 from above (see FIGS. 3 and 4). 5) in which the upper side of the stack lever 75 is opened.

In this way, by configuring the guide member 25 to be switchable between the covered state and the open state, for example, when a jam occurs in the sheet S conveyed along the first path L21, the guide member 25 can be removed from the apparatus main body 2. By removing and switching to the open state, it is possible to improve the jam processing performance of the sheet S conveyed on the first path L21.

[Variation]
In the above-described embodiment, the guide member 25 is detachably attached to the device main body 2, but it is limited to being detachably attached to the device main body 2 as long as it can be switched between the covered state and the open state. do not have. For example, the guide member 25 can be rotatably attached to the device body 2 .

The guide member 25 shown in FIG. 6 is attached to the device main body 2 so as to be rotatable about a rotation axis 25d at the rear end. In this case, the guide member 25 can be switched to the covering state covering the upper side of the stack lever 75 by rotating downward, as indicated by a two-dot chain line in FIG. By rotating upward, the upper part of the stack lever 75 can be switched to an open state.

1 image forming apparatus 2 apparatus main body 25 guide member 25a upper path surface 25b first guide surface 25c lower path surface 73 ejection tray 75 stack lever L1 transport path L11 ejection path L2 re-transport path L21 first path L21a path L21b path L22 second Route S sheet

Claims (7)

an ejection tray;
a discharge path through which the sheet discharged to the discharge tray passes;
a re-conveying path for switching back the sheet to be double-sided printed;
a rotatable stack lever that contacts the sheet discharged from the discharge path toward the discharge tray and presses the sheet toward the discharge tray;
The re-conveying path constitutes a part of the re-conveying path and extends downstream of the stack lever in the sheet discharging direction, and guides the sheet conveyed on the re-conveying path between the stack lever and the stack lever. a possible guide member;
An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein a downstream end of the guide member in the ejection direction has a first guide surface that guides the sheet conveyed on the re-conveyance path toward the ejection tray. 3. The image forming apparatus according to claim 2, wherein the first guide surface is located at a position facing a downstream end of the stack lever in the ejection direction. 4. The image forming apparatus according to claim 2, wherein the first guide surface has a curved shape that approaches the discharge tray downstream in the discharge direction. The stack lever moves between a first position where movement toward the first guide surface is restricted and a second position where the stack lever is further away from the first guide surface than the first position. is possible and
5. The upper end of the stack lever at the first position is located at the same vertical position as or below the lower end of the first guide surface. image forming device. Having a second guide surface that constitutes the lower surface of the re-conveyance path,
The image forming apparatus according to any one of claims 2 to 5, wherein a lower end of the first guide surface is located below a downstream end of the second guide surface in the discharge direction. The image forming apparatus according to any one of claims 1 to 6, wherein the guide member is switchable between a covered state covering the upper side of the stack lever and an open state in which the upper side of the stack lever is opened. .

Images