JP2001330998A - Double-sided reversing device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A reversing unit capable of performing stable recording paper conveyance and reversing operation without keeping heat in a switchback conveyance path.
Provided is a double-sided reversing device of a type in which a re-conveying unit is arranged vertically. SOLUTION: A reversing unit 210 is formed so as to protrude laterally more than a re-transporting unit 220, and a first ventilation hole (group) 215 is provided on an upper surface, so that heat trapped in the double-side reversing device 200 is provided. Is discharged to the upper part. In addition, the fan 216 is attached to the upper portion to efficiently discharge heat. Further, a second ventilation hole (group) 217 is provided below the protruding portion of the reversing portion 210, and the heat of the sheet passing through the switchback transport path 211 is efficiently discharged to the upper ventilation hole 215, and the ventilation hole is formed by the flow of heat. 217 to double-sided reversing device 20
Fresh air is taken into the chamber to increase the cooling efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, an FA
The present invention relates to a double-sided reversing device which is mounted on an image forming apparatus such as a copying machine and a copying machine, and is capable of reversing a recording sheet to record an image on both sides.

[0002]

2. Description of the Related Art As this kind of technology, for example, the invention disclosed in Japanese Patent Application Laid-Open No. Hei 10-338404 according to the present inventors is known. The present invention addresses the problems of the inventions disclosed in JP-A-6-250463 and JP-A-2-255476, and switches back and reverses a sheet of the maximum size to be used in a mounted image forming apparatus. It is intended to be able to be transported, to save space, not to interfere with the connection of other peripheral devices, and not to bother the operator. Therefore, the present invention conveys the sheet received in the switchback conveyance path until the rear end passes through the conveyance path switching means provided in the switchback conveyance path, and then switches the conveyance path switching means to convey the sheet. In a double-sided reversing device having a switchback unit that switches back the received direction in the opposite direction and guides the received path to a different transport path from the time of reception by the transport path switching unit, A sheet path switching member that switches the path of the leading end of the sheet received in the switchback path between a first direction and a second direction different from the first direction on the downstream side in the conveying direction when receiving the sheet. The configuration is provided. In the embodiment, the sheet is supplied from the lower part of the image forming unit, and after the image is formed, is fixed and comes out to the upper part. The switching with the side is performed.

[0003]

According to the present invention, the sheet fed from the fixing unit as described above is sent to the re-conveying unit via the switchback conveying path by the reversing roller, and is conveyed again to the image forming apparatus. The reversing unit and the re-transporting unit are configured vertically, but in this type of device,
The heat in the double-sided reversing device, particularly the heat of the re-conveying unit and the switchback conveying path, tends to be collected in the reversing unit disposed above the double-sided reversing device.

[0004] On the other hand, the speed of double-sided printing tends to be increased, the sheet conveyance interval becomes narrower, and the heat of the sheet heated by the fixing unit in the reversing section and the switchback conveyance path is more and more increased. Become. As described above, when heat is accumulated in the switchback conveyance path and becomes high temperature, when forming an image on both sides of the paper, the paper is sent to the re-conveyance unit while the surface on which the toner adheres contacts the switching claw,
The toner may adhere to the switching claw or the like, and may hinder the conveyance of the paper over time. Further, there is a possibility that the guide plate or the like of the resin employed due to weight reduction or the like is thermally deformed, thereby deforming the paper transport path. When the transport path is deformed in this way, the possibility of occurrence of jam increases, and when the transport path is further deformed, in the worst case, the resin guide plate may be damaged.

The present invention has been made in view of such a situation of the prior art, and an object of the present invention is to prevent the heat from being trapped in the switchback conveyance path, thereby enabling stable conveyance of recording paper and reversal operation. An object of the present invention is to provide a double-sided reversing device in which a reversing unit and a re-transporting unit are arranged vertically.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a reversing unit for reversing a sheet having an image formed on one side in a switchback conveyance path, and feeding the reversed sheet to an image forming unit. In a double-sided reversing device attached to an image forming apparatus, a re-conveying unit is disposed vertically, and means for discharging hot air in the double-sided reversing device is provided in the reversing unit.

In this case, as means for discharging the hot air, a ventilation hole is provided in a housing wall near the reversing portion.
It is further preferable that hot air is forcibly released from the ventilation holes. For example, a fan can be used as a means for forcibly releasing hot air.

The ventilation holes are provided with a first ventilation hole (group) on the upper surface side of the reversing portion and a second ventilation hole (group) on the side surface. At that time, the side of the reversing portion is made to protrude from the re-transporting portion, and the second vent hole is provided at a position corresponding to a lower portion of the protruding portion, so that outside air can flow upward from below in the reversing portion. Cooling efficiency can be increased.

[0009]

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

FIG. 1 is a schematic configuration diagram showing the overall configuration of an image forming apparatus according to an embodiment of the present invention. In FIG. 1, an image forming apparatus includes an apparatus main body 100 and a two-sided reversing apparatus 2.
00, and the paper feeding unit 11
0, an image forming unit 120, a fixing unit 130, a transport path switching unit 140, and a paper discharging unit 150. The duplex transporting apparatus 200 includes a reversing unit 210 and a re-transporting unit 220.

The paper supply unit 110 includes two paper supply trays 111a and 111b provided at a lower portion of the apparatus main body 1.
Paper feed rollers 112a and 112b for feeding out paper from the paper feed trays 111a and 111b are used to feed paper. The fed paper is separated into one sheet by separation rollers 113 a and 113 b forming a pair in the vertical direction, and is conveyed to the image forming unit 120 having the photoconductor 121. The surface of the photoreceptor 121 is irradiated with light from an exposure device 122 corresponding to an image to be formed, and a charged surface uniformly charged by a charging device (not shown) is exposed to form a latent image, and further a toner image is formed. To form a visible image (toner image).

The developed visible image is transferred onto a sheet by a transfer belt 123, and the visible image is fixed by applying heat while being pressed by a pair of fixing rollers 131 of a fixing unit 130. The sheet is switched by the switching claw 14 of the transport path switching unit 140.
1, the paper discharge tray 152
To the discharge path 151 and the double-sided reversing device 20 described below.
It is conveyed to one of the discharge paths 153 heading to zero.

The reversing unit 210 of the double-side reversing device 200 includes a switchback transport path 211, a re-transport path 212, a reversing roller 213, and a path switching claw 214.
After the sheet received from 40 into the switchback conveyance path 211 is conveyed until the rear end passes through the path switching claw 214 which is the conveyance path switching means provided in the switchback conveyance path 211, the switching claw 214 is moved to the position shown in FIG. Switch to the position indicated by the virtual line. As a result, the sheet is switched back in the direction opposite to the received direction (the direction indicated by the arrow A) and guided by the path switching claw 214 to the re-conveying path 212 which is a conveying path different from that at the time of the receiving. The switchback of the sheet is performed by a reversing roller 213 provided in the switchback transport path 211 so as to be rotatable in both forward and reverse directions.

The double-side reversing device 200 is a main body 1 of the image forming apparatus.
When the sheet on which an image is formed on one side is received from the 00 side, the sheet is guided in the direction of the reversing roller 213 by the path switching claw 214 at the rotation position indicated by the phantom line in FIG. At this time, since the reversing roller 213 is rotating clockwise in FIG. 1, the sheet is further conveyed in the direction of arrow A, and the leading end advances downward in the switchback conveyance path 211. When the trailing edge of the sheet passes through the path switching claw 214, the path switching claw 214
Is switched to the rotation position indicated by the solid line in FIG. 1, and the reversing roller 213 rotates counterclockwise in the reverse direction. Therefore, the sheet is switched back with the rear end side changed to the front end side, and is guided to the re-conveyance path 212 by the path switching claw 214.

The sheet is again conveyed from the re-conveying section 212 into the image forming apparatus main body 100, and the second sheet on which an image has not yet been formed by the image forming section 120 having the photosensitive member 121.
The image is formed on the surface, the image is fixed by the fixing unit 130, and the switching claw 141 is rotated to the position indicated by the solid line in FIG.
As a result, the sheet is discharged onto the sheet discharge tray 152 through the discharge path 151.

The reversing unit 210 is a reversing roller 2
13 and the re-conveying unit 220 indicates the part where the re-conveying roller 221 is disposed, but as shown in FIG. Is formed so as to protrude to the side, and a first ventilation hole (group) 215 is provided on the upper surface,
The heat trapped in the double-sided reversing device 200 is discharged to the upper part. Further, by attaching the fan 216 to the upper part, it is possible to discharge heat more efficiently. Further, as shown in an enlarged view of a main part of the reversing part 210 in FIG. 2, a second ventilation hole (group) 217 may be provided below the protruding part of the reversing part 210. By providing the second ventilation hole 217 in this manner, the heat of the sheet passing through the switchback conveyance path 211 can be efficiently discharged to the first ventilation hole 215 on the upper side, and the second communication hole is formed by the flow of heat. Pores 217
Thus, fresh air can be taken into the double-sided reversing device 200. As a result, the temperature rise in the reversing section 210 can be mitigated, and the toner does not adhere to the switching claw 214 or the like, and the conveyance of the sheet with time is not hindered. Furthermore, there is no risk of thermal deformation of the resin guide plate or the like employed due to weight reduction or the like, and the switchback transport path 211 and the re-transport path 212 do not deform. Therefore, there is no possibility of occurrence of jams due to deformation of the transport path, and no damage to the resin guide plate or the like.

In the embodiment shown in FIGS. 1 and 2, the second vent hole 2
Although 17 is provided, a second ventilation hole (group) 218 may be arranged on the side surface of the protruding portion of the reversing portion 210 as shown in FIG. In this case, the same effect as that shown in FIGS. 1 and 2 can be obtained.

[0018]

As described above, according to the first aspect of the present invention, since the reversing unit is provided with the means for releasing the hot air in the double-sided reversing device, heat does not accumulate in the switchback conveyance path, and the switchback conveyance path is stable. The transport and the reversal operation of the recording paper that has been performed can be performed.

According to the second aspect of the present invention, since the means for discharging hot air comprises the ventilation hole provided in the housing wall near the reversing portion, the hot air near the reversing portion can be reliably discharged. Becomes

According to the third aspect of the present invention, the means for forcibly releasing hot air from the vent hole is provided.
In addition to the effects of the invention described above, hot air can be released more efficiently.

According to the fourth aspect of the present invention, since the means for forcibly releasing hot air comprises a fan, forced cooling can be achieved with a simple configuration.

According to the fifth aspect of the present invention, since the ventilation hole is composed of the first ventilation hole provided on the upper surface side of the reversing portion and the second ventilation hole provided on the side surface, A circulation route is secured, and heat is not stored in the switchback transport route, so that reliable cooling is possible.

According to the sixth aspect of the present invention, the side of the reversing portion is protruded from the re-transporting portion, and the second ventilation hole is provided at a position corresponding to the lower portion of the protruding portion. Since cold air is introduced into the furnace and the heated air used for cooling is discharged from above, more reliable cooling becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus provided with a two-sided reversing device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part showing a cooling structure of the double-sided reversing device of FIG. 1;

FIG. 3 is an enlarged view of a main part showing another cooling structure of the double-sided reversing device of FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 image forming apparatus 200 double-sided reversing device 210 reversing section 211 switchback transport path 212 re-transport path 213 reversing roller 214 path switching claw 215 first vent 216 fan 217 second vent 218 second vent 220 re-transport Part 221 Re-conveyance roller

Claims (6)

[Claims] 1. A reversing unit for reversing a sheet on which an image is formed on one side in a switchback conveying path, and a re-conveying unit for feeding the reversing sheet to the image forming unit are vertically arranged and attached to the image forming apparatus. A double-sided reversing device according to claim 1, wherein said reversing unit is provided with a means for discharging hot air in the double-sided reversing device. 2. The double-sided reversing device according to claim 1, wherein the means for releasing the hot air is a ventilation hole provided in a housing wall near the reversing portion. 3. A double-sided reversing device according to claim 2, further comprising means for forcibly discharging hot air from said vent hole. 4. The double-sided reversing device according to claim 3, wherein said means for forcibly releasing hot air comprises a fan. 5. The air vent according to claim 2, wherein the air vent comprises a first air vent provided on an upper surface side of the reversing portion and a second air vent provided on a side surface. Double-sided reversing device. 6. The double-sided reversing device according to claim 5, wherein a side of the reversing portion is protruded from the re-transporting portion, and the second ventilation hole is provided at a position corresponding to a lower portion of the protruding portion. .