JPH0468629B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and particularly to an image forming apparatus capable of effectively preventing dew condensation jams occurring in a paper passing path.

[Conventional technology]

Generally, in an image forming apparatus, a sheet of paper that has been copied on one side in a copying section is changed in direction, conveyed below the copying section and stored in a stacker section, and then sent out again, conveyed upward, changed direction, and supplied to the copying section. However, the other side is copied, and since the paper changes direction twice between copying one side and copying the other side, it is necessary to flip the paper once during the path. . In addition to the above-mentioned functions, the image forming device also has the ability to eject paper directly from the machine after single-sided copying.
Since it is necessary to have a function such as reversing and ejecting sheets to align the pages, conventionally, a plurality of paper passing paths that can be switched arbitrarily to the paper ejecting section have been created.
The multiple paper passing paths created in this paper ejecting section are easily affected by temperature differences between the inside and outside of the machine, and if these paths are formed using guide plates, condensation may occur due to temperature differences and jams may occur. It was the cause of this. Conventionally, to prevent this condensation, a round bar on a wire (rod) has been used instead of a guide plate.

However, when making a paper guide using a round bar, the cost is higher than when making a guide using a flat plate, and there are disadvantages such as deformation of the round bar. Therefore,
To prevent condensation using conventional guide plates, the use of fans was devised. however,
Merely installing a fan cannot sufficiently prevent dew condensation within the paper passing path consisting of the movable branch and the guide plate. Therefore, there was a need for reliable measures to prevent condensation on the paper passing path caused by the fan.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus having a paper passing path that uses a fan to reliably prevent dew condensation in a paper passing path consisting of a movable branching body and a guide plate, and that does not cause jams or conveyance defects. It is.

[Structure of the invention]

In order to achieve the above object, the present invention includes a movable branch body 13 having a fan 19 in an apparatus main body, and a comb tooth gap 27 between the fixing section 3 and the downstream roller 12; The image forming apparatus has a paper passing path composed of guide plates 15, 16, and 17 facing the top and side surfaces of the fan 13, respectively, and has an entrance that collects air near the fan 19 and an inlet of the paper passing path. By providing a dedicated ventilation duct 22 with an outlet near the outside and a ventilation hole 26 provided in the guide plate constituting the paper passage path,
The wind from the fan 19 passes through the duct 22 and the through hole 26 to the movable branch body 1 having a comb tooth gap 27.
3, and the air in the paper passing path can be replaced with air outside the paper passing path supplied from a fan.

〔Example〕

Next, the present invention will be described based on embodiments shown in the accompanying drawings.

FIG. 1 shows a sectional view of an image forming apparatus to which the present invention is applied. In the figure, 1 is a paper feed unit for single-sided copying, 2 is a copying unit that copies a document image placed on a document table (not shown) onto sheets fed out one by one from the paper feed unit 1; Reference numeral 3 denotes a fixing section that receives the paper that has been copied on one side by the copying section 2 via the conveyor belt 4 and fixes the copy side. Fixing part 3
On the downstream side, there is a function for switching between a paper discharge path a in which the paper after fixing is advanced straight and discharged to the outside of the machine, and an introduction path b in which the paper is introduced into the duplex copying path 5 for double-sided copying or reversed paper discharge. A route branching device 6 is provided. At the lower part of the copying machine main body on the downstream side of the duplex copying path 5 that continues to the path branching device 6, there is a reversing mechanism 7 for reversing the sheets, a stacker section 8 for storing the reversed sheets, and a stacker section 8 for storing the reversed sheets. A refeeding mechanism 9 for the stored sheets is provided, and furthermore, a relay mechanism 10 for returning the sheets to the sheet feeding path of the copying section 2 is provided downstream of the refeeding mechanism 9.

The branching device 6 is provided with a movable branching body 13 having an inverted triangular cross section, which is swingable about a shaft 14 between an upstream roller 11 and a downstream roller 12 consisting of upper and lower rollers. Guide plates 15, 1 are provided opposite to the top and side surfaces, respectively.
6 and 17, a paper discharge path a that goes directly from the upstream roller 11 to the downstream roller 12, an introduction path b that branches from the paper discharge path a and introduces the paper into the double-sided copying path 5, and a flow surface copying path 5. A reversing paper ejection path c is formed in which the stacked paper is conveyed in the reverse direction and guided to the downstream rollers 11. This switching between the paper ejection path a and the introduction path b is performed at the tip 13a of the movable branch body 13 on the upstream roller side.
This is done by swinging the rollers 11 under the action of a solenoid (not shown) and displacing the rollers 11 up and down from the gripping point P. Further, the selection between transporting the paper in the reverse direction to the reversing paper ejection path c and transporting the paper from the duplex copying path 5 to the reversing mechanism 7 is achieved by the forward and reverse operation of the forward and reverse rollers 18 provided in the middle of the duplex copying path 5. It will be done. During this reverse transport, the paper exerts its own restoring force,
Since the distance between the lower end of the movable branch body 13 and the guide plate 16 is narrowed, there is no possibility that the water will flow back to the introduction path b.

In FIG. 2, 19 is a fan provided in the device main body 20, 21 is an exhaust port provided in the side wall of the device main body 20, and 22 is a duct for ventilation only. The ventilation duct 22 collects wind from an entrance provided near the fan 19, and directs the wind to the communication body 23 and the downstream roller 1.
Opening 25 provided in the exterior body 24 covering the second side
The air can be blown out through an outlet directed onto a guide plate 15 covering the upper surface of the movable branch body 13. The guide plate 15 is provided with a through hole 26 through which the air blown therethrough passes. Therefore, the exhaust air passes through the through hole 26 and reaches the space where the movable branch body 13 is installed. Although this movable branching body 13 is not clearly shown in the accompanying drawings, it has a comb-teeth shape, and the discharged air passes through the comb-teeth gaps 27 and is directed to the introduction path b and the reversal discharge path c. Guide plate 1
It has grown to reach up to 6.17.

〔Effect of the invention〕

As explained above, the image forming apparatus according to the present invention is configured such that the air generated from the fan can be supplied to the paper passage path including the movable branch body through the duct dedicated to ventilation. Highly humid air, which causes dew condensation, does not remain in the paper passage path, which is made up of , and is replaced by dry air from the fan. Moreover, since the dedicated duct creates an independent passage for air within the main body of the device, the air from the fan is not heated abnormally or dispersed before it is supplied to the paper passing path including the movable branch. It can be prevented. Further, since the movable branch body has comb teeth, air supplied from the fan can easily pass therethrough, and air can be smoothly exchanged in the paper passing path consisting of the movable branch body and the guide plate.

As described above, the present invention has the excellent effect of preventing jams and conveyance defects by reliably preventing dew condensation in the paper passing path made up of the movable branch and the guide plate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the entire double-sided copying apparatus of the present invention, FIG. 2 is an enlarged sectional view of the main parts, and FIG. 3 is a perspective view of the same external appearance. 6...branching device, 13...movable branching body, 15,
16, 17... Guide plate, 19... Juan, 20
...Copying device main body, 21...Exhaust port, 22...Duct, 23...Communication body, 24...Exterior body, 25...
. . . Opening, 26 . . . Through-hole in the guide plate, a . . . Paper ejection path, b .

Claims (1)

[Claims] 1. A movable branch body 13 having a fan 19 inside the apparatus main body and having a comb tooth gap 27 between the fixing section 3 and the downstream roller 12, and guides facing the upper and side surfaces of the movable branch body 13, respectively. Boards 15, 16,
17, the image forming apparatus has a paper passing path consisting of a fan 19 that collects wind, a ventilation duct 22 having an outlet near the outside of the paper passing path, and a ventilation duct 22 that collects air near the fan 19; By providing ventilation holes 26 in the guide plate constituting the paper path, the air from the fan 19 passes through the duct 22 and the holes 26 to the movable branch body 13 having the comb teeth 27. An image forming apparatus characterized in that the air can be sprayed into a paper passing path including a paper passing path, and air in the paper passing path can be replaced with air outside the paper passing path supplied from a fan.