JPH11202738A - Paper cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper cooling device constituted so that ejected papers can be excellently stacked at a paper ejecting time. SOLUTION: Heat generated from the papers 15 passed between both guide plates 3 and 5 is transferred to a heat transfer material 23 set on the upper paper guide plate 3 and taken away by cold air sent from a cooling fan 7. Thus, toner on the paper 15 is sufficiently fixed and the ejected papers can be excellently stacked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet cooling device for cooling a sheet heated to a high temperature by a fixing device provided in a copying machine, a printer or the like.

[0002]

2. Description of the Related Art Generally, a fixing device such as a copying machine or a printer fixes toner by heat, so that a sheet passed through the fixing device is in a considerably high temperature state. For this reason, when stacking sheets of paper, if the toner adhered to the sheets is not solidified, the sheets adhere to each other with the toner, causing a discharge stack failure. As a countermeasure against the discharge stack failure, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-115, a technique is known in which outside air is introduced into a sheet transport path by a fan or the like, and the outside air is sent to the transport path to cool the sheet.

[0003]

However, in the above-described method, if the wind speed of the outside air is increased, the behavior of the sheet passing through the conveyance path is affected, which causes a problem such as a jam. .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet cooling device capable of forming a good stack at the time of sheet discharge.

[0005]

According to a first aspect of the present invention, there is provided a pair of guide plates for guiding a sheet after toner fixing in an image forming apparatus, and a sheet passing between the pair of guide plates. A heat transfer material is provided on the surface of one of the guide plates and on the side opposite to the side through which the sheet is passed, and a cooling fan that blows air toward the heat transfer material.

According to the first aspect of the present invention, heat generated from a sheet passing through a pair of guide plates is transmitted to a heat transfer material provided on one of the guide plates. The heat transmitted to the heat transfer material is taken away by the cool air blown from the cooling fan. Therefore, the sheets on both guide plates are cooled, so that the toner on the sheets is sufficiently hardened, and a good discharge stack can be obtained. Further, the pair of guide plates are configured to sandwich the paper therebetween, and the air from the cooling fan does not directly hit the paper. To prevent adverse effects on the behavior of

According to a second aspect of the present invention, in the first aspect of the present invention, the one guide plate is formed with a hole that exposes the heat transfer material to the paper side. .

According to the second aspect of the present invention, since one of the guide plates is formed with a hole serving as a heat discharge path,
The heat generated from the paper passing between the guide plates can be efficiently transmitted to the heat transfer material. Further, since the cool air from the cooling fan is more easily transmitted to the heat transfer material, the cooling effect is improved.

The invention described in claim 3 is the first or second invention.
In the invention described in (1), a duct is provided on the surface of the heat transfer material to guide air from the cooling fan.

According to the third aspect of the present invention, by providing the duct for guiding the air and guiding the air blow from the cooling fan, the heat generated from the paper can be quickly discharged through the duct.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the duct forms an air flow path in a paper passing direction, and an exhaust port of the duct is directed to a paper output port. It is characterized by being.

According to the fourth aspect of the present invention, the duct forms an air flow path in the paper passing direction, and the exhaust port of the duct is directed to the paper discharge port. Discharge outside the device. Therefore, it is possible to discharge the air from the cooling fan to the outside of the apparatus with a simple configuration.

According to a fifth aspect of the present invention, in the third aspect of the present invention, the exhaust port of the duct is guided to a flow path of a main fan for exhausting the main part of the main body to the outside of the apparatus. It is characterized by.

According to the fifth aspect of the present invention, the ventilation from the cooling fan can be directly discharged from the main fan of the main body by guiding the exhaust port of the duct to the flow path of the main fan provided in the main body. The exhaust efficiency is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a sheet cooling device 1 of the present invention. The sheet cooling device 1 is disposed in the copying machine 9, is located between the fixing device 11 and the sheet discharging roller 13, and includes a sheet discharging upper guide plate 3, a sheet discharging lower guide plate 5, and a cooling fan 7. ing. Below the discharge roller 13, a discharge stack unit 17 for stacking the discharged sheets 15 is provided. Side plate 2 of copying machine 9 on paper discharge roller 13 side
In 9, a discharge port 10 for discharging the paper 15 is formed. In addition, in the copying machine 9, for example, devices such as a photosensitive drum and a transfer device are arranged in addition to the above-described devices, but in the present embodiment, the description of the configuration and operation thereof will be omitted. .

The fixing device 11 includes a fixing roller 11a and a pressure roller 11b, and fixes the toner transferred from the photosensitive drum onto the sheet 15 by the heat of a heater 11c disposed in the fixing roller 11a. Things.

The paper discharge roller 13 is a roller for discharging the paper 15 out of the copier 1, and discharges the paper 15 from here.
The sheets are stacked on the sheet discharge stacking section 17.

The upper discharge guide plate 3 and the lower discharge guide plate 5
In the meantime, the paper 15 is passed and guided to the paper discharge roller 13. The upper paper discharge guide plate 3 has a substantially rectangular plate shape and is formed of metal or the like. The width of the upper paper discharge guide plate 3 in the direction of passage of the paper 15 (hereinafter referred to as the vertical direction) is equal to that of the fixing device 11. To the vicinity of the paper discharge roller 13.

As shown in FIG. 2A, projections 19 are attached to the surface on the side where the paper 15 passes, as shown in FIG. This projection 1
Numerals 9 are arranged at equal intervals in the lateral direction of the upper paper discharge guide plate 3 and contact the paper 15 to guide the transport direction.

The upper guide plate 3 has a plurality of holes 21 formed at equal intervals between the projections 19 in the vertical direction. The holes 21 are formed to efficiently transfer heat generated from the sheet to a heat transfer material 23 described later, and serve as a heat discharge path. A heat transfer material 23 is affixed to a surface (hereinafter, referred to as a back surface) of the upper sheet discharging guide plate 3 opposite to a side on which the sheet passes.

The heat transfer material 23 is a member that absorbs the heat of the paper 15 that is generating heat through the fixing device 11. The heat transfer material 23 is attached so as to cover the entire back surface of the upper paper discharge guide plate 3, and closes the hole 21 of the upper paper discharge guide plate 3 as shown in FIG. The heat transfer material 23
The material is not particularly limited as long as it is a member that transmits heat. However, in this embodiment, a thin rubber member having high heat conductivity is used, and the material is easily attached to the upper guide plate 3 for discharging. It is supposed to be.

The lower paper discharge guide plate 5 guides the paper 15 to the paper discharge rollers 13 as described above. The configuration thereof is the same as that of the upper sheet discharging guide plate 3 except for the holes 21, the protrusions 19, and the heat transfer material 23, and thus the description thereof is omitted.

The cooling fan 7 is arranged above the upper sheet discharging guide plate 3. The cooling fan 7 blows cool air toward the upper discharge guide plate 3, and
Are arranged so as to be substantially parallel to. Then, the cooling fan 7 blows cool air toward the upper paper discharge guide plate 3 (see the arrow in FIG. 1).

Hereinafter, the operation of the first embodiment will be described based on the above-described configuration. Paper 15 on which the unfixed toner image has been transferred
Are the fixing roller 11a and the pressure roller 11 of the fixing device 11.
b, and is conveyed in the direction of the discharge roller 13. At this time, the unfixed toner image is fixed on the paper 15 by the heat from the fixing roller 11a heated by the heater 11c and the pressure by both rollers.

The paper 15 on which the toner image is fixed passes between the upper discharge guide plate 3 and the lower discharge guide plate 5. At this time,
Since the sheet 15 has just been discharged from the fixing device 11, the sheet 15 is heated. The heat generated from the sheet 15 is transmitted through a hole 21 formed in the upper sheet discharging guide plate 3 to the heat transfer material 2.
3 The heat transmitted to the heat transfer material 23 is deprived of the heat by the cool air blown from the cooling fan 7 disposed above the heat transfer material 23. Since the heat has a property of moving from a high temperature to a low temperature, the heat of the heat transfer material 23 is reduced by the cool air of the cooling fan 7, and the heat of the paper 15 is transferred to the heat transfer material 23 again.

The above-mentioned transfer of heat is repeated until the paper 15 arrives at the paper discharge roller 13, so that the toner on the paper 15 is cooled and solidified, and is discharged from the paper discharge roller 13 in that state. .

In the first embodiment, the heat generated from the paper 15 passing between the guide plates 3 and 7 is transmitted to the heat transfer material 23 provided on the upper discharge guide plate 3. The heat transmitted to the heat transfer material 23 is deprived of the heat by the cool air sent from the cooling fan 7. This repetition is performed until the paper 15 arrives at the paper discharge roller 13.
Is cooled, the toner on the paper 15 is solidified, and a good discharge stack can be formed. Further, since the guide plates 3 and 5 have a configuration in which the paper is sandwiched therebetween, and the air from the cooling fan 7 does not directly hit the paper, the air blowing from the cooling fan 7 adversely affects the behavior of the paper 15. To prevent that.
Further, since the holes 21 serving as heat discharge paths are formed in the upper sheet discharge guide plate 3, heat generated from the sheet 15 passing between the guide plates 3, 5 is efficiently transmitted to the heat transfer material 23. Can be transmitted. Further, since the cool air from the cooling fan 7 is more easily transmitted to the heat transfer material 23, the cooling effect is improved.

Next, other embodiments of the present invention will be described in order. In the description, members and portions having the same functions as the above-described members and portions are denoted by the same reference numerals, and description thereof is omitted. I do. A second embodiment will be described based on FIG.
In the second embodiment, an exhaust duct 25 and a cooling fan 7 are provided above the upper sheet discharging guide plate 3.

The exhaust duct 25 is disposed above the upper discharge guide plate 3 and extends from near the center of the upper discharge guide plate 3 to near the side plate 29 of the copying machine 9. Exhaust duct 25
Has an inverted U-shaped cross section, and covers the upper sheet discharging guide plate 3.

The cooling fan 7 is located above one end of the exhaust duct 25 on the fixing device 11 side and above the fixing device 11. The direction of the cooling fan 7 is the same as that of the cooling fan 7 in the first embodiment.

Hereinafter, the operation of the second embodiment will be described based on the above configuration. Sheet 1 discharged from fixing device 11
5 generates heat by passing through both the paper discharge guide plates. This heat is
The heat is transmitted to the heat transfer material 23 and cooled by the cool air blown from the cooling fan 7. Thereafter, the cooled air passes through the exhaust duct 25 and is discharged out of the apparatus from the outlet 10 (see the arrow in FIG. 3).

In the second embodiment, the exhaust duct 25 is mounted above the upper paper discharge guide plate 3 and the air blown from the cooling fan 7 is exhausted from the exhaust port 10, so that the cooled air is quickly discharged out of the apparatus. can do. Further, the air can be discharged out of the apparatus only by providing the exhaust duct 25, so that the configuration is simplified.

Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, as shown in FIG. 5, the main body of the copying machine 9 is provided with a communication duct 35 extending from an air inlet 33 formed in the other side plate 31 to a vent 39 of the side plate 29. This communication duct 35
Photoconductor 3 carrying a toner image on the other side plate 31 side therein
7 and a charger 41 which is located above the photoconductor 37 and charges the photoconductor 37. Further, a portion of the communication duct 35 corresponding to the fixing device 11 is
A heat discharge port 43 which is an outlet of heat generated from 1 is formed,
A main fan 45 for sucking the air in the communication duct 35 is disposed ahead of the main fan 45. An exhaust port 49 is formed below the main fan 45, and a connecting duct 47 extends from the exhaust port 49.

The connecting duct 47 extends downward from the exhaust port 49, and is bent substantially in parallel with the upper discharge guide plate 3 from near one end of the upper discharge guide plate 3.
, And an opening 51 is formed at the tip. The cooling fan 7 is arranged toward the opening 51.

The operation of the third embodiment will be described below based on the above-described configuration. As shown in FIG. 4, the heat generated from the heat transfer material 23 is cooled by the cool air of the cooling fan 7 blown from the opening 51 and then goes to the exhaust port 49. On the other hand, in the copying machine 9, ozone generated from the charger 41 and heat generated from the fixing device 11 are sucked by the main fan 45. The heat generated from the heat transfer material 23 reaches the exhaust port 49 through the connection duct 47 and is sucked by the main fan 45 together with the above-described ozone and the heat generated from the fixing device 11. The ozone and heat sucked by the main fan 45 are discharged out of the apparatus through the vent 39 (see arrows in the figure).

In the third embodiment, the connecting duct 47 is connected to the communication duct 35 having the main fan 45, and the air cooled by the cooling fan 7 is discharged from the main fan 45 as it is. Exhaust efficiency is improved.

The present invention is not limited to the above embodiment, but can be variously modified without departing from the gist thereof. For example, the four holes 21 formed in the upper sheet discharging guide plate 3 are arranged in the vertical direction, but may be formed in an oval shape by connecting the holes. Further, the holes 21 are formed between the projections 19, but may be formed every other one. Further, a similar effect can be obtained even if the cooling fan 7 in the third embodiment is not provided and the atmosphere on the heat transfer material 23 is sucked by the main fan 45 arranged in the main body. The heat transfer material 23 is attached to the lower discharge guide plate 5 and the cooling fan 7.
May be arranged below the lower discharge guide plate 5. further,
The heat transfer material 23 may be attached to both the upper discharge guide plate 3 and the lower discharge guide plate 5.

[0038]

According to the first aspect of the present invention, the toner on the paper is solidified, and a good discharge stack can be obtained. Further, the pair of guide plates are configured to sandwich the paper therebetween, thereby preventing the blowing of the cooling fan from adversely affecting the behavior of the paper.

According to the second aspect of the present invention, since the guide plate is formed with a hole serving as a heat discharge path, heat generated from the sheet can be efficiently transmitted to the heat transfer material.
The cooling effect is improved.

According to the third aspect of the invention, by providing the duct for guiding the air and guiding the air blow from the cooling fan, the heat generated from the paper can be quickly discharged through the duct. .

According to the fourth aspect of the present invention, since the duct forms an air flow path in the paper passing direction, and the exhaust port of the duct is directed to the paper output port, the cooling fan has a simple configuration. Can be discharged to the outside of the device.

According to the fifth aspect of the present invention, the exhaust efficiency is improved by guiding the exhaust port of the duct to the flow path of the main fan provided in the main body.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the vicinity of a sheet cooling device according to a first embodiment.

FIG. 2A is a perspective view of the upper sheet discharge guide plate according to the first embodiment, as viewed from the side where sheets pass, and FIG. 2B is a perspective view of FIG.
FIG. 2 is a perspective view of the device viewed from the opposite side.

FIG. 3 is a schematic sectional view showing the vicinity of a sheet cooling device according to a second embodiment.

FIG. 4 is a schematic sectional view showing the vicinity of a sheet cooling device according to a third embodiment.

FIG. 5 is a perspective view schematically showing a copying machine main body according to a third embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper cooling device 3 upper discharge guide plate (guide plate) 5 lower discharge guide plate (guide plate) 7 cooling fan 9 copying machine (image forming apparatus) 10 discharge port 15 paper 21 hole 23 heat transfer material 25 exhaust duct (duct) ) 35 Communication duct (flow path) 45 Main fan 47 Connecting duct (duct) 49 Exhaust port

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/00 530 B41J 29/00 H

Claims (5)

[Claims] A pair of guide plates for guiding the paper after toner fixing in the image forming apparatus through the paper; and passing the paper between the pair of guide plates.
A sheet cooling device comprising: a heat transfer material provided on a side opposite to a side on which sheets are passed; and a cooling fan for blowing air toward the heat transfer material. 2. The sheet cooling device according to claim 1, wherein the one guide plate is formed with a hole that exposes the heat transfer material to the sheet side. 3. The sheet cooling device according to claim 1, wherein a duct is provided on a surface of the heat transfer material to guide air from a cooling fan. 4. The sheet cooling device according to claim 3, wherein the duct forms an air flow path in a sheet passing direction, and an exhaust port of the duct is directed to a sheet discharge port. 5. The sheet cooling device according to claim 3, wherein an exhaust port of the duct is guided to a flow path of a main fan that exhausts exhaust gas from a main part of the main body to the outside of the apparatus.