JPH04143785A - Cooling device for recording paper after fixation - Google Patents

Abstract

PURPOSE:To cool discharged recording paper effectively and to suppress the occurrence of a blocking phenomenon by providing the cooling device with a means for applying a solvent on the surface of a conveyor belt and a means which dries the applied solvent. CONSTITUTION:The cooling device 30 includes upper conveyor belt rollers 31a and 31b a lower conveyor belt roller 31c, which is dipped partially in the solvent 40 at all times to dip a belt 32 at its outer periphery in the solvent. Further, this device has an enclosed container 41 which contains the solvent 40 and a fan 42 which is arranged in the container to blow air toward the belt 32 passing in the enclosed container 41 and dry the solvent sticking on the belt. Consequently, heat from the conveyed recording paper is radiated effectively to the outside of the machine to cool the recording paper, thereby precluding heat accumulation which is easily caused when the paper is stacked on a paper discharge tray and the occurrence of blocking.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a device for cooling recording paper discharged from a fixing device of an image forming apparatus such as a copying machine.

(Prior Art) In image forming devices such as copying machines, printers, and facsimile machines that utilize electrophotographic processes, static image information obtained by irradiating optical image information such as reflected light from a document onto a photoconductor is used. Toner is applied to the T4 latent image to make it visible, and after this visible image is transferred to recording paper, the toner image is fixed on the recording paper by applying pressure to the recording paper while heating it at a high temperature with a fixing device. ing.

The recording paper after fixing is discharged onto the discharge tray, but immediately after discharge, the toner on the recording paper still has viscosity due to residual heat, and if the toner is stacked after discharge, heat is accumulated between the proof sheets. As a result, a blocking phenomenon may occur in which a portion of the toner adheres to the back surface of the recording paper layered on top of the viscous toner. Particularly in high-speed machines, since the recording sheets after fixing are stacked before being sufficiently cooled, heat is accumulated and the above-mentioned blocking phenomenon is likely to occur.

Recording papers that have caused such blocking are bonded to each other by toner, making it difficult to remove them one by one, or forcibly removing them may cause the toner image to peel off, resulting in a decrease in image quality. This may cause various problems and discomfort.

From this point, for example, Utility Model No. 60-70847
The publication discloses a configuration in which a pair of upper and lower cooling rollers, at least one of which is a heat pipe, is arranged behind the fixing device, and the recording paper is cooled by passing through the nip between the pair of cooling rollers. The contact area between the recording paper in a high temperature state and the nip portion of the pair of rollers is small, and the cooling effect is not sufficient, so that the above-mentioned blocking cannot be completely eliminated. Therefore, it has been desired to solve this problem and develop effective and effective cooling means.

(Object of the Invention) The present invention has been made in view of the above, and provides a post-fixing recording paper cooling device that can effectively cool the recording paper discharged from the fixing device and suppress the occurrence of blocking phenomenon. The purpose is to provide the following.

(Structure of the Invention) To achieve the above object, the present invention provides an image forming bag equipped with a fixing device and a cooling device for cooling recording paper discharged from the fixing device! The cooling device includes an endless conveyor belt that absorbs heat while placing and conveying the recording paper discharged from the fixing device, and a cooling device that is located in a running path of the conveyor belt to cool the conveyor belt. A cooling device is provided, and the cooling device is characterized in that it includes means for applying a solvent to the surface of the conveyor belt, and means for drying the applied solvent.

Further, the solvent application means and the drying means are hermetically housed in a closed container.

Further, the business card is characterized by being made of a highly volatile organic solvent.

Further, the cooling device includes a closed container that stores the solvent in a state where outside air is airtightly shut off, and a means for applying the solvent to the conveyor belt located inside the closed container and guided into the closed container. and a fan that blows air onto the conveyor belt surface coated with the solvent to vaporize the solvent.

Furthermore, the means for applying the solvent is a solvent application roller that contacts the surface of the conveyor belt while rolling, and the solvent application roller includes a hollow cylindrical core holding a solvent therein;
It is characterized by comprising a solvent coated layer laminated around the outer periphery of the core metal, and a pinhole formed in the core metal to allow the solvent to seep into the solvent coated layer.

Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is an explanatory diagram of a schematic configuration of an image forming apparatus equipped with a cooling device according to an embodiment of the present invention, and FIG. 2 is an enlarged explanatory diagram of the main parts thereof.

The recording paper 5, on which the toner T has been transferred at the transfer section of the photosensitive drum located on the left side of the fixing device 1 in FIG. 1, enters the fixing device 1 and is heated and pressurized.

A cooling device 3 of the present invention is installed behind the fixing device 1 (on the left side of the drawing).
0 is placed.

Fuser ffi! 1 has a fixing roller 2 equipped with a heater 3 inside, and a pressure roller 4 that nips with this fixing roller 2 on its outer circumferential surface, and detects the temperature of the fixing roller 2 with a thermistor 8 to adjust the temperature to 185. It is controlled at around °C.

A pair of discharge rollers 13.14 is arranged at the discharge port of the fixing device 1, and the roller pair 13.14 sends out the toner to the cooling device 30 side. The temperature of the recording paper at this time was approximately 120°C.

The cooling device 30 includes upper conveyor belt rollers 31a, 31b and a lower conveyor belt roller (solvent coating means) 31c, which are arranged at a predetermined interval, and a conveyor belt roller 31.
The conveyor belt 32 stretched endlessly by a, 3 l b, 31 c and the relay guide plate 35 located on the introduction side of the belt 32 are the same (the conveyor guide plate 36 located on the discharge side and each A conveyance roller 37 located between guide plates 35, 36 and arranged to roll in contact with the upper running surface of the belt 32, and a lower conveyor belt roller 31.
an airtight container 41 in which c is located and contains a solvent 40;
and a fan 42 disposed inside the closed container 41 for blowing air toward the belt 32 passing through the closed container 41 to dry the adhering solvent.

The solvent 40 is a liquid with high volatility and good vaporization reaction (for example, an organic solvent such as alcohol or diethyl ether), and by vaporizing the solvent attached to the belt by the fan 42, the belt is cooled by the heat of vaporization. becomes.

A portion of the lower conveyance belt roller 31c is always immersed in the solvent 40, so that the outer belt 32 is immersed in the solvent.

Holes are formed on the top and side surfaces of the airtight container 41 having a pneumatic structure to allow the belt 32 to pass through the pneumatic structure.
can move forward and backward through this hole.

The airtight container 41 prevents the solvent inside from evaporating and dispersing, and also prevents the outside air from being contaminated by the vaporized drug.

Next, FIG. 2 [aj fbl is a schematic configuration explanatory diagram of the second embodiment of the present invention, and the configuration of the fixing device is the same as that of the first embodiment described above.
This embodiment is similar to the embodiment described above, but the configuration of the cooling device is different.

The cooling device 30 in this embodiment includes conveyor belt rollers 31a and 31b arranged at a predetermined interval, a conveyor belt 32 stretched endlessly by the conveyor belt rollers 31a and 31b, and an introduction of the belt 32. a relay guide plate 35 located on the side; a solvent application roller (solvent application means) 37 located behind the relay guide plate 35 and arranged to roll in contact with the upper running surface of the belt 32;
An airtight container 5o that surrounds the solvent application roller 37 and a part of the belt to prevent the solvent inside the solvent application roller from vaporizing and flowing out, and a closed container 5o that blows air toward the belt 32 to remove the solvent attached to the belt. and a fan 51 disposed within the container to dry the water.

As shown in the cross-sectional view in FIG. It has a felt layer (coating layer) 53.

The solvent 40 inside the core metal 52 oozes out from the pinhole 53 into the felt layer 53 and is impregnated into the felt layer 53. When the solvent attached to the belt 32 due to contact with the felt layer 53 is dried and vaporized by the air blow from the fan 51, the belt 32 is cooled and the heat of the recording paper conveyed on the belt 32 is efficiently dissipated. It can be taken away. Although the cooled recording paper is discharged onto the paper discharge tray 45, problems such as blocking do not occur.

As the solvent 40, a highly volatile liquid (for example, an organic solvent such as alcohol or diethyl ether) is used as in the first embodiment.

(Effects of the Invention) As described above, according to the present invention, the ejection belt provided near the ejection port of the fixing device is cooled using a volatile solvent, and the recording paper is conveyed by this belt. It is possible to effectively release heat from the conveyed recording paper to the outside of the machine to cool the recording paper, thereby preventing heat accumulation and blocking that are likely to occur when stacking on a paper discharge tray.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an embodiment of the present invention, and FIGS. 2A and 2B are explanatory diagrams of a configuration and a cross-sectional view showing essential parts of a second practical example of the rudder of the present invention.

Claims (5)

[Claims] (1) In an image forming apparatus equipped with a fixing device and a cooling device for cooling recording paper discharged from the fixing device, the cooling device places and transports the recording paper discharged from the fixing device. an endless conveyor belt that absorbs heat while absorbing heat, and a cooling device located in a running path of the conveyor belt to cool the conveyor belt, the cooling device comprising means for applying a solvent to the surface of the conveyor belt; 1. A recording paper cooling device after fixing, comprising means for drying the applied solvent. (2) The recording paper cooling device after fixing according to claim (1), wherein the solvent application means and the drying means are hermetically housed in a closed container. (3) The recording paper cooling device after fixing according to claim (1), wherein the solvent is a highly volatile organic solvent. (4) The cooling device applies the solvent to an airtight container containing the solvent in a state where outside air is airtightly shut off, and to the conveyor belt located inside the airtight container and guided into the airtight container. Cooling of recording paper after fixing according to claim (1), (2) or (3), characterized in that it comprises: a means for cooling the recording paper after fixing; and a fan for blowing air onto the surface of the conveyor belt coated with the solvent to vaporize the solvent. Device. (5) The means for applying the solvent is a solvent application roller that rolls into contact with the surface of the conveyor belt, and the solvent application roller has a hollow cylindrical core holding a solvent therein;
After fixing according to claim (4), the fixing method comprises a solvent coating layer laminated on the outer periphery of the core bar, and a pinhole formed in the core bar for causing the solvent to ooze out into the solvent coating layer. Recording paper cooling device.