JP3161483B2 - Transport guide device for fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyance guide device for a fixing device used in an image forming apparatus such as an electronic copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, in a fixing device of this type, a heating roll is driven to rotate while a pressing roll is pressed against the heating roll, and the heating roll is heated from the inside by a heating source, and the heating roll and the pressing roll are heated. The transfer paper carrying the unfixed toner image is passed through the nip portion of the roll, so that the toner image is fixed on the transfer paper by heat and pressure.

Further, the above-mentioned fixing device is provided with a transport guide device for guiding transfer paper fixed by a heating roll and a pressure roll, and the transport guide device includes a heating roll and a heating roll. On the discharge side of the pressure roll,
A pair of guide members are disposed so as to face up and down.

[0004] The above-mentioned prior art has the following problems. That is, in the fixing device, the moisture contained in the transfer paper evaporates due to the heat of the heating roll during the fixing process, and the water vapor adheres to the transport guide member disposed on the discharge side of the fixing device. And dew. Therefore, when the transfer paper discharged from the fixing device comes into contact with the surface of the guide member, water droplets condensed on the surface of the guide member adhere to the surface of the transfer paper, causing a problem that the image is damaged.

[0005] The dew condensation in the paper discharge section of the fixing device is caused by air heated by a heating roll or transfer paper containing moisture heated in a nip portion of the fixing device, and air containing much moisture forms a guide member. It is generated in contact with a cold sheet metal to be formed.

Japanese Patent Laid-Open Publication No. Sho 54-65550 discloses means for preventing dew condensation at the paper discharge section of the fixing device.
JP-A-54-96049, JP-A-57-3085
No. 1, JP-A-58-154867, JP-A-60-142372 and the like have already been proposed.

The guide device for a thermal fixing device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 54-65550 is heated and fused in a copying machine having a thermal fixing device for heating and fixing a toner image formed on a transfer sheet. A guide member is provided on a transfer path of the transfer sheet so as to assist continuous transfer of the transfer sheet carrying the toner image, and a guide member is disposed in a direction crossing the path. The guide member has a non-continuous plane in the direction in which the guide member is disposed so as to prevent dew condensation on the surface of the guide member that occurs while the guide member moves while contacting the guide member.

The heat-fixing discharge guide disclosed in Japanese Patent Application Laid-Open No. 54-96049 is composed of a plurality of rigid material elements mounted on a copying machine main body so as to be juxtaposed with each other. And a guide plate portion integrally provided at an end of the leg portion, and a copy paper guide surface is formed by an end face of the guide plate portion.

Further, in the method of dehumidifying a copying machine disclosed in Japanese Patent Application Laid-Open No. 57-30851, a fan is arranged near an exposing lamp that generates heat so that the lamp side is a suction side during copying, and the outside air is blown into the machine. In a copying machine which discharges outside the machine by introducing the same, a lamp is turned on during warm-up or idling, the fan is reversed, and hot air is circulated inside the machine.

The thermal fixing device disclosed in Japanese Patent Application Laid-Open No. 58-154867 is configured to include a fan device for generating an airflow near a copy paper outlet.

Further, a fixing device disclosed in Japanese Patent Application Laid-Open No. 60-142372 and the like is a device in which a transfer paper having a toner image mounted on a surface thereof is heated to fix the image. The apparatus has a means for heating the surface of the discharge guide member of the transfer paper that has passed through the fixing means at least to such a degree that dew condensation does not occur due to water vapor evaporated from the transfer paper.

[0012]

However, the above-mentioned prior art has the following problems. That is, in the case of the device according to the above proposal,
In the guide member having a characteristic shape such as disclosed in Japanese Patent Application Publication No. 550 and Japanese Patent Application Laid-Open No. 54-96049, the degree of dew condensation cannot be completely prevented, and the adverse effect due to the dew condensation can be somewhat reduced. There is a problem that only. Further, Japanese Patent Application Laid-Open Nos.
A device that prevents dew condensation by an air flow disclosed in Japanese Patent No. 154867 or the like has a problem in that the sound of the fan becomes annoying during standby because the fan must be driven to rotate during standby. Further, JP-A-60-142372
In the apparatus disclosed in Japanese Patent Application Laid-Open Publication No. H10-15095 for preventing dew condensation by warming the guide member, the guide member must be heated even when the copier is turned off, resulting in increased power consumption.

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and aims at solving all of the drawbacks of the prior art, such as airflow and heating of guide members. An object of the present invention is to provide an inexpensive conveyance guide device for a fixing device, which can effectively prevent dew condensation on a guide member without using any means.

[0014]

Means for Solving the Problems The technical problem described above is solved by a conveyance guide device for a fixing device according to the present invention.
A transfer roll is pressed against a heating roll having a heating source inside to fix an unfixed image on the transfer material. In a conveyance guide device for a fixing device in which a guide member for guiding conveyance is arranged, the guide member is
This is achieved by laminating a heat insulating layer on the surface of the substrate and providing a thin coating layer made of a material having good thermal conductivity on the surface of the heat insulating layer.

[0015]

In the present invention, the guide member is constructed such that a heat insulating layer is laminated on the surface of the substrate and a thin coating layer made of a material having good thermal conductivity is provided on the surface of the heat insulating layer. Since the coating layer covering the surface of the guide member is made of a material having good thermal conductivity, this coating layer is immediately heated by residual heat released from the heating roll, and dew condensation may occur even in an environment at a low room temperature. There is no.
Moreover, since the heat insulating layer is laminated on the back surface side of the coating layer, it is possible to prevent the heat of the coating layer from escaping to the back surface side. Furthermore, since the surface of the guide member is covered with the coating layer, the flatness of the surface of the guide member can be maintained, and the transfer material transferability can be favorably maintained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

FIG. 2 shows a fixing device to which the conveyance guide device for a fixing device according to the present invention is applied.

In FIG. 1, reference numeral 1 denotes a heating roll. The heating roll 1 is constituted by coating a surface of a metal roll 2 with a relatively thin elastic layer 3 made of heat-resistant silicon rubber or the like. . Inside the heating roll 1, a halogen lamp 4 as a heating source is housed, and the surface of the heating roll 1 is heated to a predetermined temperature from the inside. A pressure roll 5 is pressed against the heating roll 1, and the pressure roll 5 coats the surface of a metal roll 6 with a thin elastic layer 7 made of heat-resistant silicon rubber or the like. It is configured.

The fixing device rotates both the rolls 1 and 5 in a state in which the pressure roll 5 is pressed against the heating roll 1, and simultaneously drives the heating roll 1 with the halogen lamp 4.
Heating from inside. Then, as shown in FIG. 2, the transfer paper 8 carrying the unfixed toner image is passed through the nip portion between the heating roll 1 and the pressure roll 5,
The toner image is fixed on the transfer paper 8 by heat and pressure.

As shown in FIG. 3, a pair of guide members 9 and 10 for guiding the transfer of the transfer sheet 8 are arranged on the transfer sheet discharge side of the fixing device so as to face up and down. I have.

As shown in FIG. 1, the guide members 9 and 10 have a heat insulating layer 12 made of glass fiber, felt or the like laminated on the surface of a substrate 11 made of sheet metal or the like. Further, as the heat insulating layer 12, a material made of silicon rubber, EPDM rubber, or the like may be used other than glass fiber or felt.

On the surface of the heat insulating layer 12, a thin covering layer 13 made of a material having good thermal conductivity is provided. As the coating layer 13, for example, a layer formed of an aluminum deposition surface deposited on the surface of the heat insulating layer 12 is used, and the surface of the coating layer 13 is formed flat. As long as the coating layer 13 is made of a material having good heat conductivity, the coating layer 13 may be made of a vapor-deposited surface of a metal other than aluminum, or may be made of another material.

At the outlet of the guide members 9 and 10 on the paper discharge side, a paper discharge roll 14 for transporting the transfer paper 8 is provided as shown in FIG.

In the above configuration, in the conveyance guide device for the fixing device according to this embodiment, dew condensation on the guide member is prevented as follows. That is, in the fixing device, as shown in FIGS.
The rollers 1 and 5 are driven to rotate while the pressure roll 5 is pressed against the heater, and the heating roll 1 is heated from the inside by the halogen lamp 4. The transfer paper 8 carrying the unfixed toner image is passed through the nip portion between the heating roll 1 and the pressure roll 5 so that the toner image is fixed on the transfer paper 8 by heat and pressure. .

At this time, in the fixing device, the moisture contained in the transfer paper 8 is removed by the heating roll 8 with the fixing process.
In the past, there has been a phenomenon in which the water vapor evaporates, and the water vapor adheres to the conveyance guide members 9 and 10 disposed on the paper discharge side of the fixing device and forms dew condensation.

In this embodiment, as shown in FIG. 1, the guide members 9 and 10 are formed by laminating the heat insulating layer 12 on the surface of the substrate 11 and the surface of the heat insulating layer 12 is formed by a vapor deposition surface of aluminum. Since the thin coating layer 13 is provided, the coating layer 13 covering the surfaces of the guide members 9 and 10 is made of a material having good thermal conductivity. It is immediately heated by the residual heat generated, and no dew condensation occurs even in an environment where the room temperature is low. Further, since the heat insulating layer 12 is laminated on the back side of the coating layer 13, it is possible to prevent the heat of the coating layer 13 from escaping to the back side. further,
Since the surfaces of the guide members 9 and 10 are covered with the coating layer 13, the flatness of the surfaces of the guide members 9 and 10 can be maintained, and the transfer property of the transfer paper 8 can be maintained well. it can.

FIG. 4 shows another embodiment of the present invention. The same parts as those of the above embodiment are denoted by the same reference numerals. In this embodiment, the guide members 9 and 10 are laminated. Although the configuration is the same as that of the above-described embodiment, the guide members 9 and 10 are not formed on a flat plate, but a plurality of ribs 15 are formed along the transfer direction of the transfer sheet 8.
Since the sheet is conveyed only in contact with the ribs 15 of the guide members 9, 10, the contact resistance can be reduced.

The guide members 9 and 10 may be provided with notches if necessary.

The other configuration and operation are the same as those of the above-described embodiment, and the description thereof will be omitted.

[0030]

The present invention has the above construction and operation, and can effectively prevent dew condensation on the guide member without using means such as airflow and heating of the guide member, and at a low cost. It is possible to provide a conveyance guide device for a fixing device.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a conveyance guide device for a fixing device according to the present invention.

FIG. 2 is a configuration diagram showing a fixing device to which an embodiment of the transport guide device according to the present invention is applied.

FIG. 3 is a configuration diagram illustrating an identification landing device.

FIG. 4 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 heating roll, 4 halogen lamp, 9, 10 guide member, 11 substrate, 12 heat insulating layer, 13 coating layer.

Claims (1)

(57) [Claims] 1. A transfer device, which presses a pressure roll against a heating roll having a heating source therein to fix an unfixed image on a transfer material, and opposes a transfer material transport path on a transfer material discharge side.
And a guide member for guiding the transfer of the transfer material at a position where the transfer member is to be transferred, wherein the guide member is laminated with a heat insulating layer on the surface of the substrate, and heat is transferred to the surface of the heat insulating layer. Conveyance guide for a fixing device, provided with a thin coating layer made of a material having good property.
Device.