JPH08220917A - Fixing device - Google Patents

Abstract

PURPOSE: To prevent the surface of a fixing roller from being worn away by a cleaning member by providing a transporting member for transporting a release agent to a cleaning member while abutting on an oil applying roller on the downstream side of a release agent supply position and also on the upstream side of the position abutting on the fixing roller. CONSTITUTION: The end part of an oil transporting felt 7 is brought into press contact with the surface of the oil applying roller 6 on the downstream side of an oil applying felt 4, in accordance with the rotation of the oil applying roller 6, silicone oil 12 on the surface of the applying roller 6 partly infiltrates into the oil transporting felt 7. Also, the other end part of the oil transporting felt 7 is brought into close and press contact with a cleaning felt 5, the silicone oil 12 infiltrated into the oil transporting felt 7 infiltrates into the cleaning felt 5 by a capillary phenomenon. Then only when the fixing device is in use, the silicone oil 12 is supplied to the oil transporting felt 7 in accordance with the rotation of the oil applying roller 6, then, the oil infiltrates into the cleaning felt 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer and a fixing device of a copying machine for forming a toner image on a sheet by using an electrophotographic process or the like.

[0002]

2. Description of the Related Art In recent years, printers and copiers using an electrophotographic process have expanded not only to mono-color but also to full-color and other commercial fields, and a fixing device has been provided to these.

A conventional fixing device will be described below.
FIG. 4 is a block diagram of a conventional fixing device, in which a sheet on which a toner image is formed is nipped and conveyed by a heating roller 1 and a pressure roller 2 to fix the toner image. Around the heating roller 1, which is maintained at, the oil applying felt 4 for applying the silicone oil 12 for toner release to the surface of the heating roller 1 via the oil applying roller 6, and the surface of the heating roller 1. An oil regulating blade 8 that evenly distributes the oil applied to a predetermined amount and a cleaning felt 5 that wipes off the offset toner on the surface of the heating roller 1 are provided. The cleaning felt 5 is initially impregnated with the silicone oil 12 so as not to wear the surface of the heating roller 1 when sliding on the heating roller 1.

[0004]

However, in the above-mentioned conventional structure, as the apparatus is used, the silicone oil 12 in the cleaning felt 5 is consumed and becomes less, so that the heating roller 1 of the heating roller 1 is dried with the dry cleaning felt 5. Since the surface was rubbed, the surface of the heating roller 1 was abraded and lacked in durability. Further, as the number of sheets used increases, the driving load increases, and the durability reliability of the driving system is adversely affected.

[0005]

In order to solve the above-mentioned problems of the prior art, the present invention supplies a release agent that comes into contact with a fixing roller to prevent toner from offsetting to the surface of the fixing roller. On the surface of the release agent applying roller, a release agent applying roller rotatably provided for applying the agent evenly on the surface of the fixing roller, a cleaning member for abutting the fixing roller and wiping off the toner offset to the fixing roller, And a transport member that is in contact with the downstream side of the release agent supply position and upstream of the contact position with the fixing roller to send the release agent to the cleaning member.

[0006]

According to the present invention, with the above-described structure, the release agent is supplied to the cleaning member according to the usage of the fixing device, that is, the consumption of the release agent in the cleaning member, and the amount of the release agent impregnated in the cleaning member is adjusted. It can be maintained in an appropriate amount.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a fixing device in an embodiment of the present invention. The fixing device has a heater lamp 3 therein and is heated to a temperature suitable for toner fixing.
And a pressure roller 2 that is urged against the heating roller 1 so as to obtain a pressure-bonding force required for toner fixing. The heating roller 1 and the pressure roller 2 are composed of silicone rubber layers 1a and 2a whose surfaces are elastic layers, and a nip required for toner fixing is formed between the heating roller 1 and the pressure roller 2. Has been done.

An oil tank and an oil pump are connected to the oil transport pipe, and through this oil transport pipe 11, the silicone oil 12 as a release agent is applied to the oil coating felt 4 through the oil coating felt 4.
Is supplied. The oil applying felt 4 is pressed against the oil applying roller 6 by a biasing spring, and the silicone oil 12 soaked in the oil applying felt 4 is applied to the surface of the oil applying roller 6 by the rotation of the oil applying roller 6. . The silicone oil 12 applied to the surface of the oil applying roller 6 is applied to the surface of the heating roller 1 by rotating the oil applying roller 6 clockwise. Since the oil applying roller 6 having the surface made of the silicone rubber layer 6a which is the elastic layer is in pressure contact with the heating roller 1, the silicone oil 12 is leveled to some extent at the time of application to the heating roller 1. The oil regulating blade 8 has a tip portion made of fluororubber 8a, and is pressed against the surface of the heating roller 1 by a biasing spring. Oil application roller 6
Silicone oil 1 applied on the surface of heating roller 1 by
2 is leveled by the oil regulating blade 8 and excess oil is scraped off and collected in the oil tray 9. Therefore, the surface of the heating roller 1 on the downstream side is scraped by the oil regulating blade 8 and the amount of silicone oil 12 suitable for toner fixing is set. Film is formed. This prevents the toner on the sheet from being offset on the surface of the heating roller 1 during the toner fixing process. However, since a slight amount of toner is offset on the surface of the heating roller 1, the cleaning felt 5 for wiping this off is provided in a pressure contact state. The end of the oil transport felt 7 is pressed against the surface of the oil applying roller 6 on the downstream side of the oil applying felt 4, and as the oil applying roller 6 rotates, the silicone oil 1 on the surface of the applying roller 6 is rotated.
Part of 2 penetrates into the inside of the oil transport felt 7. The other end of the oil transport felt 7 is pressed against the cleaning felt 5 while being in close contact with it, and the silicone oil 12 that has penetrated into the oil transport felt 7 penetrates into the cleaning felt 5 by a capillary phenomenon.

In the fixing device of the present embodiment configured as described above, the silicone oil 12 is supplied to the oil transport felt 7 by the rotation of the oil applying roller 6 and the cleaning felt 5 is supplied only when the fixing device is used. Penetrate. When the fixing device is used, the heating roller 1 rotates so that the silicone oil 12 in the cleaning felt 5 is applied to the heating roller 1 and the cleaning felt 5 is not supersaturated with the silicone oil 12. Since the silicone oil 12 is not supplied to the oil transport felt 7 when the cleaning felt 5 is not used, the cleaning felt 5 is supersaturated with the silicone oil 12 even if the cleaning felt 5 is left for a long time without being supplied. Never be.

On the other hand, as shown in FIG. 2, when the oil transportation felt 7 is brought into close contact with the oil application felt 4, the silicone oil 12 directly penetrates into the oil transportation felt 7 regardless of the rotation of the oil application roller 6. Since the silicone oil 12 is supplied from the oil transport pipe 11 to the oil application felt 4 when the fixing device is used, an excess silicone oil 12 is accumulated. If left in this state for a long time, a large amount of silicone oil 12 will penetrate into the cleaning felt 5 through the oil transport felt 7, and the lower portion of the cleaning felt 5 will be in a supersaturated state of the silicone oil 12. Therefore, there is a problem that the silicone oil 12 adheres to the sheet passing surface side of the sheet guide plate 10 located below and the sheet is soiled. Further, the silicone oil 12 is transmitted to the lower side of the surface of the heating roller 1, and there is a problem that the paper is soiled when the toner is fixed.

FIG. 3 shows a part of the structure of the fixing device in one embodiment of the present invention. The width of the pressure contact portion of the oil transport felt 7 against the oil applying roller 6 is narrow as shown in the figure. By doing so, the amount of oil that penetrates into the oil transport felt 7 from the surface of the oil applying roller 6 in the rotational drive can be adjusted to optimize the amount of oil supplied to the cleaning felt 5.

In this embodiment, the application and cleaning of the silicone oil 12 to the heating roller 1 has been described, but the same applies to the pressure roller 2.

Silicone oil 12 is used as a release agent.
However, the same applies to the case where another mold release agent is used.

[0014]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a releasing agent is provided which contacts the fixing roller and prevents the toner from being offset to the fixing roller surface. The releasing agent is evenly distributed on the fixing roller surface. A rotatably provided release agent applying roller for applying, and a cleaning member that abuts on the fixing roller and wipes off the toner offset to the fixing roller.
On the surface of the release agent applying roller, a transport member that contacts the release agent downstream from the release agent supply position and upstream from the contact position with the fixing roller and sends the release agent to the cleaning member is provided. The fixing agent can be supplied to the cleaning member in accordance with the usage status of the fixing device, that is, consumption of the releasing agent in the cleaning member, and the amount of the releasing agent impregnated in the cleaning member can be maintained at an appropriate amount. The surface of the product is not abraded by the cleaning member, the durability can be improved, the driving load can be prevented from increasing, and the durability of the drive system can be ensured. Since it does not become over-saturated, it does not stain the paper passage with a release agent. As a result, it is possible to prevent the paper from being contaminated with the release agent during toner fixing, and to prevent wasteful consumption of the release agent. Further, in the present invention, since the release agent is supplied to the cleaning member by also using the release agent supply means used for applying the release agent, it is not necessary to add a new release agent supply means. It is inexpensive, has a simple structure, and does not increase in size. Further, when felt, which is a non-woven fabric, is used as the transportation member, capillary transportation can be performed, and an inexpensive and simple device can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a fixing device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration different from that of the fixing device according to the embodiment of the present invention.

FIG. 3 is a diagram showing a part of the configuration of a fixing device according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional fixing device.

[Explanation of symbols]

 1 Heating Roller 1a Silicone Rubber Layer 2 Pressure Roller 2a Silicone Rubber Layer 3 Heater Lamp 4 Oil Applying Felt 5 Cleaning Felt 6 Oil Applying Roller 6a Silicone Rubber Layer 7 Oil Transport Felt 8 Oil Control Blade 8a Fluorine Rubber 9 Oil Tray 10 Paper Guide Plate 11 Oil transport pipe 12 Silicone oil

Claims (3)

[Claims] 1. A recording unit for forming a toner image on a sheet,
A pair of fixing rollers that nip and convey a sheet on which a toner image is formed and fix the toner image on the sheet, and a release agent that contacts the fixing roller and prevents the toner from being offset to the surface of the fixing roller are supplied. And a rotatably provided release agent application roller for applying the release agent to the surface of the fixing roller while leveling the release agent, and a cleaning member for abutting the fixing roller and wiping off the toner offset to the fixing roller. On the surface of the release agent applying roller, downstream of the release agent supplying position in the rotation direction of the release agent applying roller, and upstream of the release agent applying roller in the rotation direction of the contact position with the fixing roller. And a transportation member that is in contact with the cleaning member and sends the release agent on the release agent application roller to the cleaning member. 2. The fixing device according to claim 1, wherein the transport member is a non-woven fabric. 3. The mold release agent application in which the axial width of the mold release agent application roller of the transport member contacting the surface of the release agent application roller is in contact with the surface of the release agent application roller of the cleaning member. The fixing device according to claim 1, wherein the width is narrower than the width of the roller in the axial direction.