JPH09292791A - Fixing device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively use oil as a releasing agent by setting the position where silicone oil oozing out from a cleaning web drips down onto the surface of a fixing roller and further upstream in the direction where the fixing roller runs than the position where the cleaning web slides over the fixing roller. SOLUTION: The center P of a supply shaft 8 is situated above the fixing roller 2 and further upstream in the direction where the fixing roller 2 runs than the position of the cleaning web 5 sliding over it, that is, it is situated above a range shown by the sign (a) in illustration. In this structure, all oil dripping from the wound cleaning web 5 falls onto the fixing roller 2. Then, the oil which has dropped reaches between the surface of the fixing roller 2 and the cleaning web 5 as the fixing roller 2 rotates, some of the oil is applied and spread onto the surface of the fixing roller 2 to prevent toner from sticking to it, and some of it is applied to the cleaning web 5 to be absorbed, and it is wound around a take-up shaft 7.

Description

Detailed Description of the Invention

[0001]

[Object of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus utilizing an electrostatic transfer process, such as an electrostatic copying machine and a printer, and more particularly to a stationary part device thereof.

In the known image forming apparatus as described above, it is necessary to fix and fix the toner image electrostatically formed on the transfer material such as paper through the transfer process. As a means for this, conventionally, a means of passing a transfer material carrying a toner image between a pair of heating rollers which are in pressure contact with each other and applying heat and pressure to the toner to fix the toner has been widely put into practical use. As is known. FIG. 8 shows a typical example of a known fixing device.

To briefly describe this, a fixing roller 2 having a heat source 4 such as a heater therein is provided inside the fixing device.
And a pressure roller 3 that presses against this and forms a nip portion N
Is provided. A hard material such as metal is used for the surface layer of the fixing roller, and an elastic material such as silicon rubber is usually used for the pressure roller 3.

A transfer material (not shown) carrying a toner image electrostatically formed at a transfer portion (not shown) is indicated by an arrow A in the figure.
When it is conveyed from the direction to the nip N and passes through the part,
It is assumed that the heated toner image is melted and fixed on the transfer material and then discharged to the outside of the apparatus.

In the fixing device having such a structure, when the transfer material passes through the nip portion, the toner image comes into contact with the fixing roller 2, so that a part of the toner adheres to the surface of the roller, which is a so-called offset phenomenon. It cannot escape.

When the offset occurs, the toner is
Next, the toner adheres to the transfer material that reaches the nip portion and causes deterioration of image quality. Further, since the toner attached to the roller 2 naturally also attaches to the pressure roller 3, there arises a problem that the back stain of the transfer material is caused by the toner.

In order to prevent the occurrence of such a phenomenon, a cleaning mechanism is provided above the fixing roller 2 in the figure. Explaining this, a cleaning web 5 made of a non-woven fabric impregnated with silicone oil or the like as a release agent is suspended between a supply shaft 8 and a take-up shaft 7 which are arranged at appropriate positions above the fixing roller 2. An elastic pressing roller 6 is disposed between the shafts 7 and 8, and the roller 6 is pressed against the cleaning web 5 via the web 5 so as to bring the cleaning web 5 into contact with the fixing roller 2. There is.

The shaft 7 is driven by a driving means (not shown) to wind up the cleaning web 5 in the direction of arrow B in the drawing, immediately in the running direction of the fixing roller 2 and in the counter direction, and the surface of the fixing roller 2 is covered by the cleaning web 5. The toner adhering to the roller is removed by rubbing.

In this case, the pressure contact nip width (the length in the running direction of the web) between the roller 6 and the fixing roller 2 is too small, and the cleaning function is deteriorated, or the release agent is not applied uniformly, and the following portion is not applied. Since there is a risk of problems such as easy adhesion of toner to the toner, it is necessary to secure a sufficient nip width.

A pressing member 9 is provided on the surface of the cleaning web 5 wound around the supply shaft 8 so as to contact the surface of the web with a spring or the like (not shown). To prevent the occurrence of slack and wrinkles on the web.

If the fixing roller 2 is not completely cleaned, as described above, the toner is transferred and adhered to the pressure roller 3 which is in contact with the fixing roller 2, and the backside of the transfer material is generated. To clean the pressure roller,
A cleaning member 11 made of felt or the like impregnated with silicon oil is configured to abut and rub against the roller 3.

In the known fixing device as described above, a large amount of the web 5 impregnated with a releasing agent such as silicon oil is present on the supply shaft 8 and a part of the web 5 drops off from the web. Since there is a risk of contaminating each part in the apparatus and the transfer material, the oil storage container 10 is arranged below the oil storage container 10 to receive the dripped oil.

On the other hand, since the fixing device itself is not so large, the container 10 is inevitably made very small, and the service person must periodically discard the accumulated oil. It is unavoidable that this will cause a decrease in maintainability.

In order to make effective use of the cleaning web recently, an apparatus using both sides of the web has been proposed. In such a case, a considerable amount of oil is used when one side of the web is used. Is discharged, there is a problem that when the other side of the web is used, the oil is insufficient and cleaning failure occurs.

Further, the cleaning member 11 for cleaning the pressure roller 3 is inevitably in an oil-deficient state as it is used, and there is a problem that a cleaning failure occurs here. Therefore, the cleaning member 11 also has a problem. However, even if it is not so polluted, it needs to be replaced if the oil runs out, and maintenance is also poor.

The present invention has been made to cope with such a situation as described above, and is provided with a fixing roller and a pressure roller which is in pressure contact with the fixing roller, and these rollers are cleaned by a cleaning member impregnated with silicone oil. In the configured fixing device, the excess oil dripping from the cleaning member is supplied again to the fixing roller or the pressure roller to effectively utilize the oil as the release agent and to improve the maintainability and to always stabilize the oil. It is an object of the present invention to provide a fixing device that can perform good fixing.

[0017]

Configuration of the Invention

In order to achieve the above-mentioned object, the present invention comprises a fixing roller, a pressure roller pressed against the fixing roller, and a cleaning web impregnated with silicone oil as a release agent. In a fixing device equipped with a cleaning means for slidingly running a cleaning web suspended between a supply shaft and a take-up shaft, which is held by a roller, on the surface of the fixing roller, the fixing device exudes from a cleaning web held on the supply shaft. The position where the silicone oil drops is
A fixing device of an image forming apparatus in which the supply shaft is arranged so as to be on the surface of the fixing roller and upstream of the position where the cleaning web slides on the fixing roller when viewed in the running direction of the fixing roller, or a fixing device. A roller, a pressure roller in pressure contact with the roller, and a cleaning web suspended between a supply shaft and a take-up shaft for winding and holding a cleaning web impregnated with silicone oil as a release agent are slid on the surface of the fixing roller. In a fixing device having a cleaning means for rubbing and running, the cleaning web is a fixing roller when the silicone oil exuding and dripping from the cleaning web held on the supply shaft is viewed in the running direction of the fixing roller on the surface of the fixing roller. Of an image forming apparatus provided with a drip oil receiving member for supplying the oil at a position upstream of the position where the oil is rubbed against the oil. The fixing device or the fixing roller of the image forming apparatus, in which the drip oil receiving member includes an oil storage container and a porous member that supplies the oil in the container to the fixing roller. A pressure roller that is in pressure contact with this and a cleaning web that is impregnated with silicone oil, which is a release agent, is wound around, and a cleaning web that is suspended between a supply shaft and a take-up shaft that holds it is slid on the surface of the fixing roller. In a fixing device provided with a cleaning means for rubbing and traveling, a fixing device of an image forming apparatus, wherein the winding shaft is arranged at a position where oil dripping from a cleaning web stack wound around the supply shaft drops.
Alternatively, a fixing roller and a pressure roller that is in pressure contact with the fixing roller,
A cleaning web is wound around a cleaning web impregnated with silicone oil as a release agent, and a cleaning web is suspended between a supply shaft and a take-up shaft for holding the cleaning web. In a fixing device in which the front side of the web is used and then suspended on a supply shaft to use the back side of the cleaning web for cleaning again, the supply shaft is wound around a position where the oil dripping from the unwinding cleaning web stack drops. A fixing device of an image forming apparatus provided with a take-up shaft, or a fixing roller, a pressure roller that comes into pressure contact with the fixing roller, and a supply shaft that winds and holds a cleaning web impregnated with silicone oil as a release agent. And a cleaning means for rubbing and running a cleaning web suspended between the winding shaft and the winding shaft on the surface of the fixing roller. After using the surface of Nguuebu,
In a fixing device in which this is suspended on a supply shaft and the back side of the cleaning web is used for cleaning again, the oil in the container is detachable from the container that receives the oil dripping from the cleaning web stack wound around the supply shaft. A fixing device of an image forming apparatus provided with a porous member that guides the fixing roller to the surface of the fixing roller, or a fixing roller, a pressure roller in pressure contact with the fixing roller, and a cleaning web impregnated with silicone oil as a release agent. A fixing device comprising: a cleaning unit that winds and holds a cleaning web, which is suspended between a supply shaft and a take-up shaft, which slides on the surface of the fixing roller, and a cleaning web wound around the supply shaft. A first container for storing the oil dripping from the stack,
An image forming apparatus comprising: a second container that applies oil to a cleaning member of the pressure roller; and a member that introduces oil from the first container into the second container. It is a fixing device.

According to this structure, in the fixing device having the cleaning web impregnated with the releasing agent such as silicone oil, the oil dripping from the piled cleaning web can be effectively used. It becomes possible and maintenance becomes easy.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS "FIG. 1" is a side sectional view of a fixing device showing a first embodiment of the present invention, the basic structure of which is the same as that of the above-mentioned known fixing device, and corresponding parts are shown. Are denoted by the same reference numerals, and description thereof will be omitted (the same applies to the embodiments described later).

In the illustrated apparatus, the cleaning web 5 suspended between the supply shaft 8 and the take-up shaft 7 reaches the take-up shaft 7 via the intermediate roller 14, and the shaft 14 and the take-up shaft 7 are taken up. By appropriately setting the position of the shaft 7, the supply shaft 8 and the cleaning web 5 wound around the supply shaft 8 are fixed to the fixing roller 2.
It is located just above.

In the illustrated apparatus, the supply roller and the take-up roller are on the left and right sides in the figure, which are different from those of the known apparatus. Therefore, the web 5 is applied to the fixing roller 2 via the intermediate roller 14 as described above. By bringing them into contact with each other, the web 5 travels in the counter direction with respect to the fixing roller 2 to improve the cleaning property.

The position of the supply shaft 8 will be further explained. The center of the shaft 8 is above the fixing roller 2 and upstream of the position of the web which rubs against the fixing roller 2 in the running direction. It is located on the side, that is, above the range of the symbol a in the figure.

With this construction, all the oil dripping from the wound cleaning web 5 falls on the fixing roller 2 and then reaches the gap between the surface of the roller 2 and the web 5 as the roller rotates. A part of them is applied and adhered to the roller surface to prevent the adhesion of toner, and a part is adhered and adsorbed to the web and taken up by the take-up shaft 7.

Therefore, according to this apparatus, a member corresponding to the container 10 for receiving the drooling oil is unnecessary, and the maintainability is improved.

FIG. 2 is a side sectional view of the fixing device showing the second embodiment of the present invention. In this device, an oil guide member 12 is arranged below the supply shaft 8, and the oil dripping from the wound web 5 falls on the oil guide 12. The oil guide 12 is formed with a guide portion 12 ′ extending in the direction of the fixing roller 2, and the guide portion 12 ′ has its tip positioned within the range of the symbol a shown in FIG. ing.

Therefore, from the web 5 to the oil guide 1
The oil dropped to 2 then reaches the upstream side of the position where the web 5 slides on the fixing roller 2 via the guide portion 12 ′, and the same operation as that of the apparatus of the above embodiment is performed.

This apparatus requires a member for receiving the oil once dropped from the web, but not only can the oil be simply stored but also be supplied to the fixing roller for use, so that the maintainability is improved. , Winding shaft 8
Since the position of is not limited to above the fixing roller, the degree of freedom in design is increased as a whole, and a more compact design is possible.

As the oil guide member 12, a protruding rib is provided on the base portion of the guide portion over the entire length (perpendicular to the paper surface) so that a certain amount of oil can be collected and then flowed out. When the delusion is vibrated, it is possible to considerably prevent the occurrence of contamination due to the scattering of oil to each part in the device.

FIG. 3 shows a third embodiment of the present invention. In the illustrated apparatus, an oil storage container 10 is arranged below the supply shaft 8 and the fixing roller 2 is provided from the container.
A coating member 13 made of a material such as felt that can utilize a capillary phenomenon is provided over the entire area.

One end of the coating member 13 has a container 10
It is immersed in the oil inside, and the other end is in contact with or in close proximity to the fixing roller 2 in the area indicated by the symbol a of the apparatus shown in FIG.

With this structure, the fixing roller 2 is coated with the oil through the coating member 13, so that the oil is uniformly coated over the entire length, which contributes to the improvement of the cleaning property.

FIG. 4 is a side sectional view of a fixing device showing a fourth embodiment of the present invention, and it is assumed that both sides of the cleaning web can be used in this device. First, an embodiment corresponding to "claim 5" which is a mode of double-sided use will be described.

A cleaning web 5 is suspended between the supply shaft 8 and the take-up shaft 7 as shown by the solid line in the drawing, and is indicated by an arrow B.
It shall run in the direction and be wound around the shaft 7. In this case, the web 5 is a surface that abuts and rubs against the fixing roller 2,
In the figure, the toner adheres to the lower side of the web portion between the roller 6 and the shaft 7 in the figure, and when the toner is wound around the shaft 7, the outer surface thereof is contaminated.

When the web 5 is completely wound around the shaft 7,
The web is removed from the shafts 7 and 8, and the portion around which the used web is wound is mounted on the shaft 8. At this time, the front end portion of the web (the portion that was originally attached to the shaft 8) is inserted between the roller 6 and the fixing roller 2 at the position shown by the dotted line in the figure, and the front end is engaged with the shaft 7. Stop.

As described above, the outer side of the web mounted on the shaft 8 at this time is contaminated by the previous use,
By suspending the web as described above, the unused inner side surface comes into contact with the fixing roller, and thereafter, the cleaning can be performed by the back side of the web by the same operation as in the case of the front side.

In such an apparatus, the center P of the supply shaft 8 is shown right above the winding shaft 7 or in the vicinity thereof, at least within the range of the length of the winding shaft 7 in the horizontal direction. The position is set. Therefore, during cleaning by the first surface of the web shown by the solid line in the drawing, the oil dripping from the web stack falls on the winding shaft 7 and is immersed in the web 5 wound around the winding shaft 7.

After consuming the first surface of the web 5, the web stack wound around the shaft 7 is mounted on the shaft 8, and this time the web is extended as shown by the dotted line in the figure, and the tip of the web 7 is passed through the roller 6 and the shaft 7. If locked and the cleaning operation is performed, the unused second side of the web can be cleaned thereafter.
Since the web has been sufficiently impregnated with the oil that has dropped during the cleaning of the surface, it is possible to preferably avoid the situation where the oil runs out during the use of the second surface. When both sides cannot be used, the embodiment corresponds to "Claim 4" and the configuration is the same.

As described above, according to the apparatus of this embodiment, when the front and back surfaces of the web are both used, sufficient oil is present at any time, and therefore it is necessary to increase the speed of the web when the second surface is used. In addition, since there is no need for a container or the like for receiving oil that drips, maintenance is improved.

"FIG. 5" and "FIG. 6" show a fifth embodiment of the present invention. In this case, the fixing device is configured so that both sides of the cleaning web as shown in FIG. 4 can be used. Yo

[FIG. 5] is the first of the cleaning web 5.
Shows that you are using a surface, which is good for web 5
The oil dripping from the container 10 is received and stored in the container 10.

After the cleaning by the first surface is completed, the shaft 7
Take off the web stack wound around and attach it to the shaft 8,
If the web is suspended along the path as shown in FIG. 6, the unused second surface of the web comes into contact with the fixing roller 2, so that cleaning can be performed by the same operation as before.

When the second surface is used for cleaning, the other end of the coating member 13 'made of felt or the like having its end portion dipped in the oil stored in the container 10 is brought into contact with the fixing roller 2 surface. Supply oil to the surface.

Since such a cleaning web is usually replaced by a service person, if the coating member 13 'is simultaneously attached to the container 10 at this time, there is no particular problem in using the apparatus.

FIG. 7 is a side sectional view of a fixing device showing a sixth embodiment of the present invention. In this device, a first oil storage container 10 for receiving oil dripping from the cleaning web 5 and a second oil storage container 16 arranged below the pressure roller 3 are provided.

An oil transmission pipe 15 communicates between the oil storage containers 10 and 16. Further, the cleaning member 11 whose end is in contact with the pressure roller 3
The other end of is located in the container 16. The length of the cleaning member 11 in the direction perpendicular to the paper surface is the pressure roller 3
It is assumed that the length of the container 16 is slightly longer than the length of the paper passing portion in the axial direction, and the length of the container 16 in the direction perpendicular to the paper surface is such that the member 11 is completely inserted.

As described above, in the known device, the cleaning member 11 runs out of oil to be impregnated when the device is used for a long period of time, so that the cleaning member 11 is often replaced even if it is not contaminated by toner. It was

In the illustrated apparatus, since the cleaning member 11 can be supplied with oil, the replacement cycle can be extended to improve the maintainability. Further, since the oil dripping from the web before use can be reused for the pressure roller side, there is an advantage that the degree of freedom of design change is increased.

[0048]

As described above, according to the present invention,
In a fixing device that includes a fixing roller and a pressure roller that is in pressure contact with the fixing roller, and the cleaning web is impregnated with a release agent such as silicon oil to prevent toner from adhering to these rollers, the fixing device droops from the cleaning web. A special container is needed to store the oil that drips from the web, because it can be applied to the fixing roller or pressure roller, or to the used web to add suitable oil to both sides of the web. Since it is possible to avoid such a problem as much as possible, it greatly contributes to the improvement of the maintainability of the apparatus. By not using the oil storage container, the degree of freedom in design is increased and the apparatus can be made compact.

[Brief description of drawings]

FIG. 1 is a side sectional view of a fixing device showing a first embodiment of the present invention.

FIG. 2 is a side sectional view of a fixing device according to a second embodiment of the present invention.

FIG. 3 is a side sectional view of a fixing device showing a third embodiment of the present invention.

FIG. 4 is a side sectional view of a fixing device showing a fourth embodiment of the present invention.

FIG. 5 is a side sectional view of a fixing device showing a fifth embodiment of the present invention.

FIG. 6 is a side sectional view showing another usage mode of the same as above.

FIG. 7 is a side sectional view of a fixing device showing a sixth embodiment of the present invention.

FIG. 8 is a side sectional view showing the configuration of a known fixing device.

[Explanation of symbols]

 1 Oil Drop 2 Fixing Roller 3 Pressure Roller 4 Heat Source 5 Cleaning Web 6 Elastic Pressing Roller 7 Winding Shaft 8 Supply Shaft 10 Oil Container 12 Oil Guide 13 Coating Member 14 Intermediate Roller

Claims (7)

[Claims] 1. A cleaning web in which a fixing roller, a pressure roller pressed against the fixing roller, and a cleaning web impregnated with silicone oil as a release agent are wound and suspended between a supply shaft and a winding shaft. In a fixing device having a cleaning means for sliding the fixing roller surface on the fixing roller surface, the position where the silicone oil exuding from the cleaning web held on the supply shaft drops on the fixing roller surface and the fixing roller moves. A fixing device of an image forming apparatus, wherein the supply shaft is arranged so as to be located upstream of a position where the cleaning web slides on a fixing roller when viewed in a direction. 2. A cleaning web having a fixing roller, a pressure roller pressed against the fixing roller, a cleaning web impregnated with silicone oil as a release agent, and a suspension shaft suspended between a supply shaft and a winding shaft for holding the cleaning web. In a fixing device having a cleaning means for sliding the fixing roller surface onto the fixing roller surface. Silicon oil exuding and dripping from the cleaning web held on the supply shaft is added to the fixing roller surface in the traveling direction. The fixing device of the image forming apparatus is provided with a drip oil receiving member for supplying the cleaning web to a position upstream of the position where the cleaning web rubs the fixing roller. 3. The fixing device for an image forming apparatus according to claim 2, wherein the drip oil receiving member comprises an oil storage container and a porous member for supplying the oil in the container to the fixing roller. 4. A cleaning web suspended between a fixing roller, a pressure roller in pressure contact with the fixing roller, a supply shaft for holding a cleaning web impregnated with silicone oil as a release agent, and a take-up shaft. An image formed by disposing the take-up shaft at a position where oil dripping from the cleaning web stack wound around the supply shaft drops Fixing device for forming device. 5. A cleaning web suspended between a fixing roller, a pressure roller pressed against the fixing roller, a supply shaft for holding a cleaning web impregnated with silicone oil as a release agent, and a take-up shaft. A cleaning means for rubbing the surface of the fixing roller against the surface of the fixing roller, and after using the surface of the cleaning web, suspending the surface of the cleaning web and using the back surface of the cleaning web for cleaning again, A fixing device for an image forming apparatus, in which a take-up shaft is arranged at a position where the oil dripping from the cleaning web stack wound around is dropped. 6. A cleaning web suspended between a fixing roller, a pressure roller pressed against the fixing roller, a supply shaft for winding and holding a cleaning web impregnated with silicone oil as a release agent, and a winding shaft. And a cleaning means for sliding the cleaning roller onto the surface of the fixing roller, and after using the surface of the cleaning web, suspending the surface of the cleaning web and using the back surface of the cleaning web for cleaning again, A fixing device for an image forming apparatus, which is provided with a porous member that is attachable to and detachable from a container that receives oil dripping from a cleaning web stack that is wound around, and that guides the oil in the container to the surface of the fixing roller. 7. A cleaning method in which a fixing roller, a pressure roller in pressure contact with the fixing roller, and a cleaning web impregnated with silicone oil as a releasing agent are wound and suspended between a supply shaft and a winding shaft. In a fixing device having a cleaning means for slidingly running a web on the surface of the fixing roller, a first container for storing oil dripping from a cleaning web stack wound around a supply shaft, and cleaning of the pressure roller A fixing device of an image forming apparatus, comprising: a second container for applying oil to a member; and a member for introducing the oil of the first container into the second container.