JPH0511171U - Fixing device for image forming apparatus - Google Patents

Abstract

(57) [Abstract] [Purpose] To replace the cleaning member for cleaning the fixing roller or the anti-adhesive agent applying means for applying the anti-adhesive agent to the fixing roller without interrupting the operation of the image forming apparatus for a long time. Further, it is possible to provide a fixing device for an image forming apparatus which does not require complicated work and which does not contaminate the periphery with an adhesion preventing agent or the like. [Construction] The cartridge 13 has a cleaning member 5, an oil supply member 6 and an oil pan 21 incorporated therein, and is handled as one unit. The cartridge 13 can be attached and detached.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fixing device mounted on an image forming apparatus such as a copying machine, a laser beam printer, and a facsimile.

[0002]

[Prior Art]

 In an electrophotographic copying machine, a toner image is formed on a photoconductor and this toner image is transferred onto a transfer paper. Then, the toner image on the transfer paper is fixed by the fixing device and then discharged to the outside of the machine. The fixing device includes a fixing roller that includes a heat source and is heated, and a pressure roller that is arranged in pressure contact with the fixing roller. Then, the transfer paper holding the toner image is passed between the rotating fixing roller and the pressure roller, and the toner image is fused and fixed to the transfer paper.

When a copying machine is used for a long period of time, toner, carrier, and the like adhere to the peripheral surface of the fixing roller, which may accumulate and cause image contamination. In addition, the transfer paper may be wound around the fixing roller due to the resin component or the like fused to the peripheral surface of the fixing roller. Therefore, it has been proposed that a cleaning member such as a blade, a web, or a roller be provided in contact with the fixing roller to scrape off the toner image adhering to the fixing roller.

[0004]

[Problems to be solved by the device]

 However, since the toner is accumulated on the cleaning member, the cleaning ability deteriorates with time. Therefore, the cleaning member must be replaced regularly. Since the fixing roller becomes hot, it is necessary to replace the cleaning section after the fixing roller is sufficiently cooled. Therefore, the copying operation of the copying machine must be interrupted for a long time. Also, the work of removing the cleaning member and installing a new cleaning member is complicated.

There is also a device that applies an oil supply member containing a low-viscosity silicone oil to the peripheral surface of the fixing roller so as to prevent the toner and the like from adhering to the fixing roller and apply the silicone oil to the fixing roller. . However, in the case of this apparatus, toner and carriers are accumulated in the oil supply member and the oil application ability is reduced, so it is necessary to replace or clean the oil supply member periodically. Therefore, it has the same drawbacks as when the cleaning member is provided.

Further, there is a possibility that silicon oil may be scattered around and pollute the device and the like. The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to replace the cleaning member and the like without interrupting the operation of the image forming apparatus for a long time, and without performing complicated work. It is another object of the present invention to provide a fixing device for an image forming apparatus that does not have a risk of contaminating the surroundings with silicon oil or the like.

[0007]

[Means for Solving the Problems]

 According to a first aspect of the present invention, a fixing roller whose peripheral surface is heated, a pressing roller provided in pressure contact with the fixing roller, and an anti-adhesion agent that prevents toner and the like from adhering to the fixing roller are supplied. The transfer paper on which the toner image is formed is passed through between the fixing roller and the pressure contact roller so that the surface on the toner image side is in contact with the peripheral surface of the fixing roller. In a fixing device of an image forming apparatus for fixing a toner image on a sheet of paper, the anti-adhesion agent supplying means is housed in a cartridge which is detachable from the image forming apparatus.

[0008]

[Action]

 In the present invention, the peripheral surface of the fixing roller is heated, and the pressing roller is pressed against the fixing roller to rotate. Then, the transfer paper on which the toner image has been transferred passes between the fixing roller and the pressure contact roller, and the toner image is fused and fixed on the transfer paper. In such an operation, the anti-adhesion agent supply means supplies the anti-adhesion agent to the fixing roller to prevent toner and the like from adhering. Since the anti-adhesion agent supply means is housed in the cartridge that is detachable from the image forming apparatus, each cartridge can be detached from the image forming apparatus. Therefore, the anti-adhesion agent supply means can be replaced with one touch.

[0009]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a heating type fixing device 100 mounted on a copying machine. In the figure, reference numeral 1 indicates a fixing roller, which is formed by covering the outer peripheral surface of the hollow roller core 1a with a heat resistant elastic layer 1b having a thickness of 15 μm to 30 μm. The hollow roller core 1a is made of aluminum, stainless steel or the like, and the heat resistant elastic layer 1bha is made of fluororubber or the like. The fixing roller is rotated counterclockwise by a drive motor (not shown). Further, a halogen heater 101 is arranged in the hollow roller core 1a.

Reference numeral 2 indicates a pressure roller. This pressure roller 2 has a metal roller core 2a on which an elastic layer 2b of silicon rubber or the like is provided on the outer peripheral surface, and a thickness is further formed on the elastic layer 2b. A fluororubber layer 2c having a thickness of about 70 μm to 300 μm is provided. By providing the fluororubber layer 2c, the transfer paper S is easily peeled from the pressure roller 2, and the elastic layer 2a is protected from external force, silicone oil, heat, etc., so that the durability and reliability of the pressure roller 2 are improved. Will be improved. The pressure roller 2 is rotatably supported by a bearing (not shown). The pressure roller 2 is pressed against the fixing roller 1 by a pressure means (not shown) and rotates together with the fixing roller 1.

Reference numeral 14 indicates an upper casing, and the upper casing 14 can be opened / closed about a support shaft 14a. A temperature sensitive element 25 such as a thermistor is attached to the upper casing 14 via the spring 4. When the upper casing 14 is closed, the temperature sensitive element 25 contacts the peripheral surface of the fixing roller 1. The temperature sensitive element 25 detects the temperature of the peripheral surface of the fixing roller 1, and the operation of the halogen heater 101 is controlled based on the detected value so that the outer peripheral surface of the fixing roller 1 becomes the melting temperature of the toner image.

Reference numeral 15 indicates a separation claw, and the separation claw 15 is rotatably held by the holding member 105 with the support shaft 17 as the center. The separation claw 15 is biased clockwise by the elastic force of the spring 16, and one end of the separation claw 15 is brought into contact with the peripheral surface of the fixing roller 1.

Reference numeral 11 denotes a lower casing, and the pressure roller 2 is housed in the lower casing 11. Reference numeral 10 indicates a guide plate. The front end of the guide plate 10 is located in the vicinity of the fixing roller 1. A screw 12 is inserted through the base end of the guide plate 10 and is attached to the lower casing 11 by this screw. The cleaning roller 8 is pressed against the peripheral surface of the pressure roller 2 by a spring 9. The cleaning roller 8 and the spring 9 are attached to the guide plate 10.

Reference numeral 13 indicates a cartridge, and the cartridge 13 accommodates a cleaning member 5 made of an elastic body. The tip of the cleaning member 5 is in contact with the peripheral surface of the fixing roller 1, and a metal plate 5a having elasticity is attached to the base end side. The metal plate 5a is held by an immovable member (not shown). There is. An oil supply member 6 is housed in the cartridge 13, and the oil supply member 6 is made of heat-resistant felt such as Conex (trade name). The oil supply member 6 is held by a holding member 6a made of sheet metal or resin, the tip end portion thereof contacts the peripheral surface of the fixing roller 1, and the base end portion thereof enters the oil pan 21.

Silicon oil as an anti-adhesion agent having a viscosity of 200 to 400 centistokes is put in the oil pan 21, and the oil supply member 6 is impregnated with the silicone oil. Reference numeral 7 denotes a coating member, which is made of the same material and has the same shape as the cleaning member 5 and is held by the same method. In this way, the cleaning member 5, the oil supply member 6, and the oil pan 21 are incorporated in the cartridge 13 and handled as one unit. The oil supply member 6, the holding member 6a, the oil pan 21, and the coating member 7 constitute an anti-adhesion agent supply means.

As shown in detail in FIG. 5, protruding portions 30 are provided at both ends on the opening side of the cartridge 13. The interval between the projecting portions 30 is set to be larger than the axial length of the fixing roller 1, so that the projecting portions 30 do not abut the fixing roller 1. The protruding portion 30 prevents the cleaning member 5 and the oil supply member 6 from being damaged when the cartridge 13 is handled. For example, the cleaning member 5 will not be damaged even if the opening side of the cartridge 13 is turned down and the cartridge 13 is pushed down or pressed against a wall or the like. A rib 43 is provided on the closed side of the cartridge 13.

A guide plate 42 is provided on the copying machine main body 26, and the cartridge 13 is installed on the guide plate 42. Further, the copying machine main body 26 is provided with an eccentric cam 41 which rotates about a shaft 40. A cutout 44 is formed in the eccentric cam 41, and the cutout 44 is formed in a portion farthest from the shaft 40. The eccentric cam 41 contacts the rib 43 of the cartridge 13.

In FIG. 1, reference numeral 19 denotes a transfer sheet conveying device, and the transfer sheet conveying device 19 is an area where the fixing roller 1 and the pressure roller 2 contact the transfer sheet S on which the toner image T is transferred. Send to the nip portion 18. As shown in FIG. 2, the copying machine main body 26 is provided with a paper feed cassette 27, a paper discharge tray 28, and an openable / closable cover 29.

Next, the fixing operation of the fixing device 100 will be described. The transfer sheet S on which the toner image on the photoconductor is transferred is conveyed to the nip portion 18 by the conveying device 19, and the transfer sheet S passes through the nip portion 18 with the surface on which the toner image is formed facing upward. At this time, the toner image is fused by the heat of the fixing roller 1 and fixing is performed. Even if the transfer sheet S adheres to the fixing roller 1, the transfer sheet S is separated by the separation claw 15.

In the fixing operation, the cleaning member 5 scrapes off the toner and the paper dust attached to the peripheral surface of the fixing roller 1. Further, the oil supply member 6 applies silicone oil to the peripheral surface of the fixing roller 1, and the application member 7 applies the applied silicone oil uniformly and thinly. By supplying the silicone oil to the peripheral surface of the fixing roller 1, it is possible to prevent the toner on the transfer sheet S from adhering to the fixing roller. In other words, the fixability of the toner image on the transfer sheet S can be improved. Further, the cleaning effect of the cleaning member 5 and the oil supply member 6 can be enhanced. The oil supply member 6 has a main role of applying silicon oil to the peripheral surface of the fixing roller 1, but also has a small role of removing the adhered toner and the like.

Next, an operation for replacing the cartridge 13 when the cleaning member 5 and the oil supply member 6 deteriorate will be described. The cover 29 is opened as shown in FIG. 2, and the eccentric cam 41 is rotated about the shaft 40 as shown in FIG. 3 to release the pressing force of the eccentric cam 41 against the cartridge 13 and tilt the cartridge 13 toward the eccentric cam 41 side. . Then, the cartridge 13 is pulled out from the copying machine main body 26.

After removing the used cartridge 13 from the main body 26 of the copying machine, a new cartridge 13 is inserted into the main body 26 of the copying machine and set on the guide 42 to obtain the state shown in FIG. Next, the eccentric cam 41 is rotated about the shaft 40 to press the rib 43, the cartridge 13 is tilted toward the fixing roller 1 side with the tip 42a of the guide 42 as a fulcrum, and the cleaning member 5, the oil supply member 6, and the coating member 7 are provided. Is brought into contact with the fixing roller 1, and the notch 44 of the eccentric cam 41 is brought into contact with the rib 43 of the cartridge 13 to fix the cartridge 13. Thus, the cartridge 13 can be replaced easily and in a short time.

Since the cartridge 13 is fixed by being brought into contact with the rib 43 of the cartridge 13, the pressure contact state of the cleaning member 5, the oil supply member 6, and the coating member 7 with respect to the fixing roller 1 is stable, and good cleaning is performed for a long period of time. However, the application of silicone oil will be guaranteed. The ribs 43 increase the rigidity of the cartridge 13 and make the axial pressing state of the cleaning member 5 or the like against the fixing roller 1 uniform.

Conventionally, a metal holding member having high rigidity has been used to hold the cleaning member and the oil supply member. Since the metal holding member has a high heat capacity and thermal conductivity, the heat of the fixing roller 1 escapes through the holding member, resulting in a long rise time of the fixing device and an increase in the output of the halogen heater 101. There are shortcomings that must be made. On the other hand, since the cartridge 13 is made of resin and is molded, the cartridge 13 avoids such inconvenience. Further, unlike the metal holding member, the cartridge 13 does not heat up so much, and therefore has an advantage that it is easy to perform the replacement work.

Since the cartridge 13 has a bottomed ship shape, it is possible to handle the silicon oil, toner, carrier, etc. accumulated in the used cartridge 13 without spilling. When the copying machine has a clam-shul structure, the upper part of the copying machine is opened and the cartridge 13 is replaced. In the above embodiments, the copying machine was shown as the image forming apparatus, but the present invention is not limited to this, and can be applied to a fixing device mounted in a laser beam printer, a facsimile, or the like.

[0026]

[Effect of the device]

 As described above, according to the present invention, the operation of the image forming apparatus is not interrupted for a long time, the complicated work is not performed, and the surroundings are not contaminated with silicon oil or the like. The oil supply member can be replaced.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a copying machine according to an embodiment of the present invention.

FIG. 3 is a view for explaining a replacement work of a cartridge provided in the fixing device of the present invention.

FIG. 4 is a view for explaining a replacement work of a cartridge provided in the fixing device of the present invention.

FIG. 5 is a perspective view of a cartridge included in the fixing device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Pressure roller 5 Cleaning member 6 Oil supply member 7 Coating member 26 Copier body 100 Heating type fixing device S Transfer paper T Toner image

Claims (1)

[Claims for utility model registration] Claims: 1. A fixing roller whose peripheral surface is heated, a pressure roller provided in pressure contact with the fixing roller, and toner and the like prevented from adhering to the fixing roller. An anti-adhesion agent supplying means for supplying an anti-adhesion agent to the transfer sheet on which the toner image is formed so that the surface on the toner image side is in contact with the peripheral surface of the fixing roller. In the fixing device of the image forming apparatus for fixing the toner image on the transfer paper through the gap, the anti-adhesion agent supply means is housed in a cartridge detachable from the image forming apparatus. .