JP3608969B2 - Fixing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device having a cleaning device in an image forming apparatus.
[0002]
[Prior art]
Conventionally, in this type of fixing device, a cleaning device having a cleaning roller is used to clean and remove excess toner, paper dust, oil, and other collected matter attached to the fixing roller (or pressure roller). Is generally done. Further, as a prior art, (1) Japanese Patent Application Laid-Open No. 4-128559 has a cleaning brush that contacts a fixing roller (or a pressure roller), and a scraper for removing a collected material is provided on the cleaning brush. However, this scraper is disclosed in which an adhesion member (felt) capable of adhering the recovered material scraped by the scraper is provided. Further, (2) Japanese Patent Application Laid-Open No. 10-247030 discloses an oil application roller provided with a brush member for removing (cleaning) excess toner adhering to the surface of the oil application roller. .
[0003]
[Problems to be solved by the invention]
However, in the case of the conventional general fixing device, the recovered material such as paper dust removed by the cleaning device is transferred (dropped) to the fixing roller (or pressure roller) or the paper again. There is a problem that it causes stains on the rollers and copy paper. In the case of the prior art publication (1), the cleaning roller is the only one that directly cleans the fixing roller itself, so that the cleaning function deteriorates depending on long-term use. The problem of causing dirt arises. In the case of (2), the oil application roller itself does not have a cleaning function, and the fixing roller itself is not cleaned by the brush member. Therefore, there is a risk that the collected material attached to the brush member will reattach to the fixing roller. Therefore, there are still problems similar to the above (1).
[0004]
Accordingly, an object of the present invention is to solve the problems of the conventional fixing device as described above, and the paper dust or the like removed from the fixing roller (or pressure roller) by the cleaning device is dropped and is again applied to each roller. An object of the present invention is to provide a fixing device capable of preventing smearing of copy paper due to adhesion.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an image forming apparatus including a fixing roller, a pressure roller, and a cleaning device for cleaning the rollers. In the fixing device, the cleaning device has a cleaning roller and a heat-resistant brush that rotate while being in contact with the roller surface of any roller, and the heat-resistant brush is provided on the upstream side of the rotation of any roller. In addition, the hair tip direction is arranged so as to oppose the rotation direction of any of the rollers.
[0006]
The invention according to claim 2 is the invention according to claim 1, wherein the contact angle between the roller surface of any of the rollers and the bristles of the heat-resistant brush is selected to be larger than the angle with the tangent. It is characterized by being.
[0007]
According to a third aspect of the present invention, in the first aspect of the present invention, a recovery cover for recovering a recovered material such as toner cleaned by the cleaning device is provided below the cleaning device together with the cover of the fixing device. It is characterized by being attached together.
[0008]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the urging force that causes the heat-resistant brush to abut against any of the rollers is also used by the urging means provided on the cleaning roller. It is a feature.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an image forming apparatus to which the fixing device of the present invention is applied. As shown in FIG. 1, the image forming apparatus A is provided with sheet feeding means 4 and 4 having a plurality of sheet feeding cassettes 2 and sheet feeding rollers 3 in the apparatus main body 1, and the sheet feeding means 4 and 4 feed the sheet. The sheet 5 is subjected to image timing by a registration roller 6 and conveyed to a photoconductor 7, and the surface of the photoconductor 7 is uniformly charged by a charging charger 8 while being driven to rotate. . On the other hand, the scanner unit 9 reads the reflected light of the original from the exposure lamp, and the read data is subjected to image processing and transmitted to the laser optical system. The laser optical system then irradiates the charged photoreceptor 7 with laser light to form an electrostatic latent image.
[0010]
The electrostatic latent image is visualized by a developer (toner) when passing through the developing device 12, and the visible image is transferred to the sheet 5 conveyed from the registration roller 6. Is conveyed to the fixing device 14. The fixing device 14 includes a fixing roller 16 and a pressure roller 17 that presses and rotates with the fixing roller 16. The fixing roller 16 includes a heater 18 such as a halogen heater inside as shown in FIG. A temperature detection member 20 such as a thermistor for detecting the roller surface temperature is provided outside. The amount of power supplied to the heater 18 is controlled by the temperature of the fixing roller 16 detected by the temperature detection member 20. On the other hand, the pressure roller 17 is supported by a pair of pressure levers 21 whose base ends on the shaft side are pivotally supported by the pivot of the apparatus main body 1, and one end of the free end of the pressure lever 21 is connected to the apparatus main body 1. The pressure roller 17 is attached to the other end of the attached spring 22, and the pressure roller 17 is pressed against the fixing roller 16 side by the tension (pressing force) of the spring 22. The sheet 5 carried into the fixing device 14 is fixed with unfixed toner by the pressurization and heating of the fixing roller 16 and the pressure roller 17, and the image formation is completed.
[0011]
3 and 4 show a first embodiment of the present invention. As shown in FIG. 3, the fixing device 14 includes a fixing roller 16 and a pressure roller 17, and a cleaning device 24 for cleaning the rollers 16 and 17. In the first embodiment, the cleaning device 24 is provided with a cleaning roller 25 that rotates while contacting the roller surface of the pressure roller 17, and a heat-resistant brush 26 at a position adjacent to the cleaning roller 25 (downward). . The cleaning roller 25 is rotatably supported by pivots 27 and 27 provided at both ends thereof, and is pressed toward the pressure roller 17 by an urging means 28 such as a leaf spring. As a result, the cleaning material such as residual toner adhering to the pressure roller 17 can be cleaned by the cleaning roller 25.
[0012]
On the other hand, as shown in FIG. 4, the heat resistant brush 26 has a base 30 attached to the tip of an urging means 29 such as a leaf spring, and the basal end of the urging means 29 is attached to a mounting screw 36 (see FIG. 6). ) And fixed to the cover side of the fixing device 14. Further, the urging means 28 is bent from substantially the center thereof in the direction approaching the pressure roller 17 side. As a result, the heat-resistant brush 26 abuts on the upstream side of the rotation with respect to the cleaning roller 25 and an urging force (elasticity) in the upward direction is applied by the urging means 28. The pressure roller 17 is pressed from the lower side. Here, the hair end direction of the heat resistant brush 26 is arranged so as to oppose the rotation direction of the pressure roller 17. As the material of the heat resistant brush 26, Teflon, PPS, PI, PAI or the like can be used. The heat-resistant brush 26 can scrape paper dust or the like mainly from the pressure roller 17 and perform cleaning. In this case, since the scraped paper dust remains in the base end portion (root) of the heat-resistant brush 26, the paper dust or the like does not fall down. Thereby, before the paper dust or the like adheres to the cleaning roller 25, such paper dust is removed in advance by the heat-resistant brush 26, and the residual toner on the surface of the pressure roller 17 is removed by the cleaning roller 25. It is possible to avoid the problem that the collected material such as paper dust is transferred again to each roller and paper, and the roller and copy paper become dirty.
[0013]
FIG. 5 shows a second embodiment of the present invention. As shown in FIG. 5, in the second embodiment, when the angle between the surface of the pressure roller 17 and the tangent line G is α °, and the contact angle with the hair end direction of the heat-resistant brush 26a is β °, the hair The first contact angle β ° is selected to be larger than the angle α ° with the tangent line G (α ° <β °). Therefore, when the selection condition according to the second embodiment is set, the hair tip of the heat-resistant brush 26a abuts on the upstream side of the rotation of the cleaning roller 25, and the hair tip direction is the rotational direction of the pressure roller 17. Since it can be made the position which opposes, the effect of 1st Embodiment mentioned above can be acquired. For this reason, the heat-resistant brush used can be used even if the normal hair tip is a straight hair type.
[0014]
FIG. 6 shows third and fourth embodiments of the present invention, respectively. As shown in FIG. 6, the third embodiment is characterized in that the exterior covers 32 and 33 of the fixing device 14 have a function as a collection guide plate for collecting paper dust and the like in advance. That is, in FIG. 6, the paper dust that has been cleaned by the heat-resistant brush 26 b provided on the fixing roller 16 side is collected by the guide plate 34 that extends substantially horizontally from the inside of the exterior cover 32, and by the pressure roller 17. With the heat-resistant brush 26 b provided on the side, the cleaned paper dust can be collected by the guide plate 35 that is a recess of the exterior cover 33. This eliminates the need for a separate collection receptacle for collecting the collected material.
[0015]
Further, as shown in FIG. 6, the urging means of the heat-resistant brush 26 b is also used as the urging means 31 of the cleaning roller 25. That is, the heat-resistant brush 26b is attached to the front end portion of the biasing means 31, and the cleaning roller 25 is rotatably attached to the substantially central portion thereof. Therefore, the urging means 31 allows the cleaning roller 25 and the heat-resistant brush 26b to exert an urging force against the fixing roller 16 and the pressure roller 17 (fourth embodiment). As a result, the combined use of the urging means facilitates the mounting of the heat-resistant brush 26b and the cleaning roller 25, simplifies the configuration, and reduces costs.
【The invention's effect】
The present invention is as described above, and the invention according to claim 1 is a fixing device of an image forming apparatus including a fixing roller, a pressure roller, and a cleaning device for cleaning these rollers. The cleaning device has a cleaning roller and a heat-resistant brush that rotate while being in contact with the roller surface of any of the rollers, and the heat-resistant brush is provided on the upstream side of any of the rollers with respect to the cleaning roller. Since the hair tip direction is arranged so as to oppose the rotation direction of any of the rollers, the collected material such as paper dust can be scraped off in advance before adhering to the cleaning roller. The effect of preventing paper dust, etc. removed from the rollers from dropping and adhering to each roller or paper again, and preventing image smears on copy paper. A.
[0017]
The invention according to claim 2 is the invention according to claim 1, wherein the contact angle between the roller surface of any of the rollers and the bristles of the heat-resistant brush is selected to be larger than the angle with the tangent. Therefore, the heat resistant brush has an effect that an ordinary straight hair type can be used.
[0018]
According to a third aspect of the present invention, in the first aspect of the present invention, a recovery cover for recovering a recovered material such as toner cleaned by the cleaning device is provided below the cleaning device. In addition, since the fixing device is also provided, there is an effect that the cost of the fixing device can be reduced and the recovery processing of the recovered material such as paper dust can be easily performed.
[0019]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the urging force for abutting the heat resistant brush of any of the rollers against any of the rollers is provided by an urging means provided on the cleaning roller. Since they are also used, it is easy to attach the heat-resistant brush and the cleaning roller, and the configuration is simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of an image forming apparatus applied to the present invention.
FIG. 2 is a schematic perspective view of an identification wearing part.
FIG. 3 is a side view of an essential part showing the first embodiment.
4 is an enlarged view of a main part of FIG. 3;
FIG. 5 is a side view of an essential part showing the second embodiment.
FIG. 6 is a side view of an essential part showing the third and fourth embodiments.
[Explanation of symbols]
A Image forming apparatus 1 Apparatus main body 2 Paper feed cassette 4 Paper feed means 7 Photoconductor 8 Charging charger 12 Developer 14 Fixing device 16 Fixing roller 17 Pressure roller 18 Heating heater 20 Temperature detection members 24 and 24a Cleaning device 25 Cleaning roller 26 , 26a, 26b Heat-resistant brush 28, 29, 31 Biasing means 34, 35 Guide plate

Claims (4)

In a fixing device of an image forming apparatus provided with a fixing roller, a pressure roller, and a cleaning device for cleaning these rollers, the cleaning device is a heat-resistant cleaning roller that rotates while contacting the roller surface of any one of the rollers. The heat-resistant brush is provided on the upstream side of the rotation of any roller with respect to the cleaning roller, and the hair tip direction is arranged to face the rotation direction of any roller. A fixing device. The fixing device according to claim 1, wherein the contact angle between the roller surface of any one of the rollers and the bristles of the heat-resistant brush is selected to be larger than the angle with the tangent. The fixing device according to claim 1, wherein a recovery cover for recovering a recovered material such as toner cleaned by the cleaning device is provided below the cleaning device together with a cover of the fixing device. . The fixing device according to claim 1, wherein an urging force for abutting the heat resistant brush against any one of the rollers is also used by an urging unit provided on the cleaning roller.

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