JP2004271761A - Thermal fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the defective cleaning of a fixing rotary member and to prevent a removed toner from being reverse-transferred. <P>SOLUTION: A toner image is fixed on a recording medium by heating/pressurizing the recording medium with the formed toner image by a heating roller 34 as the fixing rotary member and a pressure roller 35 as the fixing rotary member while holding/carrying the recording medium by the rollers. The device is provided with a freely rotatable cleaning roller 45 for removing the toner sticking to the pressure roller 35 in contact with the pressure roller 35. The cleaning roller 45 is brought into contact with the pressure roller with pressure of 0.1N to 1.0N per unit length 1 cm. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrophotographic image forming apparatus using a toner, such as a copying machine, a printer, a facsimile, or a multifunction peripheral thereof, and a heat fixing device used in the electrophotographic image forming apparatus.
[0002]
[Prior art]
Conventionally, a toner image is sequentially formed on an image carrier by repeating charging, writing, development, transfer, cleaning, charge elimination, and the like, and the toner image is sequentially transferred to a recording medium such as a recording medium or an OHP film to record the image. There is an electrophotographic image forming apparatus for forming on a medium.
[0003]
In such an electrophotographic image forming apparatus, a pressing roller or the like serving as a fixing rotating member is pressed against a heating roller or the like having a heat source therein as a fixing rotating member, and a toner image after transfer of the toner image is interposed therebetween. Mainly, there is provided a heat fixing device for fixing a toner image on the recording medium while conveying the recording medium through the recording medium.
[0004]
In this type of thermal fixing device, a phenomenon called offset, in which toner on a recording medium adheres to a heating roller, may occur. When such an offset occurs, it is known that the offset toner adheres to the pressure roller, reversely transfers the toner from the heating roller and the pressure roller to the recording medium, and stains the recording medium.
[0005]
In order to prevent such offset, in a conventional heat fixing device, for example, a fluorine coat is applied to the surface of a heating roller. However, it is difficult to completely prevent the offset depending on the environmental conditions, the type of the recording medium, and the like, and there is still a problem that reverse transfer occurs.
[0006]
Therefore, in a conventional heat fixing device, there is a rotatable cleaning member in which a cleaning roller or the like is provided in contact with a heating roller or a pressure roller, and removes toner attached to the heating roller or the pressure roller. That is, by pressing a cleaning roller having a lower surface releasability than the surface releasability against a heating roller or a pressure roller having improved surface releasability, the toner is removed from the surface releasability. It is to be removed (for example, Patent Document 1).
[0007]
[Patent Document 1]
JP 2000-112279 A
[0008]
[Problems to be solved by the invention]
However, if the pressure of the cleaning roller against the heating roller or the pressure roller is inappropriate, for example, if the pressure is insufficient, the toner adhered to the heating roller or the pressure roller cannot be sufficiently removed, or the pressure becomes high. If the temperature is too high, the thermal energy in that portion becomes high, so that the toner adhering to the cleaning member may be melted and may be reversely transferred to the heating roller or the pressure roller, so-called melting may occur.
[0009]
SUMMARY OF THE INVENTION It is an object of the present invention to prevent insufficient cleaning of a rotating member for fixing and reverse transfer of removed toner.
[0010]
[Means for Solving the Problems]
The heat fixing device according to claim 1, wherein a pair of rotatable fixing rotating members for fixing the toner image to the recording medium by applying heat and pressure while nipping and conveying the recording medium on which the toner image is formed, and A rotatable cleaning member that abuts against the fixing rotating member at a pressure of 0.1 N to 1.0 N per unit length of 1 cm to remove toner attached to the fixing rotating member.
[0011]
Therefore, the toner adhered to the fixing rotating member can be reliably removed by the cleaning member, and reverse transfer to the fixing rotating member due to melting of the removed toner can be prevented.
[0012]
According to a second aspect of the present invention, there is provided the thermal fixing device according to the first aspect, further comprising a blower that cools the cleaning member by blowing air to the cleaning member.
[0013]
Therefore, the temperature rise of the cleaning member is prevented.
[0014]
According to a third aspect of the present invention, in the thermal fixing device of the first or second aspect, a heat pipe is provided inside the cleaning member.
[0015]
Therefore, the temperature of the cleaning member can be made uniform.
[0016]
According to a fourth aspect of the present invention, in the thermal fixing device of the first, second or third aspect, a pressure adjusting mechanism for adjusting a pressure of the cleaning member on the fixing rotating member is provided.
[0017]
Therefore, it is possible to adjust the pressure of the cleaning member on the fixing rotating member.
[0018]
According to a fifth aspect of the present invention, in the image forming apparatus for forming an image on the recording medium by fixing the toner image formed on the recording medium by a thermal fixing device, the heat fixing device may be configured to include the first, second, and third aspects. 4. The heat fixing device described in No. 4.
[0019]
Therefore, it is possible to achieve the same effect as the first, second, third or fourth aspect of the present invention.
[0020]
According to a sixth aspect of the present invention, there is provided an image forming apparatus for forming an image on the recording medium by fixing a toner image formed on a recording medium by a thermal fixing apparatus, wherein the heat fixing apparatus is the same as the fourth aspect. A first pressure adjusting unit that controls the pressure adjusting mechanism so as to adjust the pressure of the cleaning member on the fixing rotating member in accordance with the toner consumption.
[0021]
Therefore, the pressure of the cleaning member on the fixing rotating member is adjusted according to the toner consumption.
[0022]
According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the pressure of the cleaning member with respect to the fixing rotating member is adjusted in accordance with the number of recording media continuously passing through the heat fixing device. And a second pressure adjusting means for controlling the pressure adjusting mechanism.
[0023]
Therefore, the pressure of the cleaning member with respect to the fixing rotating member is adjusted according to the number of recording media continuously passing through the heat fixing device.
[0024]
According to an eighth aspect of the present invention, in the image forming apparatus according to the fifth, sixth or seventh aspect, the toner is a polymerized toner manufactured by a polymerization method.
[0025]
Therefore, it is possible to output a high-quality image.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. The present embodiment is an example of application to an electrophotographic copying machine as an image forming apparatus. Here, FIG. 1 is a longitudinal sectional front view schematically showing the copying machine of the present embodiment.
[0027]
The copying machine 1 according to the present embodiment includes a printer 2 and an image reading device 3 mounted on an upper portion of the printer 2.
[0028]
An image forming unit 4 is provided at a substantially central portion in the printer 2. The image forming unit 4 includes a drum-shaped photoconductor 5 as an image carrier, a charging device 6 disposed around the photoconductor 5, It is formed by a developing device 7, a transfer device 8, a cleaning device 9, and the like. The developing device 7 is connected to the toner replenishing device 10. In the image forming section 4, the outer peripheral surface of the photoconductor 5 is charged to a predetermined potential by the charging device 6, and the outer peripheral surface of the charged photoconductor 5 is exposed by the optical writing device 11, whereby An electrostatic latent image is formed on the outer peripheral surface, and toner is supplied from the developing device 7 to the electrostatic latent image, whereby the electrostatic latent image is visualized as a toner image, and the visualized toner image is formed. Is transferred onto the recording medium S by the transfer device 8. The toner remaining on the outer peripheral surface of the photoconductor 5 without being transferred onto the recording medium S at the time of this transfer is removed by the cleaning device 9. Here, in the present embodiment, a polymerized toner manufactured by a polymerization method is used as the toner.
[0029]
Below the image forming unit 4 of the printer 2, there are provided an upper and lower two-stage paper feed cassette 12 for storing the recording medium S, a manual feed tray 13 capable of manually feeding the recording medium S, and the like. In the printer 2, the recording medium S fed from the paper feed cassette 12 or the manual feed tray 13 is conveyed toward a paper output tray 14 formed in a gap between the printer 2 and the image reading device 3. A conveyance roller 15, a registration roller 17, an image forming section 4, a heat fixing device 18, a paper discharge roller 19, and the like are arranged along the conveyance path 15. Further, on the downstream side of the thermal fixing device 18 in the transport direction of the recording medium S, a reverse transport path 20 branched from the transport path 15 is provided. The recording medium S that has passed through the heat fixing device 18 is sent to the reversing conveyance path 20, and the recording medium S is sent through the reversing conveyance path 20 to the upstream side of the image forming unit 4 with the recording medium S turned upside down. Image formation can be performed on both sides of S.
[0030]
The image reading device 3 includes an ADF (automatic document feeder) 21 for automatically feeding a document to be read, a contact glass 22, a light source 23 for illuminating the document reading surface, and sequentially reflecting light from the document reading surface. There are provided a plurality of mirrors 24, an optical lens 25 for image formation, an image sensor 26 such as a CCD, and the like. The ADF 21 feeds a document on the contact glass 22 and collects the document after the content is read. At this time, the ADF 21 has a counting function for counting the number of originals every time the original is conveyed.
[0031]
Next, the heat fixing device 18 will be described with reference to FIGS. Here, FIG. 2 is a longitudinal sectional front view schematically showing the heat fixing device 18. As shown in FIG. 2, the heat fixing device 18 includes a fixing case 31, and the fixing case 31 is provided with a recording medium inlet 32 and a recording medium outlet 33 along the transport path 15. In the fixing case 31, a heating roller 34 and a pressure roller 35, which are a pair of fixing rotating members, are arranged to face each other with the conveyance path 15 therebetween.
[0032]
The heating roller 34 is rotatably provided, and is driven by a motor (not shown). The surface of the heating roller 34 is subjected to a fluorine coating process, and a heat source 36 is provided inside the heating roller 34. The number of heat sources 36 is two in the illustrated example, but may be one or three or more. As the heating roller 34, for example, by using a roller having a thickness of 1 mm or less, the temperature responsiveness is improved, and the time for raising the temperature to the fixing temperature can be reduced to about 10 seconds.
[0033]
Around the heating roller 34, there is disposed a separating member 37 that peels off the recording medium S stuck to the heating roller 34 from the heating roller 34 and guides the recording medium S to the recording medium outlet 33. Further, a thermistor 38 and a thermostat 39 which are in contact with the peripheral surface of the heating roller 34 are provided around the heating roller 34, and the temperature of the heating roller 34 is detected by the thermistor 38. The heating roller 34 is turned on and off to maintain the heating roller 34 at a predetermined temperature.
[0034]
The pressure roller 35 is pressed toward the heating roller 34 by the first pressure mechanism 40. The first pressing mechanism 40 includes a pressing arm 42 that rotatably holds the pressing roller 35 and rotates about a fulcrum 41, and an end of the pressing arm 42 opposite to the fulcrum 41 by a heating roller 34. And a coil spring 43 biased to the side. A nip portion is formed between the heating roller 34 and the pressure roller 35 urged toward the heating roller 34 by the first pressure mechanism 40.
[0035]
A cleaning roller 45 as a cleaning member is in contact with the peripheral surface of the pressure roller 35. The cleaning roller 45 is made of solid metal, and removes the toner attached to the pressure roller 35 by using surface releasability (adhesiveness). In the present embodiment, the heating roller 34 has better surface releasability than the pressure roller 35, and the pressure roller 35 has better surface releasability than the cleaning roller 45. Thus, the toner offset from the recording medium S to the heating roller 34 is removed by the cleaning roller 45 via the pressure roller 35.
[0036]
The cleaning roller 45 is pushed toward the pressure roller 35 by the second pressure mechanism 46. The second pressing mechanism 46 supports the cleaning roller 45 rotatably and rotates around a fulcrum 47. The cleaning roller 45, which functions as a compression spring and is supported by the supporting member 48, is a pressing roller. And a coil spring 49 for urging the support member 48 so as to press the support member 35. The second pressing mechanism 46 causes the cleaning roller 45 to move the pressure roller 35 from 0.1 N (that is, 0.1 N / cm) to 1.0 N (that is, 1.0 N / cm) per unit length of 1 cm. Contact with pressure.
[0037]
Here, FIG. 3 shows the result of investigating the relationship between the pressure applied to the pressure roller 35 by the cleaning roller 45 and the amount of toner remaining on the pressure roller 35. As shown in FIG. 3, when the pressure of the cleaning roller 45 with respect to the pressure roller 35 is between 0.1 N / cm and 1.0 N / cm, it was found that no toner remains on the pressure roller 35. . This indicates that the toner adhered to the pressure roller 35 has been removed by the cleaning roller 45.
[0038]
When the pressure of the cleaning roller 45 against the pressure roller 35 was smaller than 0.1 N / cm, it was found that toner remained on the pressure roller 35. This indicates that the toner does not adhere to the cleaning roller 45 because the pressing force is low.
[0039]
It was also found that the toner remained on the pressure roller 35 even when the pressure of the cleaning roller 45 on the pressure roller 35 was greater than 1.0 N / cm. This is because a part of the melted toner remains on the pressure roller 35 without adhering to the cleaning roller 45, or the toner once adhering to the cleaning roller 45 is re-melted and reversely transferred to the pressure roller 35. Indicates that it has. From these, it was found that the optimum pressing force of the cleaning roller 45 to the pressing roller 35 was from 0.1 N / cm to 1.0 N / cm.
[0040]
FIG. 4 is a block diagram showing an electrical connection of each unit provided in the copying machine 1 of the present embodiment. As shown in FIG. 4, the copying machine 1 is provided with a microcomputer (hereinafter, referred to as a microcomputer) 50, and the microcomputer 50 drives and controls each unit. The microcomputer 50 includes a ROM (Read Only Memory) 50c for storing fixed data such as a computer program in advance through a bus line 50b to a CPU (Central Processing Unit) 50a that executes various calculations and drive control of each unit, and various data. (Random Access Memory) 50d functioning as a work area or the like for storing rewritably. The microcomputer 2 is connected to the printer 2 (the image forming unit 4 and the heat fixing device 18) and the image reading device 3.
[0041]
In such a configuration, a toner image based on the document read by the image reading device 3 is formed as a toner image on the recording medium S by the printer 2, and is fixed by the heat fixing device 18. At this time, in the heat fixing device 18, the cleaning roller 45 is in contact with the pressure roller 35 by the pressure mechanism at a pressure of 0.1 N to 1.0 N per unit length of 1 cm. Thus, insufficient cleaning of the toner adhered to the pressure roller 35 via the heating roller 34 and reverse transfer (fusion) of the toner adhered to the cleaning roller 45 to the pressure roller 35 are prevented.
[0042]
In addition, compared to a toner produced by the pulverization method using the same resin, the polymerized toner produced by the polymerization method has a uniform particle size and shape because the constituent substances of each toner particle are uniformly dispersed. It is possible to output a high-quality image with excellent image quality.
[0043]
In the present embodiment, an example in which the cleaning roller 45 is disposed on the heating roller 34 side and is in contact with the pressure roller 35 has been described. However, the present invention is not limited to this, and the cleaning roller 45 is disposed on the heating roller 34 side. The cleaning roller 45 may be disposed so as to contact the heating roller 34 with the same pressure, or two cleaning rollers 45 may be provided so as to contact both the pressing roller 35 and the heating roller 34.
[0044]
Further, in the present embodiment, the example of the heating roller 34 and the pressure roller 35 as the fixing rotating member has been described. However, the fixing rotating member is not limited to the roller, and one or both of them may be a belt. good. For example, as shown in FIG. 5, instead of the pressing roller 35, a pressing belt 52 that is wound around two rollers 51 as a fixing rotating member may be used.
[0045]
Next, a second embodiment of the present invention will be described with reference to FIGS. Note that the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted (the same applies to the following embodiments). FIG. 6 schematically shows the heat fixing device 18 of the present embodiment. FIG. 7 is a flowchart showing the flow of the cleaning roller pressure adjusting process. FIG. 8 shows the relationship between the toner consumption and the pressing force of the cleaning roller 45, and schematically shows an appropriate pressing force range with respect to the toner consumption. FIG.
[0046]
As shown in FIG. 6, the heat fixing device 18 of the present embodiment is provided with a pressure adjusting mechanism 61 for adjusting the pressure of the cleaning roller 45 on the pressing roller 35. The pressure adjusting mechanism 61 includes a second pressing mechanism 46 and a solenoid 62 that supports one end of a coil spring 49 of the second pressing mechanism 46. The coil spring 49 is expanded and contracted by the solenoid 62, and the pressure of the cleaning roller 45 with respect to the pressure roller 35 is adjusted in a range from 0.1 N / cm to 1.0 N / cm.
[0047]
Next, the cleaning roller pressure adjustment processing executed by the microcomputer 50 based on the computer program will be described with reference to FIGS. The cleaning roller pressure adjustment process is a process of adjusting the pressure of the cleaning roller 45 on the pressure roller 35 according to the amount of toner consumption (the amount of toner adhered to the recording medium S).
[0048]
First, as shown in FIG. 7, when a document is read by the image reading device 3, a necessary toner amount (toner consumption amount) is calculated based on the data amount read from the document (step S1).
[0049]
Next, the solenoid 62 of the pressure adjusting mechanism 61 is driven so as to adjust the pressure of the cleaning roller 45 to the pressing roller 35 in the range of 0.1 N / cm to 1.0 N / cm according to the calculated toner consumption. Control (step S2, first pressure adjusting means). Specifically, as shown in FIG. 8, the pressing force of the cleaning roller 45 is increased as the toner consumption increases.
[0050]
Here, as shown in FIG. 8, the appropriate pressure region of the cleaning roller 45 changes according to the toner consumption. For example, when the toner consumption is small, the width between the lower limit and the upper limit of the pressing force of the cleaning roller 45 on the pressing roller 35 is large, and when the toner consumption is large, the width is narrow. This is because when the toner consumption increases, the pressing force of the cleaning roller 45 requires a large amount of heat energy to collect the offset toner. In other words, this is because the pressing force of the toner on the pressing roller is increased by the high pressing force. This is because it is necessary to perform melting sufficiently.
[0051]
As described above, in the present embodiment, the pressing force of the cleaning roller 45 on the pressing roller 35 is adjusted according to the toner consumption amount, so that the cleaning on the pressing roller 35 is favorably performed.
[0052]
Next, a third embodiment of the present invention will be described with reference to FIGS. Here, FIG. 9 is a flowchart showing the flow of the cleaning roller pressure adjustment processing of the present embodiment, and FIG. 10 is a graph showing the relationship between the number of continuous paper passes and the pressing force of the cleaning roller 45.
[0053]
In this embodiment, a pressure adjusting mechanism 61 is provided in the heat fixing device 18 as in the second embodiment.
[0054]
Next, a cleaning roller pressure adjusting process executed by the microcomputer 50 according to the present embodiment based on a computer program will be described with reference to FIGS. In the cleaning adjustment process of the present embodiment, the cleaning roller 45 is applied in accordance with the number of recording media S that continuously passes through the heat fixing device 18 (the number of continuous papers) corresponding to a document set on the ADF 21 at one time. This is a process for adjusting the pressure on the pressure roller 35.
[0055]
First, as shown in FIG. 9, the number of recording media S (the number of continuous paper passing) that continuously passes through the heat fixing device 18 corresponding to the document set on the ADF 21 at one time is acquired (step S11). This is performed by the ADF 21 counting the number of originals set and read at one time on the ADF 21 and inputting the number of originals to the microcomputer 50.
[0056]
Next, the solenoid 62 of the pressure adjusting mechanism 61 is adjusted so that the pressure of the cleaning roller 45 with respect to the pressing roller 35 is adjusted in a range from 0.1 N / cm to 1.0 N / cm in accordance with the obtained number of continuous paper sheets. Drive control is performed (step S12, second pressure adjusting means). More specifically, as shown in FIG. 10, as the number of continuous paper sheets increases, the pressing force of the cleaning roller 45 on the pressing roller 35 is increased.
[0057]
As described above, in this embodiment, as the number of continuous sheets passed increases, the pressing force of the cleaning roller 45 against the pressing roller 35 increases. Even when the amount of toner offset to the pressure roller 35 increases, the cleaning of the pressure roller 35 can be favorably performed.
[0058]
Next, a fourth embodiment of the present invention will be described with reference to FIG. Here, FIG. 11 is an enlarged perspective view showing a part of the heat fixing device 18 of the present embodiment.
[0059]
A blower 71 is provided in the thermal fixing device 18 of the present embodiment. The blower 71 includes a sirocco fan 72 and a duct 73. The sirocco fan 72 takes in outside air, guides the outside air through the duct 73, and blows the air in a direction B orthogonal to the recording medium conveyance direction A. To cool it.
[0060]
Further, the cleaning roller 45 of the present embodiment has a hollow pipe shape, and a heat pipe 74 is provided therein. The heat pipe 74 extends in the axial direction of the heating roller 34. The heat pipe 74 seals a metal pipe formed of SUS, aluminum, or the like under reduced pressure and simultaneously encloses a working fluid such as pure water or alcohol. The working fluid in the pipe is decompressed, so it is very easy to evaporate.If there is a temperature difference between each part of the pipe, the working fluid inside the pipe will evaporate in the hotter part, causing heat From the pipe, the pressure rises, it moves to the lower temperature, where it cools down, returns to liquid again to reduce latent heat, and in its circulation plays a role in habituation of the entire pipe to the same temperature. To make the most of the performance of the heat pipe 74, it is preferable to use a metal having good heat conductivity for the surface of the cleaning roller 45, but it is most preferable to select aluminum in terms of corrosion, cost, strength and the like.
[0061]
In such a configuration, the blowing device 71 blows air to the cleaning roller 45. Accordingly, even if the heat of the heating roller 34 is transmitted to the cleaning roller 45 via the pressure roller 35, the cleaning roller 45 is cooled by the blowing device 71, so that the toner on the cleaning roller 45 is melted. This can be reliably prevented. As a result, the occurrence of reverse transfer from the cleaning roller 45 to the pressure roller 35 can be reliably prevented.
[0062]
Here, since the heat pipe 74 is built in the cleaning roller 45 so as to extend in the axial direction of the cleaning roller 45, the temperature of the entire cleaning roller 45 can be made uniform, and the cleaning roller 45 due to temperature unevenness on the surface of the cleaning roller 45. It is possible to reliably prevent the toner on the toner 45 from being melted, and thereby to surely prevent the reverse transfer from the cleaning roller 45 to the pressure roller 35 from occurring.
[0063]
In addition, by incorporating the heat pipe 74 in the cleaning roller 45, the temperature unevenness in the axial direction of the cleaning roller 45 can be eliminated, and the cooling efficiency of the cleaning roller 45 by the cooling fan is also improved. Consumption can be reduced.
[0064]
【The invention's effect】
According to the thermal fixing device of the present invention, a pair of rotatable fixing rotations for fixing the toner image on the recording medium by heating and pressing while fixing and transporting the recording medium on which the toner image is formed are held. A member, and a rotatable cleaning member that abuts against the fixing rotating member at a pressure of 0.1 N to 1.0 N per unit length of 1 cm to remove toner attached to the fixing rotating member. With this arrangement, the toner adhered to the fixing rotary member can be reliably removed by the cleaning member, and reverse transfer of the removed toner to the fixing rotary member can be prevented.
[0065]
According to the second aspect of the present invention, in the thermal fixing device according to the first aspect, an air blowing device that cools the cleaning member by blowing air to the cleaning member is provided, thereby preventing a temperature rise of the cleaning member. Therefore, the toner on the cleaning member can be prevented from melting, and the reverse transfer of the toner to the fixing rotating member can be reliably prevented.
[0066]
According to the third aspect of the present invention, in the thermal fixing device according to the first or second aspect, the temperature of the cleaning member can be made uniform by providing a heat pipe inside the cleaning member. it can.
[0067]
According to a fourth aspect of the present invention, in the thermal fixing device according to the first, second, or third aspect, a pressure adjusting mechanism for adjusting a pressure of the cleaning member with respect to the fixing rotating member is provided, so that the fixing of the cleaning member is performed. Since it is possible to adjust the pressure on the rotary member for use, it is possible to set the pressure according to the situation.
[0068]
According to the fifth aspect of the present invention, in the image forming apparatus for forming an image on the recording medium by fixing the toner image formed on the recording medium by the heat fixing apparatus, By adopting the heat fixing device according to the third or fourth aspect, it is possible to achieve the same effect as the invention according to the first, second, third or fourth aspect.
[0069]
According to a sixth aspect of the present invention, in the image forming apparatus for forming an image on the recording medium by fixing the toner image formed on the recording medium by the thermal fixing apparatus, the heat fixing apparatus may be configured to perform the thermal fixing according to the fourth aspect. A fixing device that includes a first pressure adjusting unit that controls the pressure adjusting mechanism so as to adjust a pressure of the cleaning member with respect to the fixing rotating member in accordance with the amount of consumption of the toner; Since the pressure of the cleaning member with respect to the fixing rotary member is adjusted accordingly, good cleaning of the fixing rotary member can be performed.
[0070]
According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the pressure of the cleaning member with respect to the fixing rotating member is adjusted in accordance with the number of recording media continuously passing through the heat fixing device. Is provided with a second pressure adjusting means for controlling the pressure adjusting mechanism, so that the pressure of the cleaning member with respect to the fixing rotating member is adjusted in accordance with the number of recording media continuously passing through the heat fixing device. Good cleaning of the rotating member for cleaning.
[0071]
According to the eighth aspect of the present invention, in the image forming apparatus of the fifth, sixth or seventh aspect, since the toner is a polymerized toner manufactured by a polymerization method, a high quality image can be output. it can.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional front view schematically showing a copying machine according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional front view schematically showing a heat fixing device.
FIG. 3 is a graph showing a relationship between a pressure applied to a pressure roller by a cleaning roller and a residual toner amount of the pressure roller.
FIG. 4 is a block diagram showing an electrical connection of each unit provided in the copying machine.
FIG. 5 is a longitudinal sectional front view showing a modification of the heat fixing device.
FIG. 6 is a longitudinal sectional front view schematically showing a heat fixing device according to a second embodiment of the present invention.
FIG. 7 is a flowchart illustrating a flow of a cleaning roller pressure adjustment process.
FIG. 8 is an explanatory diagram illustrating a relationship between a toner consumption amount and a pressing force of a cleaning roller, and schematically illustrating an appropriate pressing force range with respect to the toner consumption amount.
FIG. 9 is a flowchart illustrating a flow of a cleaning roller pressure adjustment process according to the third embodiment of the present invention.
FIG. 10 is a graph showing a relationship between the number of continuous sheets and the pressure of a cleaning roller.
FIG. 11 is an enlarged perspective view showing a part of a heat fixing device according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 Copier (image forming apparatus)
18 Thermal fixing device
34 Heating roller (rotating member for fixing)
35 Pressure roller (rotating member for fixing)
45 Cleaning roller (cleaning member)
61 Pressure adjustment mechanism
71 Blower
74 heat pipe
S recording medium
Step S2: First pressure adjusting means
Step S12: Second pressure adjusting means

Claims (8)

A pair of rotatable fixing rotating members for fixing the toner image to the recording medium by heating and pressing while holding and conveying the recording medium on which the toner image is formed,
A rotatable cleaning member that abuts against the fixing rotating member at a pressure of 0.1 N to 1.0 N per unit length of 1 cm to remove toner attached to the fixing rotating member;
A heat fixing device comprising: The heat fixing device according to claim 1, further comprising a blower that cools the cleaning member by blowing air to the cleaning member. The heat fixing device according to claim 1, wherein a heat pipe is provided inside the cleaning member. 4. The thermal fixing device according to claim 1, further comprising a pressure adjusting mechanism for adjusting a pressure of the cleaning member on the fixing rotating member. In an image forming apparatus that forms an image on the recording medium by fixing the toner image formed on the recording medium with a heat fixing device,
An image forming apparatus, wherein the heat fixing device is the heat fixing device according to claim 1, 2, 3, or 4. In an image forming apparatus that forms an image on the recording medium by fixing the toner image formed on the recording medium with a heat fixing device,
The heat fixing device is the heat fixing device according to claim 4,
An image forming apparatus comprising: a first pressure adjusting unit that controls the pressure adjusting mechanism so as to adjust a pressure of the cleaning member on the fixing rotating member in accordance with a consumption amount of the toner. A second pressure adjusting unit that controls the pressure adjusting mechanism so as to adjust the pressure of the cleaning member on the fixing rotating member according to the number of recording media that continuously passes through the heat fixing device. The image forming apparatus according to claim 6, wherein: The image forming apparatus according to claim 5, wherein the toner is a polymerized toner manufactured by a polymerization method.

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