JP2016142897A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reverse transfer of toner to a transfer sheet with a simple configuration.SOLUTION: A fixing device 30 conveys a sheet P carrying a toner image to a nip part formed between a fixing roller 40 and a pressure roller 50 to fix the toner image to the sheet P, and comprises: a cleaning roller 85 that is in contact with the pressure roller 50 to clean the pressure roller 50; pressure roller temperature detection means 51 that detects the temperature of the pressure roller 50; and cleaning roller temperature detection means 86 that detects the temperature of the cleaning roller 85. The fixing device executes a cooling operation of cooling the cleaning roller 85 on the basis of results of detection performed by the pressure roller temperature detection means 51 and cleaning roller temperature detection means 86.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fixing device and an image forming apparatus.

  Various image forming apparatuses using an electrophotographic system have been devised as image forming apparatuses such as copying machines, facsimile machines, printers, or their combined machines, and are well known in the art. In the image forming process, an electrostatic latent image is formed on the surface of the photosensitive drum as an image carrier, and the electrostatic latent image on the photosensitive drum is developed with a toner as a developer to be visualized and developed. The transferred image is transferred to a recording medium (also referred to as paper, transfer paper, recording paper, sheet, or recording material) by a transfer device to carry the image, and the toner image on the transfer paper is fixed by a fixing device using pressure or heat. It is established by the process.

  Various types of fixing devices have been proposed. For example, the fixing device includes a fixing roller (fixing member) having a heat source therein, and a pressure roller (pressure member) in pressure contact with the fixing roller. A roller fixing method is known in which a transfer sheet carrying an unfixed toner image is heated while being nipped and conveyed by a fixing nip portion (nip portion) formed by pressure contact between the roller and the fixing roller, and is fixed.

  The surface of the fixing roller is devised to prevent toner adhesion, such as fluorine coating, but depending on the environment, transfer paper, and other conditions, this toner may slightly adhere to the fixing roller from the transfer paper. Sometimes called a phenomenon occurs. The offset toner remains on the fixing roller and the pressure roller in contact therewith, and may eventually be reversely transferred to the transfer paper and stain the image.

  In addition, paper powder such as calcium carbonate and filler contained in the transfer paper adheres to the surface of the fixing roller, resulting in a decrease in releasability and occurrence of offset, and this part and the toner are combined. In some cases, a sticking phenomenon may occur that eventually grows and stays on the surface of the fixing roller. Further, the offset toner that has entered the pressure roller from the fixing roller may come into contact with the fixing portion on the fixing roller and grow again.

  In order to prevent these problems, it is known to provide a cleaning roller for the fixing roller and the pressure roller.

  The cleaning roller is, for example, a roller that is in pressure contact with the pressure roller by the driven rotation, and is a solid surface state roller such as metal. Then, the offset toner is collected on the cleaning roller due to the difference in performance of release (non-adhesiveness) between the cleaning roller and the pressure roller. The fixing roller has been described above. This is because the pressure roller is also provided with a surface layer for improving the release for preventing toner adhesion, and in principle, is easier to peel off than the cleaning roller.

  Further, in recent years, fixing devices have been made to reduce the warm-up time and reduce the core of the fixing roller (for example, 0.7 mm or less) to improve temperature responsiveness and enable fixing. There are many things that reduce time.

  In such a fixing device, since the heat capacity of the fixing roller is small, it can be said that heat transfer to the transfer paper and the contact member of the fixing roller is easy.

  At this time, there is a method in which several temperature control means are installed on the fixing roller so as to make the temperature distribution uniform. However, the number of heaters is controlled so that the entire area of the fixing roller is controlled uniformly according to each size and mode. It is difficult to arrange the light and temperature detection means from the viewpoint of space and cost.

  If the temperature distribution of the fixing roller becomes uneven, the occurrence of offset caused by mismatching fixing conditions and the life of the fixing roller are likely to be shortened due to thermal deterioration.

  Of these, the most serious is the problem of melting out, ie, reverse transfer to transfer paper due to remelting of the toner mass deposited on the cleaning roller in the toner using the polymerization method. This is a phenomenon that occurs remarkably in the case of a small size compared to the maximum size that can be passed.

  Specifically, in the case of a single heater for heating the fixing roller, in the case of a small size, since the area in contact with the fixing roller is small, the temperature is deprived only in a narrow range of the fixing roller. In this case, the temperature of the fixing roller does not decrease, and only the temperature of the sheet passing portion decreases. Since the lighting of the heater is controlled by the temperature detection means corresponding to that portion, the temperature of the non-sheet passing portion rises unnecessarily, and the toner adhering to the corresponding portion of the cleaning roller melts and reversely transfers. It is a phenomenon that ends up.

  On the other hand, with the energy saving of the fixing device, the toner used also has a low melting point. Although it has become possible to set the fixing temperature lower than before due to the low melting point, it can be said that it becomes sensitive to the temperature distribution of the fixing roller and offset is likely to occur.

  In addition, the toner has been made smaller in particle size and further polymerized toner for further image quality improvement, but it goes without saying that the offset becomes worse by the smaller the toner in the small particle size toner, Polymerized toners also have the property of being easily offset.

  As a technique related to the reverse transfer (melting-out) of the toner adhered to the cleaning roller, Patent Document 1 discloses that after the fixing operation, the cooling operation (fan, heat pipe, etc.) is continued for a predetermined time to perform cleaning. A thermal fixing device for cooling a roller is disclosed. Japanese Patent Application Laid-Open No. H10-228561 discloses a thermal fixing device including a blower that cools the cleaning roller.

  Further, Patent Document 3 discloses a fixing device that presses a heated cleaning pad against a cleaning roller to prevent a problem of the cleaning member caused by residual toner and to extend the life of the cleaning member.

  Further, regarding the removal of foreign matter adhesion on the surface of the fixing roller, Patent Document 4 discloses a fixing device in which a foreign matter regulating member is brought into contact with the fixing roller (heating roller).

  Patent Document 5 discloses a fixing device that detects a change in the surface state of a fixing member with an optical sensor.

  However, a configuration in which a fan or the like is provided as a cooling means, a heating means for the cleaning pad, or an optical sensor for detecting the surface state leads to an increase in cost. Further, in the configuration in which the cooling operation is executed after the fixing operation is completed as in Patent Document 1, the melting may occur during the fixing operation. Further, as in Patent Document 4, if the foreign matter regulating member is brought into contact with the surface of the fixing roller, there is a risk that the fixing roller may be scratched or worn.

  SUMMARY An advantage of some aspects of the invention is that it provides a fixing device capable of preventing reverse transfer of toner onto transfer paper with a simple configuration.

  In order to achieve the above object, a fixing device according to the present invention includes a fixing member heated by a heat source and a pressure member pressed against the fixing member, and the fixing device is provided between the fixing member and the pressure member. In a fixing device that transports a recording medium carrying a toner image to a nip portion formed on the recording medium and fixes the toner image on the recording medium, the first contact member is brought into contact with the pressure member to clean the pressure member. 1 cleaning roller, a first temperature detecting means for detecting the temperature of the pressure member, and a second temperature detecting means for detecting the temperature of the first cleaning roller, the first temperature detecting means, Based on the detection result of the second temperature detecting means, a cooling operation for cooling the first cleaning roller is executed.

  According to the present invention, reverse transfer of toner onto transfer paper can be prevented with a simple configuration.

1 is an overall schematic diagram of an image forming apparatus including a fixing device according to a first embodiment. It is explanatory drawing of cleaning roller cooling operation. 6 is a graph showing the transition of the pressure roller temperature and the cleaning roller temperature and the state of toner melting. It is a schematic sectional drawing in the axial direction of a cleaning roller. FIG. 4 is an overall schematic diagram of an image forming apparatus including a fixing device according to a second embodiment. FIG. 3 is an example of a main configuration diagram of a fixing device. It is explanatory drawing which shows the relationship between the temperature of a cleaning roller, and the contact and separation operation | movement of a cleaning roller. It is a perspective view of a fixing roller and a foreign matter detection means. It is a principal part block diagram of the fixing device provided with the foreign material detection means. It is explanatory drawing which shows the relationship between the presence or absence of a foreign material detection means, the contact of a cleaning roller, and separation | spacing operation | movement.

  Hereinafter, a configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

[First Embodiment]
The fixing device according to the present embodiment includes a fixing member (fixing roller 40) heated by a heat source (heater 42), and a pressure member (pressure roller 50) pressed against the fixing member. In a fixing device (fixing device 30) that transports a recording medium (paper P) carrying a toner image to a nip formed between the pressing member and fixes the toner image on the recording medium, the pressing member The first cleaning roller (cleaning roller 85) that contacts and cleans the pressure member, the first temperature detection means (pressure roller temperature detection means 51) that detects the temperature of the pressure member, and the first cleaning roller Second temperature detection means (cleaning roller temperature detection means 86) for detecting the temperature, and based on the detection results of the first temperature detection means and the second temperature detection means, the first cleaning roller And it executes a cooling operation to cool. In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

(Configuration of image forming apparatus)
FIG. 1 is an overall schematic diagram of an image forming apparatus 100 including a fixing device 30 according to the present embodiment.

  The sheet P fed from the sheet feeding unit 1 passes through the registration roller 3 and electrostatically attracts toner by the transfer unit 4, and is guided to the fixing device 30 from the fixing inlet guide unit 20 through the conveying unit 5. Is done. The sheet P guided to the fixing device 30 is heated and fixed at a nip portion formed between the fixing roller 40 and the pressure roller 50.

  The heat-fixed paper P is guided by the fixing separation claw 60, the fixing outlet upper guide 72, and the fixing outlet lower guide 80, enters the fixing outlet roller 90, and is conveyed. Then, the paper discharge guide 93 discharges the back surface of the main body outlet roller 95 so that the image surface is on the lower side (back surface).

(Configuration of fixing device)
The fixing device 30 includes a fixing roller 40 and a pressure roller 50 pressed against the fixing roller 40, and a sheet carrying a toner image in a nip portion formed between the fixing roller 40 and the pressure roller 50. The toner image is fixed on the paper P by carrying P and heating and pressing.

  The fixing roller 40 has a single heater 42 as a heat source. The heater 42 is, for example, a halogen heater. Further, a fixing roller temperature detecting means 41 for detecting the surface temperature of the fixing roller 40 is provided.

  The pressure roller 50 is provided with a cleaning roller 85 that contacts the pressure roller 50 and cleans the surface of the pressure roller 50.

  The pressure roller 50 is provided with pressure roller temperature detection means 51 for detecting the surface temperature of the pressure roller 50.

  The cleaning roller 85 is provided with a cleaning roller temperature detecting means 86 for detecting the surface temperature of the cleaning roller 85. In addition, in the example of FIG. 1, although each temperature detection means has shown the example of a contact type, a non-contact type may be sufficient.

  The detection information of the pressure roller temperature detection means 51 and the cleaning roller temperature detection means 86 is input to the control unit 31, and the control unit 31 performs a cleaning roller cooling operation (hereinafter simply referred to as “cleaning roller cooling operation”). A determination is made as to whether or not to perform a cooling operation.

(Cleaning roller cooling operation)
As described above, conventionally, as a cooling means for cooling the cleaning roller, a fan or the like as a cooling means is provided in the vicinity of the cleaning roller, and the cleaning roller cooling operation is executed by the rotation operation of the fan.

  On the other hand, in this embodiment, the following cleaning roller cooling operation is performed. FIG. 2 is an explanatory diagram of the cleaning roller cooling operation.

  As shown in FIG. 2, during printing, the set temperature (fixing roller target temperature) of the fixing roller 40 is controlled to temperatures such as Tf1 and Tf2, and accordingly the temperatures of the pressure roller 50 and the cleaning roller 85 are illustrated. The curve changes.

  Here, when the detection temperature of the pressure roller temperature detection means 51 (that is, the pressure roller temperature) and the detection temperature of the cleaning roller temperature detection means 86 (that is, the cleaning roller temperature) are in the state of Tp and Tc, respectively. Then, the printing operation is stopped and the cooling operation is executed at the fixing set temperature Tf0.

  In the cooling operation based on the pressure roller temperature and the cleaning roller temperature, the cooling operation is performed when the total value of the pressure roller temperature Tp and the cleaning roller temperature Tc exceeds a predetermined set value.

For example, in the following equations (1) and (2), when the total amount of the pressure roller temperatures Tp and Tp ′ and the cleaning roller temperatures Tc and Tc ′ is less than A, the cooling operation is not executed, and A is The cooling operation is executed when the time is exceeded.
A = Tp + Tc (1)
A = Tp ′ + Tc ′ (2)

For example, when the pressure roller temperature is saturated and the cleaning roller temperature is rising, when the pressure roller temperature Tp is 150 ° C. and the toner melting temperature of the cleaning roller 85 is 138 ° C., A is 285 It can be set to ° C. In this case, the following equation (3) is satisfied and the cooling operation is executed, so that no toner melts out.
A (285) = Tp (150) + Tc (135) (3)

  Further, the fixing set temperature Tf0 during cooling is 140 ° C. or less and the idling operation is performed. The idling operation refers to an operation in which the set temperature of the fixing roller 40 is set lower than during printing and the fixing roller 40 is rotated without passing paper. At this time, the cleaning roller 85 is in contact with the pressure roller 50.

  FIG. 3 is a graph showing the transition of the pressure roller temperature and the cleaning roller temperature when the cooling operation is not performed, and the state of toner melting. FIG. 3 shows an example in which when the pressure roller temperature is saturated at Tp and the cleaning roller temperature reaches Tx, the temperature condition of A <Tp + Tx is satisfied and the toner melts.

  For example, in the case of a fixing device with a linear velocity of V = 180 mm / s, when the set temperature during printing is 160 ° C., if continuous printing is continued, the pressure roller temperature Tp becomes 150 ° C., and the cleaning roller temperature is the melting temperature. It exceeds 138 ° C. which is Tx.

  Therefore, by setting the fixing set temperature Tf0 during the idling operation to 140 ° C. or less, for example, the pressure roller temperature Tp becomes 130 ° C. or less. Therefore, the cleaning roller temperature melts even under various printing conditions. It is possible to prevent the temperature Tx from exceeding 138 ° C.

  The cleaning roller 85 is preferably configured to include a heat pipe inside the aluminum material. FIG. 4 is a schematic cross-sectional view of the cleaning roller 85 in the axial direction. As shown in FIG. 4, it is preferable to use a roller in which a heat pipe 88 is built in an aluminum pipe 87. As a result, the heat distribution in the axial direction can be made uniform, high thermal responsiveness in the cross-sectional direction and in the axial direction is ensured, the temperature becomes partially high and the portion is prevented from melting, and the cleaning roller 85 Can be effectively cooled.

  The surface of the cleaning roller 85 is preferably coated with a cross-linking agent that reacts with the toner to increase the viscosity. As a result, the toner collected on the cleaning roller 85 can be melted by the crosslinking reaction, and the temperature can be changed to a high state. By effectively holding the toner collected on the cleaning roller 85, the toner can be melted more effectively. The occurrence of sticking out can be prevented.

  As described above, according to the fixing device 30 according to the present embodiment, the temperature of the pressure roller 50 and the temperature of the cleaning roller 85 in contact with the temperature are detected at the same time, and the cleaning is performed based on this value. By determining whether or not the cooling operation of the roller 85 can be performed, the cleaning roller 85 can be effectively cooled with a simple configuration, and the occurrence of melting can be suppressed.

  For example, when the total temperature of the pressure roller temperature and the cleaning roller temperature exceeds a predetermined value, the timing of occurrence of melting is predicted by executing a cooling operation, and high production is achieved in a state where there is no melting. Sex can be maintained.

  Further, as the cooling operation, the idle rotation operation is performed at a temperature lower by 10 ° C. or more than the fixing setting temperature at the time of printing, so that the cleaning roller 85 can be efficiently cooled and a state in which no melt-out occurs. Can be maintained.

[Second Embodiment]
Hereinafter, other embodiments of the fixing device according to the present invention will be described. The fixing device according to the present embodiment includes a fixing member (fixing roller 40) heated by a heat source (heater 42), and a pressure member (pressure roller 50) pressed against the fixing member. The fixing member is cleaned in a fixing device (fixing device 30) that transports a recording medium (paper P) carrying a toner image to a nip formed between the pressing member and fixes the toner image on the recording medium. A second cleaning roller (cleaning roller 45), a displacement means (drive unit 47) for bringing the second cleaning roller into contact with and separating from the fixing member, and a third temperature detecting means for detecting the temperature of the second cleaning roller (Cleaning roller temperature detecting means 46), and the displacing means applies the second cleaning roller to the fixing member based on the detected temperature of the third temperature detecting means. Or it is intended to be separated from each other. In addition, the description about the same point as the said embodiment is abbreviate | omitted suitably.

(Configuration of image forming apparatus)
FIG. 5 is an overall schematic diagram of the image forming apparatus 100 including the fixing device according to the present embodiment.

  The sheet P fed from the sheet feeding unit 1 passes through the registration roller 3 and electrostatically attracts toner by the transfer unit 4, and is guided to the fixing device 30 from the fixing inlet guide unit 20 through the conveying unit 5. Is done. The sheet P guided to the fixing device 30 is heated and fixed at the nip portion.

  The heat-fixed paper P is guided by the fixing separation claw 60, the fixing outlet upper guide 72, and the fixing outlet lower guide 80, enters the fixing outlet roller 90, and is conveyed. Then, the paper discharge guide 93 discharges the back surface of the main body outlet roller 95 so that the image surface is on the lower side (back surface).

(Configuration of fixing device)
The fixing device 30 includes a fixing roller 40 and a pressure roller 50 pressed against the fixing roller 40, and a sheet carrying a toner image in a nip portion formed between the fixing roller 40 and the pressure roller 50. The toner image is fixed on the paper P by carrying P and heating and pressing.

  In the vicinity of the fixing roller 40, a cleaning roller 45 that contacts the fixing roller 40 and cleans the surface of the fixing roller 40 is disposed. The cleaning roller 45 is provided with a cleaning roller temperature detecting means 46 for detecting the surface temperature of the cleaning roller 45. It is also preferable to include a fixing roller temperature detecting means 41 and a pressure roller temperature detecting means 51. In addition, in the example of FIG. 5, although each temperature detection means has shown the example of a contact type, a non-contact type may be sufficient.

  The cleaning roller 45 of the fixing roller 40 performs cleaning of the fixing roller 40 in accordance with the temperature detected by the cleaning roller temperature detecting unit 46.

  FIG. 6 is a configuration diagram of a main part of the fixing device 30. The cleaning roller 45 has a drive unit 47 (see FIG. 9) as a displacement means, and moves from a position indicated by a dotted line to a position indicated by a solid line at a predetermined timing.

  In the present embodiment, when the temperature detected by the cleaning roller temperature detection means 46 exceeds a predetermined temperature, the cleaning roller temperature detection unit 46 is separated from the fixing roller 40.

  FIG. 7 is an explanatory diagram showing the relationship between the temperature of the cleaning roller 45 and the contact and separation operations of the cleaning roller 45.

  As shown in FIG. 7, the cleaning roller 45 is in contact with the fixing roller 40 when cold. Then, when the temperature detected by the cleaning roller temperature detecting means 46 reaches the melting temperature Tx (first predetermined temperature), the cleaning roller temperature detecting means 46 is separated from the fixing roller 40. After the separation, when the temperature of the cleaning roller decreases and falls to a temperature Tz (second predetermined temperature) lower than the melting temperature by a predetermined temperature, the cleaning roller comes into contact again. Thereafter, this operation is repeated.

  As described above, when the cleaning roller temperature reaches a predetermined temperature based on the temperature detection result of the cleaning roller 45, the cleaning roller 45 is separated from the fixing roller 40, so that the toner accumulated in the cleaning roller 45 is dissolved. Therefore, the toner collected by the cleaning roller 45 can be effectively retained.

  Similarly, in the vicinity of the pressure roller 50, a cleaning roller 85 that contacts the pressure roller 50 to clean the surface of the pressure roller 50, and a cleaning roller temperature detection unit that detects the surface temperature of the cleaning roller 85. 86 is preferably provided. And it is preferable to have a drive part and to make the cleaning roller 85 contact and separate from the pressure roller 50 based on the temperature detection result of the cleaning roller temperature detection means 86.

  Further, the fixing roller 40 is preferably provided with foreign matter detection means 120 that detects a change in surface property of the fixing roller 40. FIG. 8 is a perspective view of the fixing roller 40 and the foreign matter detection means 120.

  The sensor portion 120A of the foreign matter detection means 120 is disposed with a gap h in the fixing roller 40 axial direction. When the height of the foreign matter on the surface of the fixing roller 40 exceeds h, the sensor unit 120A rotates around the fulcrums 121A and 121B, the sensor unit 120A side is lifted and pushed into the displacement detection unit 120B on the opposite side, thereby causing the foreign matter. The presence of is to be detected. The sensor unit 120A can be made of, for example, a metal rigid body having a fluorine-based coating such as Teflon (registered trademark) or a heat resistant resin such as polyimide or liquid crystal polymer.

  The operations of the foreign matter detection means 120 and the cleaning roller 45 will be described below. FIG. 9 is a main part configuration diagram of the fixing device 30 including the foreign matter detection means 120. The cleaning roller 45 is normally at a position indicated by a dotted line, and moves to a position indicated by a solid line at a predetermined timing.

  For example, the cleaning roller 45 is displaced in accordance with the presence or absence of foreign matter detection by the foreign matter detection means 120 and performs cleaning of the fixing roller 40. For example, as shown in FIG. 9, when the foreign matter A adheres to the surface of the fixing roller 40 and grows and the height exceeds a predetermined height (for example, 0.1 mm), the sensor of the foreign matter detecting means 120 120A comes into contact with the part 120A, and the sensor part 120A is pushed up in the direction of arrow B. Thereby, the foreign material detection means 120 detects a foreign material.

  FIG. 10 is an explanatory diagram showing the relationship between the presence / absence of detection by the foreign matter detection means 120 and the operation of the cleaning roller 45.

  As shown in FIG. 10, at the same time as the foreign matter detection means 120 detects the foreign matter, the cleaning roller 45 of the fixing roller 40 moves from the position indicated by the dotted line to the position indicated by the solid line. As a result, the cleaning roller 45 contacts the fixing roller 40, removes the foreign matter, and continues to contact until the foreign matter detection unit 120 detects no foreign matter.

  The cleaning roller 45 of the fixing roller 40 moves from the position indicated by the solid line to the position indicated by the dotted line at a timing when the foreign object detection unit 120 does not detect the foreign object. As a result, the cleaning roller 45 is separated from the fixing roller 40.

  As described above, the fixing device 30 according to the present embodiment includes the cleaning roller 45 that can be separated from the fixing roller 40 and the cleaning roller temperature detection unit 46, and the cleaning roller temperature exceeds a predetermined temperature. In this case, by separating the cleaning roller 45 from the fixing roller 40, it is possible to prevent reverse transfer of the toner onto the transfer paper with a simple configuration.

  In addition, by providing a foreign matter detection means for detecting foreign matter on the surface of the fixing roller 40, it is possible to effectively prevent image contamination due to offset and toner adhesion, and to detect foreign matter on the surface of the fixing roller 40 for effective cleaning. Can be done.

  In addition, when the foreign matter detection means 120 detects an offset or a fixed toner, the image contamination can be surely eliminated by bringing the cleaning roller 45 into contact with the surface of the fixing roller 40 until there is no foreign matter.

  In addition, according to the image forming apparatus including the fixing device 30 according to the first and second embodiments, it is possible to provide an image forming apparatus that suppresses the occurrence of offset, fixation, and melting and obtains a good fixed image. be able to.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Paper feed part 3 Registration roller 4 Transfer part 5 Conveyance part 20 Fixing entrance guide part 30 Fixing apparatus 31 Control part 40 Fixing roller (fixing member)
41 Fixing roller temperature detection means 42 Heater 45 Cleaning roller (second cleaning roller)
46 Cleaning roller temperature detection means (third temperature detection means)
47 Drive unit 50 Pressure roller (Pressure member)
51 Pressure roller temperature detection means (first temperature detection means)
60 Fixing separation claw 72 Fixing exit upper guide 80 Fixing exit lower guide 85 Cleaning roller (first cleaning roller)
86 Cleaning roller temperature detection means (second temperature detection means)
87 Aluminum pipe 88 Heat pipe 90 Fixing exit roller 93 Discharge guide 95 Main body exit roller 100 Image forming apparatus 120 Foreign matter detecting means 120A Sensor portion 120B Displacement detecting portion P Paper

JP 2004-271556 A JP 2004-198749 A JP 2010-139883 A JP-A-11-102141 JP 2014-21205 A

Claims (10)

A fixing member heated by a heat source;
A pressure member pressed against the fixing member,
In a fixing device that transports a recording medium carrying a toner image to a nip formed between the fixing member and the pressure member, and fixes the toner image on the recording medium.
A first cleaning roller that contacts the pressure member and cleans the pressure member;
First temperature detecting means for detecting the temperature of the pressure member;
Second temperature detecting means for detecting the temperature of the first cleaning roller,
A fixing device that performs a cooling operation for cooling the first cleaning roller based on detection results of the first temperature detection unit and the second temperature detection unit. A fixing member heated by a heat source;
A pressure member pressed against the fixing member,
In a fixing device that transports a recording medium carrying a toner image to a nip formed between the fixing member and the pressure member, and fixes the toner image on the recording medium.
A second cleaning roller for cleaning the fixing member;
Displacement means for bringing the second cleaning roller into contact with and separating from the fixing member;
A third temperature detecting means for detecting the temperature of the second cleaning roller,
The fixing device is characterized in that the displacing means makes the second cleaning roller contact or separate from the fixing member based on a temperature detected by the third temperature detecting means.   The said cooling operation is performed when the total value of the detected temperature of the said 1st temperature detection means and the detected temperature of the said 2nd temperature detection means exceeds predetermined value. Fixing device.   The fixing device according to claim 1, wherein in the cooling operation, the setting temperature of the fixing member is set to a predetermined temperature or less to idle. The displacement means separates the second cleaning roller in contact with the fixing member from the fixing member when the detected temperature of the third temperature detecting means reaches a first predetermined temperature,
The fixing device according to claim 2, wherein the second cleaning roller is brought into contact with the fixing member when a temperature detected by the third temperature detecting unit is lowered to a second predetermined temperature. A first cleaning roller for cleaning the pressure member;
Second temperature detecting means for detecting the temperature of the first cleaning roller,
The fixing device according to claim 2, wherein the first cleaning roller is brought into contact with or separated from the pressure member based on a temperature detected by the second temperature detection unit. A foreign matter detection means for detecting foreign matter on the surface of the fixing member;
The fixing device according to claim 2, wherein the displacement unit causes the second cleaning roller to contact the fixing member when the foreign material detection unit detects the foreign material.   The fixing device according to claim 1, wherein the first cleaning roller and / or the second cleaning roller is an aluminum material with a built-in heat pipe.   9. The surface layer of the first cleaning roller and / or the second cleaning roller is coated with a crosslinking agent that increases in viscosity by reacting with toner. Fixing device.   An image forming apparatus comprising the fixing device according to claim 1.

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