JP2006343665A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for smoothly carrying out a fixing process of a toner image to a recording medium by simply and easily removing toner which is being attached and accumulated, or else already attached and accumulated, to a contact member which is installed in contact to a heated fixing rotational member. <P>SOLUTION: The image forming apparatus contains: the heated fixing rotational member 91, a pressurizing rotational member 92 brought into a pressurized contact with the a fixing rotational member 91 and at least one of contact members (a separating claw 93 and a thermistor 94) for a predetermined purpose which is installed in contact with the fixing rotational member 91. The image forming apparatus is provided with a fixing apparatus 9, by which the process for fixing the toner image onto the recording medium S under heat and pressure can be carried out by having the recording medium S retaining the toner image pass through a nip part N between the two rotational members. The image forming apparatus is provided with a control part Cont controlling the rotating actions of both rotational members 91 and 92 in the fixing apparatus 9. The control part Cont rotates at least the fixing rotational member 91, among the two rotational members 91 and 92 of the fixing apparatus 9 in a reverse direction from that at the time of the fixing process at a predetermined timing which is other than at toner image fixing process. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a combination machine combining two or more of these, and more particularly to a fixing device in the apparatus.

  Various types of image forming apparatuses are known. However, in a typical monochrome image forming apparatus, for example, the surface of an image carrier such as a photoconductor is charged to a predetermined potential, and the charged area is within the charged area. Image exposure is performed in accordance with the original image to form an electrostatic latent image, the electrostatic latent image is developed with a developer to form a visible toner image, and the visible toner image is transferred to a recording medium such as recording paper. Then, the recording medium is passed through a fixing device to fix the toner image on the recording medium under heat and pressure.

  In a color image forming apparatus, for example, a toner image of each color formed on an image carrier such as a photoconductor is primarily transferred onto an intermediate transfer member such as an intermediate transfer belt, and multiple toners on the intermediate transfer member. The image is secondarily transferred to a recording medium such as recording paper, and the secondly transferred toner image is fixed to the recording medium in a fixing device under heat and pressure.

  Such a fixing device generally has a fixing rotation member in the form of a roller or an endless belt and a pressure rotation member in the form of a roller that is pressed against the fixing rotation member. Generally, at least the fixing rotation member Is heated to the fixing temperature by a heat source (for example, a halogen lamp heater or a heat generating film or layer provided on the fixing rotating member) and the toner image is directed to the fixing rotating member. In this manner, the toner image is fixed on the recording medium under heat and pressure by passing through the contact nip portion between the fixing rotating member and the pressure rotating member.

  A member for a predetermined purpose may be disposed in contact with the fixing rotation member. For example, in a toner image fixing process, a separation claw for separating the recording medium coming out of the nub portion between the fixing rotating member and the pressure rotating member from the fixing rotating member, and a temperature sensor for detecting the temperature of the fixing rotating member (For example, a thermistor).

For example, Japanese Patent Laid-Open No. 2000-352890 discloses that a separation claw is brought into contact with a heated fixing roller.
JP 2000-352890 A

  However, when a contact member arranged in contact with the fixing rotation member heated in this way is provided, the softened or melted toner on the recording medium is deposited on the contact member by offset adhesion. is there.

  For example, when toner accumulates on the separation claw, toner contamination occurs at the leading edge of the recording medium, or the recording medium is not smoothly separated from the fixing rotation member, and the leading edge of the recording medium is damaged. In extreme cases, the progress of the recording medium is hindered, and so-called jam occurs. Further, for example, when toner adheres to and accumulates on the temperature sensor, the accuracy of the temperature detected by the temperature sensor decreases, leading to poor fixing.

  Accordingly, the present invention provides a fixing rotating member to be heated, a pressure rotating member pressed against the fixing rotating member, and at least one contact member for a predetermined purpose disposed in contact with the fixing rotating member. An image forming apparatus having a fixing device capable of fixing the toner image to the recording medium under heat and pressure by passing the recording medium holding the toner image through the nip portion of the two rotating members. Another object of the present invention is to provide an image forming apparatus capable of easily and easily removing toner that adheres to and accumulates on the contact member and thereby smoothly fixes a toner image to a recording medium. To do.

In order to solve the above problems, the present invention provides a fixing rotating member to be heated, a pressure rotating member pressed against the fixing rotating member, and at least one predetermined object arranged in contact with the fixing rotating member. An image having a fixing device capable of fixing the toner image to the recording medium under heat and pressure by passing a recording medium holding the toner image through a nip portion between the rotating members. A forming device,
A controller that controls the rotational operation of both rotating members in the fixing device;
The controller provides an image forming apparatus that rotates at least a fixing rotating member of both rotating members of the fixing device in a direction opposite to that during the fixing process at a predetermined timing other than during the toner image fixing process. .

  According to the image forming apparatus of the present invention, the toner is attached or deposited on the contact member arranged in contact with the fixing rotation member of the fixing device in the fixing process of the toner image onto the recording medium. However, under the instruction of the control unit, at least the fixing rotating member that is in contact with the contact member may be rotated in a direction opposite to that during the fixing process at a predetermined timing other than during the toner image fixing process. Therefore, the reverse rotation of the contact member attracts or deposits toner on the contact member, and the toner on the contact member is removed, and the removal is simple only by the reverse rotation of the fixing rotation member. Made easy. As a result, the fixing process of the toner image onto the recording medium can be performed smoothly.

The fixing rotating member may be of a roller type (fixing roller) or an endless belt type (fixing belt) as long as it can function as a fixing rotating member.
As long as the pressure rotating member can function as a pressure rotating member, it may be in the form of a roller (pressure roller) or in the form of an endless belt (pressure belt).

  Examples of the contact member to the fixing rotation member include a separation claw that separates the recording medium from the fixing rotation member during the fixing process and a temperature sensor that detects the temperature of the fixing rotation member.

  As the control unit, for example, based on at least one of the factors of toner adhesion to the contact member accompanying the fixing process, at least the fixing rotating member of both rotating members in the fixing device is fixed to the toner image. An example is one that rotates in a direction opposite to that during the fixing process at a predetermined timing other than during the process.

  When toner adheres to and accumulates on the contact member, the amount of adhesion and the amount of accumulation are the number of recording media passed through the fixing device for the fixing process, the number of rotations of a rotating member such as a fixing rotating member, It increases in accordance with the integrated value of the length in the through direction of the recording medium passed through the fixing device for processing, the integrated value of the print area on the recording medium passed through the fixing device for the fixing processing, and the like. Also, the amount of toner adhering to the contact member and the amount of accumulation differ depending on the type of recording medium (such as recording paper or overhead projector recording medium (OHP)) passed through the fixing device for fixing processing. come.

  Therefore, the control unit passes the number of recording media passed through the fixing device for the fixing process, the number of rotations of the rotating member (at least the fixing rotating member), and passes the fixing device for the fixing process. The integrated value of the length in the through direction of the recording medium, the integrated value of the print area in the recording medium passed through the fixing device for the fixing process, and the type of the recording medium passed through the fixing apparatus for the fixing process Based on at least one of them, at least the fixing rotating member of both rotating members of the fixing device may be rotated in a direction opposite to that during the fixing process at a predetermined timing other than during the toner image fixing process. Good.

  In addition, the control unit reverses at least the fixing rotating member of the rotating members of the fixing device in a direction opposite to that during the fixing process at a predetermined timing other than during the toner image fixing process. The amount of rotation is determined on the basis of at least one of the contact members (for example, a separation claw), and at least the portion of the fixing rotating member that is in contact with the reference contact member during the fixing process is in contact with the fixing rotating member. It may be set larger than the amount of rotation required to reach the mutual nip portion with the rotating member.

  Accordingly, at least the toner peeled from the reference contact member is returned into the nip portion by the reverse rotation of the fixing rotation member, and can be transferred to the pressure rotation member there.

  At least one of the contact members (for example, the separation claw and the temperature sensor) (for example, the separation claw) may be separated from the fixing rotation member at a time other than the fixing process.

  The image forming apparatus according to the present invention may be any one of a copying machine, a printer, a facsimile machine, a multi-function machine combining two or more of these, and may be a monochrome image forming apparatus or a color image forming apparatus.

  As described above, according to the present invention, the fixing rotating member to be heated, the pressure rotating member pressed against the fixing rotating member, and at least one predetermined object arranged in contact with the fixing rotating member are provided. An image having a fixing device capable of fixing the toner image to the recording medium under heat and pressure by passing a recording medium holding the toner image through a nip portion between the rotating members. Provided is an image forming apparatus that can easily and easily remove toner that adheres to or accumulates on the contact member, thereby facilitating fixing of a toner image onto a recording medium. can do.

  Embodiments of the present invention will be described below. FIG. 1 shows an example of an image forming apparatus according to the present invention. The image forming apparatus includes a drum-type photosensitive member 1 that is rotationally driven. Around the periphery thereof, a charger 2, an image exposure device 3, a developing device 4, a transfer roller 5, which is an example of a rotary transfer member, The separation claw 6, the cleaner 7 and the eraser 8 are arranged in this order.

  According to this image forming apparatus, the surface of the photosensitive member 1 is uniformly charged to a predetermined potential by the charger 2, and image exposure according to the original image is performed from the image exposure device 3 to the charged region. An electrostatic latent image is formed. The electrostatic latent image is developed by the developing roller 41 of the developing device 4 to which a developing bias is applied, and becomes a visible toner image.

  On the other hand, the recording media are pulled out one by one by the paper feed roller 101 from the cassette 10 containing the recording medium S such as recording paper, and supplied to the timing roller pair 11. The timing roller pair 11 synchronizes with the toner image on the photoreceptor 1 and sends the recording medium S between the photoreceptor 1 and the transfer roller 5 to which a transfer voltage is applied. Thus, when the recording medium S is passed through the mutual nip portion between the photoreceptor 1 and the transfer roller 5, the toner image is transferred to the recording medium and subsequently fixed on the recording medium S by heating and pressurization by the fixing device 9. Is done.

  Transfer residual toner or the like remaining on the photosensitive member 1 after the transfer is removed and cleaned by the cleaner 7, and the residual electrification is erased by the eraser 8 to prepare for the next image formation.

  As shown in FIG. 2, the fixing device 9 includes a fixing roller 91 including a heat source (halogen lamp heater in this example) H and a pressure roller 92. The pressure roller 92 is pressed against the fixing roller 91 by a pressing device (not shown) including a roller rotation shaft pressing spring and the like, and a pressure nip portion N is formed between the pressure roller 92 and the fixing roller 91. A separation claw 93 and a thermistor 94 are disposed in contact with the fixing roller 91.

  The fixing roller 91 is obtained by laminating an intermediate layer 912 and a surface layer 913 on the peripheral surface of a core metal 911. The outer diameter of the fixing roller 91 is arbitrary, but is preferably about 20 mm to 50 mm.

The cored bar 911 is made of a material having high rigidity, such as a metal material such as aluminum or iron, and has a hollow cylindrical shape with a thickness of about 0.1 mm to 5 mm.
The intermediate layer 912 is an elastic layer and is preferably formed from a material having high heat resistance such as silicone rubber or fluororubber. The thickness can be exemplified by about 0.05 mm to 5 mm.

  The surface layer 913 can be exemplified by a thickness of about 5 μm to 100 μm. The surface layer 913 preferably has a releasability formed by, for example, attaching a fluororesin tube to the intermediate layer 912, coating with a fluororesin, or the like.

  The pressure roller 92 is obtained by laminating an intermediate layer 922 and a surface layer 923 on the peripheral surface of the cored bar 921. The outer diameter of the pressure roller 92 is arbitrary, but is preferably about 20 mm to 50 mm.

The core metal 921 can be exemplified by a hollow cylindrical shape made of a material having high rigidity, for example, a metal material such as aluminum or iron, and having a thickness of about 0.1 mm to 5 mm. However, it may be a solid member having a circular cross-sectional shape, or may be an irregular shape such as a three-headed cross-sectional shape.
The intermediate layer 922 is an elastic layer and is preferably formed from a material having high heat resistance such as silicone rubber or fluororubber. The thickness can be exemplified by about 1 mm to 20 mm.

  The surface layer 923 can be exemplified by a thickness of about 5 μm to 100 μm. The surface layer 923 preferably has releasability formed by, for example, attaching a fluororesin tube to the intermediate layer 922, coating with a fluororesin, or the like. In some cases, it may be conductive.

  The separation claw 93 separates the recording medium S, which has been subjected to the toner image fixing process, coming out of the mutual nip portion N between the fixing roller 91 and the pressure roller 92 from the fixing roller 91 and swings about the shaft 931. The front end of the spring 93s is in contact with the surface of the fixing roller 91.

  The separation claw 93 is formed of an organic material such as a resin, a metal, an inorganic material, or the like. It is also possible to coat the surface with a fluororesin having good releasability. In order to further improve the releasability, the surface may be roughened.

The thermistor 94 detects the surface temperature of the fixing roller 93 and is disposed in contact with the surface of the fixing roller on the downstream side of the separation claw 93 in the rotation direction during the fixing process of the fixing roller.
The thermistor 94 is also preferably coated with a fluororesin tube or a fluororesin coating on the surface in contact with the fixing roller 93 in order to improve releasability.

  The relationship between the temperature of the fixing roller 91 and the pressure roller 92 during the toner image fixing process on the recording medium is such that the fixing roller temperature ≧ the pressure roller temperature. At this time, the fixing roller temperature is about 120 ° C. to 300 ° C. The pressure roller temperature may be the same as the fixing roller temperature, but is usually 10 ° C. to 100 ° C. lower than the fixing roller temperature.

  In the fixing device 9, during the fixing process of the toner image onto the recording medium, the fixing roller 91 is rotationally driven in the CCW direction in FIG. 2 by the fixing device driving unit D including a motor, a gear train, and the like. 2 rotates in the CW direction in FIG. 2 following the movement of the recording medium S fed to the fixing roller 91 or the nip portion N.

FIG. 3 shows a control circuit for controlling the rotation direction of the fixing roller 91 (and hence the pressure roller 92) of the fixing device 9. This control circuit uses a control unit Cont that controls the operation of the entire image forming apparatus.
Information on the number of sheets of recording medium passed through the fixing device 9 is input to the control unit Cont from a recording medium passage number detection unit (not shown).

  Further, if necessary, information on the number of roller rotations of the fixing device 9, information on the integrated length of the recording medium passed through the fixing device 9, and integrated value of the print area on the recording medium passed through the fixing device 9 And information on the type of recording medium (recording paper, OHP, etc.) passed through the fixing device 9 are input from the respective detection units (not shown). Temperature information detected by the thermistor 94 is also input. In addition, various information and signals necessary for the operation of the image forming apparatus are also input.

The fixing device driving unit D rotationally drives the fixing roller 91 (and hence the pressure roller 92) based on an instruction from the control unit Cont, and controls the rotation direction thereof.
The drive circuit C for the heater H built in the fixing roller 91 also energizes the heater H based on an instruction from the controller Cont.

  According to the fixing device 9 described above, the fixing device driving unit D rotates the fixing roller 91 in the CCW direction in FIG. 2 in accordance with an instruction from the control unit Cont during the fixing process of the toner image onto the recording medium. . The pressure roller 92 rotates following the fixing roller 91 and rotates in the CW direction in FIG.

  Further, the control unit Cont instructs the heater drive circuit C based on the detected temperature information from the thermistor 94 to cause the temperature of the fixing roller 91 to reach the fixing temperature for the toner image fixing process, and to reach that temperature. Let it be maintained.

  As described above, the recording medium S on which the toner image is transferred from the photosensitive member 1 by the transfer roller 5 is directed to the nip portion N between the fixing roller 91 and the pressure roller 92, and the toner image is directed toward the fixing roller 91. Is sent. The recording medium S holding the toner image is conveyed while being nipped by the nip portion N, and the toner image is fixed to the recording medium S under heat and pressure during that time. The recording medium S coming out from the nip portion N is separated from the fixing roller 91 by the separation claw 93.

  As the fixing process is repeated in this manner, the softened or melted toner (T1, T2) on the recording medium S is deposited on the separation claw 93 with an offset adhesion, as illustrated in FIG. It becomes. The toner may also adhere to and accumulate on the thermistor 94.

  As the toner adheres and accumulates on the separation claw 93, toner contamination occurs at the front end of the recording medium S, or the recording medium S is not smoothly separated from the fixing roller 91, and the front end of the recording medium is moved. If it is damaged or, in extreme cases, the progress of the recording medium is hindered and so-called jam occurs. As the toner adheres and accumulates on the thermistor 94, the accuracy of the detected temperature decreases, leading to poor fixing.

  Therefore, the control unit Cont cannot ignore the separation claw 93, which has been obtained in advance through experiments or the like based on the input of information on the number of recording media passed through the fixing device 9 for fixing processing. It is determined whether or not the number of toner deposits and deposits has been reached, and if so, the fixing device driving unit D is instructed to fix the fixing roller 91 (and hence the pressure roller 92) during the fixing process. Rotate in the opposite direction.

At this time, the control unit Cont may determine whether to perform the reverse rotation by multiplying the input number information by a coefficient in consideration of the recording medium type. If the recording medium is OHP, an example in which the count is doubled with respect to plain paper can be given.
Note that the control unit Cont replaces the number of recording media and the type of media with information on the number of roller rotations of the fixing device 9, information on the accumulated direction length of the recording medium passed through the fixing device 9, and the fixing device. The fixing roller 91 may be reversely rotated based on the information of the integrated value of the print area in the recording medium passed through 9, or based on two or more of these including the number of recording media and the medium type. .

  When toner adheres to and accumulates on the separation claws 93, for example, as shown in FIG. The toner T1 that accumulates in this way aggregates and exists as a lump. On the other hand, when the fixing roller 91 is heated or heated, there is a semi-molten toner T2 extending from the tip of the separation claw to the fixing roller 91.

When the fixing roller 91 is rotated in the reverse direction, the toner T2 is pulled by the fixing roller 91, and the aggregated toner lump T1 is thereby broken and easily falls from the back surface of the separation claw.
Even when there is no toner straddling from the tip of the separation claw 93 to the fixing roller 91, the toner on the separation claw 93 falls due to the separation claw vibration caused by the reverse rotation of the fixing roller 91.
The same applies to toner adhesion accumulation in the thermistor 94 and toner peeling due to reverse rotation of the fixing roller 91.

  In order to drop the toner more reliably, a manual drive unit may be provided for at least one of the contact members such as the separation claw 93. For example, as illustrated in FIG. 4, a handle 95 may be connected to the swinging shaft 931 of the separation claw so that the toner can be dropped by moving the separation claw 93 by operating the handle. The thermistor 94 may also be provided with a manual drive unit.

  The controller Cont rotates the fixing roller 91 in reverse at a predetermined timing other than during the toner image fixing process. Examples of such predetermined timing include one or more of immediately after the recording medium S passes through the nip N of the rollers 91 and 92, during standby before image formation, and when the image forming apparatus is turned on. Can do.

The roller rotation speed when the fixing roller 91 is rotated in reverse is arbitrary, but is preferably in the range of about 0.1 to 1.5 times the normal roller rotation speed during image formation.
The amount of reverse rotation when the fixing roller 91 is reversely rotated is arbitrary, but at least one of the contact members such as the separation claw 93 and the thermistor 94 is defined as a reference, and the portion on the fixing roller 91 that the reference contact member contacts with. However, it is desirable that the rotation amount be larger than the rotation amount required to reach the nip portion N by reverse rotation of the fixing roller.

For example, in the example of FIG. 2, if the separation claw 93 is used as a reference, the reverse rotation amount is larger than the reverse rotation amount corresponding to the center angle θ1, and if the thermistor 94 is used as a reference, the reverse rotation amount is the center angle. This amount is larger than the reverse rotation amount corresponding to θ2.
In the former case, at least all or almost all of the toner that has been peeled off from the separation claw 93 and dropped, and in the latter case, all or almost all of the toner that has been peeled off from the separation claw 93 and the thermistor 94 and has fallen in the nip N. Until the temperature is changed to the pressure roller 92 which is lower than the fixing roller temperature.

Further, for example, when the surface of the fixing roller 91 is a pure PFA tube and the surface of the pressure roller 92 is a PFA tube containing a conductive material, the roller 92 has a ratio that the PFA as a release material is present on the tube surface. Therefore, the releasability is worse on the surface of the pressure roller. Therefore, the toner is easily transferred to the pressure roller 92 side.
Immediately after passing 3 sheets of A4 size plain paper printed at a BW ratio (printing area ratio relative to the whole) of 30% in the vertical direction (distance from the separation claw 93 to the nip portion N) +10 mm, the fixing roller 91 is reversed. An example of rotation can be given.

  Next, various examples of the separation claw 93 are shown in FIG. Among the separation claws shown in FIG. 5, the claw of FIG. (B) has a small contact width with the fixing roller and the fixing belt in order to reduce contamination at the tip. In the nail of FIG. (C), the back portion is partially removed in order to reduce the number of places where toner accumulates. The nail of FIG. (D) has a shape in which the back surface is inclined in both side directions so that the accumulated toner is easily slipped off. The shape of the separation claw is not limited to that shown in FIG. Other shapes may be used as long as they can contact the fixing roller and the fixing belt.

The separation claw 93 and the thermistor 94 may be prevented from being damaged by being separated from the fixing roller 91 by a driving unit (not shown) at times other than the fixing process.
Although the monochrome image forming apparatus has been described above, the present invention can also be applied to a color image forming apparatus.

  INDUSTRIAL APPLICABILITY The present invention can be used to form and provide a high-quality image by suppressing a decrease in image quality caused by a fixing device when an image is formed by an image forming apparatus.

1 is a diagram illustrating an example of an image forming apparatus according to the present invention. FIG. 2 is a cross-sectional view of a main part of a fixing device mounted on the image forming apparatus of FIG. 1. FIG. 4 is a block diagram of a circuit that controls a rotation direction of a rotation roller in the fixing device. It is a figure explaining the removal of the toner which adheres and accumulates on a separation nail. It is a figure which shows some examples of a separation nail | claw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charger 3 Image exposure apparatus 4 Developing apparatus 41 Developing roller 5 Transfer roller 6 Separation claw 7 Cleaner 8 Eraser 9 Fixing apparatus 10 Recording medium cassette 101 Paper feed roller 11 Timing roller pair S Recording medium 91 Fixing roller 911 Core metal 912 Intermediate layer 913 Surface layer H Heater 92 Pressure roller 921 Core bar 922 Intermediate layer 923 Surface layer N Nip part 93 Separation claw 931 Shaft 93s Spring T1 Separation claw rear toner T2 Toner 94 across the separation claw and fixing roller Thermistor 95 Handle Cont control unit D fixing device driving unit C heater driving circuit

Claims (6)

A fixing rotating member to be heated; a pressure rotating member pressed against the fixing rotating member; and at least one contact member for a predetermined purpose disposed in contact with the fixing rotating member. An image forming apparatus having a fixing device capable of fixing a toner image to the recording medium by heating and pressurizing the recording medium by passing the recording medium holding the toner image through a nip portion of a rotating member;
A controller that controls the rotational operation of both rotating members in the fixing device;
The control unit rotates at least a fixing rotating member of both rotating members in the fixing device in a direction opposite to that during the fixing process at a predetermined timing other than during the toner image fixing process. Forming equipment.   The controller controls at least the fixing rotating member of both rotating members of the fixing device other than during the toner image fixing process based on at least one of the causes of toner adhesion to the contact member accompanying the fixing process. The image forming apparatus according to claim 1, wherein the image forming apparatus is rotated in a direction opposite to that during the fixing process at a predetermined timing.   The control unit may cause the number of recording media passed through the fixing device for the fixing process, the number of rotations of the rotating member, Therefore, the integrated value of the length in the through direction of the recording medium passed through the fixing device, the integrated value of the print area of the recording medium passed through the fixing device for the fixing process, and the fixing for the fixing process The image forming apparatus according to claim 2, wherein at least one of the types of recording media passed through the apparatus is adopted.   When the control unit rotates at least the fixing rotating member of both rotating members of the fixing device in a direction opposite to that during the fixing process at a predetermined timing other than during the toner image fixing process, the reverse rotation amount Is determined based on at least one of the contact members, and at least a portion of the fixing rotating member that the reference contact member contacts during the fixing process is a mutual nip portion between the fixing rotating member and the pressure rotating member. The image forming apparatus according to claim 1, wherein the image forming apparatus is set to be larger than a rotation amount required to reach the position.   5. The image forming apparatus according to claim 1, wherein at least one of the contact members is separated from the fixing rotation member at a time other than the fixing process.   6. The contact member to the fixing rotation member is a separation claw that separates a recording medium from the fixing rotation member during the fixing process, and a temperature sensor that detects the temperature of the fixing rotation member. Image forming apparatus.