JP6929053B2 - Image forming device - Google Patents

Description

The present invention includes an image forming unit that forms a toner image on a recording material and a fixing device that heat-fixes the toner image formed by the image forming unit to the recording material, and the fixing device is replaced with another fixing device. The present invention relates to an image forming apparatus capable of forming an image.

Examples of the image forming apparatus include a copier, a printer, a facsimile, etc., which obtain a hard copy by a transfer method or a direct method using an electrophotographic process or the like.

In recent years, the types of media (recording material, recording material: hereinafter referred to as paper or paper) required for electrophotographic photography have been diversified to meet the needs of various customers. Above all, when passing special paper such as envelopes and film paper, it is widely proposed to change the pressure and speed of the fuser.

Further, in the field of commercial printing, in-plane uniformity of gloss on an image may become an issue. As a typical problem of this, when paper of the same size is continuously passed through, the surface roughness of the fixing member differs due to the difference between the passing area and the non-passing area with respect to the fixing member of the paper. , There is a case where a gloss difference occurs on the image.

Therefore, for example, the fixing conditions for determining the final image quality need to be finely adjusted depending on the thickness and surface properties of the paper, the required image density and glossiness of the product, and the like.

In order to solve these problems, prepare a dedicated fuser according to the type and size of the paper, and replace (replace) the fuser according to the type of paper used to obtain the optimum image quality. be able to.

As a proposal to realize such a means, Patent Document 1 has a configuration in which a dedicated fuser is replaced to correspond to paper such as an envelope, and in the case of image formation other than paper corresponding to the fuser, replacement of the fuser is urged. The message is displayed.

Japanese Unexamined Patent Publication No. 2008-58365

The image forming apparatus according to an embodiment of the present invention sandwiches and conveys an image forming portion that forms a toner image on a recording material and a recording material on which the toner image is formed by a nip portion between them, and fixes them by heat and pressure. Fixing having a pair of rotating bodies to be attached and a attachment / detachment mechanism in which the pair of rotating bodies are pressed into contact with each other to form the nip portion and separated from each other or a detached state in which the pressing force of the nip portion is reduced. An image forming apparatus provided with a device and capable of performing image formation by replacing the fixing device with another fixing device, and an exchange detecting means for detecting that the fixing device has been replaced. A state detecting means for detecting whether the pair of rotating bodies of the remounted fuser are in the attached state or the detached state, and a deformation elimination mode for eliminating the compression residual deformation of the pair of rotating bodies. The control unit includes a control unit for executing the above and a temperature detection element for detecting the surface temperature of at least one of the pair of rotating bodies. when said state detecting means detects the deposition states, and said temperature sensing element and executes the deformation elimination mode if you are detecting the temperature lower than a predetermined temperature.
Further, the image forming apparatus according to the embodiment of the present invention sandwiches and conveys an image forming portion that forms a toner image on a recording material and a recording material on which the toner image is formed between a nip portion between them, and heat and pressure. A pair of rotating bodies to be fixed in the above, and a detachable mechanism for pressing and contacting the pair of rotating bodies to form the nip portion and separating them from each other or removing the pressing force of the nip portion. An image forming apparatus including a fixing device having a storage means for storing a history, and capable of performing image formation by replacing the fixing device with another fixing device, and the fixing device can be replaced. It is stored in the storage means, a replacement detecting means for detecting that the work has been done, a state detecting means for detecting whether the pair of rotating bodies of the remounted fuser are in the wearing state or the detaching state. The reading means for reading the information, the leaving time acquisition unit for acquiring the leaving time of the fixing portion mounted based on the information read from the reading means, and the compression residual deformation of the pair of rotating bodies are eliminated. The control unit has a control unit that executes a deformation elimination mode for the purpose, and the control unit detects the landing state of the mounted fuser and is acquired by the leaving time acquisition unit. It is characterized in that the deformation elimination mode is executed when the leaving time exceeds a predetermined time.
Further, the image forming apparatus according to the embodiment of the present invention forms an image forming portion for forming a toner image on the recording material and a nip portion for fixing the toner image formed on the recording material by the image forming portion. A pair of rotating bodies, a transition portion that shifts the pair of rotating bodies from a pressurized state to a separated state when the fixing process is completed, and whether the pair of rotating bodies are in a pressurized state or a separated state. A first warm-up process including a rotation process of rotating the pair of rotating bodies in a pressurized state when the pair of rotating bodies are separated from each other when the main power is turned on. On the other hand, when the pair of rotating bodies are in a pressurized state when the main power is turned on, a second warm-up process including the rotation process in which the execution time is longer than that of the first warm-up process is performed. It is characterized by having a controller for executing the above.

In the compression residual deformation, the elastic layer of the rotating body is irreversibly deformed by compression, and then the shape of the elastic layer does not return even when the pressure is released, and the shape remains as it was when the nip portion was formed. It is a phenomenon. Since the rotating body that has been compressed and residually deformed cannot uniformly heat the toner image, it causes poor fixing, non-uniformity of gloss, noise, and the like, and deteriorates the performance as a fixing device.

Therefore, the fuser is provided with a attachment / detachment mechanism that converts a pair of rotating bodies into a wearing state in which a pair of rotating bodies are pressure-welded to form a nip portion and a detached state in which the nip portion is formed. If the fuser is attached to the main body of the image forming apparatus, the pair of rotating bodies are held in the detached state by the attachment / detachment mechanism at the time of non-image formation such as the standby state of the image forming apparatus, and the compression residual deformation occurs. I try to prevent it.

Further, the rotation of the rotating body of the fixing device, which is removed from the main body of the apparatus when the fixing device is replaced, is stopped, and the pair of rotating bodies are held in the detached state by the attachment / detachment mechanism. Then, even if the fuser is removed from the main body of the apparatus, the pair of rotating bodies are held in the detached state by the attachment / detachment mechanism. Therefore, even if the fuser is left for a long period of time before being used next time, the occurrence of compression residual deformation of the rotating body is prevented.

However, the fuser that is removed from the main body of the apparatus when the fuser is replaced is not in a detached state in which a pair of rotating bodies are separated, but in a wearing state, that is, a pressurized state in which a nip portion is formed by pressure contact. Cases can also occur. For example, it may occur when the power supply of the device is turned off by an incorrect method such as a momentary interruption of the power supply while the pair of rotating bodies are in the wearing state, or when a trouble occurs in the attachment / detachment mechanism. Then, in many cases, the user (operator, user) replaces the fuser without noticing this. If the fuser is left for a long period of time until it is removed from the main body of the apparatus and used next time, the rotating body will undergo compression residual deformation.

Further, even if the fuser is removed from the main body of the device while the pair of rotating bodies are separated from each other, the attachment / detachment mechanism malfunctions due to an impact in the subsequent handling of the fuser, and the pair It is possible that the rotating body of the body changes from the detached state to the attached state. If this fuser is left for a long time before it is used next time, compression residual deformation will occur in the rotating body.

Then, when the fuser in which the rotating body is subjected to the residual compression deformation as described above is used by being remounted on the main body of the apparatus, image defects due to the residual compression deformation may occur in the rotating body.

An object of the present invention is to prevent the occurrence of image defects that may occur when a fuser in which compression residual deformation is generated in a rotating body is replaced in an image forming apparatus of a fuser remounting system.

A typical configuration of the image forming apparatus according to the present invention for achieving the above object is
An image forming part that forms a toner image on the recording material,
A pair of rotating bodies in which the recording material on which the toner image is formed is sandwiched and conveyed between the nip portions and fixed by heat and pressure, and a landing state in which the pair of rotating bodies are pressure-welded to form the nip portion. It is provided with a fixing device having a detaching mechanism for separating or removing the pressing force of the nip portion to reduce the pressing force, and a fixing device having.
An image forming apparatus capable of forming an image by replacing the fixing device with another fixing device.
A replacement detection means that detects that the fuser has been replaced, and
A state detecting means for detecting whether the pair of rotating bodies of the remounted fuser are in the attached state or the detached state, and
It has a control unit that executes a deformation elimination mode for eliminating the compression residual deformation of the pair of rotating bodies.
When the replacement detecting means detects the replacement of the fuser, the control unit executes the deformation elimination mode when the state detecting means detects the wearing state, and when the state detecting means detects the detached state, the control unit executes the deformation eliminating mode. It is characterized by performing control without executing the deformation elimination mode.

According to the present invention, it is possible to prevent the occurrence of image defects that may occur when a fuser in which compression residual deformation is generated in a rotating body is replaced.

Control flow diagram according to the first embodiment Schematic diagram of the schematic configuration of the image forming apparatus according to the first embodiment Schematic diagram of the structure of the fuser in the pressurized state Schematic diagram of the structure of the fuser in the depressurized state Control system block diagram Deformation elimination mode implementation flow chart Implementation flow diagram of fuser replacement work Display screen of the display unit during fuser replacement work (Part 1) Similarly display screen (2) Similarly display screen (3) Similarly display screen (4) Control flow diagram according to the second embodiment Control flow diagram according to the third embodiment

Hereinafter, the present invention will be described in more detail with reference to examples. Although these examples are examples of the best embodiments of the present invention, the present invention is not limited to the configurations of these examples.

<< Example 1 >>
(Image forming part)
FIG. 2 is a schematic configuration diagram of the image forming apparatus 1 in this example. This device 1 is a tandem four-color full-color printer using a transfer-type electrophotographic process, and a toner image corresponding to image information input from a host device 300 to a control unit (controller) 100 is printed on paper (recording material) P. It is formed in and output.

The host device 300 is an external terminal such as a personal computer (PC). The control unit 100 exchanges various electrical information with the operation unit (UI panel unit) 200 and the host device 300, and comprehensively controls the image formation operation of the device 1 according to a predetermined control program or reference table. .. The control unit 100 stores the input information, determines the image formation conditions based on the stored information, and performs image formation under the predetermined conditions at the time of image formation. That is, the control unit 100 comprehensively controls the operation of the device 1.

The operation unit 200 is a user interface (UI) that receives instructions from the user, and has an operation key unit 201 and a display unit (liquid crystal display, etc.) 202 as input units. The operation unit 200 not only issues an image formation start command by the user using the operation key unit 201 and the display unit 202, but also specifies printing conditions such as image quality setting and information input of paper P to be set in the paper feed cassette 11. You can perform operations to do so. The display unit 202 can display various messages such as the status and error of the device 1, information such as jams, and settings.

The apparatus 1 includes an image forming unit 3 for forming a toner image on the paper P inside the apparatus main body 2. The image forming unit 3 includes an image forming unit UY that forms a yellow (Y) color toner image, an image forming unit UM that forms a magenta (M) color toner image, and an image forming unit UC that forms a cyan (C) color toner image. It has an image forming unit UBk that forms a black (Bk) color toner image.

Each image forming unit U (Y, M, C, Bk) is an electrophotographic process mechanism, and is a photosensitive drum 4, a charger 5, a laser scanner 6, a developer 7, a primary transfer charger 8, and a photosensitive drum, respectively. It has a cleaner 9. In order to avoid complication of the drawing, the description of the reference numerals for those devices in the image forming units UM, UC, and UBk other than the image forming unit UY is omitted. Further, since the electrophotographic process and the image forming operation of the image forming unit 3 having the above configuration are known, the description thereof will be omitted.

Toner images of each color are predeterminedly superimposed on the intermediate transfer belt 10 from the drum 4 of each image formation unit U and primary transfer is performed. As a result, a color toner image in which four colors of Y + M + C + Bk are superimposed is formed on the belt 10.

One sheet of paper P is separately fed from the paper feed cassette 11, and a predetermined control timing is applied to the secondary transfer nip portion, which is the pressure contact portion between the belt 10 and the secondary transfer roller 14, by the transport path 12 including the resist roller 13. Introduced in. As a result, the toner images of the four colors superimposed on the belt 10 are sequentially secondarily transferred to the paper P. The paper P that has passed through the secondary transfer nip portion is introduced into a fixing device (fixing portion: hereinafter referred to as a fixing device) 15, and the toner image is fixed (fixed) by heat and pressure as a fixed image.

In the single-sided printing mode, the paper P leaving the fixing device 15 is guided to the transport path 18 side by the flapper 17 whose attitude is controlled by the control unit 100, and is discharged to the discharge tray 19 as a single-sided printed matter.

In the double-sided printing mode, the single-sided printed paper P leaving the fuser 15 is changed to the switchback transport path 20 side by the flapper 17 whose attitude is controlled by the control unit 100. Then, the paper P is switchback-conveyed and introduced into the double-sided transfer path 21, enters the transfer path 12 again, and is introduced into the secondary transfer nip portion in a state where the first surface and the second surface are inverted, so that the second surface is transferred. Receives a secondary transfer of the toner image to. After that, the paper P is discharged to the discharge tray 19 as double-sided printed matter through the same route as in the single-sided printing mode.

(Fixer)
The fuser 15 is detachably attached to the fuser mounting portion 16 of the apparatus main body 2 by a user in a predetermined operation procedure. The apparatus 1 can perform image formation by replacing the fuser 15 with another fuser.

Reference numeral 70 denotes a presence / absence detection mechanism (replacement detection means) for the fixing device 19 in the mounting portion 16. Although the specific configuration of the presence / absence detection mechanism 70 is omitted in the figure, for example, when the fuser 16 is mounted on the mounting portion 16, it operates on, and when the fixing device 16 is removed from the mounting portion 16. Is a switch mechanism that operates off.

The control unit 100 determines that the fuser 16 is mounted on the mounting unit 16 based on the on-operation signal from the presence / absence detection mechanism 70, and determines that the fixing device 16 is removed from the mounting unit 16 based on the off-operation signal. Further, the control unit 100 determines that the fuser has been replaced (replaced) with respect to the apparatus main body 2 based on the signal transition in which the on operation signal from the presence / absence detection mechanism 90 becomes the off operation signal and becomes the on operation signal again. The presence / absence detection mechanism 90 may adopt an appropriate means configuration other than the above.

FIG. 3 is an enlarged cross-sectional schematic view of the fuser 15 in this example. The fixing roller 15 is a fixing roller as a pair of rotating bodies in which the toner image T formed on the paper P is sandwiched and conveyed by a nip portion (heating nip portion: fixing nip portion) N between them and fixed by heat and pressure. It has a (heating rotating body) 40 and a pressure roller (pressurizing rotating body) 41.

The fixing roller 40 is a heat fixing member that comes into contact with the image surface. The fixing roller 40 is configured to have a diameter of 80 mm by arranging an elastic layer 40c having a thickness of 3 mm on the outer peripheral surface of a core metal 40b of an aluminum cylinder and a release layer 40d having a thickness of 50 μm in contact with the image surface on the outer peripheral surface thereof. It is an elastic roller. The elastic layer 40c is an HTV (high temperature vulcanization type) silicon rubber layer, and the release layer 40d is coated with a tube containing a copolymer of ethylene tetrafluoride and perfluoroalkoxy ethylene (hereinafter, PFA) as a main material. ing.

The pressure roller 41 is a pressure fixing member that presses against the fixing roller 40 with a predetermined pressing force to form a nip portion N with the fixing roller 40. The pressure roller 41 is an elastic roller having a diameter of 60 mm by arranging an elastic layer 41c having a thickness of 1 mm on the outer peripheral surface of a core metal 41b of an aluminum cylinder and a release layer 41d on the outer peripheral surface thereof. .. Like the fixing roller 40, the elastic layer 41c is an HTV silicone rubber layer, and the release layer 41d thereof is covered with a PFA tube.

Both ends of the fixing roller 40 are rotatably supported and arranged between one end side and the other end side of the fixing device frame (fixing device housing) 43 via bearing members (not shown). ing. The pressurizing rollers 41 are arranged substantially parallel to the fixing roller 40, and both ends thereof are rotatably supported between the side plates on one end side and the other end side of the frame body 43, respectively, via a bearing member. .. The pressure roller 41 resists the elasticity of the elastic layer 40c of the fixing roller 40 and the elastic layer 41c of the pressure roller 41 by, for example, a pressure mechanism (not shown) composed of a pressure spring, a pressure lever, or the like. It is pressure-welded with a predetermined pressing force.

In this example, the pressure roller 41 is pressed against the fixing roller 40 at a total pressure of 784 N (about 80 kg), and a nip having a predetermined width in the paper transport direction (recording material transport direction) X between the pressurizing rollers 41 and the rollers 40 and 41. Part N is formed. The fixing roller 40 and the pressurizing roller 41 are first motors in which gears fixed to one of the shaft ends are connected to each other by a gear mechanism (not shown), and the gear mechanism is controlled by a control unit 100. The driving force of M1 (FIG. 5) is transmitted. As a result, the fixing roller 40 and the pressurizing roller 41 are rotationally driven at predetermined peripheral speeds in the clockwise direction of the arrow R40 and the counterclockwise direction of the arrow R41, respectively.

Halogen heaters 40a and 41a as heating sources for heating the rollers 40 and 41 from the inside are arranged non-rotatingly at the center of rotation of the fixing roller 40 and the pressure roller 41, respectively. In this example, the halogen heater 40a has a rated power of 1200 W, and the halogen heater 41a has a rated power of 400 W. The halogen heaters 40a and 41a are energized from the feeding unit 72 (FIG. 5) controlled by the control unit 100. As a result, the fixing roller 40 and the pressurizing roller 41 are heated from the inside by the heat generated by the heaters 40a and 41a, respectively.

Then, the surface temperatures of the fixing roller 40 and the pressure roller 41 are detected by thermistors 42a and 42b as temperature detecting elements, respectively, and the detected temperature information is fed back to the control unit 100. The control unit 100 is the same as the halogen heater 40a from the power feeding unit 72 so that the surface temperatures of the fixing roller 40 and the pressurizing roller 41 are raised and maintained at predetermined target temperatures based on the feedback detection temperature information. The power supply to 41a is controlled respectively.

As described above, in a state where the fixing roller 40 and the pressurizing roller 41 are rotationally driven and the surface temperature of each of the rollers 40 and 41 is raised to a predetermined target temperature and the temperature is adjusted, the image forming unit 3 side. The paper P on which the unfixed toner image T is formed is introduced into the fixing device 15. Then, the paper P is sandwiched and conveyed by the nip portion N, so that the toner image is thermally and pressure-fixed as a fixed image.

When the image of the apparatus 1 is formed, the pressurizing roller 41 is pressed against the fixing roller 40 with a predetermined pressing force by the pressurizing mechanism to form a nip portion N having a predetermined width as shown in FIG. It has moved to the position (wearing state: pressurized state) 41A. Further, the pressure roller 41 is depositioned from the fixing roller 40 as shown in FIG. 4 during non-image formation such as standby or warm-up of the device 1 or when a jam occurs (deposition state: separated state). It is moved to 41B and held.

The conversion of the pressurizing roller 41 to the landing position 41A and the depositioning position 41B is arranged in the fuser 15 and is performed by the attachment / detachment mechanism (transition unit) 44 controlled by the control unit (controller) 100. As the fixing process is completed, the control unit 100 shifts the fixing roller 40 and the pressure roller 41 from the landing position 41A to the depositioning position 41B by the attachment / detachment mechanism 44.

Although the specific configuration of the attachment / detachment mechanism 44 is omitted in the drawing, for example, the pressurizing lever of the pressurizing mechanism that pressurizes the pressurizing roller 41 is pressed at the pressurizing position where the pressurizing roller 41 is pressurized and the pressurization. It can be a mechanism having a cam that changes to the pressure release position where the pressure is released. By controlling the rotation angle of the cam by the second motor M2 (FIG. 5) controlled by the control unit 100, the pressure roller 41 is selectively moved to the landing position 41A and the depositioning position 41B. The attachment / detachment mechanism 44 may have an appropriate means configuration other than the above.

When the pressurizing roller 41 is held in the deposition 41B during non-image formation such as during standby or warm-up of the device 1, the pressure contact between the fixing roller 40 and the pressurizing roller 41 is released. The occurrence of compression residual deformation of both rollers 40 and 41 is prevented. Further, since the pressure roller 41 is held in the deposition 41B even when a jam occurs, the jam paper sandwiched between the nip portions N can be easily removed.

Here, it is assumed that the depositioning 41B of the pressurizing roller 41 is sufficiently separated from the fixing roller 40 and also includes a state in which the pressing force is almost zero or light pressure is in contact with the fixing roller 40. Further, in this example, the pressure roller 41 is pressed against the fixing roller 40 and is detached and moved, but the present invention is not limited to this. The fixing roller 40 may be brought into pressure contact with the pressure roller 41 and may be detached and moved. Further, both the fixing roller 40 and the pressure roller 41 may be pressure-contacted with each other and may be detached and moved.

Further, the fixing device 15 or the device main body 2 is provided with a attachment / detachment determination mechanism (state detection means) 71 of the pressure roller 41 in the fixing device 15 mounted on the mounting portion 16. Although the specific configuration of the attachment / detachment determination mechanism 71 is omitted in the drawing, for example, when the pressure roller 41 is located at the landing position 41A, it operates on, and when it is located at the removal position 41B, it operates off. It is a switch mechanism.

The control unit 100 determines that the pressurizing roller 41 is located at the landing position 41A based on the on operation signal from the attachment / detachment determination mechanism 71, and determines that the pressurizing roller 41 is located at the depositioning position 41B based on the off operation signal. do. The attachment / detachment determination mechanism 71 may have an appropriate means configuration other than the above.

A memory tag (storage means such as an IC chip) 45 for storing various information regarding the type and usage history of the fuser is arranged on the outer surface of the frame 43 of the fuser 15. A communication unit 73 for reading the information stored in the memory tag 45 is arranged on the device main body 2 side. The memory tag 45 is predeterminedly opposed to the communication unit 73 on the device main body 2 side in a state where the fuser 15 is predeterminedly mounted on the mounting portion 16.

In this state, the control unit 100 can read the information stored in the memory tag 45 via the communication unit 73. Further, the control unit 100 can write new information to the memory tag 45 via the communication unit 73. The control unit 100 can read paper information suitable for the fixing device from the memory tag 45 via the communication unit 73 and use it in the printer control unit.

In the case of a device configuration having the memory tag 45 and the communication unit 73, the memory tag 45 and the communication unit 73 can be used as a presence / absence detection mechanism for the fuser 19 in the mounting unit 16. That is, the control unit 100 determines that the fuser 16 is attached to the attachment unit 16 when the communication unit 73 can communicate with the memory tag 45, and the fuser 16 is removed from the attachment unit 16 when communication is not possible. Judge. Further, the control unit 100 determines that the fuser has been replaced (replaced) with respect to the apparatus main body 2 because the communication unit 73 has changed from being unable to communicate with the memory tag 45 to being able to communicate with the memory tag 45.

(Control unit)
FIG. 5 is a schematic block diagram of the control system of the control unit 100, and mainly shows the control system of the fuser 15. The control unit 100 has a CPU 81. The CPU 81 is electrically connected to a RAM 82, a ROM 83, an image processing unit 84, an I / F unit 85, a timer 86, a paper feed control unit 87, and a controller 88.

The operation unit 200, the paper feed mechanism unit of the paper feed cassette 11, and the host device 300 such as a PC are electrically connected to the CPU 81 through the I / F unit 85, the paper feed control unit 87, and the controller 88, respectively. The operation unit 200 may be the host device 300. The CPU 81 measures the time with the timer 86.

Further, the CPU 81 electrically includes various control units of the fuser 15, a temperature detection unit 89, a heater control unit 90, a motor control unit 91, a state determination unit 92, a replacement detection unit 93, and a memory tag detection unit 94. It is connected.

The detection temperature information of the thermistors 42a and 42b is input to the temperature detection unit 89. The heater control unit 90 controls the electric power input from the power feeding unit 72 to the heaters 40a and 41a. The motor control unit 91 controls the first and second motors M1 and M2. An on operation signal and an off operation signal are input to the state determination unit 92 from the attachment / detachment determination mechanism 71. An on operation signal and an off operation signal are input to the exchange detection unit 93 from the presence / absence detection mechanism 70. The memory tag detection unit 94 is connected to the memory tag 45 and the communication unit 73 for exchanging information.

Image information such as printing conditions from the host device 300 is sent to the CPU 81 through the controller 88. The CPU 81 can form an image by processing the received image information in the image processing unit 84. The ROM 83 stores programs for controlling the image processing unit 84, the paper feed control unit 87, the operation unit 200, the control units 89 to 94 of the fuser 15, and the like. The RAM 82 is used as a work area when the CPU 81 executes a program.

By being controlled by the CPU 81 in such a configuration, the fuser 15 controls the transport speed of the paper P, the surface temperature of the fixing roller 40, the pressure roller 41, and the like, and fixes the toner image on the paper P. Can be done.

(Replacement of fuser)
As mentioned above, the types of paper used are diversifying due to the needs of various customers. In particular, there is a demand for both image quality and productivity for paper used in commercial printing, such as envelopes and paper with a high basis weight. In order to deal with these problems, a fuser set according to the paper is a dedicated fuser. By replacing the dedicated fuser corresponding to the paper to be used on the apparatus main body 2 and operating the image forming apparatus, it becomes possible to correspond to a wide range of special papers.

Table 1 shows an example of a dedicated fuser. Table 1 shows three types, a fuser A, a fuser B, and a fuser C.

Conventionally, only the fuser A has been used for a wide range of papers. This fuser A is usually used as a fuser. When passing paper that is 4 to 5 times as large as the paper with a basis weight of 64 to 80 gsm used in a normal office, the amount of heat is insufficient even if the fixing temperature is raised by several tens of degrees Celsius if the fixing setting of the normal fixing device A is set. do. Further, since the thick paper has a large pressure at the nip portion N and a large pressure difference between the paper-passing area and the non-paper-passing area, the stress on the fixing roller 40 and the pressure roller 41 is large. For this reason, the surface deterioration and wear of the members are large, and it is necessary to frequently replace the members.

For this reason, the fuser B is configured to emphasize the fixing of thick paper, widen the nip width, and disperse the pressure. This fuser B is used as a thick paper fuser. However, in the case of this thick paper fuser B setting, when the thickness of the paper is thin, the speed difference becomes large at the fixing nip during transportation, and wrinkles and uneven gloss are likely to occur. ing.

The fuser C specializes in fixing envelopes. In the case of envelopes, stress on the paper is reduced and wrinkles and uneven gloss are eliminated by operating the pressure at about half that of the normal fixing device A. This is used as an envelope fuser. This envelope fuser C cannot sufficiently fix ordinary paper, especially thick paper that requires a large amount of heat. Therefore, there may be adverse effects such as cold offset in which the toner is not fixed to the paper and is offset to the fixing roller side, and gloss is deteriorated because the toner is not sufficiently melted and the surface surface is roughened.

Further, as an advantage of using a special fixing device suitable for the paper, there is uneven gloss in the paper-passing area and the non-paper-passing area on the fixing roller 40 and the pressure roller 41 by continuous paper passing. This is because the paper hits the fixing roller 40 and the pressure roller 41 in the paper passing area, so that the surface layer of the fixing roller is leveled. On the other hand, in the non-paper-passing area, the fixing roller 40 and the pressure roller 41 are always in contact with each other and driven, so that the surface states of the fixing roller 40 and the pressure roller 41 are different. For this reason, when a paper having a width wider than the portion having a different surface condition is passed through, a glossy step on the toner surface may occur, which may be visually recognized as a defect in the image.

By replacing and operating the dedicated fuser corresponding to each width of the paper, such a problem can be solved and the optimum image quality can be obtained. Table 2 shows an example of using a dedicated fuser properly according to the width of the paper.

Normally, the fuser A is used, but when the user handles a product that pays particular attention to the surface of the paper, the fuser is replaced and operated in order to eliminate uneven gloss as described above. For example, when handling both a two-sided postcard size paper and an image of A3 Nobi, a fuser D (here, a small size fuser) is used for a 200 mm wide two-sided postcard. Also, in the case of A3 Novi printing, replace it with a fuser E (a large size fuser). As a result, the portions of the surface layer of the fixing roller having different surface states can be fixed without hitting the position of the toner surface of the paper, and a product product without uneven gloss can be obtained.

As described above, there is a great advantage in using the dedicated fuser by replacing it, but there is also an adverse effect that it can handle only a certain range of paper. However, in the field of commercial printing, it is often the case that a large number of copies of the same type of paper are produced at one time, and even if the entire fuser is replaced, the advantage of being able to handle a wide range of paper is greater. be. Therefore, we believe that it will be a print-on-demand business.

Naturally, in consideration of users who frequently mix paper, the setting is basically such that the fuser A can cover all states. The dedicated fuser described here is one of the countermeasures proposed in order to support better image quality and paper.

(Compression residual deformation)
As described above, in the fixing device 15 mounted on the mounting portion 16 of the device main body 2, the pressure roller 41 is moved to the landing position 41A by the attachment / detachment mechanism 44 with respect to the fixing roller 40 when the image of the device 1 is formed. The pressure is applied by a pressurizing mechanism. As a result, the nip portion N required for image fixing is formed between the two rollers, and the image forming operation is executed.

On the other hand, during non-image formation such as during standby, the pressure roller 41 is moved to and held in the deposition 41B separated from the fixing roller 40 by the attachment / detachment mechanism 44. That is, the control unit 100 shifts the fixing roller 40 and the pressure roller 41 from the landing position 41A to the depositioning position 41B by the attachment / detachment mechanism 44 as the fixing process is completed. As a result, the pressure contact between the fixing roller 40 and the pressure roller 41 is released, so that even if the device 1 is left for a long time, the occurrence of compression residual deformation of both rollers 40 and 41 is prevented.

When using a dedicated fuser, it is expected that the user will frequently replace the fuser. When the currently mounted fuser is taken out from the apparatus main body 2 for the fuser replacement, the apparatus 1 is in the standby state. Therefore, normally, the currently mounted fuser is in a state in which the pressure roller 41 is moved and held by the detachable mechanism 44 to the deposition 41B separated from the fixing roller 40, and the fuser in that state is held. It is taken out from the device body 2 and stored until it is used next time.

However, as described above, there may be a case where the pressurizing roller 41 of the fuser taken out from the apparatus main body 2 is in the landing position 41A and is in a state of being pressed against the fixing roller 40 by the pressurizing mechanism. Further, even if the fuser is removed from the main body of the apparatus while the pressurizing roller 41 is in the deposition 41B separated from the fixing roller 40, it is caused by an impact in the subsequent handling of the fixing device. The pressure roller 41 may be converted to the landing 41A. If such a fixing device is left for a long period of time before being used next time, compression residual deformation will occur in the fixing roller 40 and the pressure roller 41.

Table 3 shows the results of investigating the occurrence of compression residual deformation when the fixing device in which the fixing roller 40 and the pressure roller 41 are left in the pressurized state is taken out from the apparatus main body 2 and left as it is. be. It is assumed that the image forming apparatus is operating the image forming apparatus until immediately before the fixing device is taken out and is used for image fixing. Therefore, the temperatures of the fixing roller 40 and the pressure roller 41 of the fixing device at the time of being taken out are in a temperature state substantially corresponding to the fixing temperature control temperature, respectively.

Then, the decrease transition of the surface temperature of the fixing roller 40 and the pressurizing roller 41 at each time point of the leaving time of 0 hour, 1 hour, 2 hours, 3 hours, 4 hours, and 8 hours was installed in each roller. The measurement was performed with the thermistor 42a and 42b. In addition, the presence or absence of density unevenness due to the residual compression deformation of the fixing roller 40 and the pressure roller 41 when the fixing device was reattached to the apparatus main body 2 and used for image fixing was investigated at each time point of the above-mentioned leaving time. ..

The fixing roller 40 corresponds to the thermistor 42a, and the pressure roller 41 corresponds to the thermistor 42b. As shown in Table 3, the surface temperature of the fixing roller 40 and the pressure roller 41 of the taken-out fixing device decreases with time. Then, after a certain leaving time, density unevenness due to residual deformation occurs.

(Warm-up operation)
Next, the normal operation after the fuser is replaced will be described. When the fuser for the device main body 2 is replaced (when the main power is turned on from off), the control unit 100 warms up the attached fuser. In this warm-up operation, the fixing roller 40 and the pressure roller 41 are rotationally driven at a rotation speed of 100 mm / s, and at this time, the pressure roller 41 is held in a detached state from the fixing roller 40. The heaters 41a and 42a are energized to heat the fixing roller 40 and the pressure roller 41. Then, the surface temperatures of the fixing roller 40 and the pressure roller 41 are raised to a state where the toner can be melted.

Specifically, when it is necessary to adjust the temperature of the fixing roller 40 to 160 ° C., the temperature of the fixing roller 40 is once raised to 170 ° C., and then the temperature is controlled to wait until it cools to 160 ° C. Similarly, when it is necessary to adjust the temperature of the pressure roller 41 to 120 ° C., the temperature is raised to 130 ° C. and then waits until it cools to 120 ° C. By giving each member an extra amount of heat in this way, the entire member including the temperature of the frame of the fuser and the temperature of the end of each member can be sufficiently heated, and the temperature drop at the end can be improved. can.

After the warm-up operation is completed, if there is no print job, the control unit 100 shifts the device to the standby state. In this standby state, the fixing roller 40 and the pressure roller 41 are rotationally driven at "100 mm / s", and the pressure roller 41 is held in a detached state from the fixing roller 40. Further, the temperature of the fixing roller 40 and the pressure roller 41 are adjusted during standby. The temperature control temperature during standby is 40: 160 ° C. for the fixing roller and 41: 120 ° C. for the pressurizing roller, which are started by the warm-up operation.

(Deformation elimination mode)
As described above, in the fuser used by being mounted on the apparatus main body 2, the fixing roller 40 and the pressure roller 41 are left in the pressurized state, so that the fixing roller 40 and the pressure roller 41 remain compressed. Some may be deformed. Such a fuser causes poor fixing, non-uniformity of gloss, noise and the like, and deteriorates the performance as a fuser.

In this example, when it is determined that the fixing roller 40 or the pressurizing roller 41 is equipped with a fixing device that may have compression residual deformation on the apparatus main body 2, the control unit 100 uses the fixing roller 40 or the fixing roller 40. The deformation elimination mode for eliminating the compression residual deformation of the pressure roller 41 is executed. As a result, it is possible to prevent the occurrence of image defects that may occur when the fixing device in which the compression residual deformation is generated is replaced on the fixing roller 40 or the pressure roller 41.

In order to eliminate the compression residual deformation of the fixing roller 40 and the pressure roller 41, it is effective to continue to apply a constant strain to the entire roller. Therefore, in this example, a method in which the fixing roller 40 and the pressure roller 41 are heated to make both rollers 40 and 41 easily distorted, and both rollers 40 and 41 are pressurized and rotated to continuously apply a constant strain. To eliminate the residual deformation. FIG. 6 is a flowchart of the deformation elimination mode.

First, in the replaced fuser, the fixing roller 40 and the pressurizing roller 41 are in a pressurized state. Therefore, in order to separate the two rollers 40 and 41, the control unit 100 controls the attachment / detachment mechanism 44 to operate the pressure roller 41 from the landing position 41A to the depositioning position 41B (step S101). Next, the control unit 100 starts energizing the heater 40a and the heater 41a to heat the fixing roller 40 and the pressurizing roller 41 (S102).

Here, the above-mentioned predetermined temperature can be set to 40 ° C. to 160 ° C. for the fixing roller 40 and 25 ° C. to 130 ° C. for the pressure roller 41 based on the temperature in Table 3 and the result of the occurrence of compression residual deformation. A high temperature setting close to the target temperature or that temperature is preferable. In this example, the fixing roller 40 has a predetermined temperature of 160 ° C., and the pressure roller 40 has a predetermined temperature of 130 ° C.

When the thermistors 42a and 42b detect that the surface temperatures of the fixing roller 40 and the pressure roller 41 are equal to or higher than the predetermined temperatures by this heating (S103), the pressure roller 41 is pressed against the fixing roller 40 (S104). This pressure welding is performed by the control unit 100 controlling the attachment / detachment mechanism 44 to operate the pressurizing roller 41 from the depositioning position 41B to the landing position 41A, and the pressing force of the pressurizing mechanism works.

When the attachment / detachment determination mechanism 71 detects that the pressure roller 41 has moved to the landing position 41A, the control unit 100 rotates the fixing roller 40 and the pressure roller 41 at a predetermined rotation speed for a predetermined time (S105, S106). ..

Here, the rotation speeds of the fixing roller 40 and the pressurizing roller 41 in step S105 are set to be slower than the rotation speed of the device 1 in the standby state: 100 mm / s and the rotation speed during image formation: 400 mm / s. Is preferable. This is because if the fixing roller 40 and the pressure roller 41 are rotated at high speed in a state of being compressed and residual deformed, the motor load may increase due to abnormal noise or torque increase, and peripheral members may be damaged. In this example, the low speed rotation of 50 mm / s is set (low speed setting).

Further, the predetermined time in step S106 is set to a time during which the compression residual deformation of the fixing roller 40 and the pressure roller 41 can be substantially eliminated. The time varies depending on the predetermined temperature set in step S103. The higher the predetermined temperature is, the shorter the time can be set. In this example, in the predetermined temperature setting of the fixing roller 40: 160 ° C. and the pressure roller 40: 130 ° C., the predetermined time: 120 seconds is set. As a result, it is possible to substantially eliminate the compression residual deformation of the fixing roller 40 and the pressure roller 41.

When a predetermined time has elapsed from the start of operation of the fixing roller 40 and the pressure roller 41 (S106), the deformation elimination mode ends. Then, the control operation of the device 1 shifts to the warm-up operation.

(Fixer replacement work)
A work flow at the time of replacing the fuser will be described with reference to FIG. 8 to 11 are display images (display screens) of the display unit 202 of the operation unit 200 or the display unit of the host device 300 at that time.

This will be described according to the work flow of FIG. When the fuser replacement (replacement of the fuser) is required, the user starts the mode of the fuser replacement work from the management setting of the device setting (S200). By canceling the fuser replacement mode without starting it (S202), the normal UI screen is restored (S203).

When the fuser replacement mode is started (S201) (FIG. 8), the fuser replacement mode is prepared (FIG. 9). If the fuser is canceled in the middle of the process, or if the fuser is not actually replaced, a cancellation message is displayed and the replacement is canceled (S205 / S206) (FIG. 10). When the replacement work is completed, the normally completed display (S207) (FIG. 11) appears, the fuser replacement flag is turned ON (S208), and the fuser replacement work is completed (S209). Then, the image forming apparatus resumes the preparation for making it ready for printing.

(Judgment of residual compression deformation)
Next, the determination of the compression residual deformation of the fixing roller 40 and the pressure roller 41 for the fixing device mounted on the apparatus main body 2 will be described by the flow shown in FIG.

When the fuser replacement work is completed (S300, S301), the control unit 100 determines the position of the mounted fuser pressurizing roller 41 by the attachment / detachment determination mechanism 71 (S302, S303). That is, it is determined whether the pressure roller 41 is located at the landing position (landing state) 41A or the depositioning (depositioning state) 41B.

At this time, if it is determined that the pressure roller 41 is out of position 41B, the control unit 100 determines that the fixing roller 40 and the pressure roller 41 of the remounted fuser have no compression residual deformation. Then, a command is issued to perform a normal warm-up operation (S305).

However, when it is determined in step S303 that the pressure roller 41 is in the landing position 41A, the control unit 100 states that the fixing roller 40 and the pressure roller 41 of the remounted fuser may have compression residual deformation. judge. In this case, the deformation elimination mode described with reference to FIG. 6 is executed (S304). After executing this mode, a command is issued to perform a normal warm-up operation (S305).

The configuration of the image forming apparatus 1 of the first embodiment described above is summarized as follows. This is an image forming apparatus including an image forming unit 3 for forming a toner image T on paper P and a fixing device 15, and capable of forming an image by replacing the fixing device with another fixing device.

The fixing device 15 has a fixing roller 40 and a pressure roller 41 as a pair of rotating bodies that sandwich and convey the paper P on which the toner image is formed by the nip portion N between them and fix it by heat and pressure. Further, the fixing roller 40 and the pressure roller 41 are brought into pressure contact with each other to form a nip portion N, which is separated from the attached state, or the nip portion N is provided with a detachable mechanism 44 which reduces the pressing force of the nip portion N.

A replacement detecting means 70 that detects that the fuser has been replaced, and a state detecting means that detects whether the fixing roller 40 and the pressure roller 41 of the replaced fuser are in the attached state or the removed state. Has 71. That is, the state detecting means 71 is a detection unit that detects whether the fixing roller 40 and the pressure roller 41, which are a pair of rotating bodies, are in the pressure state or in the separated state.

Then, it has a control unit 100 that executes a deformation elimination mode for eliminating the compression residual deformation of the fixing roller 40 and the pressure roller 41. When the replacement detecting means 70 detects the replacement of the fuser, the control unit 100 executes the deformation eliminating mode when the state detecting means 71 detects the wearing state, and executes the deformation eliminating mode when detecting the detached state. Do not execute, control.

It can also be said that the control unit (controller) 100 performs the following control. .. That is, a first warm-up process including a rotation process of rotating the fixing roller 40 and the pressure roller 41 in a pressurized state when the fixing roller 40 and the pressure roller 41 are separated from each other when the main power is turned on. To execute. On the other hand, when the fixing roller 40 and the pressurizing roller 41 are in the pressurized state when the main power is turned on, the second warm-up including the rotation process in which the execution time is longer than that in the first warm-up process. Let the process be executed.

At the time of the second warm-up process, the control unit (controller) 100 shifts the fixing roller 40 and the pressure roller 41 to a separated state and heats them until the temperature rises to a predetermined temperature, and then performs the rotation process for a predetermined time. Let it run.

As described above, in most cases, the user replaces the fuser, but by determining the state of the fuser as described above, it is possible to prevent abnormal images in advance and also to prevent abnormal images. It is also possible to omit unnecessary controls.

<< Example 2 >>
Since the image forming apparatus configuration and the fuser configuration other than the following items are the same as those in the first embodiment, the description thereof will be omitted again.

As described in Table 3, even when the fixing device in which the fixing roller 40 and the pressure roller 41 are in a pressurized state is taken out from the apparatus main body 2 and left to stand, the temperatures of the fixing roller 40 and the pressure roller 41 are at a certain temperature. If it is the above, it can be determined that no residual deformation has occurred. In Table 3, when the temperature of the fixing roller 40 is 40 ° C. or higher and the temperature of the pressure roller 41 is 25 ° C. or higher, no residual deformation occurs.

Therefore, in this example, as shown in FIG. 12, in the flow of FIG. 1, step S303A and step S303B are joined between step S303 and step S304.

That is, if it is determined in step S303 that the pressure roller 41 is in the landing position 41A, the control unit 100 then goes to read the temperatures of the fixing roller 40 and the pressure roller 41 (S303A). This temperature detection is performed by the thermistors 42a and 42b.

At this time, if the temperatures of the fixing roller 40 and the pressure roller 41 are equal to or higher than a predetermined temperature, the control unit 100 determines that the fixing roller 40 and the pressure roller 41 of the replaced fixing device have no compression residual deformation. .. Then, a command is issued to perform a normal warm-up operation (S305).

In this example, the predetermined temperature of step S303B is set to 40:40 ° C. for the fixing roller and 41:25 ° C. for the pressurizing roller from Table 3.

On the other hand, if the temperatures of the fixing roller 40 and the pressure roller 41 are lower than the predetermined temperature, the control unit 100 determines that the fixing roller 40 and the pressure roller 41 of the replaced fixing device are subjected to compression residual deformation. do. In this case, the deformation elimination mode described with reference to FIG. 6 is executed (S304). After executing this mode, a command is issued to perform a normal warm-up operation (S305).

<< Example 3 >>
Since the image forming apparatus configuration and the fuser configuration other than the following items are the same as those in the first embodiment, the description thereof will be omitted again.

The memory tag 45 of the fuser 16 stores in advance the usage information of the paper to be used for the fixing. Paper size and paper type are stored as paper usage information, the size represents A4, A3, LTR, etc., and the type represents an envelope, etc. The control unit 100 reads these information from the memory tag 45 via the communication unit 73, and determines whether or not a fuser suitable for the print job specifications is attached.

As a result of the determination, if a fuser suitable for the print job specifications is not installed, the display unit 202 of the operation unit 200 is notified that the fuser is inappropriate. Further, the control unit 100 can store the time when the fuser was last replaced by using the memory tag 45 of each dedicated fuser.

Further, as described in Table 3, even when the fixing device in which the fixing roller 40 and the pressure roller 41 are in a pressurized state is taken out from the apparatus main body 2 and left to stand, the fixing roller 40 is left as long as the leaving time is within a predetermined time. It can be determined that the pressure roller 41 does not undergo compression residual deformation.

Therefore, in this example, the information of the memory tag 45 mounted on the fixing device 15 is used to determine the compression residual deformation of the fixing roller 40 and the pressure roller 41 for the fixing device mounted on the apparatus main body 2. doing.

Therefore, in this example, as shown in FIG. 13, in the flow of FIG. 1, step S303C and step S303D are joined between step S303 and step S304.

That is, if it is determined in step S303 that the pressurizing roller 41 is in the landing position 41A, then the control unit (leaving time acquisition unit) 100 uses the fuser stored in the memory tag 45 mounted on the fuser. Read the history (usage history information on the device body, mounting history). Then, the leaving time until the fixing device is attached is acquired (calculated) (S404). That is, the leaving time is acquired from the date and time when the fuser stored in the memory tag 45 was previously removed from the apparatus main body and the date and time when the fuser was attached to the apparatus main body this time.

At this time, if the acquired leaving time is within a predetermined time, the control unit 100 determines that the fixing roller 40 and the pressure roller 41 of the replaced fixing device have no compression residual deformation. Then, a command is issued to perform a normal warm-up operation (S305).

The predetermined time (leaving time) in step S303D is set to 4 hours from Table 3 in this example.

On the other hand, when the acquired leaving time exceeds a predetermined time, the control unit 100 determines that the fixing roller 40 and the pressure roller 41 of the replaced fixing device are subjected to compression residual deformation. In this case, the deformation elimination mode described with reference to FIG. 6 is executed (S304). After executing this mode, a command is issued to perform a normal warm-up operation (S304).

The form described above makes it possible to eliminate the residual deformation immediately after the fuser is replaced, and it is possible to prevent the image adverse effect due to the residual deformation.

<< Other matters >>
Although the above embodiment has been described above as an application example of the present invention, it is possible to replace various configurations with other configurations within the scope of the idea of the present invention.

(1) For example, the image forming apparatus is not limited to the color image forming apparatus, and may be a monochromatic (monochromatic) image forming apparatus such as a monochrome image.

(2) For example, the fixing device is not limited to a device that heats and fixes an unfixed toner image formed on a recording material. It also includes an apparatus (also referred to as a fuser) that is also used in the process of reheating a semi-fixed or fixed toner image to adjust the surface gloss of the image.

(3) For example, the pair of rotating bodies of the fuser is not limited to the roller body of the embodiment. The device configuration may also use an endless belt (endless belt) having flexibility in either one or both. Further, the heating mechanism of the rotating body is not limited to the halogen heater. Other appropriate heating mechanisms such as a ceramic heater method and an electromagnetic induction heating method can be adopted.

1 ... image forming device, 3 ... image forming part, 15 ... fixing device, 40.41 ... pair of rotating bodies (fixing roller and pressure roller), N ... nip part, P ... recording material, T ... toner image, 44 ... attachment / detachment mechanism, 70 ... replacement detection means, 71 ... state detection means, 100 ... control unit

Claims (6)

An image forming part that forms a toner image on the recording material,
A pair of rotating bodies in which the recording material on which the toner image is formed is sandwiched and conveyed between the nip portions and fixed by heat and pressure, and a landing state in which the pair of rotating bodies are pressure-welded to form the nip portion. It is provided with a fixing device having a detaching mechanism for separating or removing the pressing force of the nip portion to reduce the pressing force, and a fixing device having.
An image forming apparatus capable of forming an image by replacing the fixing device with another fixing device.
A replacement detection means that detects that the fuser has been replaced, and
A state detecting means for detecting whether the pair of rotating bodies of the remounted fuser are in the attached state or the detached state, and
A control unit that executes a deformation elimination mode for eliminating compression residual deformation of the pair of rotating bodies, and
It has a temperature detecting element for detecting the surface temperature of at least one of the pair of rotating bodies.
When the replacement detecting means detects the replacement of the fuser, the control unit detects the wearing state of the state detecting means and the temperature detecting element detects a temperature lower than a predetermined temperature. An image forming apparatus characterized in that the deformation elimination mode is executed. An image forming part that forms a toner image on the recording material,
A pair of rotating bodies in which the recording material on which the toner image is formed is sandwiched and conveyed between the nip portions and fixed by heat and pressure, and a landing state in which the pair of rotating bodies are pressure-contacted to form the nip portion. It is provided with a fixing device having a detaching mechanism for separating or removing the pressing force of the nip portion to reduce the pressing force, and a storage means for storing the usage history.
An image forming apparatus capable of forming an image by replacing the fixing device with another fixing device.
A replacement detection means that detects that the fuser has been replaced, and
A state detecting means for detecting whether the pair of rotating bodies of the remounted fuser are in the attached state or the detached state, and
A reading means for reading information stored in the storage means, and a reading means.
A leaving time acquisition unit that acquires the leaving time of the fixing portion mounted based on the information read from the reading means, and a leaving time acquisition unit.
It has a control unit that executes a deformation elimination mode for eliminating the compression residual deformation of the pair of rotating bodies.
The control unit sets the deformation elimination mode on the mounted fuser when the state detecting means detects the wearing state and the leaving time acquired by the leaving time acquisition unit exceeds a predetermined time. An image forming apparatus characterized by performing. The deformation elimination mode is
a: A step of converting the pair of rotating bodies from the attached state to the detached state by the detachable mechanism.
b: A step of heating the pair of rotating bodies to a predetermined temperature, respectively.
c: A step of converting the pair of rotating bodies from the detached state to the attached state by the attachment / detachment mechanism.
d: The image forming apparatus according to claim 1 or 2 , further comprising a step of rotating the pair of rotating bodies at a predetermined rotation speed for a predetermined time. The predetermined rotation speed is set to be lower than the rotation speed of the pair of rotating bodies during image formation of the image forming apparatus or the rotating speed of the pair of rotating bodies during standby of the image forming apparatus. The image forming apparatus according to claim 3. An image forming part that forms a toner image on the recording material,
A pair of rotating bodies forming a nip portion for fixing a toner image formed on a recording material by the image forming portion, and a pair of rotating bodies.
A transition unit that shifts the pair of rotating bodies from the pressurized state to the separated state as the fixing process is completed, and
A detection unit that detects whether the pair of rotating bodies are in a pressurized state or a separated state, and
When the main power supply is turned on, when the pair of rotating bodies are in a separated state, the first warm-up process including the rotation process of rotating the pair of rotating bodies in a pressurized state is executed, while the main power supply is When the pair of rotating bodies are in a pressurized state when turned on, a controller that executes a second warm-up process including the rotation process having an execution time longer than that of the first warm-up process, and a controller.
An image forming apparatus characterized by having. The controller is characterized in that, at the time of the second warm-up process, the pair of rotating bodies are moved to a separated state and heated until the temperature rises to a predetermined temperature, and then the rotation process is executed for a predetermined time. The image forming apparatus according to claim 5.

Images