JP2015011167A - Image heating device and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contact of a separation member with a fixing film at the start-up of a fixing device due to the fluttering of the fixing film.SOLUTION: An image heating device includes a separation plate moving mechanism that makes the gap between a separation plate and a fixing film variable, and a control function to repair a nip mark when detected the state where a fixing nip part is left unused while being applied with pressure to cause the occurrence of the nip mark, so as to constantly optimize the gap between the fixing film and separation plate.

Description

  The present invention relates to an image heating apparatus and an image forming apparatus including the same.

  Examples of the image heating device include a fixing device that fixes an unfixed toner image formed on a recording material as a fixed image. Further, a glossiness adjusting device (image modifying device) that adjusts the surface glossiness of an image by reheating a toner image that has been semi-fixed or fixed on a recording material can be used.

  The image forming apparatus forms a toner image on a recording material by a transfer method or a direct method using an image forming process such as an electrophotographic image forming method, an electrostatic recording image forming method, or a magnetic recording image forming method. . For example, a copying machine, a printer (laser beam printer, LED printer, etc.), a facsimile machine, a multi-function machine thereof, a word processor, and the like are included.

  The recording material is a sheet-like member on which an image is formed by the image forming apparatus. Examples include regular or irregular plain paper, cardboard, envelope, postcard, seal, resin sheet, OHT sheet, glossy paper, electrofax sheet, electrostatic recording paper, printing paper, format paper, and the like.

  In an image forming apparatus, as a means for fixing an unfixed toner image of image information formed and supported on a recording material, toner is recorded by a fixing member comprising a fixing member having a heat source and a pressure member pressed against the fixing member. Thermal fixing devices that are welded to each other are widely used.

  In recent years, from the viewpoint of quick start and energy saving, a film heating type fixing device having a small heat capacity and heating through a fixing film has been put to practical use as a method with high heat transfer efficiency and quick start-up of the device. The fixing film is an endless heating rotator having flexibility.

  In a film heating type fixing device, for example, a pressure nip is formed by sandwiching a fixing film as a heat transfer member between a ceramic heater as a heating member and a pressure roller as a pressure member. Then, a recording material on which an unfixed toner image is formed and supported is introduced between the fixing film and the pressure roller in the fixing nip portion, and is nipped and conveyed together with the fixing film. Thus, an unfixed toner image is fixed on the surface of the recording material with the pressure of the fixing nip portion while applying heat from the ceramic heater through the fixing film.

  At this time, since the melted toner has adhesiveness, the recording material tends to adhere to the surface of the fixing film. Therefore, as one of the technical problems of the fixing device, there is a case where the recording material on which the toner image is fixed at the fixing nip portion is wound around the fixing film after passing through the fixing nip portion.

  In order to solve this problem, as one method for separating the recording material that has passed through the fixing nip from the fixing film and transporting it in a predetermined direction, a separating member (separating plate) is provided over the entire recording material conveying area in the longitudinal direction of the fixing film. Are placed close together. A method of separating the recording material from the fixing film by putting the leading end portion of the separating member between the recording material and the fixing film has been put into practical use.

  Separation performance improves as the gap between the separation member and the fixing film becomes smaller. However, when the separation member comes into contact with the fixing film, the fixing film may be scratched to cause an image defect.

  Accordingly, a fixing device that can adjust the gap between the separation member and the fixing film to a predetermined size and an image forming apparatus including the fixing device have been disclosed (Patent Document 1). Against this background, in order to satisfy the high productivity and high image quality required for copying machines in recent years, a technique for further optimizing the gap between the separating member and the fixing film is required.

JP 2010-197920 A

  In the film heating type fixing device, for example, when the main body of the image forming apparatus is urgently stopped due to a power failure and does not return for a long time, the fixing nip portion of the fixing device is left in a state of receiving pressure, Nip marks due to compression may occur on the fixing film.

  Also, if the fixing film end is left fitted on the substantially elliptical fixing film inner surface guide portion of the fixing flange disposed at the end of the substantially cylindrical fixing film, the fixing flange mark is generated. There are things to do. This is a case in which a trace following the substantially elliptical inner surface guide portion is generated on the substantially cylindrical fixing film, and the fixing film is deformed.

  In the state where the nip mark or fixing flange mark is generated, the rotation trajectory of the fixing film may flutter and may not be stable. Had to be in the distance.

  When the fixing film is not sufficiently warm, such as immediately after the main unit is turned on, the fixing film is more likely to cause uneven rotation than when the fixing film is warm, and the fixing film swells and flutters in the recording material conveyance direction. Follow the trajectory.

  When the fixing film is sufficiently warmed, the fluctuation of the rotation trajectory of the fixing film in the recording material conveyance direction is smaller than that when the fixing film is not sufficiently warmed. As a cause of the phenomenon that the fixing film becomes difficult to flutter in the recording material conveyance direction when the fixing film is warmed, the following can be cited. That is, the grease applied in the fixing film is warmed to reduce the viscosity of the grease. As a result, the slip phenomenon of the fixing film can be suppressed, and the distortion due to the nip marks accumulated on the base material due to the fixing film being warmed can be reduced by the temperature rise.

  When the fixing film has a nip mark or fixing flange mark as described above, the interference between the separation member and the fixing film prevents the recording material from being wrapped around the fixing film if it fluffs downstream in the recording material conveyance direction. May happen. If the surface of the fixing film is damaged due to interference with the separation member, the scar will appear on the image surface of the recording material.Therefore, the separation member is not sufficiently warmed to the fixing film even when it is started up. Had to be placed in a position where they would not touch.

  However, when the temperature of the fixing device is controlled and the trajectory of the fixing film is stabilized, the gap between the fixing film and the separating member is widened. Therefore, when fixing a full-color image with a relatively large amount of toner, or fixing a recording material such as thin paper or moisture-absorbing paper, which is relatively weak, the recording material may be wrapped around the jam or separated. Image unevenness may occur due to defects.

  The object of the present invention is to optimize the gap with the separation member without considering the flapping of the heating rotor track when a nip mark or a flange mark is generated on a flexible endless heating rotor. An object of the present invention is to provide an image heating apparatus that can satisfy high image quality when possible.

  In order to achieve the above object, a typical configuration of the image heating apparatus according to the present invention includes a flexible endless heating rotator, and a recording material carrying an image in mutual pressure contact with the heating rotator. A pressure member that forms a nip portion that sandwiches and conveys the heat, and a first position that has a predetermined first gap with respect to the heating rotator on the downstream side of the nip portion in the recording material conveyance direction. A separation member that is positioned and separates the recording material that has exited the nip from the heating rotator, a pressurizing operation that pressurizes the heating rotator and the pressurizing member, and a pressure release operation that releases the pressurization A pressurizing mechanism for moving the separation member, and a separation member movable mechanism for moving the separation member between the first position and a second position where a predetermined second gap larger than the first gap is formed. And control means, the control means when the apparatus power is turned on, Prior to the start of recording material introduction, the pressurizing mechanism is operated to pressurize, and the separating member movable mechanism is operated so that the separating member moves from the first position to the second position. The heating rotator is heated and rotated for a predetermined time to execute a repair mode for repairing the outer shape of the heating rotator.

  According to the present invention, it is possible to optimize the gap with the separation member without considering the flapping of the heating rotor track when the nip mark or the flange mark is generated on the heating rotor, thereby improving the image quality. I can be satisfied.

Control flow chart in the first embodiment Configuration schematic diagram of an example of an image forming apparatus FIG. 2 is a schematic cross-sectional view illustrating a part of the fixing device according to the first embodiment, and a block diagram of a control system. Side view of the fixing device FIG. 5 is a diagram of the attached state and the detached state of the pressure mechanism of the fixing device according to the first embodiment. Schematic diagram of the separation member moving mechanism (part 1) Schematic diagram of the separation member movable mechanism (part 2) Schematic diagram explaining the operation of the separation member movable mechanism Illustration of measuring method for fixing film trajectory Relationship between fixing film temperature and trajectory Control flowchart in Embodiment 2 Schematic diagram of the separation member moving mechanism (part 1) Schematic diagram of the separation member movable mechanism (part 2) Explanatory drawing of the sensor and sensor flag in Embodiment 3 The figure which showed the rotation position relation of a sensor flag, a pressurization cam, and a link lever (the 1) Diagram showing the rotational position of sensor flag, pressure cam, and link lever (Part 2) Diagram showing the rotational position of sensor flag, pressure cam and link lever (No. 3) Schematic diagram of the separation member moving mechanism (part 1) Schematic diagram of the separation member movable mechanism (part 2) Control flowchart in Embodiment 3 Schematic schematic diagram of fixing device configuration according to Embodiment 4 Schematic schematic diagram of another fixing device configuration according to Embodiment 4

  Hereinafter, the present invention will be described more specifically with reference to embodiments. Although these embodiments are examples of embodiments to which the present invention can be applied, the present invention is not limited to these embodiments, and various modifications are possible within the scope of the idea of the present invention. It is.

[Embodiment 1]
(1) Image Forming Unit FIG. 2 is a schematic configuration diagram of an example of the image forming apparatus 1 in which the image heating apparatus according to the present invention is mounted as the fixing device 40. The apparatus 1 can form a toner image corresponding to image information input from the host apparatus 300 (FIG. 3) to the control unit (control circuit unit: control unit) 45 on the recording material P by using an electrophotographic technique. It is a color printer.

  Reference numeral 2 denotes an image forming unit which is fed from the cassette 19 or 20 or the multi-feed tray 21 and has four types for forming an image on the recording material P conveyed by the conveyance mechanism 22 including the registration roller pair 22a. It has image forming stations 3Y, 3M, 3C, 3K. Each station has a rotating drum type photoreceptor 4, a charging member 5, a laser scanner 6, a developing device 7, a transfer member 8, and a photoreceptor cleaner 9. Stations 3Y, 3M, 3C, and 3K form yellow, magenta, cyan, and black toner images, respectively.

  Further, the image forming unit 2 includes an intermediate transfer unit 10, and a combined toner image, which is primarily transferred from the stations 3 Y, 3 M, 3 C, and 3 K on the intermediate transfer belt 11 by superimposing the color toner images, is transferred by the secondary transfer roller 12. Collective secondary transfer is performed on the recording material P. Since the above-described operation of the image forming unit 2 and the color image forming process are well known, detailed description thereof will be omitted.

  The recording material P on which the unfixed toner image is secondarily transferred in the image forming unit 2 is sent to the fixing device 40, where the toner image is heated and fixed. The recording material P exiting the fixing device 40 is routed to the first path 14 side or the second path 15 side by the flapper 13 in accordance with a preselected mode. The recording material P introduced into the first path 14 is discharged to the face down tray 16 on the upper surface side of the apparatus. The recording material P introduced into the second path 15 is discharged to the face-up tray 17 on the side surface of the apparatus.

  In the double-sided image forming mode, the recording material P on which the first-side image has been formed that has exited the fixing device 40 is once introduced into the first path 14, then switched back and introduced into the third path 18. Then, the sheet is conveyed again through the conveyance mechanism 22 while being reversed with respect to the image forming unit 2.

(2) Fixing Device (2-1) Schematic Configuration of Fixing Device Here, the seat axis added to the drawings of FIGS. 2 to 8 and the like explains the direction in space, and the x direction (+ x direction) is The conveyance direction of the recording material P in the fixing device 40 is represented. The direction opposite to the x direction is the −x direction, and is the direction opposite to the conveyance direction of the recording material P in the fixing device 40. The y direction (+ y direction) is the front side of the fixing device 40. The direction opposite to the y direction is the −y direction, which is the back side of the fixing device 40. The z direction (+ z direction) represents the direction opposite to the direction of gravity (upward direction). The direction opposite to the z direction is the -z direction, which is the direction of gravity (downward).

  The fixing device 40 according to the first embodiment includes a flexible fixing film 101 in which an elastic layer is formed on a cylindrical thin metal base layer as a flexible endless heating rotating body (fixing member). This is a fixing device using a film heating system and a pressure roller driving system. FIG. 3 is a schematic sectional view showing a part of the fixing device 40 as viewed from the + y direction and a block diagram of a control system. FIG. 4 is a side view seen from the −x direction.

  The configuration of the fixing device 40 according to the first embodiment will be described mainly with reference to FIGS. The fixing device 40 roughly includes a film unit 111 including a fixing film 101, and a pressure roller 106 as a pressure member (nip forming member: driving rotating body).

  The film unit 111 has a ceramic heater 110 as a heating member, a fixing film 101, and two fixing flanges (flange members) 104a and 104b (FIG. 4) installed on the back side and the front side of the fixing film. Further, the film unit 111 includes a separation guide 108 as a separation member for peeling the recording material P after the fixing process from the fixing film 101, and back and front plates for bringing the separation guide 108 close to the fixing film 101. It has springs 107a and 107b (FIG. 7). The leaf springs 107a and 107b are components of a separation guide movable mechanism (separation member movable mechanism) 201 described later.

  The film unit 111 includes a pressure contact member (backup member) 103 and a stay 102 that are disposed inside the fixing film 101. The pressure contact member 103 is a member that forms a nip portion N between the pressure film 106 and the fixing film 101. The stay 102 is a member for ensuring the strength of the pressure contact member 103. Further, the film unit 111 includes a thermistor 152 as a temperature detecting unit that is fixed to the longitudinal center portion of the pressure contact member 103 and detects the temperature of the inner surface of the fixing film by contacting the temperature detecting unit 152 a with the inner surface of the fixing film 101. .

  The pressure roller 106 is an elastic roller that forms a nip portion N for nipping and conveying the recording material P carrying an image while being in pressure contact with the fixing film 101 and heating it. The pressure roller 106 is composed of a metal cored bar 106a and a heat-resistant / elastic material layer 106b made of silicone rubber, fluororubber, fluororesin or the like that is concentrically formed and coated around the cored bar in a roller shape. Yes. A release layer 106c is provided on the surface layer of the elastic material layer 106b. For the release layer 106c, for example, a material having good release properties and heat resistance such as fluororesin, silicone resin, fluorosilicone rubber, fluororubber, silicone rubber, PFA, PTFE, and FEP can be selected.

  In order that the elastic material layer 106b of the pressure roller 106 stably conveys the recording material P in the nip portion N without generating wrinkles or the like, the outer diameter shape may be an inverted crown shape. The pressure roller 106 is provided with bearing members 113a and 113b made of heat-resistant resin such as PEEK, PPS, and liquid crystal polymer at both ends of the core metal 106a, and between the back side and the front side plates 112a and 112b of the fixing frame 112. It is disposed so as to be freely rotatable.

  In the first embodiment, the fixing film 101 is a cylindrical and flexible heat transfer member that transfers heat to the recording material P, and is loosely fitted to the press contact member 103 and the stay 102. In order to reduce the heat capacity and improve the quick start property, the fixing film 101 may be a single layer film of PTFE, PFA or FEP having a heat resistance of 100 μm or less, preferably 50 μm or less and 20 μm or more.

  Alternatively, the fixing film 101 may be a composite layer film in which PTFE, PFA, FEP or the like is coated on the outer peripheral surface of polyimide, polyamideimide, PEEK, PES, PPS or the like. Alternatively, the fixing film 101 may be a metal film or a composite film having a metal film as a base layer.

  The pressure contact member 103 is a heat-resistant and heat-insulating member having a substantially semicircular cross section having a longitudinal direction in the direction intersecting the recording material conveyance direction. Materials having good insulation and heat resistance such as phenol resin, polyimide resin, polyamide resin, polyamideimide resin, PEEK resin, PES resin, PPS resin, PFA resin, PTFE resin, and LCP resin are used. The pressing member 103 serves to back up the fixing film 101, pressurize the nip N formed by pressing with the pressure roller 106, and transport stability when the fixing film 101 rotates.

  The stay 102 is a member for imparting longitudinal strength to the pressure contact member 103 by pressing it against the back surface of the relatively flexible resin pressure contact member 103 and for correcting the pressure contact member 103.

  The fixing flanges 104a and 104b are fitted into both ends of the assembly of the pressure contact member 103 and the stay 102 to guide the rotation of the fixing film 101 and prevent the fixing film 101 from coming off.

  In the first embodiment, the heating member 110 is a ceramic heater (hereinafter referred to as a heater). The heater 110 is basically composed of an elongated and thin plate-like ceramic substrate and an energization heating resistor layer provided on the substrate surface, and the temperature rises with a steep rise characteristic as a whole by energization of the heating resistor layer. It is a low heat capacity heater. The heater 110 is fitted and supported in a fitting groove 103c provided on the lower surface of the pressure contact member 103 along the longitudinal direction.

  The fixing flanges 104a and 104b are fitted into both ends of the assembly of the pressure contact member 103 and the stay 102 to guide the rotation of the fixing film 101 and prevent the fixing film 101 from coming off. In other words, the fixing flanges 104a and 104b guide the circumferential movement of the fixing film 101 (free belt system) that rotates in accordance with the rotational drive of the pressure roller 106 and the inner peripheral surface of the end of the fixing film. Regulate the shape of the direction.

  For this purpose, the fixing flanges 104a and 104b have a seat portion for receiving the end face of the fixing film as a first restricting portion for restricting the movement of the fixing film 101 in the longitudinal direction. In addition, it has an inner surface guide portion as a second restricting portion that is fitted into the end portion of the fixing film and guides the inner surface of the end portion of the fixing film. When the fixing film 101 having flexibility is rotated by the rotational driving of the pressure roller 106, the fixing film 101 rotates with an approximately elliptical cross section. Therefore, the inner surface guide portion is configured to guide the inner surface of the end portion of the fixing film 101 so that the above-described elliptical shape is maintained when the fixing film is driven to rotate.

  The film unit 111 is substantially parallel to the pressure roller 106 on the upper side of the pressure roller 106 disposed so as to be freely rotated between the side plates 112a and 112b of the fixing frame 112, with the heater 110 facing downward. It is arranged. The rear and front fixing flanges 104a and 104b are held so as to be slidable in the vertical direction with respect to the side plates 112a and 112b of the fixing frame 112, respectively. The fixing flanges 104a and 104b on the back side and the front side are pressed with a predetermined pressing force downward in the −z direction by a pressing operation of a pressing mechanism 202 (FIG. 5A), which will be described later.

  As a result, the unit 111 is pressed against the pressure roller 106 with a predetermined pressing force, and the heater arrangement portion of the pressure contact member 103 and the pressure roller 106 are pressed against each other with the fixing film 101 interposed therebetween. That is, a nip portion N having a predetermined width is formed between the fixing film 101 and the pressure roller 106 in the recording material conveyance direction. The heater 110 is positioned in the longitudinal direction (fixing film longitudinal direction) of the press contact member at a portion corresponding to the nip portion N of the press contact member 103.

(2-2) Fixing Operation The fixing operation of the fixing device 40 is as follows. The control unit 45 activates a motor (for example, a stepping motor) 140 that is a driving unit at a predetermined control timing. The driving force of the motor 140 is transmitted to the pressure roller gear 144 via the gear box 141 (FIG. 6). As a result, the pressure roller 106 serving as a drive rotator is rotationally driven at a predetermined speed in the counterclockwise direction indicated by an arrow R106 in FIG. The control of rotation and stop of the pressure roller 106 is performed by the control unit 45 performing clutch control of the drive transmission system on the pressure roller side in the gear box 140 in a predetermined clutch.

  When the pressure roller 106 is rotated, rotational torque acts on the fixing film 101 at the nip portion N due to frictional force with the pressure roller 106. As a result, the fixing film 101 slides in close contact with the surface of the heater 110 while the inner surface of the fixing film 101 contacts the outer surface of the pressure contact member 103 and the stay 102 at a speed substantially corresponding to the speed of the pressure roller 106. Followed rotation. A semi-solid lubricant is applied to the inner surface of the fixing film 101 to ensure the slidability between the heater 110 and the pressure contact member 103 and the inner surface of the fixing film 101 in the nip portion N.

  In addition, the control unit 45 energizes the heater 110 from the power supply unit 47. This energization causes the heater 110 to rapidly rise in temperature within the effective heat generation area width. As a result, the fixing film 101 is heated. The temperature of the fixing film 101 is detected by the thermistor 152, and the detected temperature information is input to the control unit 45.

  The control unit 45 samples the output from the thermistor 152 at a predetermined cycle, and is configured to reflect the temperature information thus obtained in the temperature control. That is, the control unit 45 determines the temperature control content of the heater 110 based on the output of the thermistor 152, and the power supply unit 47 supplies the temperature to the heater 110 so that the temperature of the fixing film 101 becomes the target temperature (set temperature). It plays the role of controlling energization. Note that the temperature of the heater 110 may be adjusted by detecting the temperature of the heater 110 with the thermistor 152.

  In the control state of the fixing device 40 described above, the recording material P carrying the unfixed toner image is conveyed from the image forming unit 2 side to the fixing device 40 side and introduced into the nip portion N. Heat and pressure are applied to the recording material P while it is nipped and conveyed at the nip portion N, and the unfixed toner image is fixed on the surface of the recording material P as a fixed image. The recording material P that has exited the nip portion N is separated from the fixing film 101 by curvature, guided by a separation guide 108 as a separation member (separation plate), and moved from the fixing device 40 in the discharge direction.

  The separation guide 108 is a member that separates the recording material P from the fixing film 101 on the downstream side in the recording material conveyance direction from the recording material outlet portion of the nip portion N. The separation guide 108 is positioned at a first position with a predetermined first gap (gap) with respect to the fixing film 101, and guides (separates) the recording material P that has been separated from the fixing film 101 by curvature. Auxiliary) to prevent wrapping around the fixing film 101.

  When the printing operation is completed, the control unit 45 stops power supply from the power supply unit 47 to the heater 110 and stops the motor 140 in response to an instruction to end the fixing operation. Further, the pressurization of the film unit 111 by the pressurization mechanism 202 is released.

(2-3) Separation guide movable mechanism The separation guide movable mechanism (separation member movable mechanism) 201 moves the separation guide 108 between the first position and a predetermined second gap larger than the first gap. It is a mechanism for moving between the formed second positions. The separation guide movable mechanism 201 will be described with reference to FIGS. 3 and 7. FIG. 7 is an exploded perspective view of the separation guide movable mechanism 201.

  In the first embodiment, the separation guide 108 is made of SUS and has a surface coated with a PFA coat. The separation guide 108 is disposed along the longitudinal direction of the fixing film 101 on the downstream side of the fixing film 101 in the recording material conveyance direction of the fixing device 40, and peels off the recording material P fixed at the nip portion N from the fixing film 101. It is configured to be possible. The separation guide 108 is held at its back and front fixing flanges 104a and 104b so as to be movable in a direction approaching the fixing film 101 and a direction away from the fixing film 101, respectively.

  The mounting configuration of the back end of the separation guide 108 to the back fixing flange 104a is the same as the mounting configuration of the front end of the separation guide 108 to the front fixing flange 104b. Below, the attachment structure with respect to the back side fixing flange 104a of the back side edge part of the separation guide 108 is demonstrated as a representative.

  The surfaces 108a-a and 108a-b of the rear end 108a in the longitudinal direction of the separation guide 108 are fitted to the surfaces 104a-c and 104a-d of the fixing flange 104a. While the recording material P is being introduced into the fixing device 40, the surface 108a-e of the separation guide 108 is in contact with the surface 104a-e of the fixing flange 104a.

  The broken line in FIG. 3 represents a schematic cross section of the longitudinal center of the separation guide 108, and the tip 108g of the separation guide 108 and the fixing film 101 have a certain gap δ. While the recording material P is being introduced into the fixing device 40, the surface 108a-e of the separation guide 108 is in contact with the surface 104a-e of the fixing flange 104a, so that the gap between the leading end 108g of the separation guide 108 and the fixing film 101 is reached. Is minimized.

  A member for abutting the separation guide 108 against the fixing flange 104a is a leaf spring 107a (manufactured by SUS). The portions 107a-a and 107a-b of the leaf spring 107a are attached to the fixing flange portions 104a-a and 104a-b, respectively, and the surfaces 107a-c always move the surfaces 108a-f of the separation guide 108 by the spring force. Pushing in the F direction.

  The attachment configuration of the front end portion of the separation guide 108 to the front fixing flange 104b is the same as described above. The separation guide 108 is urged to move toward the fixing film 101 by the spring force of the leaf springs 107a and 107b, and the separation guide tip 108g and the fixing film 101 are held at a predetermined minimum gap. . In other words, the separation guide 108 is positioned at the first position where the leading end portion of the separation guide 108 has a predetermined first gap (gap) with respect to the fixing film 101.

  Further, the separation guide 108 can move in a direction away from the fixing film 101 against the spring force of the leaf springs 107a and 107b. In other words, the separation guide 108 is movable to the first position and the second position where a predetermined second gap larger than the first gap is formed.

(2-4) Pressure Mechanism The pressure mechanism 202 that presses the film unit 111 and the pressure roller 106 will be described with reference to FIGS. 5A and 5B. The pressure mechanism 202 performs a pressure operation for pressing the film unit 111 including the fixing film 101 and the pressure roller 106 and a pressure release operation for releasing the pressure.

  FIG. 5A shows a cross-sectional view of the fixing device 40 as viewed from the + y direction. In the film unit 111, the surface 104b-g and the surface 104b-f of the fixing flange 104b on the front side are fitted into grooves formed by the surfaces 112b-a and 112b-b of the fixing frame 112.

  The pressure plate 130b, which is rotatably held in the direction of arrow B around the fulcrum A shown in FIG. 5A, receives a force in the direction of arrow C in the figure by the pressure spring 109b (compression spring). ing. By the spring force of the pressure spring 109b, the fixing flange 104b receives the force from the surface 130b-a of the pressure plate 130b on the surface 104b-h to pressurize the film unit 111 and the pressure roller 106 (pressure operation: this operation: Hereinafter, the state is expressed as a wearing state). As a result, a nip N having a predetermined width is formed between the fixing film 101 and the pressure roller 106 in the recording material conveyance direction.

  The pressure cam 131 b is fitted and held on a pressure release shaft 147 that is rotatably attached to the fixing frame 112. In the attached state, the cam surface 131b-a of the pressure cam 131b is not in contact with the surface 130b-a of the pressure plate 130b.

  A state in which the film unit 111 and the pressure roller 106 are not pressurized (pressure release operation: hereinafter referred to as a detached state) will be described with reference to FIG. 5B is different from the wearing state shown in FIG. 5A, the pressure cam 131b is centered on the pressure release shaft 147 and the cam surface 131b-a of the pressure cam 131b. Rotates in the direction of arrow D so as to push up the surface 130b-a of the pressure plate 130b in the + z direction. The rotation is such that the surface 131b-a of the pressure cam 131b receives the spring force from the pressure spring 109b, so that no force from the pressure spring 109b is applied to the fixing flange 104b.

  In the first embodiment, this detached state means that a straight line connecting the rotation shaft center of the pressure cam 131b and the vertex E of the pressure cam 131b is ± 45 with respect to the Z axis indicated by the broken line in FIG. It shall be in the state of °. The pressurizing mechanism, the attached state, and the detached state of the back side fixing flange 104a are the same as those of the front side fixing flange 104b.

  In the rotation angle control of the pressure cams 131a and 131b for switching the pressure mechanism 202 between the attached state and the detached state, the driving force of the motor 140 is transmitted to the pressure release shaft 147 via the gear box 141. Then, the control unit 45 performs predetermined clutch control of the drive transmission system on the pressure release shaft side of the gear box 141.

(2-5) Separation guide movable mechanism Next, the linkage between the pressure mechanism 202 of the fixing device 40 and the separation guide movable mechanism (separation member movable mechanism) 201 in the first embodiment will be described. FIG. 6 is a cross-sectional view (cross-section BB in FIG. 2) of the fixing device 40 according to the first embodiment viewed from the + z direction. In FIG. 6, the portion filled with black in the y-axis direction represents the axis.

  Drive is transmitted from the motor 140 to the pressure release gear 145 in the gear box 141 attached to the image forming apparatus body, and the pressure release shaft 147 fitted and attached to the pressure release gear 145 is rotated. In addition to the pressure release gear 145, pressure cams 131a and 131b and a sensor flag 143 are fitted and attached to the pressure release shaft 147. The film unit 111 and the pressure roller 106 of the fixing device 40 are attached and detached by the rotation of the pressure cams 131a and 131b.

  The pressurizing cams 131a and 131b have the same shape and are fitted to the pressure releasing shaft 147 so as to rotate at the same rotation angle by driving the motor 140. The pressurizing cams 131a and 131b and the sensor flag (rotating member) 143 are arranged to rotate at the same rotation angle. A sensor 142 for detecting the rotational position of the sensor flag 143 is attached to the side plate 112a on the back side of the fixing frame 112, and the attachment / detachment state is detected by detecting the presence or absence of the sensor flag 143 by the sensor 142. The position detection sensor 142 and the sensor flag 143 are detection means for detecting the operating state of the pressure mechanism 202.

  The drive of the motor 140 can be transmitted to the pressure roller gear 114 attached to the pressure roller shaft 106a through the gear box 141. In the first embodiment, the separation guide 10 of the separation guide movable mechanism 201 is moved by a solenoid 150. Reference numeral 151 denotes a separation guide movable member for transmitting the force from the solenoid 150 to the separation guide 108.

  7A, which is an exploded perspective view of the separation guide movable mechanism 201 according to the first embodiment, and a mechanism (FIG. 7) in which each component is assembled, with respect to a mechanism for moving the separation guide 108 in the separation guide movable mechanism 201. This will be described with reference to b).

  In FIG. 7A, both end portions 108 a and 108 b of the separation guide 108 are fitted and held in the holes 151 a and 151 b of the separation guide movable member 151. The solenoid 150 has a surface 150 a fixed to the fixing device 40, and a protrusion 150 c is fitted into the hole 151 c of the separation guide movable member 151. The movable portion (plunger) 150b of the solenoid is slidably held in the hole 150d of the solenoid 150.

  The movable portion 150b of the solenoid 150 moves in the direction of the arrow + when turned on by an electric signal from the solenoid control portion 46 (FIG. 3) controlled by the control portion 45, and when it is turned off, the spring force of the leaf springs 107a and 107b. To move in the arrow-direction.

  When the electric signal from the solenoid control unit 46 is turned on, the driving force of the movable unit 150b of the solenoid 150 moving in the arrow + direction is transmitted to the separation guide 108 via the separation guide movable member 151 connected to the protrusion 150c. As a result, the separation guide 108 is moved away from the fixing film 101 against the spring force of the leaf springs 107a and 107b.

  A gap δ between the separation guide tip 108g and the fixing film 101 when the separation guide 108 is moved will be described with reference to FIGS. 8A and 8B which are CC cross sections of FIG.

  FIG. 8A shows a schematic cross-sectional view of the separation guide moving mechanism when the solenoid 150 is turned off. The gap δ between the separation guide tip 108g and the fixing film 101 indicated by a broken line in the drawing is δ = δmin, which is the smallest within the movable range of the separation guide. In this state, the separation guide 108 is positioned at the first position where the leading end portion of the separation guide 108 has a predetermined first gap (gap) with respect to the fixing film 101.

  When the solenoid 150 is turned on, the separation guide 108 is moved in the direction of the arrow + in the figure, and stops when the surface 150b-1 hits the surface 150e. FIG. 8B is a schematic cross-sectional view when the solenoid 150 is turned on. The gap δ between the separation guide tip 108g and the fixing film 101 in the drawing is δ = δmax which is the maximum within the movable range of the separation guide. In the first embodiment, δ = δmax is a distance at which the separation guide 108 and the fixing film 101 do not come into contact with each other no matter how the orbit of the fixing film 101 fluctuates.

  In this state, the separation guide 108 is positioned at the second position where the tip end portion forms a predetermined second gap larger than the first gap.

(2-6) Measuring Method for Fixing Film Trajectory Next, FIG. 9A shows a measuring method for the fixing film trajectory of the fixing film 101 when the fixing device 40 used in the first embodiment is started up in the morning. . As shown in FIG. 9A, the trajectory at the position of the separation guide tip 108g of the fixing film 101 is measured by the sensor S from the downstream side in the recording material conveyance direction (the arrow direction in the figure).

  The fixing film trajectory measured by the method of FIG. 9A is shown in FIG. The vertical axis represents the flutter amount of the fixing film trajectory from zero when the flutter center of the fixing film 101 in the state where the flutter of the fixing film 101 in the recording material conveyance direction has converged. The horizontal axis represents time t [s] from the start of rotation of the pressure roller 106.

  In FIG. 9B, the flutter of the fixing film trajectory decreases with time, and the fluttering of the fixing film trajectory stably enters the range of ± 0.1 mm after about 10 seconds. Become. While the trajectory of the fixing film 101 is fluttering (0 to 10 seconds), the film fluttering state, and when the trajectory of the fixing film after t = 10 sec is not fluttering, the stable state is defined.

  In the first embodiment, the time from the start of rotation of the pressure roller 106 is set to t [s], and the separation guide and the fixing are fixed by setting the solenoid ON state until t = 10 seconds when the trajectory of the fixing film 101 becomes stable. The gap δ with the film is set to δmax. Then, when 10 seconds have elapsed from the start of rotation of the pressure roller 106 (t = 0 second), the solenoid is turned off, so that the gap δ between the leading end 108 g of the separation guide 108 and the fixing film 101 is set to δ = δmin.

  In this example, when the reference gap between the fixing film 101 and the separation guide tip 108g is x [δ = x + 0.5 (maximum flutter of fixing film) mm], the gap that has been δ = x + 0.5 mm until now is δ = x + 0. .1mm can be achieved.

(2-7) Control Flowchart A flowchart from the power switch MSW-ON (power ON) of the image forming apparatus 1 according to the first embodiment to a state where the recording material P can be introduced into the fixing nip N (start) is shown. It is shown in 1. The operation control of the fixing device 40 is executed by the control unit 45 which is a control unit. Note that control other than the fixing device 40 is omitted in the flowchart.

  When the power switch MSW of the image forming apparatus 1 is turned on (step A), the fixing device 40 is then put on (B). Next, when the solenoid 150 is turned on, the separation guide 108 moves to a position where it does not contact the fixing film 101 (δ = δmax) (C).

  Next, rotation of the pressure roller 106 is started (D). Next, the pressure roller 106 is continuously rotated until 10 seconds have elapsed from the start of the rotation of the pressure roller 106 (E). When 10 seconds have elapsed from the start of rotation of the pressure roller 106, the solenoid 150 is turned off to set the gap δ between the separation guide 108 and the fixing film 101 to δ = δmin (F). Then, the fixing device sheet feeding start (G) is performed.

  In step E, a nip mark or a flange mark that may have occurred on the fixing film 101 is repaired. During this time, the separation guide 108 is moved and held at a position where it does not come into contact with the fixing film 101, so that the fixing film 101 is not damaged. In step E, it is preferable to energize the heater 110.

  The above-described control in the first embodiment is summarized as follows. The controller 45 executes the repair mode prior to the start of introduction of the recording material P when the apparatus power is turned on. In the repair mode, the pressurizing mechanism 202 is pressurized. Then, the fixing film 101 is heated and rotated for a predetermined time in a state in which the separation member movable mechanism 201 is operated so that the separation member 108 moves from the first position to the second position, thereby changing the outer shape of the fixing film 101. It is a control mode to repair.

  Then, the control unit 45 operates the separation member movable mechanism 201 so that the separation member 108 moves from the second position to the first position after the elapse of the predetermined time.

  As described above, according to the first embodiment, the gap between the separation guide 108 and the separation guide 108 can be reduced without considering the flapping of the fixing film trajectory when the nip mark, the flange mark, or the nip mark is generated on the fixing film 101. High image quality can be satisfied by enabling optimization.

[Embodiment 2]
In the second embodiment, the ON / OFF control of the solenoid 150 is not performed for 10 seconds from the start of rotation of the pressure roller 106 as in the first embodiment, but is performed in conjunction with the temperature detection of the thermistor 152. The case will be described. In the third embodiment, the flow from solenoid ON (step C) to solenoid OFF (step F) in the flowchart shown in FIG. 1 of the first embodiment is different from that of the first embodiment.

  When the fixing nip portion N of the fixing device 40 is left in a state where it receives pressure or the weight of the film unit 111, the amount of deformation of the fixing film 101 due to the nip mark generated for a certain period of time (about 3 in the third embodiment). 1 hour) increases in proportion to the standing time. The above deformation amount of the fixing film 101 is a shape difference when compared with the case where the fixing film 101 has no nip mark.

  The deformation amount of the fixing film 101 due to the nip mark of the fixing film 101 at the start of the rotation of the pressure roller is, for example, the next recording material introduction / conveying operation immediately after a certain recording material introduction / conveying operation ends and the fixing device 40 stops. When is started: That is, since the fixing device 40 is stopped and a long time has passed and the fixing device 40 is started from the morning when the fixing device 40 is cooled, the time for the fixing film trajectory to be fluttered is shortened.

  FIG. 10 is a graph in which the vertical axis represents the temperature of the fixing film 101 detected by the thermistor 152 of the first embodiment, and the horizontal axis represents time. It is a relationship diagram. From this figure, for example, when the temperature of the fixing film 101 is detected at 150 ° C. at the start of rotation of the pressure roller, the deformation amount of the fixing film 101 due to the nip mark is smaller than that at 25 ° C. in the morning. In that case, as in the first embodiment, even if the elapsed time from the start of rotation of the pressure roller 106 is less than 10 seconds, the trajectory of the fixing film 101 may be in a stable state.

  FIG. 11 shows a flowchart from the power switch MSW-ON (power ON) of the image forming apparatus 1 according to the second embodiment to the state where the recording material P can be introduced (started) into the fixing nip portion. Control of the operation of the fixing device 40 is executed by the control unit 45 which is a control means. Note that control other than the fixing device 40 is omitted in the flowchart.

  When the power switch MSW of the image forming apparatus 1 is turned on (step A), the fixing device 40 is then put on (B). Next, when the solenoid 150 is turned on, the separation guide moves so that the gap between the separation guide tip 108g and the fixing film 101 is δ = δmax (C). Next, the temperature control of the fixing device 40 is started (D), and the rotation of the pressure roller 106 is started (E).

  Next, the temperature of the thermistor 152 is detected (F). If the temperature detected by the thermistor 152 is equal to or higher than the temperature at which the recording material P can be introduced (T = 170 ° C.), the solenoid 150 is turned off so that the gap between the separation guide tip 108g and the fixing film 101 becomes δ = δmin. The separation guide 108 is moved (G). Then, the fixing device sheet feeding start (H) is performed.

  Between Step E and Step F, nip marks and flange marks that may have occurred on the fixing film 101 are repaired. During this time, the separation guide 108 is moved and held at a position where it does not come into contact with the fixing film 101, so that the fixing film 101 is not damaged.

  The above control in the second embodiment is summarized as follows. The controller 45 executes the repair mode prior to the start of introduction of the recording material P when the apparatus power is turned on. In the repair mode, the separation member movable mechanism 201 is operated so that the separation member 108 moves from the first position to the second position. The control mode is to restore the outer shape of the fixing film 101 by heating and rotating the fixing film 101 for the time until the temperature detecting unit 152 reaches a predetermined temperature.

  Then, the control unit 45 operates the separation member movable mechanism 201 so that the separation member 108 moves from the second position to the first position after the elapse of time until the predetermined temperature is reached.

  As described above, according to the second embodiment, the gap with the separation guide 108 can be optimized without considering the flapping of the fixing film trajectory when the nip mark or the flange mark is generated on the fixing film 101. Can satisfy high image quality.

[Embodiment 3]
In the third embodiment, the solenoid 152 used in the first and second embodiments is not used, and the separation guide 108 is moved by the interlocking mechanism 203 that is interlocked with the attaching / detaching operation of the pressurizing mechanism 202. The gap δ with the fixing film 101 is changed. Since the description other than the interlocking mechanism 203 for interlocking the separation guide 108 of the third embodiment with the attaching / detaching operation of the pressurizing mechanism 202 is the same as that of the first and second embodiments, the description thereof is omitted.

  The interlocking configuration of the pressurizing mechanism 202 and the separation guide movable mechanism 201 in the third embodiment will be described with reference to FIGS. FIG. 12 is a cross-sectional view (cross section BB in FIG. 2) of the movable mechanism 201 of the separation guide 108 according to the third embodiment viewed from the + z direction. In FIG. 12, the portion filled with black in the y-axis direction represents the axis. In the third embodiment, the interlocking configuration is a mechanism that changes the gap δ between the fixing film 101 and the separation guide 108 by moving the separation guide 108 in conjunction with the attachment / detachment state of the pressure mechanism 202.

  Drive is transmitted from the motor 140 through a gear box 141 to a side shaft 132a that is rotatably mounted between the rear side plates 112a and 112b of the fixing frame 112. A pressure cam 131a, a sensor flag (rotating member) 143, and a link lever 136a are fitted and attached to the side shaft 132a. A sensor 142 for detecting the rotational position of the sensor flag 143 is attached to the back side plate 112 a of the fixing frame 112. The sensor 142 and sensor flag 143 are detection means for detecting the operating state of the pressurizing mechanism 202.

  As shown in FIG. 13, a center shaft 137 is rotatably attached to the link lever 136a on a shaft different from the side shaft 132a. A link lever 136b is rotatably attached to the center shaft 137 on the opposite side of the link lever 136a. A pressure cam 131b and a link lever 136b are fitted and attached to the side shaft 132b on the same axis.

  Here, the link levers 136a and 136b (for example, made of PPS) have the same shape, and are arranged on the side shafts 132a and 132b and the center shaft 137 so as to rotate at the same rotation angle by driving the motor 140, respectively. The pressurizing cams 131a and 131b have the same shape and are fitted to the side shafts 132a and 132b so as to rotate at the same rotation angle by driving the motor 140, respectively. The sensor flag 143, the pressure cams 131a and 131b, and the link levers 136a and 136b are arranged to rotate at the same rotation angle.

  As shown in FIG. 13, a link member A 138 and a link member B 139 (for example, made of PPS) have a portion 138 a and a portion 139 a attached to the center shaft 137 so as to be rotatable on the portions 137 a and 137 b of the center shaft 137. The portions 138b and 139b are rotatably attached to the portions 108c and 108d of the separation guide 108. The drive of the motor 140 can be transmitted to the pressure roller gear 144 attached to the pressure roller shaft 106a through the gear box 141.

  A method for detecting the sensor flag 143 by the sensor 142 according to the third embodiment will be described. FIG. 14A is a cross-sectional view taken along the line DD in FIG. 12 and shows a front view of the sensor flag 143 and the sensor 142. 14B is a side view of the sensor flag 143 and the sensor 142 in the EE sectional view of FIG.

  The sensor flag 143 has a disk shape in which three surfaces 143a, 143b, and 143c are notched, and rotates in the direction of arrow D about the side shaft 132a. A broken line in FIG. 14B represents a position where the sensor 142 detects the sensor flag 143.

  FIGS. 15, 16, and 17 show the rotational positional relationship of the sensor flag 143, the pressure cam 131b, and the link lever 136a.

  In the rotation operation of the sensor flag 143, the sensor 142 first detects the surface 143a (sensor ON → OFF) and then detects the home position 143b (OFF → ON). The sensor flag 143 is controlled by the rotation of the motor 140 from the control unit 45 so that the sensor flag 143 rotates 90 ° in one second by the rotation of the side shaft 132a.

  The position where the sensor 142 detects the surface 143a and stops after 0.01 second is when the fixing device 40 is in the wearing state, and the distance between the separation guide tip 108g and the fixing film 101 is δmax within the movable range of the separation guide 108. . This position is set as a separation guide retracting position (i).

  Next, at the position where the sensor flag 143 has been rotated by the motor 140 for 2 seconds from the position (i) (the position rotated by 180 °), the fixing device 40 is in the wearing state. Further, the distance between the separation guide tip 108g and the fixing film 101 within the movable range of the separation guide 108 and the fixing film 101 is δmin. This position is defined as a recording material introduction conveyance position (ii).

  Next, at a position where the sensor flag is rotated by the motor 140 for 1 second from the position (ii) (position where the sensor flag is rotated 90 °), the fixing device 40 is in a detached state. This position is referred to as “deposition (iii)”.

  The sensor flag sequentially passes through positions (i) → (ii) → (iii) by rotation in the arrow D direction.

  The movement of the separation guide 108 at each position (i), (ii), and (iii) will be described with reference to FIGS. 18 and 19, which are FF cross-sectional views of FIG. A broken line in the drawing represents a schematic cross section of a longitudinal center portion of the separation guide 108.

  In the separation guide retracting position (i) shown in FIG. 18A, the gap δ between the separation guide tip 108g and the fixing film 101 is δ = δmax which is the maximum within the separation guide movable range. The portion 139b-a of the link member 139 pulls the portion 108a-g of the separation guide 108, thereby moving the separation guide 108 against the spring force F of the leaf spring 107a.

  At this position (i), the fixing device 40 is in a worn state. In this position (i), the fixing film 101 and the separation guide 108 do not come into contact with each other no matter how much the fixing flange mark or nip mark of the fixing film 101 progresses. In the separation guide 108, the portions 108a-g of the separation guide 108 slide in the round elongated holes 139b-b of the link member 139b.

  In FIG. 18B, the recording material introduction conveyance position (ii) is the receiving position, and the 104a-e surface of the fixing flange 104a and the 108a-e surface of the separation guide 108 are in contact with each other. In this state, the gap δ between the separation guide tip 108g and the fixing film 101 is the minimum δ = δmin within the separation guide movable range.

  In the deposition position (iii) in FIG. 18, the fixing device 40 is in a detached state. At this time, the gap δ between the separation guide tip 108g and the fixing film 101 satisfies δmin <δ <δmax.

  Finally, FIG. 20 shows a flowchart from the power switch MSW-ON (power ON) N of the image forming apparatus 1 according to the third embodiment to the state in which the recording material P can be introduced into the fixing nip portion (start). Control of the operation of the fixing device 40 is executed by the control unit 45 which is a control means. Note that control other than the fixing device 40 in the third embodiment is omitted here.

  The power switch MSW of the image forming apparatus 1 is turned on (step A). Then, the motor 140 is rotated until the sensor flag 143 is detected from OFF to ON (until the home position), and the gap δ between the separation guide tip 108g and the fixing film 101 is maximized (δ = δmax) within the separation guide movable range.

  Next, temperature control of the fixing device is started (C), and then the pressure roller is rotated (D). When the detected temperature of the thermistor 152 is T ° C. or higher (170 ° C. in this embodiment) (E), the motor 140 is rotated for 2 seconds (the gap δ between the separation guide tip 108g and the fixing film 101 is set to δ = δmin). . Then, the recording material introduction start (G) for the fixing device 40 is started. When the recording material introduction conveyance is finished, the motor 140 is rotated for 1 second to be in the detached state.

  Between Step D and Step E, the fixing flange mark and nip mark that may have occurred on the fixing film 101 are repaired. During this time, the separation guide 108 is moved and held at a position where it does not come into contact with the fixing film 101, so that the fixing film 101 is not damaged. As described above, according to the fourth embodiment, the gap with the separation guide 108 is optimized without considering the flapping of the fixing film trajectory when the fixing flange mark or the nip mark is generated on the fixing film 101. It becomes possible to satisfy high image quality.

[Embodiment 4]
1) The heating member 110 is not limited to a ceramic heater. For example, as shown in FIG. 21, in the fixing device 40 of the first to third embodiments, the heating member 110 is an electromagnetic induction heating member (such as an iron plate) that generates heat by the action of an alternating magnetic flux. And it can also be set as the apparatus structure which arrange | positioned the induction coil 204 which makes an alternating magnetic flux act on the electromagnetic induction heat generating member 110, and makes an electromagnetic induction heat_generation | fever.

  2) It is also possible to adopt a device configuration that heats the fixing film 101 itself that is a heating rotator. For example, as shown in FIG. 22, the fixing film 101 is provided with a conductive member layer, and the induction coil 204 that heats the belt 101 by causing an alternating magnetic flux to act on the conductive member layer to heat the belt 101 is provided on the outside of the fixing film 101 or It is also possible to adopt a device configuration arranged inside.

  3) Alternatively, the fixing film 101 may be provided with a resistance heating element layer that generates heat upon energization, and the resistance heating element layer may generate heat upon energization to heat the fixing film 101.

  4) The fixing film 101 as a heating rotator is stretched between a plurality of support members and is rotationally driven by a drive member. In addition, an apparatus configuration in which a pressure roller as a pressure member that forms a nip portion N by mutual pressure contact with the fixing film 101 is driven and rotated by the rotation driving of the fixing film 101 may be employed.

  As described above, in the apparatus configuration in which the fixing film 101 serving as the heating rotator is rotated, the pressure member (nip forming member) is not necessarily a roller-shaped member. It can be in the form of a non-rotating member such as a pad or a plate-like member having a small friction coefficient on the surface which is a contact surface with the fixing film 101 or the recording material P. The pressurizing member may be in the form of a rotatable (rotatable) endless belt.

  Even in the case of such an apparatus configuration, if the nip portion is left in a state where it receives pressure, a nip mark due to compression may be generated in the fixing film 101 which is a heating rotator. Therefore, by applying the same control configuration as that of the fixing device 40 according to the first to third embodiments, the separation guide 108 can be used without considering the flapping of the fixing film trajectory when the nip mark is generated on the fixing film 101. High image quality can be achieved by optimizing the gap.

[Other matters]
1) It is of course possible to adopt an image heating apparatus configuration in which the apparatus configurations and controls of Embodiments 1 to 4 are appropriately combined.

  2) The image heating apparatus of the present invention is not limited to use as a fixing apparatus that heats and presses an unfixed toner image carried on the recording material P as in the embodiment and heat-fixes it as a fixed image. The present invention is also applied to a heat treatment apparatus that adjusts the surface property of an image, such as improving the glossiness by heating and pressing an image (fixed image or semi-fixed image) once fixed or presupposed to the recording material P. Can be applied.

  3) The image forming unit of the image forming apparatus is not limited to the electrophotographic system. The image forming unit may be an electrostatic recording system or a magnetic recording system. Further, the toner image is not limited to the transfer method, and a toner image may be formed directly on the recording material.

  4) In the embodiment, the fixing device 40 may be implemented by an image forming apparatus other than the electrophotographic printer of the embodiment, a color copying machine, a facsimile, a color printer, a composite machine thereof, or the like. That is, the fixing device and the electrophotographic printer of the example are not limited to the combination of the above-described constituent members, and may be realized in another embodiment in which a part or all of the replacement members are replaced.

  40 ·· Image heating device (fixing device), 101 · · Heating rotating body (fixing film), 106 · · Pressure member (pressure roller), N · · Nip part, P · · Recording material, · · · Separation Member (separation guide), 201 .. separation member movable mechanism, 202 .. pressurization mechanism, 142.

Claims (18)

An endless heating rotor having flexibility;
A pressurizing member that forms a nip portion for sandwiching and transporting and heating a recording material carrying an image in mutual pressure contact with the heating rotator;
The recording material that is located at a first position with a predetermined first gap with respect to the heating rotator on the downstream side in the recording material conveyance direction from the nip portion, and that rotates the recording material that has exited the nip portion. A separating member for separating from the body;
A pressurizing mechanism that pressurizes the heating rotator and the pressurizing member, and a pressurizing mechanism that performs a pressurizing release operation that releases the pressurization;
A separation member movable mechanism that moves the separation member between the first position and a second position where a predetermined second gap larger than the first gap is formed;
Control means;
The control means operates to pressurize the pressurizing mechanism prior to the start of introduction of the recording material when the apparatus power is turned on, and the separation member moves from the first position to the second position. An image heating apparatus that executes a repair mode of repairing the outer shape of the heating rotator by rotating the heating rotator for a predetermined time in a state in which the separation member moving mechanism is operated to move. . An endless heating rotor having flexibility;
A pressurizing member that forms a nip portion for sandwiching and transporting and heating a recording material carrying an image in mutual pressure contact with the heating rotator;
The recording material that is located at a first position with a predetermined first gap with respect to the heating rotator on the downstream side in the recording material conveyance direction from the nip portion, and that rotates the recording material that has exited the nip portion. A separating member for separating from the body;
A separation member movable mechanism that moves the separation member between the first position and a second position where a predetermined second gap larger than the first gap is formed;
Control means;
The control means operates the separation member movable mechanism so that the separation member moves from the first position to the second position prior to the start of introduction of the recording material when the apparatus power is turned on. An image heating apparatus that executes a repair mode for repairing the outer shape of the heating rotator by heating and rotating the heating rotator for a predetermined time in a state where the heating rotator is in a state of being caused to move. An endless heating rotor having flexibility;
A pressurizing member that forms a nip portion for sandwiching and transporting and heating a recording material carrying an image in mutual pressure contact with the heating rotator;
The recording material that is located at a first position with a predetermined first gap with respect to the heating rotator on the downstream side in the recording material conveyance direction from the nip portion, and that rotates the recording material that has exited the nip portion. A separating member for separating from the body;
A separation member movable mechanism that moves the separation member between the first position and a second position where a predetermined second gap larger than the first gap is formed;
Temperature detecting means for detecting the temperature of the heating rotating body;
Control means;
The control means operates the separation member movable mechanism so that the separation member moves from the first position to the second position prior to the start of introduction of the recording material when the apparatus power is turned on. An image heating characterized by executing a repair mode for repairing the outer shape of the heating rotator by rotating the heating rotator for a time until the temperature detecting means reaches a predetermined temperature in the state of being heated. apparatus.   The image heating apparatus according to claim 3, further comprising a pressurizing mechanism that performs a pressurizing operation for pressurizing the heating rotator and the pressurizing member and a pressurizing releasing operation for releasing the pressurization.   The control unit is configured to move the separation member moving mechanism so that the separation member moves from the second position to the first position after the predetermined time has elapsed or after the time until the predetermined temperature is reached. The image heating apparatus according to claim 1, wherein the image heating apparatus is operated.   6. The image heating apparatus according to claim 1, wherein the operation of the separation member moving mechanism is interlocked with the operation of the pressurizing mechanism.   The back-up member is provided inside the heating rotator, and the back-up member is opposed to the pressure member with the heating rotator interposed therebetween. Image heating device.   The image heating apparatus according to claim 7, wherein a heating member is disposed along a longitudinal direction at a portion corresponding to the nip portion of the backup member.   The image heating apparatus according to claim 8, wherein the heating member is a ceramic heater that generates heat when energized.   The image heating apparatus according to claim 8, wherein the heating member is an electromagnetic induction heating member that generates heat by the action of an alternating magnetic flux.   The image according to any one of claims 1 to 7, wherein the heating rotator includes a conductive member layer, and includes an induction coil that causes an alternating magnetic flux to act on the conductive member layer to generate electromagnetic induction heat. Heating device.   The image heating apparatus according to claim 1, wherein the heating rotator has a resistance heating element layer that generates heat when energized.   The image heating apparatus according to claim 1, wherein the pressure member is an elastic roller.   The image heating apparatus according to claim 13, wherein an outer diameter shape of the elastic roller is an inverted crown shape.   The image heating apparatus according to claim 1, wherein the pressurizing member is a drive rotator, and the heating rotator is rotated by the rotation of the drive rotator.   The image heating apparatus according to any one of claims 1 to 14, wherein the heating rotator is driven to rotate, and the pressure member rotates following the rotation of the heating rotator.   The image heating apparatus according to claim 1, wherein the heating rotator is rotationally driven, and the pressure member is a non-rotating member that slides on the heating rotator.   An image forming apparatus comprising the image heating apparatus according to claim 1.