JP6289228B2 - Image forming apparatus and fixing device - Google Patents

Description

  The present invention relates to an image forming apparatus including a heat fixing type fixing device, and a fixing device mounted on the image forming apparatus.

  In image forming apparatuses such as electrophotographic copying machines, printers (for example, LED printers, laser beam printers, etc.), facsimile machines, word processors, etc., an unfixed toner image is formed on a recording material by a transfer method or a direct method. . The toner image on the recording material is generally fixed as a fixed image by a heat fixing type fixing device.

  Such a heat fixing type fixing device generally includes a heat roller having a built-in heater or the like as a heating means, and a pressure roller in pressure contact with the heat roller. A configuration is widely used in which a toner image is fixed on a recording material by heating and pressurizing the recording material carrying the toner image while nipping and conveying the recording material carrying the toner image at a fixing nip portion that is a pressure contact portion between both rollers. The recording material exiting the fixing device is discharged to the discharge portion in the single-sided image forming mode. If it is a double-sided image forming mode (automatic double-sided mode), it is conveyed to a double-sided conveyance unit.

  In the fixing device, a heat fixing member such as a heat roller acts on the recording material at a high temperature and high pressure to fix the toner image. Therefore, when it starts from a low internal temperature, it is generated by moisture contained in the recording material. There is a problem that dew condensation occurs inside the apparatus due to the water vapor.

  As countermeasures against this problem, Patent Documents 1 to 3 disclose that a moisture absorbing member is disposed at the upper portion of the fixing device, and that a water droplet holding member and a moisture absorbing material are provided on the downstream side in the recording material conveyance direction. In addition, by providing an air passage that communicates with the inside of the fixing device, water droplets generated by internal condensation are discharged to the outside through the duct, and water vapor adheres to the metal plate and prevents water droplets from adhering. Is also shown.

  Further, the following configuration is used as a method for performing processing such as jamming of recording material around the fixing device. That is, after opening the opening / closing door of the image forming apparatus main body in the vicinity of the fixing device, the user can access the inside of the fixing device by opening the opening / closing portion provided in the exposed fixing device. In this configuration, it is possible to handle jams.

Japanese Utility Model Publication No. 3-2367 Japanese Patent Laid-Open No. 1-251072 JP-A-3-100708

  However, since the heat roller and the pressure roller that form a nip portion that sandwiches and conveys the recording material to heat and fix the toner image become extremely high when fixing the toner image of the recording material, when the recording material starts to be introduced The entire fixing device begins to heat up violently.

  In such a state, the user opens the open / close door of the main body of the image forming apparatus in order to perform jam processing or the like inside the fixing device. Then, when an attempt is made to access the inside of the fixing device by opening the opening / closing portion provided in the exposed fixing device, the user touches the opening / closing portion because the opening / closing portion of the fixing device is very hot. It may be difficult to handle the jam.

  In addition, as a countermeasure against condensation, a conventional apparatus in which a moisture absorbing member is provided on a duct for discharging water vapor to the outside of the apparatus, an upper portion of the fixing device, or a downstream side in the conveyance direction of the recording material. Water droplets attached to the surface may not be removed sufficiently. In such a state, when the user opens the opening / closing portion provided in the fixing device in order to perform jam processing or the like inside the fixing device, water droplets attached to the opening / closing portion are moved by the movement of the opening / closing portion. It may be scattered inside and near the electrical equipment. For this reason, a situation that causes a failure of the electrical component is also assumed.

  Also, if the outer surface of the fixing device is configured as a part of the conveying surface of the double-sided conveying unit used in the double-sided image forming mode, both sides of the fixing device start to violently heat up after the recording material starts to be introduced. The outer surface of the fixing device constituting a part of the conveying surface is also very hot. In such a state, when the recording material passes through the double-sided conveyance unit, the recording material has a non-uniform temperature distribution in the width direction due to the heat of the conveyance surface, curling occurs at both ends in the width direction, and jamming is likely to occur during double-sided conveyance. turn into. Further, wrinkles are likely to occur due to the stress of the recording material caused by the non-uniform temperature distribution, causing problems such as image transfer failure and fixing failure on the second side.

  The present invention solves the above problems. In other words, an object of the present invention is to provide an image forming apparatus and a fixing device that allow a user to perform processing such as clogging of a recording material inside the fixing device without difficulty.

  It is another object of the present invention to provide an image forming apparatus and a fixing device that do not cause a problem due to water droplets when a user performs processing such as clogging of a recording material inside the fixing device.

  It is another object of the present invention to provide an image forming apparatus and a fixing apparatus that can stabilize the transportability of the second side in the double-sided image forming mode.

A typical configuration of the image forming apparatus according to the present invention for achieving the above object is as follows:
A fixing device for fixing the unfixed image is heated while conveying the unfixed image recording material formed on the recording medium at the nip portion, and a frame body which accommodates the fixing portion, the said frame An image forming apparatus including a fixing device having an opening and closing member that can be opened and closed with respect to the frame body at a downstream side of the nip portion in the recording material conveyance direction,
A duct provided in the opening / closing member and having an inlet for taking in air in a space area downstream of the nip portion in the recording material conveyance direction inside the frame and an outlet for taking out the intake air to the outside of the frame; ,
An intake port provided in the frame body for taking air into the space region from the outside of the frame body ;
At least one of sending air from the intake port to the space area and causing an air flow from the space area side to the outlet side in an air passage formed by the space area, the inlet, the duct, and the outlet . Air blowing means;
It is characterized by having.

Further, a typical configuration of the fixing device according to the present invention for achieving the above object is as follows:
A fixing device mounted on an image forming apparatus for forming an image on a recording material,
A fixing unit for fixing the unfixed image on the recording material by heating while conveying the recording material on which the unfixed image is formed at the nip portion;
A frame housing the fixing unit;
And the opening-and-closing possible closing member relative to the frame in the recording material conveyance direction downstream side of the nip portion of the frame body,
A duct provided in the opening / closing member and having an inlet for taking in air in a space area downstream of the nip portion in the recording material conveyance direction inside the frame and an outlet for taking out the intake air to the outside of the frame; ,
An intake port provided in the frame body for taking air into the space region from the outside of the frame body ;
It is characterized by having.

  According to the image forming apparatus or the fixing apparatus of the present invention, the user can perform processing such as clogging of a recording material inside the fixing apparatus without difficulty. Further, when the user performs processing such as clogging of the recording material inside the fixing device, a problem due to water droplets does not occur. Further, the transportability of the second side in the double-sided image forming mode is stabilized.

FIG. 5 is a diagram illustrating airflow around the fixing device in the image forming apparatus according to the first exemplary embodiment. 1 is a schematic longitudinal front view showing the internal configuration of the image forming apparatus according to the first embodiment. A perspective view of the image forming apparatus main body with the open / close door open External perspective view of the fixing device viewed from the front and right side External perspective view of the fixing device viewed from the front and left side Cross-sectional front view of the fixing device External perspective view of fixing device with opening / closing member opened Cross-sectional front schematic view of the fixing device with the opening / closing member open External perspective view of the inside of the opening / closing member Perspective view of decal roller (A) is the external appearance perspective view which showed the principal part of the fixing device of Example 2, (b) is an enlarged view of the part in a circle of (a). FIG. 7 is a diagram illustrating an air flow in the apparatus when a recording material is introduced in the fixing apparatus according to the second exemplary embodiment. FIG. 7 is a diagram illustrating an air flow in the apparatus when no recording material is introduced in the fixing apparatus according to the second exemplary embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Example 1>
[Entire configuration of image forming apparatus]
FIG. 2 is a schematic longitudinal sectional front view showing the internal configuration of the image forming apparatus 1 in this embodiment. The apparatus 1 is an electrophotographic color laser beam printer having a double-sided image forming function. FIG. 1 is a partially enlarged view of a main part of the apparatus 1 of FIG. Here, with respect to the device 1 or the components / devices of the device 1, the front side is the front side surface in FIG. 2, the back side is the opposite side surface, and the left and right surfaces are the left side or the left side when viewed from the front side. This is the right side. Up and down are up or down in the direction of gravity.

  The image forming unit 2 for forming an unfixed toner image (unfixed image) on the conveyed recording material (sheet) S is yellow (Y), magenta (M), cyan (C), black (Bk). ) It has four image forming units 3 (Y, M, C, Bk) that respectively form color toner images. Each unit 3 is an electrophotographic mechanism having a photosensitive drum 4 and process devices such as a charger, a developing device, a cleaning device, and a primary transfer roller that act on the photosensitive drum 4. The image forming unit 2 includes a laser scanner unit 5, an intermediate transfer unit 7 having a transfer belt 6, a secondary transfer roller 9 that forms a secondary transfer unit (nip portion) 8 with the transfer belt 6, and the like.

  The toner image of Y color, M color, C color, and Bk color is superimposed and primarily transferred onto the transfer belt 6 that is circulated in the counterclockwise direction of the arrow as the image forming unit 2 performs the image forming operation. As a result, a four-color full-color unfixed toner image is formed on the transfer belt 6. Then, the toner image is secondarily transferred to the recording material S fed to the transfer portion in the secondary transfer portion 8. Since the image forming principle and operation of the image forming unit 2 are well known, detailed description thereof is omitted.

  The recording material S stored in the cassette 10 is separated and fed by the feeding roller 11, conveyed from below to above by the vertical conveying path 12 including the registration roller pair 13, and sent to the secondary transfer unit 8. Alternatively, the recording material placed on the manual feed tray 14 is separated and fed by the feeding roller 15 and is also introduced into the vertical conveying path 12 by the conveying roller pair 16 and sent to the secondary transfer unit 8.

  The tray 14 is incorporated in an openable / closable opening / closing door 17 disposed on the right side surface of the image forming apparatus main body 1A. When not in use, the tray 14 is closed with respect to the open / close door 17 as indicated by a solid line, and when in use, the tray 14 is opened as indicated by a two-dot chain line to place a recording material.

  The recording material S is nipped and conveyed through the secondary transfer unit 8 from below to receive the secondary transfer of the toner image from the transfer belt 6 side. The recording material S exiting the secondary transfer portion 8 enters the fixing device 18 from the bottom to the top, and the unfixed toner image is fixed as a fixed image by heating and pressing.

  In the single-sided image forming (single-sided printing) mode, the recording material on which the single-sided image is formed sent upward from the fixing device 18 is held in the first posture (the posture shown by the solid line in FIGS. 1 and 2). The flag (distribution guide member) 19 is guided to the discharge roller pair 20 side. Then, the sheet is discharged onto the stacking tray 21 on the upper surface side of the apparatus main body 1A by the roller pair 20.

  In the double-sided image formation (double-sided printing) mode, the flag 19 is switched to the second posture (the posture indicated by the broken line in FIG. 1) and held. Then, the recording material S on which the image has been formed on the first surface fed upward from the fixing device 18 is guided to the switchback roller pair 22 side through the upper side of the flag 19 and is switched by the roller pair 22 that is normally driven. It is conveyed to the back tray 23.

  Although the rear end portion of the recording material S has passed the flag 19, the roller pair 22 is controlled to be driven in reverse rotation at a predetermined timing when the nip portion of the roller pair 22 has not come off. Further, the flag 19 is returned from the second posture to the first posture. As a result, the recording material (recording material having the first surface fixed) S conveyed to the tray 23 is switchback conveyed and enters the double-sided conveyance path (double-sided conveyance path) 24 through the upper side of the flag 19 in the first posture. .

  The duplex conveying path 24 extends downward from the roller pair 22 through the right side of the fixing device 18 in FIGS. 1 and 2 to the conveying roller pair 16. The recording material S that has entered the double-sided conveyance path 24 is intermediately relayed by the conveyance roller pair 25 and conveyed downward, and is reversed to the registration roller pair 13 of the vertical conveyance path 12 via the conveyance roller pair 16. Will be resent.

  Thereafter, as in the case of the single-sided image forming mode, the recording material S is sent to the secondary transfer unit 8 by the roller pair 13 and receives the secondary transfer of the toner image on the second side. Then, the recording material on which images have been formed on both the first and second surfaces is discharged to the tray 21 along the path of the fixing device 18, the first posture flag 19, and the discharge roller pair 20.

  3 is a perspective view of the apparatus main body 1A in a state where the open / close door 17 including the manual feed tray 14 is opened, as viewed from the right side and the back side. The door 17 can be opened and closed about a vertical hinge shaft portion 26 disposed on the back side of the apparatus with respect to the right side surface of the apparatus body 1A. When the door 17 is opened by the user, the right side surface of the apparatus main body 1A is largely opened. Reference numeral 27 denotes the open opening.

On the inner surface side of the door 17, the right side component among the left and right component members of the guide portion and the conveyance roller pair 25 constituting the portion from the flag 19 of the duplex conveyance path 24 to the conveyance roller pair 16 is arranged. It is installed.

  Therefore, when the door 17 is opened, among the left and right components constituting the double-sided conveyance path 24, the right component on the door 17 side is separated from the left component on the apparatus main body 1A side. As a result, the portion from the flag 19 of the duplex conveyance path 24 to the conveyance roller pair 16 is opened. Therefore, the user can remove the recording material jammed in the duplex conveying path 24. Further, the right side portion of the fixing device 18 on the apparatus main body 1 </ b> A side is exposed to the opening 27. As a result, the user can access the fixing device 18 and can open and close the opening / closing member 45 of the fixing device 18 to be described later to remove the jammed recording material.

  Note that the jam detection of the recording material S in the recording material conveyance path is performed based on the recording material sensors (not shown) arranged at important points of the recording material conveyance path and the input status of the recording material detection signal from the sensors. This is done by the control unit that determines whether or not the occurrence of the occurrence of the occurrence of the occurrence of the occurrence of the occurrence of the occurrence of the occurrence of the occurrence of the occurrence of the above.

  The fixing device 18 is configured as a fixing unit that can be attached to and detached from the mounting portion 28 on the apparatus main body 1A side in a predetermined manner. Therefore, the user can open and close the fixing device 18 with respect to the mounting portion 28 by opening the door 17. FIG. 3 shows a state where the fixing device 17 is not attached to the attachment portion 28.

[Fixing device]
4 is an external perspective view of the fixing device 18 mounted on the image forming apparatus 1 as viewed from the front side and the right side. FIG. 5 is an external perspective view of the fixing device 18 as viewed from the front side and the left side. 6 is a schematic cross-sectional front view of the fixing device 18.

  The fixing device 18 is a device that is long in the front-rear direction with the direction parallel to the direction X (FIG. 10) perpendicular to the conveyance direction X (FIG. 10) of the recording material S as the longitudinal direction. The fixing device 14 is roughly divided into an inlet guide member 33, a fixing unit 34, left and right conveying guide surfaces 35 and 36, a decurling roller pair (a curl correcting roller pair) 37 in order from the upstream side to the downstream side in the recording material conveying direction. And a frame (housing) 31 that accommodates them.

  A slit-shaped recording material inlet portion 32 that is long in the front-rear direction is disposed on the lower surface of the frame body 31. The entrance guide member 33 is a member that guides the recording material S entering the entrance portion 32 from below to the nip portion N of the fixing portion 34.

  The fixing unit 34 is a fixing mechanism unit that fixes the unfixed image on the recording material by heating and pressing the recording material S on which the unfixed toner image is formed while being nipped and conveyed by the nip portion N. In this embodiment, the fixing unit 31 is a film (belt) using a fixing film unit (belt unit) 39 as a first fixing member and a heat-resistant and elastic pressure roller 40 as a second fixing member. ) Heating system—Pressure member driving system mechanism. Since this type of fixing mechanism is known from Japanese Patent Laid-Open No. 4-44075 and the like, its description will be briefly stopped.

The unit 39 and the pressure roller 40 are members that are long in the front-rear direction, and are disposed in parallel in the left and right sides in the frame body 31. The unit 39 includes a ceramic heater 41 that is elongated in the front-rear direction as a heating means (heating source), a holder 42 that holds the heater 41 fixedly, and a flexibility that is loosely fitted to the holder 42. And a cylindrical fixing film (belt) 43.

  The heater 41 is directed rightward, and the heater 41 and the pressure roller 40 are brought into pressure contact with a predetermined pressing force with the film 43 interposed therebetween. Thus, a fixing nip N having a predetermined width is formed between the film 43 and the pressure roller 40 in the recording material conveyance direction.

  The pressure roller 40 is rotationally driven in the clockwise direction indicated by an arrow R40 in FIG. 1 at a predetermined peripheral speed. Along with this, the film 43 rotates following the counterclockwise direction of the arrow R43 while the inner peripheral surface of the film slides on the surface of the heater 41 around the outside of the holder 42. Further, the heater 41 generates heat by energization and is raised to a predetermined temperature to be adjusted in temperature. In this state, the recording material S on which the unfixed toner image is formed introduced into the nip portion N of the fixing unit 34 is heated and pressed while being nipped and conveyed, and the unfixed image is fixed on the recording material.

  At the nip portion N, the film 43 of the unit 39 contacts the unfixed toner image carrying surface of the recording material S, and the pressure roller 40 contacts the surface of the recording material S opposite to the surface. The recording material S sandwiched and transported from the bottom through the nip portion N is guided by the transport guide surface 36 or 35 and reaches the decurling roller pair 37.

  A slit-shaped recording material outlet portion 38 that is long in the front-rear direction is provided on the upper surface of the frame 31, and a roller pair 37 is disposed at the outlet portion 38. The exit portion 38 is substantially blocked by the roller pair 37. The roller pair 37 is rotationally driven at a predetermined peripheral speed in the discharge conveyance direction of the recording material S, and the recording material S is discharged and conveyed upward from the fixing device 18 while being corrected (reduced) by the roller pair 36.

  FIG. 10 shows a perspective view of the decurling roller pair 37. The roller pair 37 is a through roller having a length (width) W36 larger than the width WS of the recording material S of the maximum width size usable in the apparatus. Inside the frame 31 of the fixing device 18, the space region B on the downstream side in the recording material conveyance direction of the nip N of the fixing unit 34 is on the fixing unit 34 side and the outlet unit 38 side, and the nip portion N of the fixing unit 34 and the roller pair 37. Since it is blocked by the nip portion, the space region is almost sealed.

  The outer surface side of the right side surface portion of the frame 31 is a left guide surface 44 that constitutes the double-sided conveyance path portion 24. The substantially upper half and upper surface of the right side surface of the frame 31 are formed as an opening / closing member 45 that can be opened and closed with respect to the frame 31 about the horizontal axis 46. The opening / closing member 45 is provided with a right guide surface 36, a decurling roller pair 37, and a recording material outlet portion 38 which are fixing device constituent members / portions downstream of the nip portion N of the fixing portion 34 in the recording material conveyance direction. It is installed. FIG. 9 is an external perspective view of the inside of the opening / closing member 45 as viewed. Further, the outer surface side of the right side surface portion of the opening / closing member 45 is a left side conveyance guide surface 47 constituting the double-sided conveyance path portion 24.

In this embodiment, the conveyance guide surfaces 35, 36, 44, and 47 all extend in the recording material conveyance direction, and a plurality of them are arranged at predetermined intervals in a direction orthogonal to the recording material conveyance direction. It is comprised by the rib group.

1 , 2 , 4 to 6 show a state in which the opening / closing member 45 is closed with respect to the frame body 31. In this closed state, the decurling roller pair 37 and the recording material outlet portion 38 are located at a predetermined position on the upper surface side of the frame 31. Further, the right conveyance guide surface 36 is positioned to face the left conveyance guide surface 35 in a predetermined manner.

  7 and 8 show a state in which the opening / closing member 45 is opened to the right outside from the frame 31 with the horizontal axis 46 as the center. By opening the opening / closing member 45, the space region B in the fixing device 18 is largely opened. When a jam of the recording material S occurs in the fixing device 18 during the operation of the image forming apparatus 1, the opening / closing door 17 is opened to expose the right side of the fixing device 18 mounted on the mounting portion 28. Then, by opening the opening / closing member 45 of the fixing device 18 from the right side surface portion of the frame 31 to the right outer side, the space region B in the fixing device 18 is greatly opened, and the recording material jammed in the fixing device can be removed. It becomes.

Next, a countermeasure against dew condensation inside the fixing device will be described. Inside the opening / closing member 45 of the fixing device 18, there is a duct 48 that ventilates the space region B inside the frame and the outside of the frame. In this embodiment, the duct 48 communicates the space region B and the outside of the frame inside the opening / closing member between the conveyance guide surface 36 on the inner side of the opening / closing member 45 and the double-sided conveyance guide surface 47 on the outer side of the right side surface. have. An opening (inlet) 49 facing the space region B of the duct 48 is located in a rib group constituting the conveyance guide surface 36. An opening (exit) 50 facing the outside of the frame of the duct 48 is located on the upper surface of the opening / closing member 45.

Further, as shown in FIG. 5, intake louvers (intake ports) 51 communicating with the space region B are provided on the front side and the back side of the left side surface portion of the frame 31. In the mounting portion 28 to which the fixing device 18 of the apparatus main body 1A is mounted, when the fixing device is mounted on the mounting portion 28 in a predetermined manner, the louvers 51 on the front side and the back side of the left side portion of the frame 31 are respectively provided. A fan (air blowing means) 60 is disposed at the corresponding position as shown in FIG. As shown in FIG. 1, the fan 60 sends air into the space region B inside the frame body via the louver 51.

  The air sent into the frame 31 by the fan 60 flows in the duct 48 of the opening / closing member 45 from the opening 49 side to the opening 50 side together with the heated internal air in the space region B, and flows outside the frame 31. Get out. Then, the air is discharged out of the machine from a fan (air blowing means) 62 disposed on the apparatus main body 1A side through a duct 61 (FIG. 3) provided in the opening / closing door 17 closed in the apparatus main body 1A. . A is an air flow around the fixing device.

  In this embodiment, the fans 60 and 62 are provided on both the intake side and the exhaust side with respect to the fixing device 18, but if the fan is provided on either the intake side or the exhaust side, the air permeability is Although different, the airflow A can be realized.

  By providing the above air path, the opening and closing member 45 continues to reliably receive the airflow A air from the fan through the duct 48, so even if the recording material S starts to be introduced and the fixing device 18 starts to heat up violently. The opening / closing member 45 itself does not heat up significantly. Accordingly, the temperature of the double-sided conveyance guide surface 47 on the outer side surface of the opening / closing member 45 does not increase greatly.

  Further, when the amount of water contained in the recording material S is very large, the amount of water vapor increases, so that it is possible to cope with a situation where water droplets generated by condensation cannot be sufficiently removed. That is, the water droplets adhering to the opening / closing member 45 itself are sufficiently removed by the air that has been reliably bathed by the airflow A by the fan.

  Due to the effect of the airflow configuration of the present embodiment, the user can easily jam the fixing device. That is, when the user attempts to access the inside of the fixing device by opening the opening / closing door 17 of the apparatus main body 1A and opening the opening / closing member 45 of the exposed fixing device 18 for the jam processing, the user touches the opening / closing member 45. It becomes possible to process without difficulty without having a hot thought.

  Further, even when the opening / closing member 45 is opened, water droplets are not securely attached to the opening / closing member 45 itself, so that there is no concern that the movement of the opening / closing member 45 will cause water droplets to scatter inside the fixing device and in the vicinity of the electrical equipment.

  Furthermore, the double-sided conveyance path surface does not become very high in the double-sided image forming mode. For this reason, even when the recording material S passes through the double-sided conveyance unit 24, the temperature of the conveyance surface is not uneven due to the heat of the conveyance surface, and the jam and wrinkle of the recording material due to the curl at both ends in the width direction. There is no problem of image transfer failure or fixing failure.

[Example 2]
Next, the configuration and effect of the opening / closing portion and the air path of the fixing device according to the second embodiment will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  In the second embodiment, in addition to the configuration of the fixing device 18 of the first embodiment, a second duct 52 is provided. That is, in the space region B inside the frame 31, the suction louver 51 and the duct 48 inside the opening / closing member 45 are disposed in the region on the outer end side of the width WS of the recording material S of the maximum width size usable in the apparatus. Is provided.

  With this configuration, the recording material S is transported between the space region B inside the frame, that is, between the nip portion N of the fixing unit 34 and the decurling roller pair 37, and the air path in the region from the fan 60 to the duct 48 is transported. The following effects can be obtained even when the recording material is largely blocked. That is, the air taken into the frame body 1 from the fan 60 via the louver 51 is smoothly ventilated to the duct 48 without greatly reducing the ventilation efficiency by passing through the second duct 52 as shown in FIG. It is possible to A shows an error flow.

  FIG. 13 shows an error flow A when the recording material S is not conveyed between the decal roller pair 27 from the space region B inside the frame, that is, the fixing nip portion 29. In this case, most of the air taken into the frame 1 by the fan 60 is ventilated through the space region B into the duct 38 without passing through the duct 52.

  Even when the recording material is continuously introduced and the space area B from the fan 60 to the duct 48 is largely blocked by the surface of the recording material for a long time, the opening / closing member 45 can be used. Air is reliably bathed from the fan 60 through the second duct 52. As a result, even if the fixing device 18 starts to heat up violently after the recording material S is introduced, the opening / closing member 45 itself does not heat up significantly, and the double-sided conveyance guide surface 47 on the outer surface of the opening / closing member 15 is accordingly accompanied. The temperature will not increase greatly. Thus, in the case of the second embodiment, the same effect as described in the first embodiment can be obtained.

[Other matters]
1) The dimensions, materials, shapes, relative arrangements, and the like of the components described in the above-described embodiments are not intended to limit the scope of the present invention only to those unless otherwise specified. .

  2) The image forming unit 2 of the image forming apparatus 1 is not limited to the electrophotographic system using the electrophotographic photosensitive member 4 as the image carrier. The image forming unit configuration may be an electrostatic recording method using an electrostatic recording dielectric as an image carrier, a magnetic recording method using a magnetic recording magnetic material, or other image forming methods.

  3) In the fixing device 18, the first fixing member 39 constituting the fixing unit 34 having the nip portion N may be a rotating roller. The heating means (heating mechanism) of the first fixing member 39 is not limited to a ceramic heater. A halogen heater, nichrome wire heater, infrared lamp, electromagnetic induction coil, or the like can be used. An external heating method can also be used.

  The second fixing member 40 may be a non-rotating member. For example, a non-rotating member such as a pad or plate on which the first fixing member 39 and the recording material S slide and move can be used.

  1 .... Image forming device, 18 .... Fixing device, S..Recording material, 31..Frame body, 34..Fixing portion, N..Nip portion, B..Beneath of nip portion N in recording material conveyance direction Side space area, 45 ... Opening / closing member, 48 ... Duct, 51 ... Opening, 60/62 ... Air blowing means (fan), A ... Air flow

Claims (7)

A fixing device for fixing the unfixed image is heated while conveying the unfixed image recording material formed on the recording medium at the nip portion, and a frame body which accommodates the fixing portion, the said frame An image forming apparatus including a fixing device having an opening and closing member that can be opened and closed with respect to the frame body at a downstream side of the nip portion in the recording material conveyance direction,
A duct provided in the opening / closing member and having an inlet for taking in air in a space area downstream of the nip portion in the recording material conveyance direction inside the frame and an outlet for taking out the intake air to the outside of the frame; ,
An intake port provided in the frame body for taking air into the space region from the outside of the frame body ;
At least one of sending air from the intake port to the space area and causing an air flow from the space area side to the outlet side in an air passage formed by the space area, the inlet, the duct, and the outlet . Air blowing means;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein a conveyance guide surface for the recording material is provided on an outer surface side of the opening / closing member.   3. The image forming apparatus according to claim 2, wherein the conveyance guide surface is a conveyance guide surface of a double-side conveyance path for conveying an image to be formed on the second surface of the recording material on which the first surface is fixed.   The opening / closing member has a pair of rollers that sandwich the recording material that has come out of the nip portion and feed the recording material to the outside of the frame, and the pair of rollers is longer than the width of the maximum width recording material that can be used in the apparatus. The image forming apparatus according to claim 1, wherein the pair is a long threading roller pair.   5. The image forming apparatus according to claim 1, wherein the opening / closing member is provided with a conveyance guide surface of a recording material passing through the space area on an inner surface side. 6. A second duct for ventilating the inlet and the inlet in a region on the outer end side of a width of a recording material having a maximum width size usable in the apparatus in the space region. The image forming apparatus according to claim 1. A fixing device mounted on an image forming apparatus for forming an image on a recording material,
A fixing unit for fixing the unfixed image on the recording material by heating while conveying the recording material on which the unfixed image is formed at the nip portion;
A frame housing the fixing unit;
And the opening-and-closing possible closing member relative to the frame in the recording material conveyance direction downstream side of the nip portion of the frame body,
A duct provided in the opening / closing member and having an inlet for taking in air in a space area downstream of the nip portion in the recording material conveyance direction inside the frame and an outlet for taking out the intake air to the outside of the frame; ,
An intake port provided in the frame body for taking air into the space region from the outside of the frame body ;
A fixing device.