JP6028370B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

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

  2. Description of the Related Art Conventionally, electrophotographic image forming apparatuses are known as printers, copiers, and the like. In this image forming apparatus, a series of processes are executed in which an image is transferred to a sheet, and then the image is fixed to the sheet by passing the sheet through a fixing nip formed by a pair of fixing members. By the way, in this type of fixing device, there is a problem that the sheet that has passed through the fixing nip portion is wound around the fixing member and is not separated from the fixing member. Therefore, a so-called air separation method is known in which a sheet is separated from a fixing member by blowing a gas such as air.

  By the way, in such an air separation method, since the space formed on the paper discharge side of the fixing nip portion is narrow, the gas to be blown acts to disturb the air flow in the space, and the sheet is sent out from the fixing nip portion. It may cause a situation such as flapping.

  For example, Patent Document 1 discloses a fixing device that suppresses such flapping of paper. Specifically, this fixing device has a suction port in the vicinity of the paper exit on the upper surface of the paper transport path, and sucks and exhausts air discharged near the paper exit from the suction port. And an exhaust passage formed as described above.

JP 2011-191373 A

  According to the technique disclosed in Patent Document 1, it is possible to guide the air flow in the space on the paper discharge side by sucking air from the suction port of the exhaust passage. Thereby, it becomes possible to suppress the turbulence of the air in the space. However, it is also assumed that the air flows to the suction port, so that the paper is guided to the duct wall surface that guides air for air separation or the suction port. In this case, inconveniences such as image noise and jamming occur. Can happen.

  The present invention has been made in view of such circumstances, and an object of the present invention is to suppress flapping of the paper fed out from the fixing nip portion, and to suppress inconveniences such as image noise and jam.

In order to solve such a problem, the first invention includes a pair of fixing members, and the image is fixed on the sheet when the sheet passes through a fixing nip portion formed by press-contacting the pair of fixing members. Provided is a fixing device having a fixing unit and a separating unit that outputs a separation wind for separating the sheet from the fixing member. In this case, the separation unit guides the gas blown from the blower and the gas blown from the blower to the separation wind output port, and the separation wind output port faces the paper discharge side of the fixing nip portion. comprising a duct disposed, the said duct, the duct wall surface facing the paper fed from the fixing nip portion, provided with a blowout hole for blowing a part of the gas flowing inside the duct to the duct outside the separation unit Includes an adjusting member for setting the air volume distribution of the gas blown out from the blowout holes to a state in which the air volume is different in the sheet conveyance direction.

According to a second aspect of the present invention, there is provided a fixing unit that includes a pair of fixing members, and that fixes the image on the paper when the paper passes through a fixing nip portion formed by pressing the pair of fixing members. There is provided a fixing device having a separation unit that outputs a separation wind for separating a sheet from a member. In this case, the separation unit guides the gas blown from the blower and the gas blown from the blower to the separation wind output port, and the separation wind output port faces the paper discharge side of the fixing nip portion. A duct disposed on the duct wall faced with the sheet fed from the fixing nip portion, and a blowout hole for blowing out part of the gas flowing inside the duct to the outside of the duct. Includes an adjusting member that sets a blowing range in the paper width direction of the gas blown from the blowing holes to a range corresponding to the paper size.

  According to a third aspect of the present invention, there is provided a fixing unit that includes a pair of fixing members, and that fixes the image on the paper when the paper passes through a fixing nip portion formed by pressing the pair of fixing members. There is provided a fixing device having a separation unit that outputs a separation wind for separating a sheet from a member. In this case, the separation unit guides the gas blown from the blower and the gas blown from the blower to the separation wind output port, and the separation wind output port faces the paper discharge side of the fixing nip portion. A duct disposed on the duct wall faced with the sheet fed from the fixing nip portion, and a blowout hole for blowing out part of the gas flowing inside the duct to the outside of the duct. Comprises a shutter member capable of changing the blowing range of the gas blown out from the blowing hole.

  Here, in the third invention, it is preferable that the shutter member stops the gas blowing from the blowout hole.

  According to a fourth aspect of the present invention, there is provided a fixing unit that includes a pair of fixing members, and that fixes an image on the paper when the paper passes through a fixing nip portion formed by pressing the pair of fixing members. There is provided a fixing device having a separation unit that outputs a separation wind for separating a sheet from a member. In this case, the separation unit guides the gas blown from the blower and the gas blown from the blower to the separation wind output port, and the separation wind output port faces the paper discharge side of the fixing nip portion. A duct disposed on the duct wall surface facing the sheet fed from the fixing nip portion, and a blowout hole for blowing a part of the gas flowing inside the duct to the outside of the duct, and the inside of the duct. And a partition plate that separates the first and second partition walls, wherein the partition plate guides the gas flowing through the duct to the separation wind output port, and the gas flowing through the duct to the outlet hole. And a second flow path leading to

  Here, in 4th invention, it is preferable that the said air blower is each provided corresponding to the said 1st flow path and the said 2nd flow path.

  In any one of the second to fourth inventions, the separation unit preferably includes an adjustment member that sets the air volume distribution of the gas blown out from the blowout holes to a state in which the air volume is different in the paper conveyance direction. .
  Further, it is preferable that the adjustment member is set in a state in which the upstream air volume in the paper conveyance direction is increased more than the downstream air volume.
  Further, it is preferable that the adjustment member is set in a state in which the air volume at the end of the sheet is larger than the air volume at the center of the sheet in the sheet width direction.

  In the first to fourth aspects of the invention, the blowout holes may be arranged in parallel or discretely in the paper conveyance direction and the paper width direction so as to suppress paper fluttering due to the separation air. It is preferable that a plurality are arranged.

  In each of the above-described inventions, it is preferable that the blowout hole has an inclined shape or a curved shape in which the peripheral shape appearing on the surface side of the duct wall surface suppresses interference with the leading edge of the paper.

  Furthermore, in each of the above-described inventions, it is preferable that the blowout hole is set so that an angle formed by the direction of the gas blown from the blowout hole and the paper transport direction does not become an obtuse angle.

  According to a fifth aspect of the present invention, there is provided an image forming apparatus comprising: an image forming unit that transfers an image onto a sheet; and the above-described fixing device that fixes the transferred image onto the sheet.

  According to the present invention, a force in a direction away from the wall surface of the duct acts on the paper by the air blown out from the blowout hole, so that a steady force acts on the paper from one direction. , Paper flapping can be suppressed. In addition, by suppressing the flapping of the paper in this way, it is possible to suppress the occurrence of jam and the occurrence of image noise.

Explanatory drawing which shows the structure of an image forming apparatus typically Schematic diagram showing the main part of the fixing device Explanatory drawing showing an enlarged view of the vicinity of the separation wind output port of the duct Explanatory drawing which shows the blowing hole formed in the duct wall surface Explanatory drawing schematically showing the shape of the small holes Explanatory drawing which shows a shutter member typically Explanatory drawing which shows the structure of the shutter member which changes distribution of the blowing range Sectional view schematically showing the structure of the duct

(First embodiment)
FIG. 1 is a configuration diagram schematically illustrating an image forming apparatus according to the present embodiment. This image forming apparatus is an electrophotographic image forming apparatus such as a copying machine, and forms a full-color image by arranging a plurality of photoconductors facing one intermediate transfer belt in a vertical direction. A tandem type color image forming apparatus.

  The image forming apparatus mainly includes a document reading device SC, four sets of image forming units 10Y, 10M, 10C, and 10K, a sheet conveying unit 20, and a fixing device 30, and these are housed in one casing.

  The document reader SC scans and exposes an image of the document with the optical system of the scanning exposure device, reads the reflected light with a line image sensor, and obtains an image signal. This image signal is subjected to processing such as A / D conversion, shading correction, and compression, and then input to the control unit 11 as image data. Note that the image data input to the control unit 11 is not limited to data read by the document reading device SC, but is, for example, data received from a personal computer connected to the image forming device or another image forming device. Also good.

  The four image forming units 10Y, 10M, 10C, and 10K include an image forming unit 10Y that forms a yellow (Y) image, an image forming unit 10M that forms a magenta (M) image, and a cyan (C) image. The image forming unit 10 </ b> C to be formed and the image forming unit 10 </ b> K for forming a black (K) image are configured.

  The image forming unit 10Y includes a photosensitive drum 1Y and a charging unit 2Y, an optical writing unit 3Y, a developing device 4Y, and a drum cleaner 5Y arranged around the photosensitive drum 1Y. Similarly, the image forming units 10M, 10C, and 10K include photoconductor drums 1M, 1C, and 1K and charging units 2M, 2C, and 2K, optical writing units 3M, 3C, and 3K, and developing devices 4M, 4C, 4K and drum cleaners 5M, 5C, 5K.

  The surfaces of the photosensitive drums 1Y to 1K are uniformly charged by the charging units 2Y to 2K, and latent images are formed on the photosensitive drums 1Y to 1K by scanning exposure by the optical writing units 3Y to 3K. Is done. Further, the developing devices 4Y to 4K develop latent images on the photosensitive drums 1Y to 1K by developing with toner. Thereby, a toner image of a predetermined color corresponding to any one of yellow, magenta, cyan, and black is formed on the photosensitive drums 1Y to 1K.

  The toner images formed on the photosensitive drums 1Y to 1K are sequentially transferred to predetermined positions on the intermediate transfer belt 6 by primary transfer rollers 7Y, 7M, 7C, and 7K. The intermediate transfer belt 6 is configured so as to be rotatable around a plurality of rollers. On the intermediate transfer belt 6, toner images are sequentially transferred from the plurality of photosensitive drums 1 </ b> Y to 1 </ b> K, thereby forming a superimposed image, that is, a full-color toner image. The full-color toner image transferred onto the intermediate transfer belt 6 is transferred to the paper P conveyed at a predetermined timing by a secondary transfer roller 9 that is pressed against the intermediate transfer belt 6 to form a transfer nip portion. .

  The paper transport unit 20 transports the paper P along the transport path of the paper P. The paper P is stored in the paper feed tray 21, and the paper P stored in the paper feed tray 21 is taken in by the paper feed unit 22 and sent out to the transport path. The paper P fed from the paper feed tray 21 is sequentially transported by a plurality of intermediate transport rollers and reaches the registration roller 23. When the registration roller 23 starts rotating at a predetermined timing so as to synchronize with the toner image carried by the intermediate transfer belt 6, the registration roller 23 conveys the paper P to the transfer nip portion. The paper P that has passed through the transfer nip is conveyed to the fixing device 30.

  The fixing device 30 is a device that performs a fixing process on the paper P on which the toner image is transferred, that is, the paper P sent out from the transfer nip portion. This fixing process is a process for fixing the toner image onto the paper P through the action of pressure and heat. Details of the fixing device 30 will be described later.

  The paper discharge roller 24 conveys the paper P after the fixing process by the fixing device 30 and discharges it to the paper discharge tray 25. On the other hand, in the case of duplex printing in which image formation is performed on each of the front and back surfaces of the paper P instead of single-sided printing in which image formation is performed only on the front surface of the paper P, the paper discharge guide fixes the toner image on the front surface of the paper P. The processed paper P is transported to the re-feeding unit below. The refeed reverse roller 26, which is one of the components of the refeed unit, reverses the paper P by nipping the rear end of the paper P and then reverses the paper P and sends it to the refeed conveyance path. The paper P is transported through the re-feed transport path, whereby the paper P is used for image formation on the back surface.

  FIG. 2 is a configuration diagram schematically illustrating a main part of the fixing device 30. The fixing device 30 according to the present embodiment includes a fixing unit and a separation unit.

  The fixing unit is composed of a pair of fixing members, and these fixing members are pressed against each other to form a fixing nip portion. The fixing unit fixes the toner image on the paper P when the paper P passes through the fixing nip portion.

  One fixing member is disposed on the fixing target surface of the paper P, that is, on the side facing the surface on which the toner image is transferred and left unfixed, in the present embodiment, on the upper side of the paper surface to be conveyed. Yes. The one fixing member includes a pressure roller 31, an upper fixing roller 32, and an endless fixing belt 33. The pressure roller 31 and the upper fixing roller 32 are spaced apart from each other by a predetermined distance, and a fixing belt 33 is stretched between these rollers 31 and 32. A heater 34 for heating the upper fixing roller 32 is built in the upper fixing roller 32. As the heater 34, for example, a halogen heater can be used, and the heater 34 is operated by being energized. The fixing upper roller 32 is heated through radiant heat from the heater 34, and the fixing belt 33 stretched over the fixing upper roller 32 is thereby heated.

  The other fixing member is disposed on the side facing the back surface of the fixing target surface of the paper P, that is, on the lower side of the transported paper surface in this embodiment. The other fixing member is constituted by a fixing lower roller 35. The lower fixing roller 35 is disposed to face the pressure roller 31 with the fixing belt 33 interposed therebetween, and is urged toward the pressure roller 31 with a predetermined force. A fixing nip portion is formed between the fixing belt 33 and the lower fixing roller 35 by pressing the lower fixing roller 35 and the pressure roller 31 through the fixing belt 33.

  The separation unit has a function of outputting a separation air for separating the paper P from the fixing member, specifically, the fixing belt 33, and is disposed on the paper discharge side of the paper P in the fixing nip portion. The separation unit includes a blower 36 and a duct 37, and the blower 36 and the duct 37 are connected to each other.

  The blower 36 is configured by, for example, a multi-blade fan that is rotatably provided with a large number of forward blades. The blower 36 takes air around the fan into the main body and blows the taken air toward the duct 37. The shape and configuration of the fan is not limited to the above, and the blower 36 may have any form other than the fan as long as it has a function of blowing air like a compressor. The medium blown by the blower 36 may be a gas other than air.

  The duct 37 is a flat cylindrical member that guides air blown from the blower 36 to the fixing member. The blower 36 is connected to one opening 38 of the duct 37, and the other opening 39 functions as a separation wind output port for blowing the separation wind toward the fixing member (hereinafter also referred to as “separation wind output port 39”). Say). The duct 37 is arranged so that the separation wind output port 39 faces the paper discharge side of the paper P in the fixing nip portion. In this case, the duct 37 is arranged so that the separation wind output port 39 faces a position offset toward the pressure roller 31 side from the front position on the paper discharge side of the paper P in the fixing nip NP. Such an arrangement of the duct 37 is known that the fixing belt 33 in contact with the surface to be fixed of the paper P of the fixing belt 33 and the lower fixing roller 35 tends to wind the paper P more strongly. It is based on profit. Further, the duct 37 is set to have a shape whose width decreases from the opening 38 on the blower 36 side to the separation wind output port 39 in order to increase the flow velocity of the air blown from the separation wind output port 39.

  FIG. 3 is an explanatory view showing the vicinity of the separation wind output port 39 of the duct 37 in an enlarged manner, and FIG. 4 is an explanatory view showing an outlet hole 41 formed in the duct wall surface 40. The duct 37 is provided with a blowing wall 41 for blowing a part of the air flowing inside the duct to the outside of the duct on the duct wall surface 40 facing the sheet P fed from the fixing nip portion, in this embodiment, the duct wall surface 40 corresponding to the lower surface. I have. The blowing hole 41 functions as an opening for blowing air from the upper surface side of the paper P to suppress flapping of the paper P sent out from the fixing nip portion.

  Specifically, the blow hole 41 is formed so that the air blown from the blow hole 41 satisfies a predetermined range in the paper width direction CD that is a direction perpendicular to the paper transport direction FD. Further, the blowout hole 41 is formed so that the air blown from the blowout hole 41 satisfies a predetermined range in the paper transport direction FD. In the present embodiment, the blowout holes 41 are realized by a plurality of small holes 41a that are arranged in a matrix, that is, discretely arranged in the paper transport direction FD and the paper width direction CD.

  In the fixing device 30 having such a configuration, the sheet P passes through the fixing nip portion between the fixing belt 33 and the lower fixing roller 35 in the process of being conveyed. As a result, the toner image is fixed onto the paper P through the action of the pressure applied by the pressure roller 31 and the lower fixing roller 35 and the heat of the fixing belt 33.

  On the other hand, the air blown from the blower 36 is sent into the duct 37, guided inside the duct 37, and then blown out from the separation wind output port 39. Separation of the paper P from the fixing belt 33 is facilitated by air blown from the separation air output port 39, that is, separation air output from the separation unit (air separation).

  In addition, the air flowing inside the duct 37 is blown out of the duct 37 through individual small holes 41 a, part of which forms the blowout holes 41. Since the space formed on the paper discharge side of the fixing nip portion is narrow, the air from the separation wind output port 39 acts to disturb the air flow in the space, and the paper P fed from the fixing nip portion is discharged. It can happen that you can flutter. In this respect, according to the present embodiment, as described above, a force in a direction away from the duct wall surface 40 acts on the paper P by the air blown out through the individual small holes 41a. A steady force acts on the paper P from one direction, and flapping of the paper P can be suppressed. In addition, by suppressing the flapping of the paper P in this way, it is possible to suppress a situation in which the surface of the paper P contacts the duct wall surface 40. Thereby, generation | occurrence | production of jam and generation | occurrence | production of image noise can be suppressed.

  Here, about the some small hole 41a which comprises the blowing hole 41, arbitrary magnitude | sizes and shapes are employable. However, in order to achieve the above-described effects more effectively, the following forms can be adopted.

  As shown in FIG. 3, a paper guide member 42 is disposed on the downstream side of the fixing nip portion in the conveyance path of the paper P. In this case, the formation range of the plurality of small holes 41a in the paper conveyance direction FD may be set so as to reach the downstream side of the paper guide member 42. Thus, the blowing range in the paper transport direction FD by the plurality of small holes 41 a can be set to a state extending to the downstream side of the paper guide member 42.

  According to such a configuration, flapping of the paper P can be suppressed until the paper P is conveyed to the paper guide member 42. This suppresses the situation in which the paper P contacts the duct wall surface 40 or enters between the duct 37 and the paper guide member 42, thereby suppressing the occurrence of a jam or the occurrence of image noise. Can do.

  As shown in FIG. 4, the plurality of small holes 41 a may be set so that the opening area decreases from the upstream side to the downstream side in the paper transport direction FD. Thereby, the air volume distribution in the paper conveyance direction FD by the plurality of small holes 41a can be set to a state in which the upstream air volume in the paper conveyance direction FD is larger than the downstream air volume.

  Due to the air blown out from the separation wind output port 39, the flickering of the paper P tends to be larger on the upstream side in the paper transport direction FD than on the downstream side. In that respect, by setting the air volume distribution by the plurality of small holes 41a as described above, it is possible to set an optimum gradient for the force applied by the blown air, so that the flapping of the paper P is effectively suppressed. can do. However, as a method of forming the air volume distribution, in addition to adjusting the opening area, it may be adjusted by the arrangement density of the openings, or may be adjusted by a combination of both.

  As shown in FIG. 3, the direction of the air blown out from each small hole 41a is set based on the paper conveyance direction FD in the plurality of small holes 41a.

  When the air blown from the separation air output port 39 hits the fixing member, the direction is reversed and tends to flow along the paper transport direction FD. Therefore, by setting the direction of the air blown out from the small holes 41a so as to avoid the counter direction facing the paper transport direction FD, it is possible to suppress the situation where the air flows face each other. Thereby, since the air flow in the space can be smoothly guided, the flapping of the paper P can be effectively suppressed. That is, the direction of the air blown out from the small hole 41a may be a relationship that avoids the counter direction, and the direction of the air blown out from the small hole 41a is in the same direction as the paper conveyance direction FD so as to be along the paper conveyance direction FD. It is preferable to set the angle so that the formed angle does not become an obtuse angle.

  In addition, each of the small holes 41a preferably has a peripheral shape that appears on the surface side of the duct wall surface 40 having an inclined shape or a curved shape that suppresses interference with the leading edge of the paper P. Specifically, as shown in FIG. 5A, the small hole 41a may be set in a tapered shape in which the peripheral edge on the surface side of the duct wall surface 40 is chamfered when this is taken in a sectional view. This chamfered shape may be not only a tapered shape but also a rounded curved shape. Further, as shown in FIGS. 5B and 5C, the small hole 41a has a curved shape or an inclined shape when the shape of the downstream side of the peripheral edge on the surface side of the duct wall surface 40 is a flat shape. A streamlined shape including a shape may be set.

  According to this configuration, even when the leading edge of the paper P comes into contact with the duct wall surface 40, the leading edge of the paper P can be prevented from being caught in the small hole 41a. As a result, it is possible to suppress the occurrence of a situation in which the conveyance of the paper P is hindered by the small holes 41a.

  FIG. 6 is an explanatory diagram of the shutter member 43. For the purpose of stopping the blowing of air from the plurality of small holes 41a, the duct wall surface 40 may be provided with a shutter member 43 that is slidably attached along the surface. The shutter member 43 is formed of, for example, an aluminum flat plate, and the sliding operation can be realized by a driving mechanism such as an electric motor or manually by a user. The shutter member 43 is normally set at a position where the plurality of small holes 41a are opened, and can be set at a position where the plurality of small holes 41a are closed by sliding as necessary (see FIG. 6). ).

  As described above, by providing the shutter member 43, it is possible to stop the blowing of air from the plurality of small holes 41a. The flickering of the paper P differs depending on the type of the paper P, such that the paper P is more likely to flutter as the thin paper or the paper P having a smaller basis weight. Therefore, in this way, by stopping the blowing of air from the plurality of small holes 41a as necessary by the shutter member 43, it is possible to suppress the situation where air is unnecessarily blown out.

  Further, the shutter member 43 may be composed of a plurality of members divided in the paper width direction CD as virtually indicated by a one-dot chain line in FIG. In this case, it is preferable that the division position of the shutter member 43 is determined according to the size of the paper P to be conveyed. Thereby, the shutter member 43 not only opens and closes all of the small holes 41a, but also opens and closes the small holes 41a existing in the range corresponding to the size of the paper P. can do. Thereby, the shutter member 43 can set the blowing range in the paper width direction CD by the plurality of small holes 41a to a range corresponding to the paper size.

  According to such a configuration, it is possible to set the blowing range in the paper width direction CD by the plurality of small holes 41a according to the size of the paper P to be conveyed. Thereby, air can be selectively blown out from the small hole 41a corresponding to the location where the paper P is conveyed. Thereby, it becomes possible to blow out air efficiently. In order to suppress flapping of the paper P, the blowout range in the paper width direction CD by the plurality of small holes 41a is expanded in a range that does not cause air blowout loss rather than strictly matching the size of the paper P. It is preferable that

  Moreover, you may implement | achieve the several small hole which comprises the blowing hole 41 with the following forms. Specifically, as shown in FIG. 7, the duct wall surface 40 is provided with a single opening 41b as the blowout hole 41, while the duct wall surface 40 is slidable along the surface of the shutter member 43. And the shutter member 43 is provided with a plurality of small holes 43a. In this case, the shutter member 43 can selectively use a plurality of members 43A and 43B in which the formation range of the small holes 43a is set according to the size of the paper P.

  Thus, the blowout hole 41 can be realized by the combination of the single opening 41b of the duct wall surface 40 and the plurality of small holes 43a of the shutter member 43, as in the above-described embodiment. Further, the air volume distribution and the blowing range can be freely set according to the range and size of the small hole 43a.

  Further, since the fluttering of the paper P tends to be larger on the edge side of the paper P, the airflow at the paper edge in the paper width direction CD by the blowout holes 41 is larger than the airflow at the paper center. The state may be set. Such a setting is realized by a method in which the opening area of the small hole 41a corresponding to the end portion of the sheet P to be conveyed is set larger than the small hole 41a corresponding to the central portion. can do. However, when such a method is applied, it is preferable that the small holes 43a are formed in a range corresponding to the size of the paper P as shown in FIG.

  As described above, as one of the features of the present embodiment, the plurality of small holes 41a (43a) themselves or the shutter member 43, or both of them function as an adjustment member that adjusts the air volume of the gas blown from the blowing holes 41. doing. With such an adjustment member, the air blown out from the blowing hole 41 is stopped, the air volume distribution in the paper transport direction CD or the paper width direction FD is adjusted, or the blowout range in the paper transport direction CD or the paper width direction FD is adjusted. be able to.

  In addition, as one of the features of the present embodiment, it is also effective to apply the following method to the duct 37. FIG. 8 is a cross-sectional view schematically showing the configuration of the duct 37. The duct 37 may further include a partition plate 44 that separates the inside of the duct from each other. In this case, the partition plate 44 forms a first flow path that guides the gas flowing inside the duct to the separation wind output port 39 and a second flow path that guides the gas flowing inside the duct to the blowout hole 41. The

  According to this configuration, the flow of air inside the duct can be divided into a flow of air for air separation and a flow of air for blowing from the blowing holes 41. Thereby, since the flow of air for air separation can be secured quantitatively, the separation performance of the paper P can be secured appropriately.

  In this case, you may provide the air blower 36 corresponding to a 1st flow path and a 2nd flow path, respectively. Thereby, it is possible to individually set the air flowing through the first flow path and the air flowing through the second flow path.

  In the above-described embodiment, the blowout hole 41 is realized by a plurality of small holes 41a, but the present embodiment is not limited to this. For example, the blowout hole 41 may be a rectangular opening formed wide in the paper width direction CD and narrow in the paper transport direction FD, or in this way to form a blowout range in the paper transport direction FD. May be arranged in parallel in the paper transport direction FD. Further, the blowout hole 41 may be a rectangular opening formed narrow in the paper width direction CD and wide in the paper transport direction FD, or in order to form a blowout range in the paper width direction CD. May be formed in parallel in the paper width direction CD. Furthermore, as long as the above-described function is achieved, it is sufficient that the blowout hole 41 is realized by one or more openings.

  The image forming apparatus according to the embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the invention. . Further, the fixing device itself constituting the image forming apparatus also functions as part of the present invention.

10Y to 10K Image forming section 6 Intermediate transfer belt 9 Secondary transfer roller 20 Paper transport section 21 Paper feed tray 22 Paper feed section 23 Registration roller 30 Fixing device 31 Pressure roller 32 Upper fixing roller 33 Fixing belt 34 Heater 35 Lower fixing roller 36 Blower 37 Duct 38 Opening 39 Separation Air Output 40 Duct Wall 41 Blowout Hole 41a Small Hole 41b Opening 42 Paper Guide Member 43 Shutter Member 43a Small Hole 44 Partition Plate

Claims (13)

A fixing unit including a pair of fixing members, and fixing the image on the paper when the paper passes through a fixing nip portion formed by pressing the pair of fixing members.
A separation unit that outputs a separation air for separating the paper from the fixing member,
The separation unit is
A blower for blowing gas;
A duct arranged to guide the gas blown from the blower to the separation wind output port, and the separation wind output port facing the paper discharge side of the fixing nip portion, and
The duct is provided with a blowout hole for blowing a part of the gas flowing inside the duct to the outside of the duct on a duct wall surface facing a sheet fed from the fixing nip portion,
The fixing device includes an adjustment member that sets an air volume distribution of the gas blown from the blowing holes to a state in which the air volume is different in the sheet conveyance direction . A fixing unit including a pair of fixing members, and fixing the image on the paper when the paper passes through a fixing nip portion formed by pressing the pair of fixing members.
A separation unit that outputs a separation air for separating the paper from the fixing member,
The separation unit is
A blower for blowing gas;
A duct arranged to guide the gas blown from the blower to the separation wind output port, and the separation wind output port facing the paper discharge side of the fixing nip portion, and
The duct is provided with a blowout hole for blowing a part of the gas flowing inside the duct to the outside of the duct on a duct wall surface facing a sheet fed from the fixing nip portion,
The fixing device includes an adjustment member that sets a blowout range in a paper width direction of gas blown from the blowout hole to a range corresponding to a paper size . A fixing unit including a pair of fixing members, and fixing the image on the paper when the paper passes through a fixing nip portion formed by pressing the pair of fixing members.
A separation unit that outputs a separation air for separating the paper from the fixing member,
The separation unit is
A blower for blowing gas;
A duct arranged to guide the gas blown from the blower to the separation wind output port, and the separation wind output port facing the paper discharge side of the fixing nip portion, and
The duct is provided with a blowout hole for blowing a part of the gas flowing inside the duct to the outside of the duct on a duct wall surface facing a sheet fed from the fixing nip portion,
The fixing device includes a shutter member capable of changing a blowout range of a gas blown from the blowout hole . The fixing device according to claim 3 , wherein the shutter member stops a gas blowout from the blowout hole. A fixing unit including a pair of fixing members, and fixing the image on the paper when the paper passes through a fixing nip portion formed by pressing the pair of fixing members.
A separation unit that outputs a separation air for separating the paper from the fixing member,
The separation unit is
A blower for blowing gas;
A duct arranged to guide the gas blown from the blower to the separation wind output port, and the separation wind output port facing the paper discharge side of the fixing nip portion, and
The duct is
A blowout hole that blows out part of the gas flowing inside the duct to the outside of the duct on the duct wall face facing the sheet fed from the fixing nip portion ,
A partition plate that separates the inside of the duct from each other, and
The partition plate forms a first flow path for guiding the gas flowing in the duct to the separation wind output port, and a second flow path for guiding the gas flowing in the duct to the outlet hole. A fixing device characterized by the above . The fixing device according to claim 5 , wherein the blower is provided corresponding to each of the first flow path and the second flow path.   The said separation part is provided with the adjustment member which sets to the state from which an air volume differs in a paper conveyance direction about the air volume distribution of the gas blown out from the said blowing hole, It was described in any one of Claim 2 to 6 Fixing device. The adjusting member, fuser device according to claim 7, characterized in that setting the air volume of the upstream side have contact to the paper conveyance direction in a state of increased than the air volume of the lower stream side. The adjusting member, fuser device according to claim 7 or 8, wherein setting the air volume of the sheet edge in a state of increased than the air volume of the sheet central portion in use the sheet width direction.   The plurality of the blowout holes are arranged in parallel or discretely in each of the paper transport direction and the paper width direction so as to suppress flapping of the paper due to the separation wind. The fixing device according to any one of 9. The outlet hole is peripheral shape appearing on the surface side of the duct wall has been described in claim 1, wherein it comprises a suppressing inclined shape or curved shape interference with the leading edge of the paper 10 either Fixing device. The outlet hole is described in any one of claims 1, characterized in that the angle between the direction and the sheet conveyance direction of the gas blown out from the blowout hole is set so as not to be an obtuse angle 11 of Fixing device. An image forming unit for transferring an image to paper;
The fixing device according to any one of claims 1 to 12 , wherein the transferred image is fixed to a sheet.
An image forming apparatus comprising:

Images