JP2008096480A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of efficiently cooling paper on which an image is thermally fixed. <P>SOLUTION: Regarding the image forming apparatus equipped with a thermal-fixation fixing device for fixing the image on the paper by using a heat roll and a pressure roll, the paper 20 with the image fixed in the fixing device is supported by a plurality of ribs 24, then, a cavity is formed in such the state that the paper surface of the paper 20 is exposed, and an air current generated by driving an air supply fan 27 is guided to the cavity through a duct 26, then, the air current coming in contact with the paper surface of the paper 20 and in parallel to the paper surface of the paper 20 is formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  In general, an electrophotographic image forming apparatus forms an image on a sheet by an image forming process including charging, exposure, development, transfer, and fixing. In the fixing process, the toner image transferred to the paper in the previous transfer process is fixed on the paper by heating and pressing. For this reason, the fixing device is provided with a pair of fixing rolls, one of which is a heating roll and the other is a pressure roll.

  As described above, regarding an image forming apparatus including a heat fixing type fixing device that fixes an image (toner) to paper using heat, the air is blown to the paper sent from the fixing device to cool the paper and curl it. A technique for suppressing (correcting) the occurrence of this is known (for example, see Patent Document 1).

JP 2000-75709 A

  An object of the present invention is to provide an image forming apparatus capable of efficiently cooling a sheet on which an image is fixed using heat.

  According to the first aspect of the present invention, there is provided a fixing device that fixes an image on a sheet using at least heat, and an air that is in contact with the sheet surface of the sheet on which the image is fixed by the fixing unit and is parallel to the sheet surface of the sheet. An image forming apparatus comprising an air flow forming means for forming a flow.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the air flow forming means forms an air flow in a direction along the paper transport direction.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the air flow forming means forms an air flow from the downstream side to the upstream side in the paper transport direction. is there

  According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, the air flow forming unit is provided on the downstream side of the fixing device in the paper conveyance direction to form a space where the paper surface of the paper is exposed. A sheet conveyance guide member for forming the air flow in the space.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the fourth aspect, the paper transport guide member contacts the paper surface of the paper in a point contact state or a line contact state downstream of the fixing device in the paper transport direction. A plurality of paper support members are included.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect of the present invention, the sheet supporting member is constituted by a rotatable roller.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the fourth aspect, the paper transport guide member includes an open plane member in which a plurality of holes are formed.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the fourth aspect of the present invention, a sheet pressing member that presses a sheet against the sheet conveyance guide member is provided.

  According to the first aspect of the present invention, the heat applied to the paper by fixing the image can be efficiently taken away by the air flow, and a wide contact area between the air flow and the paper can be secured. For this reason, it is possible to efficiently cool the sheet immediately after fixing with an air flow.

  According to the second aspect of the present invention, it is possible to cool the paper uniformly so that there is no difference in the cooling effect of the paper between the upstream side and the downstream side of the air flow.

  According to the third aspect of the present invention, since the relative speed difference between the paper and the air flow in the paper transport direction becomes large, the paper can be efficiently cooled.

  According to the fourth aspect of the present invention, the air flow can be brought into contact with the paper without waste by forming the air flow in the space where the paper surface of the paper is exposed.

  According to the fifth aspect of the present invention, it is possible to ensure a wide area of the paper exposed in the space where the air flow is formed.

  According to the sixth aspect of the present invention, the sheet conveyance resistance can be reduced.

  According to the seventh aspect of the present invention, paper flapping can be prevented by utilizing the negative pressure generated in the hole portion of the opening plane member.

  According to the invention described in claim 8, it is possible to prevent paper flapping due to contact with the air flow.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment of the present invention, the same reference numerals are assigned to the corresponding parts for explanation.

  FIG. 1 is a schematic diagram showing a configuration example of an image forming apparatus to which the present invention is applied. The illustrated image forming apparatus 1 includes a receiving unit 5 connected to the image reading device 2 and an external device (such as a personal computer) 3 through a communication line 4, and an image writing unit based on image data received by the receiving unit 5. 6, an image recording control unit 7 that controls 6, a drum-shaped image carrier (photosensitive drum) 8 on which an electrostatic latent image is written by the image writing unit 6, and a circumferential direction of the image carrier 8. A charging device 9, a developing device 10, a cleaner 11, a roll-shaped transfer body (hereinafter referred to as “transfer roll”) 12 that transfers a toner image formed on the image holding body 8 to a paper, and a paper The fixing device 13 that fixes the transferred toner image, the conveyance roll pair 14 that conveys the paper on which the toner image is fixed by the fixing device 13 to the downstream side in the conveyance direction, and the paper that is conveyed by the conveyance roll pair 14 Out of the plane The paper passes through a discharge roll pair 15 to be discharged, a discharge tray 16 for storing the paper discharged by the discharge roll pair 15 in a stacked state, and a position (nip position) between the image carrier 8 and the transfer roll 12. A formed paper transport path 17, a paper stacking tray 18 that stores paper used for image formation in a stacked state, a paper supply unit 19 that supplies the paper stacked on the paper stacking tray 18 to the paper transport path 17, and It is the composition provided with. The image reading device 2 may exist as one functional unit of the image forming apparatus 1 or may exist as a functional unit separate from the image forming apparatus 1.

[First Embodiment]
FIG. 2 is a schematic diagram showing the configuration of the image forming apparatus according to the first embodiment of the present invention. In the figure, the fixing device 13 is configured by using two rolls constituting a pair of fixing rolls, that is, a heating roll 21 and a pressure roll 22. The heating roll 21 and the pressure roll 22 are arranged in contact with each other at a predetermined pressure. The heating roll 21 and the pressure roll 22 are provided so as to be rotatable in the direction of the arrow, with one roll as the driving side and the other roll as the driven side. The heating roll 21 and the pressure roll 22 constituting the fixing roll pair sandwich the paper 20 between them and rotate in the direction of the arrow, thereby feeding the paper 20 downstream in the transport direction.

  At this time, the heating roll 21 is disposed so as to contact the first surface of the paper 20, and the pressure roll 22 is disposed so as to contact the second surface of the paper 20. The first side and the second side of the paper 20 are in a front-back relationship. The first surface of the paper 20 is a paper on which the toner image is transferred when the paper passes between the image carrier 8 and the transfer roll 12 disposed on the upstream side of the fixing device 13 in the paper conveyance direction. The opposite surface is the second surface (non-image retaining surface) of the paper 20. Further, the fixing of the toner image onto the paper is performed by the heat applied to the paper 20 by the heating roll 21 and the pressure roll 22 when the paper 20 passes between the heating roll 21 and the pressure roll 22 (contact portion). This is done using the pressure applied to 20. For this reason, the contact portion between the heating roll 21 and the pressure roll 22 is a position where the fixing device 13 fixes the image on the paper 20 (hereinafter also referred to as “fixing position”).

  The conveyance roll pair 14 is provided downstream of the fixing device 13 in the sheet conveyance direction. The transport roll pair 14 is configured by using a pair of rolls in which one roll is a driving side and the other roll is a driven side. The pair of rolls constituting the conveyance roll pair 14 are arranged in a state of contacting each other with a predetermined pressure. The conveyance roll pair 14 conveys the sheet 20 on which the image has been fixed by sandwiching and rotating the sheet 20 sent from the fixing position of the fixing device 13 by the rotation of the heating roll 21 and the pressure roll 22. It conveys to the downstream of the direction.

  The fixing device 13 and the conveyance roll pair 14 are arranged at a predetermined distance in the sheet conveyance direction. Further, the sheet is transported horizontally in the sheet conveyance section from the fixing device 13 to the conveyance roll pair 14, and the sheet conveyance guide member 23 is provided in this conveyance section. The sheet conveyance guide member 23 is disposed in a state facing the first surface side of the sheet 20 in the conveyance section. Further, air flow forming means is provided at a position facing the second surface of the paper 20 in the transport section. Hereinafter, the configuration of the air flow forming means will be described.

  First, a plurality of ribs 24 are provided at a position facing the second surface of the paper 20 as shown in FIGS. The plurality of ribs 24 serve as a sheet support member that constitutes a sheet conveyance guide member that forms a pair with the sheet conveyance guide member 23 described above. Each of the ribs 24 is formed in a thin plate shape, and is disposed at a predetermined interval in a direction (paper width direction) orthogonal to the paper transport direction. Each rib 24 stands vertically from a flat base member 25 with its plate surface oriented in the horizontal direction (paper width direction), and the edge longitudinal direction of the rib upper end is parallel to the paper transport direction. It is arranged in the direction. For this reason, a space having ribs 24 as partition plates is formed between adjacent ribs 24 in a direction (paper width direction) orthogonal to the paper transport direction. This space is a space for forming an air flow along the paper surface of the paper.

  On the other hand, an air supply fan 27 serving as a source of air flow is provided inside the duct 26. The duct 26 is formed so as to extend in the paper width direction orthogonal to the paper transport direction starting from the attachment portion of the air supply fan 27. The duct 26 is formed so that the cross-sectional area of the duct gradually decreases from one to the other in the paper width direction. An inclined portion 28 is provided on the long side portion of the duct 26 extending in the paper width direction. The inclined portion 28 deflects the direction of the air flow generated by the rotation of the exhaust fan 27 in a direction along the paper surface of the paper 20 (horizontal direction in the illustrated example). The duct 26 formed in this manner expands the range of air flow generated by the rotation of the air supply fan 27 in the paper width direction, and deflects the expanded air flow direction by the inclined portion 28, thereby The air flow is guided to the space between the ribs 24. Note that the inclination angle and size of the inclined portion 28 are appropriately set so that an air flow parallel to the paper surface of the paper is formed when the air flow is actually deflected by the inclined portion 28. The air flow forming means is configured as described above.

  In the image forming apparatus configured as described above, the sheet is formed by the sheet conveyance guide member 23 provided in the sheet conveyance section from the fixing device 13 to the conveyance roll pair 14 and the plurality of ribs 24 facing the sheet conveyance guide member 23. A conveyance path is formed, and the image-fixed sheet is conveyed along the sheet conveyance path. At this time, the upper end of each rib 24 comes into contact with the second surface of the paper 20 on which the toner image is fixed through the fixing device 13 between the heating roll 21 and the pressure roll 22 (contact portion). The sheet 20 to be conveyed is supported by the plurality of ribs 24 from below. At this time, the contact state between the second surface of the paper 20 and each rib 24 is a line contact state because the paper surface contacts the edge of the upper end of the rib. Further, the second surface of the paper 20 is exposed to a space formed between the ribs 24.

  Further, by introducing the air flow generated by the rotational drive of the air supply fan 27 through the duct 26 and flowing into the spaces between the ribs 24, the spaces between the ribs 24 are as shown in FIG. An air flow in one direction parallel to the paper surface of the paper 20 is formed. Incidentally, when air is blown perpendicularly to the paper surface of the paper, the air hits the paper surface of the paper and disperses in the other direction, so that it flows in one direction along the paper surface of the paper 20 as in this embodiment. An air flow cannot be formed.

  An air flow path is formed between the ribs 24 so as to be sandwiched between the base member 25 and the second surface of the paper 20. For this reason, the air flow formed in the space between the ribs 24 flows in one direction while contacting the paper surface of the paper 20. In the transport section, an air supply fan 27 serving as a source of air flow is provided on the upstream side in the paper transport direction. For this reason, the air flow flows in the direction along the paper transport direction from the upstream side to the downstream side in the paper transport direction.

  By forming an air flow that is in contact with the paper surface of the paper 20 on which the image has been fixed by the fixing device 13 and is parallel to the paper surface of the paper 20, the heat applied to the paper 20 by the image fixing is generated by the air flow. While being able to take away efficiently, the contact area of an airflow and the paper 20 can be ensured widely. For this reason, for example, when an air flow forming means is provided on the downstream side in the paper conveyance direction of the fixing device 13 as a curl correcting device for correcting the curling of the paper, and the paper immediately after fixing is cooled by the air flow to suppress the curling. The sheet immediately after fixing can be efficiently cooled with an air flow, and curling can be effectively suppressed.

  In addition, as a configuration of the air flow forming unit, an air flow may be formed in a direction along the paper width direction orthogonal to the paper transport direction. In that case, the air flow forming unit is directed from one to the other in the paper width direction. Thus, the air flow is formed, and the paper is conveyed in a direction intersecting (orthogonal) with the air flow. Therefore, there is a difference in the paper rejection effect between the upstream side and the downstream side of the air flow. On the other hand, when the configuration in which the air flow is formed in the direction along the paper conveyance direction, the air flow is formed from one side to the other in the paper conveyance direction, and the paper is directed in the direction along the flow of the air flow. Therefore, there is no difference in the cooling effect of the paper between the upstream side and the downstream side of the air flow.

  Further, by forming an air flow in the space between the ribs 24 where the second surface of the paper 20 is exposed, the air flow can be brought into contact with the paper 20 without waste. Further, by configuring the sheet transport guide member with the plurality of ribs 24, it is possible to ensure a wide area of the sheet 20 exposed to the space where the air flow is formed.

  Further, as the configuration of the air flow forming means, various configurations other than those using a plurality of ribs 24 can be adopted.

[First Modification of Air Flow Forming Means]
6-8 is a figure which shows the 1st modification of an airflow formation means. As shown in the drawing, two side plates 29 are provided on the base member 25 so as to be positioned on one side and the other side in the paper width direction. A plurality of linear members 30 each having an L shape are provided between the two side plates 29. Each linear member 30 is attached in a direction parallel to the paper transport direction. Further, the respective linear members 30 are arranged at a predetermined interval in the paper width direction orthogonal to the paper transport direction.

  When the sheet conveyance guide member is configured using the plurality of linear members 30 as described above, the contact state between the second surface of the sheet 20 and each linear member 30 is a line contact state along the sheet conveyance direction. Become. Further, the second surface of the sheet 20 is exposed to the space formed by each linear member 30. Therefore, the air flow can be brought into contact with the paper 20 without waste, and a large area of the paper 20 exposed in the space where the air flow is formed can be secured.

[Second Modification of Air Flow Forming Means]
9-11 is a figure which shows the 2nd modification of an airflow formation means. As illustrated, a plurality of rollers (paper support members) 31 are provided on the base member 25 between two side plates 29 provided on one side and the other side in the paper width direction. Each roller 31 is formed in a disc shape, and is rotatably provided in a state where the plate surface (side surface) of the disc is directed in a direction (paper width direction) orthogonal to the paper transport direction. The rollers 31 are provided in a plurality of rows (four rows in the example) aligned in a direction orthogonal to the paper transport direction, and are also provided in a plurality of rows (three rows in the diagram) in the paper transport direction.

  Thus, when a paper conveyance guide member is comprised using the several roller 31, the contact state of the 2nd surface of the paper 20 and each roller 31 will be a line contact state. Further, the second surface of the paper 20 is exposed to the space formed by each roller 31. Therefore, the air flow can be brought into contact with the paper 20 without waste, and a large area of the paper 20 exposed in the space where the air flow is formed can be secured. Further, the conveyance resistance of the paper 20 can be reduced by the rotation of each roller 31.

  Although not shown, for example, instead of the roller 31 described above, it is also possible to configure the paper transport guide member using a conical member with a rounded tip. When such a configuration is adopted, the contact state between the paper surface of the sheet and the conical member is a point contact state. Further, the paper surface of the paper is exposed to a space formed by each conical member. Therefore, the same effect as described above can be obtained.

[Third Modification of Air Flow Forming Means]
12-14 is a figure which shows the 3rd modification of an airflow formation means. As shown in the drawing, a plurality of ribs 32 are provided on the base member 25 in the paper width direction, and an opening plane member 33 is provided so as to cover these ribs 32. The opening plane member 33 is a flat plate-like member as a whole. A plurality of holes 34 are formed in the opening plane member 33. Each hole 34 is formed in a circular shape so as to penetrate the opening flat member 33 in the plate thickness direction. Each of the holes 34 is formed in a row at a predetermined interval (three in the illustrated example) between the ribs 32 adjacent in the paper width direction at regular intervals.

  When the sheet conveyance guide member is configured using the opening plane member 33 as described above, a plurality of holes formed in the opening plane member 33 when an air flow is poured into the space formed between the ribs 32. The surface of the sheet 20 and the air flow come into contact with each other via the line 34. At that time, as shown in FIG. 15, a negative pressure is generated by the air flow flowing through the space formed by the ribs 32 at each hole 34 forming portion, and the sheet 20 is applied to the opening plane member 33 by the action of this negative pressure. Sucked. For this reason, flapping of the paper 20 conveyed along the opening plane member 33 can be prevented.

  In addition, as shown in FIG. 16, when the opening plane member 33 serving as a sheet conveyance guide member is configured by a mesh-like member, by appropriately setting the mesh interval in the opening plane member 33, the air flow and the sheet In addition to ensuring a wide contact area, it is possible to prevent paper flapping by applying negative pressure to the paper surface of the paper.

[Second Embodiment]
FIG. 17 is a schematic diagram showing a configuration of an image forming apparatus according to the second embodiment of the present invention. The image forming apparatus according to the second embodiment is different from the first embodiment in the configuration of a fan serving as an air flow generation source. That is, in the first embodiment, the air flow is formed using the air supply fan 27, but in the second embodiment, the air flow is formed using the exhaust fan 35. For this reason, when the air flow is generated by driving the exhaust fan 35, the air flow along the paper surface of the paper flows from the downstream side to the upstream side in the paper transport direction. In this case, the paper traveling direction and the air flow direction are opposite to each other. For this reason, as compared with the case where the air flow is formed from the upstream side to the downstream side in the paper conveyance direction as in the first embodiment, the relative speed difference between the paper and the air flow in the paper conveyance direction becomes large. . Therefore, the paper can be efficiently cooled.

[Third Embodiment]
FIG. 18 is a schematic view showing a configuration of an image forming apparatus according to the third embodiment of the present invention. In the image forming apparatus according to the third embodiment, an exhaust fan 35 is provided on the downstream side in the sheet conveyance direction in the sheet conveyance section from the fixing device 13 to the conveyance roll pair 14. When an air flow is generated by driving the exhaust fan 35, the air flow along the paper surface of the paper flows from the upstream side to the downstream side in the paper transport direction.

[Fourth Embodiment]
FIG. 19 is a schematic diagram showing the configuration of an image forming apparatus according to the fourth embodiment of the present invention. In the image forming apparatus according to the fourth embodiment, an air supply fan 27 is provided on the downstream side in the paper transport direction in the paper transport section from the fixing device 13 to the transport roll pair 14. When an air flow is generated by driving the air supply fan 27, the air flow along the paper surface of the paper flows from the downstream side to the upstream side in the paper transport direction. In this case as well, for the same reason as in the second embodiment, the relative speed difference between the paper and the air flow increases in the paper transport direction, so that the paper can be efficiently cooled.

[Fifth Embodiment]
FIG. 20 is a schematic diagram showing the configuration of an image forming apparatus according to the fifth embodiment of the present invention. In the image forming apparatus according to the fifth embodiment, an air supply fan 27 is provided on the upstream side in the paper transport direction in the paper transport section from the fixing device 13 to the transport roll pair 14, while the downstream side in the paper transport direction. The exhaust fan 35 is provided in the configuration. When an air flow is generated by driving these fans 27 and 35, the air flow along the paper surface of the paper flows from the upstream side to the downstream side in the paper transport direction. In this case, a relatively strong air flow can be formed along the paper surface of the paper due to the synergistic effect of air supply and exhaust.

[Sixth Embodiment]
FIG. 21 is a schematic diagram showing the configuration of an image forming apparatus according to the sixth embodiment of the present invention. In the image forming apparatus according to the sixth embodiment, an exhaust fan 35 is provided on the upstream side in the paper transport direction in the paper transport section from the fixing device 13 to the transport roll pair 14, and on the downstream side in the paper transport direction. The air supply fan 27 is provided. When an air flow is generated by driving these fans 27 and 35, the air flow along the paper surface of the paper flows from the downstream side to the upstream side in the paper transport direction. In this case as well, for the same reason as in the second embodiment, the relative speed difference between the paper and the air flow increases in the paper transport direction, so that the paper can be efficiently cooled. Further, as in the fifth embodiment, a relatively strong air flow can be formed along the paper surface of the sheet due to the synergistic effect of air supply and exhaust.

  In the second to sixth embodiments, the plurality of ribs 24 described above are used as the configuration of the sheet conveyance guide member disposed in the sheet conveyance section from the fixing device 13 to the conveyance roll pair 14. It is possible to employ the configuration and the configuration of the sheet conveyance guide member described in the first to third modifications.

[Seventh Embodiment]
22 to 24 are schematic views showing the configuration of an image forming apparatus according to the seventh embodiment of the present invention. In the image forming apparatus according to the seventh embodiment, a paper transport guide member 36 that is paired with the paper transport guide member 23 is provided at a position facing the paper transport guide member 23 described above. The sheet conveyance guide member 36 includes a support portion 36A that supports the sheet 20 fed out by the fixing roller pair (21, 22) from the lower side, and a recess portion 36B that is recessed from the support portion 36A in a direction away from the sheet surface of the sheet. have. In the paper width direction, concave portions 36B are formed on both sides of the support portion 36A. In addition, the sheet conveyance guide member 36 forms an air flow path from one recess 36B through the lower side of the support portion 36A to the other recess 36B. The air flow path is formed along the paper width direction orthogonal to the paper transport direction. A blower 37 is provided on one end side of the sheet conveyance guide member 36. The blower 37 is connected to an air flow path formed by the paper transport guide member 36.

  On the other hand, a sheet pressing member 38 is attached to the upper sheet conveyance guide member 23. The sheet pressing member 38 is constituted by a film-like member having appropriate elasticity (flexibility) such as a thin plastic film. The sheet pressing member 38 is formed in a rectangular shape in plan view. In addition, the edge portion of the sheet pressing member 38 arranged on the upstream side in the sheet conveyance direction is fixed in a state where it is attached to the sheet conveyance guide member 23 using, for example, an adhesive or the like. The portion is pressed toward the sheet conveyance guide member 36 by the elastic force of the sheet pressing member 38 itself.

  In the image forming apparatus configured as described above, a sheet conveyance path is formed by the sheet conveyance guide member 23 provided in the sheet conveyance section from the fixing device 13 to the conveyance roll pair 14 and the sheet conveyance guide member 36 opposed thereto. Then, the paper on which the image has been fixed is transported along the paper transport path. At that time, the first surface of the paper 20 on which the toner image has been fixed through the contact between the heating roll 21 and the pressure roll 22 by the fixing device 13 comes into contact with the paper pressing member 38, so that the image has been fixed. The sheet 20 is pressed against the sheet conveyance guide member 36 by the sheet pressing member 38. For this reason, flapping of the paper 20 on the paper transport path can be prevented.

  Further, the second surface of the paper 20 is transported downstream in the transport direction along the support portion 36 </ b> A of the paper transport guide member 36. At that time, when air is sent to the air flow path formed by the paper transport guide member 36 by driving the blower 37, the air passes from one recess 36B through the space below the support portion 36A and reaches the other recess 36B. It flows along the air flow path. At this time, the second surface of the paper is exposed in the space formed by the concave portions 36B on both sides. Therefore, the air flow that flows along the air flow path is a one-way air flow that is in contact with the paper surface (second surface) of the paper 20 on which the image is fixed by the fixing device 13 and is parallel to the paper surface of the paper 20. .

  Therefore, the heat applied to the paper 20 by fixing the image can be efficiently taken away by the air flow, and a wide contact area between the air flow and the paper 20 can be secured. For this reason, for example, when an air flow forming means is provided on the downstream side in the paper conveyance direction of the fixing device 13 as a curl correcting device for correcting the curling of the paper, and the paper immediately after fixing is cooled by the air flow to suppress the curling. The sheet immediately after fixing can be efficiently cooled with an air flow, and curling can be effectively suppressed.

  Further, the sheet pressing member 38 can be provided in the image forming apparatus according to the first to sixth embodiments.

  In each of the above embodiments, the configuration in which the paper 20 is horizontally transported in the paper transport section from the fixing device 13 to the transport roll pair 14 is shown. However, the present invention is not limited to this, and for example, as shown in FIG. Thus, the present invention can be similarly applied to a configuration in which the sheet 20 is vertically conveyed in the sheet conveyance section from the fixing device 13 to the conveyance roll pair 14.

  In each of the above-described embodiments, the configuration in which the air flow is formed on the second surface side of the sheet 20 sent out from the fixing device 13 is not limited to this. For example, as illustrated in FIG. It is also possible to adopt a configuration in which an air flow is formed on both the first surface side and the second surface side of the sheet 20 sent out from the sheet 13. Although not shown, it is also possible to adopt a configuration in which an air flow is formed on the first surface side of the sheet 20 sent out from the fixing device 13.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus to which the present invention is applied. 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. It is a figure (the 1) which shows the structural example of an air flow formation means. It is a figure (the 2) which shows the structural example of an airflow formation means. It is FIG. (3) which shows the structural example of an air flow formation means. It is a figure (the 1) which shows the 1st modification of an airflow formation means. It is a figure (the 2) which shows the 1st modification of an airflow formation means. It is FIG. (3) which shows the 1st modification of an airflow formation means. It is a figure (the 1) which shows the 2nd modification of an airflow formation means. It is a figure (the 2) which shows the 2nd modification of an airflow formation means. It is a figure (the 3) which shows the 2nd modification of an airflow formation means. It is a figure (the 1) which shows the 3rd modification of an airflow formation means. It is a figure (the 2) which shows the 3rd modification of an airflow formation means. It is a figure (the 3) which shows the 3rd modification of an airflow formation means. It is a figure for demonstrating the effect | action of the negative pressure produced by an air flow. It is a figure which shows the other structural example of an opening plane member. It is the schematic which shows the structure of the image forming apparatus which concerns on 2nd Embodiment of this invention. It is the schematic which shows the structure of the image forming apparatus which concerns on 3rd Embodiment of this invention. It is the schematic which shows the structure of the image forming apparatus which concerns on 4th Embodiment of this invention. It is the schematic which shows the structure of the image forming apparatus which concerns on 5th Embodiment of this invention. It is the schematic which shows the structure of the image forming apparatus which concerns on 6th Embodiment of this invention. It is the schematic (the 1) which shows the structure of the image forming apparatus which concerns on 7th Embodiment of this invention. It is the schematic (the 2) which shows the structure of the image forming apparatus which concerns on 7th Embodiment of this invention. FIG. 10 is a schematic diagram (part 3) illustrating a configuration of an image forming apparatus according to a seventh embodiment of the present invention. FIG. 10 is a diagram illustrating an application example when a sheet is conveyed in a vertical direction. It is a figure which shows the example of application in the case of forming an air flow on both surfaces of a paper.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 13 ... Fixing device, 24 ... Rib, 25 ... Base member, 26 ... Duct, 27 ... Air supply fan, 28 ... Inclined part, 29 ... Side plate, 30 ... Linear member, 31 ... Roller, 32 ... Rib, 33 ... Open plane member, 34 ... Hole, 35 ... Exhaust fan, 36 ... Paper transport guide member, 37 ... Blower, 38 ... Paper holding member

Claims (8)

A fixing device that fixes an image on paper using at least heat;
An image forming apparatus comprising: an air flow forming unit that forms an air flow in contact with a paper surface of the paper on which the image is fixed by the fixing device and parallel to the paper surface of the paper. The image forming apparatus according to claim 1, wherein the air flow forming unit forms an air flow in a direction along a paper conveyance direction. The image forming apparatus according to claim 2, wherein the air flow forming unit forms an air flow from the downstream side toward the upstream side in the paper conveyance direction. The air flow forming means includes a paper transport guide member that is provided downstream of the fixing device in the paper transport direction and forms a space in which the paper surface of the paper is exposed, and forms the air flow in the space. The image forming apparatus according to claim 1, wherein: 5. The image forming apparatus according to claim 4, wherein the sheet conveyance guide member includes a plurality of sheet support members that are in contact with the paper surface of the sheet in a point contact state or a line contact state on the downstream side in the sheet conveyance direction of the fixing device. apparatus. The image forming apparatus according to claim 5, wherein the sheet supporting member is configured by a rotatable roller. The image forming apparatus according to claim 4, wherein the sheet conveyance guide member includes an opening plane member in which a plurality of holes are formed. The image forming apparatus according to claim 4, further comprising a sheet pressing member that presses a sheet against the sheet conveyance guide member.

Images