JP2007271890A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of performing an appropriate image forming operation by preventing failures such as toner-melting and toner-sticking in a cleaning device for an intermediate transfer body. <P>SOLUTION: The image forming apparatus 1 for performing the image forming operation by using an intermediate transfer belt 8 as the intermediate transfer body is provided with a cooling device 20 which is arranged on the downstream side of the secondary transfer part 11 in a belt rotating direction and on the upstream side of the belt cleaning device 12 and includes: an air blow fan 22 for blowing the surface of the intermediate transfer belt 8; an exhaust duct 21 for guiding the heat of the intermediate transfer belt 8 and the toner left on the surface of the intermediate transfer belt 8; and a toner recovery tank 24 for recovering the residual toner guided by the exhaust duct 21. Consequently, before the intermediate transfer belt 8 reaches the belt cleaning device 12 after the toner image is secondarily transferred to a paper P, the intermediate transfer belt 8 itself and also the toner left on the surface of the intermediate transfer belt 8 are directly cooled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus represented by a copying machine or a printer.

  In an image forming apparatus represented by a copying machine or a printer, a heat roller fixing method is widely adopted as a method for fixing an unfixed toner image on a sheet. In the heat roller fixing method, a heat source is built in at least one roller of a roller pair forming a nip, and a toner carrying an unfixed toner image is inserted into the nip of the roller pair heated by the heat source, thereby supplying toner to the paper. To fix.

  However, in an image forming apparatus using an intermediate transfer body, the intermediate transfer body itself can easily retain heat. Particularly in recent image forming apparatuses, speeding up has been promoted, and the temperature rise is remarkable. There is a concern that this temperature increase of the intermediate transfer member hinders the operation of the image forming apparatus.

  When the temperature of the intermediate transfer member rises, the toner remaining on the surface of the intermediate transfer member after the toner image transfer may melt and adhere to the surface of the intermediate transfer member. This may adversely affect the next image formation and may cause image defects such as image offset. When the toner fixed on the surface of the intermediate transfer member is further accumulated, the image quality is greatly deteriorated. Therefore, it is necessary to cool the intermediate transfer member after the toner image transfer immediately.

  On the other hand, the temperature rise around the cleaning device for removing the toner remaining on the surface of the intermediate transfer body after the toner image transfer due to the temperature rise of the intermediate transfer body is also a serious problem. When the temperature around the cleaning device rises, the toner in the device melts and the fluidity deteriorates, and there is a possibility that the toner adheres to a screw or the like for conveying and stirring the toner. When the toner adheres to the screw and further accumulates, the toner conveyance performance is significantly reduced. Then, there is a possibility that the waste toner overflows and contaminates the surrounding area, or the waste toner adheres to the intermediate transfer member again and the cleaning performance deteriorates. Moreover, there is a possibility that the screw may be damaged by braking the rotation of the screw.

In order to solve such a problem, various methods for avoiding the temperature rise of the intermediate transfer member have been proposed, and examples thereof can be seen in Patent Documents 1 and 2. In the image forming apparatus described in Patent Document 1, the intermediate transfer belt is cooled by blowing air to the belt surface by a fan on the downstream side in the belt rotation direction of the cleaning device for cleaning the surface of the intermediate transfer belt (intermediate transfer member). ing. Further, in the image forming apparatus described in Patent Document 2, a partition member that partitions between the fixing device and the image forming unit is provided so that the intermediate transfer belt is not affected by the heat of the fixing device.
Japanese Patent Laying-Open No. 2003-29540 (page 3-4, FIG. 1) Japanese Patent Laying-Open No. 2005-301112 (page 4-6, FIG. 3)

  In the image forming apparatus described in Patent Document 1, it is possible to prevent the temperature of the intermediate transfer belt (intermediate transfer member) from rising by blowing air toward the belt surface using a fan. However, since the portion to be cooled is downstream of the intermediate transfer belt cleaning device in the belt rotation direction, the toner remaining on the surface of the intermediate transfer belt is directly cooled after the toner image is transferred and before reaching the cleaning device. I can't. As a result, the heated toner is collected by the cleaning device and may be melted and fixed in the device.

  In the image forming apparatus described in Patent Document 2, since the partition member does not affect the heat of the fixing device, an increase in the temperature of the intermediate transfer belt (intermediate transfer member) due to radiant heat from the fixing device is prevented. It is possible. However, this method cannot cool the heat transferred from the paper to the intermediate transfer belt during duplex printing in the transfer unit that transfers the toner image to the paper, and cannot prevent the heat from being transferred. . Therefore, it is difficult to reliably prevent the toner from adhering to the intermediate transfer belt and the occurrence of problems in the cleaning device due to the influence of heat.

  The present invention has been made in view of the above points, and after the secondary transfer of a toner image onto a sheet and before reaching the cleaning device, the intermediate transfer member itself and the toner remaining on the surface of the intermediate transfer member are efficiently removed. It is an object of the present invention to provide an image forming apparatus that can be cooled and that can prevent an unintended melting and fixing of the toner and the like and perform a suitable image forming operation.

  In order to solve the above problems, the present invention primarily transfers a toner image of at least one color from an image carrier to an intermediate transfer member, and secondary transfer from the intermediate transfer member to a sheet, and secondary transfer of the toner image Thereafter, in the image forming apparatus for cleaning the toner remaining on the surface of the intermediate transfer member by a cleaning device, the intermediate transfer member is disposed downstream of the secondary transfer portion in the intermediate transfer member rotation direction and upstream of the cleaning device. A blowing fan that blows air onto the surface of the sheet, an exhaust duct that induces heat of the intermediate transfer member and residual toner on the surface of the intermediate transfer member, and a toner collection tank that collects residual toner induced in the exhaust duct. The cooling device provided was provided.

  In the image forming apparatus configured as described above, the exhaust duct includes a guide plate that guides the air blown by the blowing fan to a substantially central portion in the width direction of the intermediate transfer member.

  In the image forming apparatus configured as described above, the exhaust duct includes an exhaust fan that forcibly generates an air flow.

  Further, the present invention primarily transfers a toner image of at least one color from an image carrier to an intermediate transfer member, secondary transfer from the intermediate transfer member to a sheet, and after the toner image is secondarily transferred, In the image forming apparatus for cleaning the toner remaining on the surface of the intermediate transfer body, the heat is applied from the back surface of the intermediate transfer body to the downstream side of the secondary transfer portion in the rotation direction of the intermediate transfer body and upstream of the cleaning device. The cooling device includes a heat absorption part that absorbs heat and a heat radiation part that releases heat to the outside, and is provided with a heat pipe that moves heat between the heat absorption part and the heat radiation part.

  In the image forming apparatus having the above configuration, the heat radiating unit includes a heat radiating fin and a cooling fan for cooling the heat radiating fin.

  According to the configuration of the present invention, in the image forming apparatus that cleans the toner remaining on the surface of the intermediate transfer member by the cleaning device after the secondary transfer of the toner image onto the paper, the secondary transfer unit on the downstream side in the rotation direction of the intermediate transfer member A blowing fan that blows air onto the surface of the intermediate transfer member, an exhaust duct that induces heat of the intermediate transfer member and residual toner on the surface of the intermediate transfer member, and the exhaust duct on the upstream side of the cleaning device And a cooling device provided with a toner recovery tank for recovering the residual toner induced in the intermediate transfer member, the residual toner on the surface of the intermediate transfer member is removed downstream of the intermediate transfer member cleaning device in the rotation direction of the intermediate transfer member. Direct cooling is possible. Further, since the toner collecting means is also provided, it is possible to prevent the residual toner from being scattered due to the blowing of air onto the surface of the intermediate transfer member. Thereby, after the secondary transfer of the toner image onto the paper and before reaching the cleaning device, the intermediate transfer member itself and the toner remaining on the surface of the intermediate transfer member can be efficiently cooled. Accordingly, it is possible to avoid the temperature increase of the intermediate transfer member, and it is possible to prevent the occurrence of various problems due to the temperature increase such as unintended melting and fixing of toner in the cleaning device, and to perform a suitable image forming operation. Image forming apparatus can be provided.

  Further, since the exhaust duct is provided with a guide plate that guides the air blown by the blowing fan to the substantially central portion in the width direction of the intermediate transfer member, the exhaust duct is provided at the central portion in the width direction of the intermediate transfer member that is relatively likely to rise in temperature. On the other hand, air can be sprayed intensively. As a result, the cooling efficiency of the intermediate transfer member can be increased, and the effect of preventing the occurrence of problems such as melting and fixing of toner can be improved.

  In addition, since the exhaust duct is provided with an exhaust fan that forcibly generates an air flow, the air heated from the intermediate transfer member can be quickly discharged. Therefore, it is possible to further improve the cooling efficiency of the intermediate transfer member, and it is possible to further enhance the effect on the execution of a suitable image forming operation that prevents the occurrence of problems such as melting and fixing of toner.

  Further, according to the configuration of the present invention, in the image forming apparatus that cleans the toner remaining on the surface of the intermediate transfer body by the cleaning device after the secondary transfer of the toner image to the paper, the rotation direction of the intermediate transfer body of the secondary transfer unit A downstream side, upstream of the cleaning device, has a heat absorbing part that absorbs heat from the back surface of the intermediate transfer member, and a heat radiating part that releases heat to the outside. The intermediate transfer member can be cooled on the downstream side of the intermediate transfer member rotation direction of the intermediate transfer member cleaning device. Further, since the back surface of the intermediate transfer member is cooled by the heat pipe, the residual toner is not scattered due to air blowing or the like. Thereby, after the secondary transfer of the toner image onto the paper and before reaching the cleaning device, the intermediate transfer member itself and the toner remaining on the surface of the intermediate transfer member can be efficiently cooled. Accordingly, it is possible to avoid the temperature increase of the intermediate transfer member, and it is possible to prevent the occurrence of various problems due to the temperature increase such as unintended melting and fixing of toner in the cleaning device, and to perform a suitable image forming operation. Image forming apparatus can be provided.

  Further, since the heat radiating section includes the heat radiating fin and the cooling fan for cooling the heat radiating fin, the heat taken from the intermediate transfer member can be quickly radiated to cool the heat pipe. Therefore, it is possible to further improve the cooling efficiency of the intermediate transfer member, and it is possible to further enhance the effect on the execution of a suitable image forming operation that prevents the occurrence of problems such as melting and fixing of toner.

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

  First, the image output operation of the image forming apparatus according to the first embodiment of the present invention will be described while explaining the outline of the structure with reference to FIG. FIG. 1 is a schematic vertical sectional front view of an image forming apparatus. This image forming apparatus is of a color printing type in which a toner image is transferred onto a sheet using an intermediate transfer belt.

  As shown in FIG. 1, a cassette type paper feeding unit 3, which is a paper storage unit, is disposed below the main body 2 of the image forming apparatus 1. In the cassette type paper feeding section 3, paper P such as cut paper before printing is stacked and stored, and the paper P is separated and sent out one by one. The cassette type paper feed unit 3 includes a two-stage paper cassette 4. The paper feed cassette 4 can be pulled out by sliding to the front side with respect to the main body 2.

  A manual paper feeder 5 is provided outside the upper right side of the main body 2. On the manual sheet feeding unit 5, paper P having a size that is not accommodated in the cassette type sheet feeding unit 3 or a sheet to be fed one by one such as an OHP sheet is placed.

  The image forming apparatus 1 includes a paper transport unit 6 therein. The sheet conveyance unit 6 is located on the right side in the sheet feeding direction in terms of the cassette type sheet feeding unit 3, and is located on the left side in terms of the manual sheet feeding unit 5. The paper P delivered from the cassette type paper feed unit 3 is conveyed vertically upward along the side surface of the main body 2 by the paper conveyance unit 6, and the paper P delivered from the manual paper supply unit 5 is conveyed substantially horizontally to the left.

  A registration roller 7 is provided at the downstream end of the sheet conveying unit 6 in the sheet conveying direction and immediately upstream of the secondary transfer unit 11. The registration roller 7 feeds the paper P toward the secondary transfer unit 11 in synchronization with the toner image formed on the surface of the intermediate transfer belt 8 while correcting the oblique feeding of the paper P.

  Above the position of the registration roller 7, an intermediate transfer belt 8 which is an intermediate transfer body used in the form of an endless belt is provided. The intermediate transfer belt 8 is wound around and supported by a plurality of rollers, and is rotated clockwise in FIG. 1 by a driving device (not shown).

  The intermediate transfer belt 8 is wound around each roller so that the cross-sectional shape perpendicular to the axial direction of each roller supporting the intermediate transfer belt 8 is substantially triangular. The intermediate transfer belt 8 is provided such that the upper surface thereof is substantially horizontal, and a total of five image forming units 9 are provided on the upper surface. The five image forming units 9 are of a so-called tandem type arranged in a line along the rotation direction of the intermediate transfer belt 8 from the upstream side to the downstream side in the rotation direction.

  In each image forming unit 9, an electrostatic latent image of a document image is formed by laser light irradiated by an exposure device (not shown), and a toner image is developed from the electrostatic latent image. A primary transfer unit 10 is provided at a location where each image forming unit 9 contacts the intermediate transfer belt 8, and in this primary transfer unit 10, the toner image formed by the image forming unit 9 is primary transferred onto the surface of the intermediate transfer belt 8. Is done. Then, the toner images of the respective image forming units 9 are sequentially transferred to the intermediate transfer belt 8 at a predetermined timing as the intermediate transfer belt 8 rotates, so that a total of five color toner images are superimposed on the surface of the intermediate transfer belt 8. A multiple full color toner image is formed.

  A secondary transfer unit 11 is disposed at a position where the intermediate transfer belt 8 is suspended on the sheet conveyance path. The color toner image on the surface of the intermediate transfer belt 8 is secondarily transferred by the secondary transfer unit 11 onto the paper P sent in synchronization by the registration roller 7.

  After the secondary transfer of the toner image, the toner remaining on the surface of the intermediate transfer belt 8 is cleaned and collected by a belt cleaning device 12 provided downstream of the secondary transfer portion 11 in the belt rotation direction.

  A fixing unit 13 is provided on the downstream side of the secondary transfer unit 11 in the sheet conveyance direction. The paper P carrying the unfixed toner image in the secondary transfer unit 11 is sent to the fixing unit 13 where the toner image is heated and pressed by a heat roller and a pressure roller to be fixed.

  A branching portion 14 is provided on the downstream side of the fixing portion 13 and in the vicinity of the left side surface of the main body 2. The sheet P discharged from the fixing unit 13 is discharged from the branching unit 14 to a sheet receiving tray 15 which is a sheet discharging unit outside the apparatus when double-sided printing is not performed.

  A double-sided printing unit 16, which is a double-sided printing device, is provided below the portion from the registration roller 7 to the branching unit 14 and above the cassette type paper feeding unit 3. When performing double-sided printing, the paper P that has been printed on the first side and discharged from the fixing unit 13 is sent to the double-sided printing unit 16 through the branching unit 14. The transport direction of the paper P sent to the duplex printing unit 16 is subsequently switched for printing on the second side, and is sent again to the secondary transfer unit 11 via the paper transport unit 6 and the registration roller 7.

  In such an image forming apparatus 1, a cooling device 20 for cooling the surface of the intermediate transfer belt 8 is provided downstream of the secondary transfer unit 11 in the belt rotation direction and upstream of the belt cleaning device 12. ing.

  Next, the detailed configuration of the cooling device 20 will be described with reference to FIGS. 2 to 4 in addition to FIG. 2 is a schematic vertical sectional front view of the cooling device, FIG. 3 is a perspective view of the cooling device, and FIG. 4 is a partially enlarged perspective view showing the periphery of the blowing fan of the cooling device. 2 and 4, white arrows in the drawings indicate the direction in which air flows.

  As shown in FIGS. 2 and 3, the cooling device 20 is provided with an exhaust duct 21, a blowing fan 22, an exhaust fan 23, and a toner recovery tank 24.

  The exhaust duct 21 is downstream of the intermediate transfer belt 8 in the belt rotation direction of the secondary transfer unit 11 and upstream of the belt cleaning device 12, and the exhaust duct 21 of the main body 2 of the image forming apparatus 1 shown in FIG. It is provided so as to extend to the left side.

  As shown in FIG. 2, a heat absorption box 21 a is provided at the most upstream portion of the exhaust duct 21 in the air circulation direction and closest to the intermediate transfer belt 8 to remove the heat. The endothermic box 21a has a box-like shape having a rectangular parallelepiped extending in the belt width direction perpendicular to the belt rotation direction and having a surface facing the surface of the intermediate transfer belt 8 open below the intermediate transfer belt 8. The exhaust duct 21 removes heat from the surface of the intermediate transfer belt 8 from the opening of the heat absorption box 21a.

  As shown in FIG. 3, a blowing fan 22 is provided at a location of the heat absorption box 21 a of the exhaust duct 21. The blowing fans 22 are provided at two locations on both ends of the heat absorption box 21 a in the belt width direction of the intermediate transfer belt 8. The blowing fan 22 is a sirocco fan, and is arranged in such a manner that air sucked from the outside of the image forming apparatus 1 is blown onto the surface of the intermediate transfer belt 8. As shown in FIGS. 3 and 4, the air blown by the blowing fan 22 is placed inside the endothermic box 21 a and beyond the outlet 22 a of the blowing fan 22. A guide plate 21b is provided for guiding it to a substantially central portion in the belt width direction. One guide plate 21b is provided for each of the two blowing fans 22 (see FIG. 3).

  Further, an exhaust fan 23 is provided inside the heat absorption box 21a and downstream of the guide plate 21b in the air flow direction. The exhaust fan 23 is configured by a cross flow fan, and the axis thereof is provided so as to be substantially parallel to the surface of the intermediate transfer belt 8 in the belt width direction. The exhaust fan 23 forcibly generates an air flow in the exhaust duct 21.

  As shown in FIG. 2, an exhaust port 21 c is provided on the most downstream side of the exhaust duct 21 in the air flow direction. The exhaust port 21c is provided on the left side surface of the image forming apparatus main body 2 (see FIG. 1). Air flowing through the exhaust duct 21 is discharged from the exhaust port 21c to the outside of the image forming apparatus 1.

  A filter 21 d is provided slightly upstream of the exhaust port 21 c of the exhaust duct 21. The filter 21d collects the residual toner contained in the air sucked into the exhaust duct 21 from the location of the heat absorption box 21a so as not to be discharged to the outside from the exhaust port 21c.

  On the other hand, the exhaust duct 21 branches at a location immediately upstream of the filter 21d into a flow path that continues to the exhaust port 21c and a flow path that continues downward. A toner recovery tank 24 is provided at the end of the flow path continuing below. The residual toner collected by the filter 21d is collected in the toner collection tank 24 by free-falling or applying vibration to the filter 21d. For this reason, as shown in FIG. 2, the filter 21d is mounted in the exhaust duct 21 in an inclined state from the vertical direction.

  In this way, in the image forming apparatus 1 that cleans the toner remaining on the surface of the intermediate transfer belt 8 that is an intermediate transfer member by the belt cleaning device 12 after the secondary transfer of the toner image onto the paper P, the secondary transfer unit 11 on the downstream side in the belt rotation direction and upstream of the belt cleaning device 12, the blowing fan 22 that blows air onto the surface of the intermediate transfer belt 8, the heat of the intermediate transfer belt 8, and the intermediate transfer belt 8. Since the cooling device 20 provided with the exhaust duct 21 for guiding the residual toner on the surface and the toner recovery tank 24 for recovering the residual toner guided to the exhaust duct 21 is provided, the cleaning device 12 of the intermediate transfer belt 8 is provided. It is possible to directly cool the residual toner on the surface of the intermediate transfer belt 8 on the downstream side in the belt rotation direction. Further, since the toner collection tank 24 which is a toner collection unit is also provided, it is possible to prevent the residual toner from being scattered due to the blowing of air onto the surface of the intermediate transfer belt 8. Thus, after the secondary transfer of the toner image onto the paper P and before reaching the belt cleaning device 12, the intermediate transfer belt 8 itself and the toner remaining on the surface of the intermediate transfer belt 8 can be efficiently cooled. . Accordingly, a temperature increase of the intermediate transfer belt 8 can be avoided, and various problems caused by the temperature increase such as unintentional melting and fixing of toner in the belt cleaning device 12 can be prevented and a suitable image forming operation can be performed. An image forming apparatus 1 that can do this can be provided.

  Further, since the exhaust duct 21 includes a guide plate 21b that guides the air blown by the blowing fan 22 to the substantially central portion in the width direction of the intermediate transfer belt 8, the center in the width direction of the intermediate transfer belt 8 that is relatively easy to rise in temperature. The air can be intensively blown against the part. As a result, the cooling efficiency of the intermediate transfer belt 8 can be increased, and the effect of preventing the occurrence of problems such as toner melting and fixing can be improved.

  Further, since the exhaust duct 21 includes the exhaust fan 23 that forcibly generates an air flow, the air heated by the intermediate transfer belt 8 can be quickly discharged. Accordingly, the cooling efficiency of the intermediate transfer belt 8 can be further improved, and the effect on the execution of a suitable image forming operation that prevents the occurrence of problems such as melting and fixing of toner can be further enhanced.

  Next, the structure of the image forming apparatus according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic vertical sectional front view of the image forming apparatus. Since the basic configuration of this embodiment is the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals as those in the previous embodiment, and the drawings of the common portions are used. Drawing and description shall be omitted.

  In the second embodiment, the cooling device 20 includes a heat pipe 25. The heat pipe 25 includes a heat absorbing part 26 and a heat radiating part 27.

  The heat pipe 25 is located downstream of the intermediate transfer belt 8 in the belt rotation direction of the secondary transfer unit 11 and upstream of the belt cleaning device 12. The heat pipe 25 of the main body 2 of the image forming apparatus 1 shown in FIG. It is provided so as to extend to the left side.

  The heat absorption part 26 is provided at a position of the heat pipe 25 closest to the intermediate transfer belt 8. The heat absorbing portion 26 extends substantially parallel to the belt width direction above the intermediate transfer belt 8, that is, at the back surface of the intermediate transfer belt 8, and is provided in contact with the back surface of the intermediate transfer belt 8. The heat pipe 25 absorbs heat from the back surface of the intermediate transfer belt 8 by the heat absorbing portion 26.

  The heat dissipating part 27 is provided in the vicinity of the left side surface of the image forming apparatus main body 2 extending from the heat absorbing part 26 of the heat pipe 25. The heat dissipating part 27 is also configured to extend in the belt width direction like the heat absorbing part 26. The heat dissipating part 27 includes heat dissipating fins 28 and cooling fans 29.

  The radiating fins 28 have a thin flat plate shape, and a plurality of the radiating fins 28 are arranged in the direction in which the heat pipe 25 extends, that is, the depth direction of the paper surface of FIG.

  The cooling fan 29 is provided so as to face the left side surface of the image forming apparatus main body 2. When the cooling fan 29 is driven, an air flow from the inside to the outside of the main body 2 is generated, and air is circulated between the fins at the location of the radiation fins 28. As a result, the radiating fins 28 are cooled by the cooling fan 29.

  Thus, in the image forming apparatus 1 that cleans the toner remaining on the surface of the intermediate transfer belt 8 by the belt cleaning device 12 after the secondary transfer of the toner image onto the paper P, the belt rotation direction of the secondary transfer portion 11 On the downstream side, on the upstream side of the belt cleaning device 12, there is a heat absorbing portion 26 that absorbs heat from the back surface of the intermediate transfer belt 8 and a heat radiating portion 27 that releases heat to the outside. Since the cooling device 20 provided with the heat pipe 25 that moves heat between the portion 26 and the heat radiating portion 27 is provided, the intermediate transfer belt 8 is located downstream of the cleaning device 12 in the belt rotation direction of the intermediate transfer belt 8. 8 can be cooled. Furthermore, since the back surface of the intermediate transfer belt 8 is cooled by the heat pipe 25, the residual toner is not scattered due to air blowing or the like. Thus, after the secondary transfer of the toner image onto the paper P and before reaching the belt cleaning device 12, the intermediate transfer belt 8 itself and the toner remaining on the surface of the intermediate transfer belt 8 can be efficiently cooled. . Accordingly, a temperature increase of the intermediate transfer belt 8 can be avoided, and various problems caused by the temperature increase such as unintentional melting and fixing of toner in the belt cleaning device 12 can be prevented and a suitable image forming operation can be performed. An image forming apparatus 1 that can do this can be provided.

  Further, since the heat radiating section 27 includes the heat radiating fins 28 and the cooling fan 29 that cools the heat radiating fins 28, the heat taken from the intermediate transfer belt 8 can be quickly dissipated to cool the heat pipe 25. it can. Therefore, the cooling efficiency of the intermediate transfer belt 8 can be further improved, and the effect on the execution of a suitable image forming operation that prevents the occurrence of problems such as melting and fixing of toner can be further enhanced.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  For example, in the first embodiment of the present invention, the blowing fan 22 and the exhaust fan 23 are each composed of a sirocco fan and a cross flow fan, but the types of each fan are limited to these. However, it may be replaced with another type of fan that can blow air onto the surface of the intermediate transfer belt 8 and generate a forced airflow in the exhaust duct 21.

  The present invention can be used in an image forming apparatus that performs an image forming operation using an intermediate transfer member.

1 is a schematic vertical sectional front view of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic vertical sectional front view of a cooling device of the image forming apparatus shown in FIG. 1. It is a perspective view of the cooling device shown in FIG. It is a partial expansion perspective view which shows the blowing fan periphery of the cooling device of FIG. FIG. 5 is a schematic vertical sectional front view of an image forming apparatus according to a second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body 8 Intermediate transfer belt (intermediate transfer body)
11 Secondary transfer section 12 Belt cleaning device (cleaning device)
DESCRIPTION OF SYMBOLS 13 Fixing part 20 Cooling device 21 Exhaust duct 21b Guide plate 22 Blowing fan 23 Exhaust fan 24 Toner collection tank 25 Heat pipe 26 Heat absorption part 27 Heat radiation part 28 Radiation fin 29 Cooling fan

Claims (5)

A toner image of at least one color is primarily transferred from the image bearing member to the intermediate transfer member, and is secondarily transferred from the intermediate transfer member to the paper. After the secondary transfer of the toner image, the toner image remains on the surface of the intermediate transfer member by a cleaning device. In an image forming apparatus for cleaning toner to be
A blowing fan that blows air onto the surface of the intermediate transfer member, downstream of the secondary transfer unit in the intermediate transfer member rotation direction and upstream of the cleaning device, heat of the intermediate transfer member, and intermediate transfer member An image forming apparatus comprising: a cooling device provided with an exhaust duct for inducing residual toner on the surface and a toner recovery tank for recovering residual toner induced in the exhaust duct.   The image forming apparatus according to claim 1, wherein the exhaust duct includes a guide plate that guides air blown by the blowing fan to a substantially central portion in a width direction of the intermediate transfer member.   The image forming apparatus according to claim 1, wherein the exhaust duct includes an exhaust fan that forcibly generates an air flow. A toner image of at least one color is primarily transferred from the image bearing member to the intermediate transfer member, and is secondarily transferred from the intermediate transfer member to the paper. After the secondary transfer of the toner image, the toner image remains on the surface of the intermediate transfer member by a cleaning device. In an image forming apparatus for cleaning toner to be
A heat transfer part that absorbs heat from the back surface of the intermediate transfer body and a heat dissipation part that releases heat to the outside on the downstream side of the secondary transfer part in the rotational direction of the intermediate transfer body and upstream of the cleaning device. An image forming apparatus comprising: a cooling device provided with a heat pipe that moves heat between the heat absorbing portion and the heat radiating portion.   The image forming apparatus according to claim 4, wherein the heat radiating portion includes a heat radiating fin and a cooling fan that cools the heat radiating fin.

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