JP2018054668A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can efficiently exhaust moisture in the vicinity of fixing means.SOLUTION: An image forming apparatus comprises: fixing means (pressure roller 32 and fixing film 33) that fixes a toner image to a recording material S ; cover members (conveyance guides 38 and 39, decurling roller 40, fixing covers 41 and 42, and entrance guide 37) that cover the fixing means; slits 43 that are provided in the fixing cover member 42; and a suction fan 52 that sucks air 20 from the slits 43.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, and a facsimile machine.

  An electrophotographic recording type image forming apparatus includes a fixing device that heat-fixes a toner image onto a recording material by a heating member and a pressure roller. Since the fixing device heats the toner and the recording material at a high temperature, a part of the water contained in the recording material is generated in the image forming apparatus as water vapor. This may cause condensation on the pressure roller surface of the fixing device.

  When condensation of a predetermined amount or more occurs on the surface of the pressure roller, a phenomenon that the fixing film or recording material in contact with the pressure roller slips occurs, causing problems such as jamming and image defects. In addition, when an image forming apparatus such as a cold start is in a low temperature state, water vapor adheres to the surface of the conveyance roller or the conveyance guide as water droplets, and if it adheres to the recording material, an image defect may occur during duplex printing. is there.

  In order to solve such a problem, in Patent Documents 1 and 2, air is blown onto the surface of the pressure roller to remove water adhering to the surface of the pressure roller. Moreover, in patent document 3, the water droplet receiving member which receives the water droplet which fell from the conveyance roller axis | shaft is installed.

JP 2007-206275 A JP 2008-116858 A JP 2003-146514 A

  However, in Patent Documents 1 and 2, the air blown to the surface of the pressure roller flows downstream in the transport direction together with the recording material. Although a certain amount of water droplets on the pressure roller side can be removed across the fixing nip portion, water droplets on the heating member side can hardly be removed. This may cause water droplets to adhere to the conveyance guide near the fixing nip and the conveyance roller downstream from the fixing nip.

  In Patent Document 3, water droplets on the surface of the pressure roller cannot be removed. Further, until the water droplet falls, the water droplet is attached to the conveyance roller shaft. When the transport roller shaft rotates with water droplets attached, the water droplets do not necessarily drop onto the water droplet receiving member. For example, water droplets may scatter and adhere to the conveyance guide surface or recording material.

  SUMMARY An advantage of some aspects of the invention is to provide an image forming apparatus capable of efficiently exhausting water vapor in the vicinity of a fixing unit.

  In order to achieve the above object, a typical configuration of an image forming apparatus according to the present invention includes a fixing unit that fixes a toner image on a recording material, a cover member that covers the fixing unit, and an opening provided in the cover member. And suction means for sucking air from the opening.

  According to the present invention, water vapor in the vicinity of the fixing unit can be exhausted efficiently.

1 is an explanatory cross-sectional view illustrating a configuration of an image forming apparatus according to the present invention. FIG. 2A is a cross-sectional explanatory view illustrating a state in which the recording material is exhausted outside the apparatus in the image forming apparatus of the first embodiment. (B) and (c) are cross-sectional explanatory views showing a state in which the recording material is conveyed to the double-sided conveyance path in the image forming apparatus of the first embodiment. FIG. 2 is an explanatory cross-sectional view illustrating a configuration of a fixing device according to the first embodiment. FIG. 2 is an explanatory perspective view illustrating a configuration of a fixing device according to the first embodiment. FIG. 3A is a perspective explanatory view seen from the front side of the image forming apparatus showing a state in which the fixing device of the first embodiment is mounted on the image forming apparatus. FIG. 2B is a perspective explanatory view seen from the front side of the image forming apparatus showing a state in which the fixing device of the first embodiment is mounted on the image forming apparatus. FIG. 3 is an explanatory cross-sectional view illustrating the air flow in the fixing device according to the first embodiment. FIG. 6 is an explanatory perspective view illustrating a configuration of a fixing device according to a second embodiment. FIG. 6A is a perspective explanatory view seen from the front side of the image forming apparatus showing a state in which the fixing device of the second embodiment is mounted on the image forming apparatus. FIG. 9B is a perspective explanatory view seen from the front side of the image forming apparatus showing a state in which the fixing device of the second embodiment is mounted on the image forming apparatus. (A) is a perspective explanatory drawing which shows the structure of the fixing device of 3rd Embodiment. FIG. 8B is a cross-sectional explanatory diagram illustrating a configuration of a fixing device according to a third embodiment. FIG. 9A is a perspective explanatory view seen from the front side of the image forming apparatus showing a state in which the fixing device of the third embodiment is mounted on the image forming apparatus. FIG. 7B is a perspective explanatory view seen from the front side of the image forming apparatus showing a state in which the fixing device of the third embodiment is mounted on the image forming apparatus.

  The configuration of the first embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS.

<Image forming apparatus>
First, the configuration of the image forming apparatus 1 of the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional explanatory view showing the configuration of the image forming apparatus 1 of the present embodiment. An image forming apparatus 1 illustrated in FIG. 1 is an image forming apparatus 1 that forms a full-color image using toner of each color of yellow Y, magenta M, cyan C, and black B. The main body of the image forming apparatus 1 is configured to be detachable from a plurality of image forming units 2a to 2d that form toner images of respective colors. For convenience of explanation, the image forming units 2a to 2d for the respective colors may be used as a representative for the description using the image forming unit 2. The same applies to other image forming process means.

  Each image forming unit 2 is provided with a photosensitive drum 17 serving as an image carrier so as to be rotatable clockwise in FIG. A charging roller 18 serving as charging means is provided around the photosensitive drum 17 that rotates clockwise in FIG. Further, an exposure device 19 serving as an image exposure unit is provided. Further, a developing device 29 serving as a developing unit is provided.

  The image forming apparatus 1 is provided with an intermediate transfer unit 3 having an intermediate transfer belt 4 that is an intermediate transfer member. The intermediate transfer belt 4 is stretched so as to be rotatable counterclockwise in FIG. 1 by stretching rollers 4a to 4c. A secondary transfer roller 5 serving as a secondary transfer unit is provided opposite to the stretching roller 4a with the intermediate transfer belt 4 interposed therebetween. A secondary transfer nip portion 15 is formed by the outer peripheral surface of the intermediate transfer belt 4 and the secondary transfer roller 5.

  A primary transfer roller 47 serving as a primary transfer unit is provided on the inner peripheral surface side of the intermediate transfer belt 4 so as to face each photosensitive drum 17. Further, a cleaning blade 48 serving as a cleaning unit is provided. Further, on the downstream side of the secondary transfer nip portion 15, a fixing device 30 having a fixing film 33 and a pressure roller 32 serving as fixing means for thermally fixing the toner image to the recording material S is provided.

  Below the image forming apparatus 1, a transport device 6 that transports the recording material S to the secondary transfer nip portion 15 is provided. The transport device 6 includes a feeding roller 8 that feeds the recording material S from a feeding cassette 7 that stores a plurality of recording materials S, and a separation roller 9 that is a separating unit. The recording material S accommodated in the feeding cassette 7 is pressed by the rotation of the feeding roller 8, separated by the separation roller 9, and fed one by one.

  The recording material S separated and fed by the cooperation of the feeding roller 8 and the separation roller 9 is conveyed along the conveyance path 14 and is abutted against the nip portion of the registration roller 10 whose tip portion is temporarily stopped. . Then, the skew is corrected by being handled by the waist strength of the recording material S. Thereafter, the recording material S is nipped by a registration roller 10 that rotates at a predetermined timing and conveyed to the secondary transfer nip portion 15.

<Image forming operation>
When each photosensitive drum 17 rotates in the clockwise direction in FIG. 1, the surface of the photosensitive drum 17 is uniformly charged by each charging roller 18. Thereafter, a laser beam 49 corresponding to the image information is emitted from the exposure device 19 and applied to the uniformly charged surface of the photosensitive drum 17. Thereby, an electrostatic latent image is formed. Each color toner is supplied from each developing device 29 to the electrostatic latent image formed on the surface of each photosensitive drum 17.

  As a result, a toner image is developed on the surface of each photosensitive drum 17. A primary transfer bias is applied to each primary transfer roller 47 by a primary transfer bias power source (not shown), and a toner image formed on the surface of each photosensitive drum 17 is sequentially primary-transferred and superimposed on the outer peripheral surface of the intermediate transfer belt 4. Residual toner remaining on the surface of each photosensitive drum 17 after the primary transfer is scraped off by the cleaning blade 48 and collected in the cleaner container 53.

  Thereafter, a positive secondary transfer bias is applied to the secondary transfer roller 5 at the secondary transfer nip portion 15 by a secondary transfer bias power source (not shown). As a result, the toner images of a plurality of colors carried on the outer peripheral surface of the intermediate transfer belt 4 are secondarily transferred to the recording material S conveyed to the secondary transfer nip portion 15. The recording material S carrying the unfixed toner image secondarily transferred from the outer peripheral surface of the intermediate transfer belt 4 is conveyed to the fixing device 30.

  The fixing device 30 includes a heating unit 31 as a heating member constituting a fixing unit, and a pressure roller 32 as a pressure member. A fixing nip portion N is formed when the heating unit 31 and the pressure roller 32 are in pressure contact with each other. The recording material S carrying the unfixed toner image is conveyed to the fixing nip portion N, and is nipped and conveyed by the heating unit 31 and the pressure roller 32, whereby the unfixed toner image is heated and melted by heat. The material S is heat-fixed. The heat-fixed recording material S is nipped and conveyed by the discharge roller 12 and discharged onto the discharge tray 13.

  The discharge unit 11 provided with the discharge roller 12 is provided with a flapper 24 and a reverse roller 27. FIG. 2A is a cross-sectional explanatory view showing a state in which the recording material S is discharged out of the apparatus in the image forming apparatus 1 of the present embodiment. 2B and 2C are cross-sectional explanatory views showing how the recording material S is conveyed to the double-sided conveyance path 22 in the image forming apparatus 1 of the present embodiment.

  In order to discharge the recording material S thermally fixed by the fixing device 30 to the discharge tray 13, the flapper 24 rotates about the rotation shaft 25 in the counterclockwise direction of FIG. Is conveyed toward the discharge roller 12. Thereafter, the sheet is nipped by the discharge roller 12 and conveyed to the discharge path 23.

  2B and 2C show a reverse conveyance operation for performing double-sided printing. The flapper 24 shown in FIG. 2B rotates about the rotation shaft 25 in the clockwise direction of FIG. 2B, whereby the recording material S coming out of the fixing device 30 is guided by the conveyance guide 26. Then, it is conveyed toward the reversing roller 27. Thereafter, the sheet is nipped by the reversing roller 27 and conveyed to the reversing path 21.

  In a state where the rear end portion of the recording material S is sandwiched by the reversing roller 27, the flapper 24 shown in FIG. 2C rotates about the rotation shaft 25 in the counterclockwise direction of FIG. The reverse roller 27 rotates in the reverse direction. As a result, the recording material S is guided to the double-sided conveyance path 22 with its traveling direction reversed.

  Thereafter, the recording material S is nipped and conveyed by the conveying rollers 16 and 54 provided in the double-sided conveying path 22 shown in FIG. 1, the front and back surfaces are reversed, and the recording material S merges with the conveying path 14 and the leading end of the recording material S temporarily stops. It is abutted against the nip portion of the stopped registration roller 10. Then, the skew is corrected by being handled by the waist strength of the recording material S. Thereafter, the recording material S is nipped by a registration roller 10 that rotates at a predetermined timing and conveyed to the secondary transfer nip 15, and a toner image is secondarily transferred to the second surface in the same manner as described above.

  Thereafter, as shown in FIG. 2A, the recording material S on which the toner image is thermally fixed by the fixing device 30 rotates the flapper 24 around the rotation shaft 25 in the counterclockwise direction of FIG. Accordingly, the recording material S is conveyed toward the discharge roller 12. Thereafter, the paper is nipped and conveyed by the discharge roller 12, conveyed to the discharge path 23, and discharged onto the discharge tray 13.

  In this embodiment, the discharge roller 12 that discharges the recording material S to the discharge tray 13 and the reversing roller 27 that rotates in reverse to perform double-sided printing are provided. A configuration may be adopted in which S is discharged to the discharge tray 13. When the recording material S is discharged to the discharge tray 13, the recording material S can be discharged to the discharge tray 13 by rotating the recording material S forwardly without being reversely rotated while the recording material S is sandwiched by the reversing roller 27.

<Fixing device>
Next, the configuration of the fixing device 30 that is a feature of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is an explanatory cross-sectional view showing the configuration of the fixing device 30 of the present embodiment. FIG. 4 is a perspective explanatory view showing the configuration of the fixing device 30 of the present embodiment.

  A fixing device 30 serving as a fixing unit illustrated in FIG. 3 includes a heating unit 31 and a pressure roller 32. The heating unit 31 includes an endless fixing film 33, a heater 34, a film guide 35 that rotatably supports the fixing film 33, and a reinforcing member 36 that reinforces the film guide 35. The A heater 34 is supported on the film guide 35.

  The heating unit 31 and the pressure roller 32 are supported by a frame (not shown), and are pressed with a predetermined pressure by a pressure means (not shown), and between the outer peripheral surface of the fixing film 33 and the surface of the pressure roller 32. A fixing nip portion N is formed on the surface.

  In the secondary transfer nip portion 15, the toner image carried on the outer peripheral surface of the intermediate transfer belt 4 is secondarily transferred to the recording material S, and the recording material S carrying the unfixed toner image is conveyed to the fixing device 30. . Then, the leading end portion of the recording material S is guided to the fixing nip portion N while being guided by the inlet guide 37 provided at the inlet portion of the fixing device 30.

  In the fixing nip portion N, the toner image is heated and pressurized and melted to be thermally fixed to the recording material S. Thereafter, the recording material S is transported to the nip portion of the decurling roller 40 with the leading end being guided by the transport guides 38 and 39 in the transport path 14 downstream from the fixing nip portion N. The conveyance guide 38 is disposed on the pressure roller 32 side with respect to the recording material S. The conveyance guide 39 is disposed on the heating unit 31 side with respect to the recording material S.

  The curl generated in the recording material S by being heated and pressed in the fixing nip portion N is corrected in the process of being conveyed through the nip portion of the decurling roller 40. The recording material S sandwiched and conveyed by the decurling roller 40 is conveyed to the discharge unit 11 shown in FIG. The decurling roller 40 is composed of a pair of through rollers that are longer than the maximum width in the direction orthogonal to the conveying direction of the recording material S. As a result, the entire width direction of the recording material S is held by the nip portion of the decurling roller 40.

<Cover member>
In the fixing device 30, the side surface on the pressure roller 32 side with respect to the conveyance path 14 of the recording material S is covered with a fixing cover 41. Further, the side surface on the heating unit 31 side and the lower surface of the fixing device 30 are covered with a fixing cover 42. The fixing cover 42 is configured as a cover member that covers the fixing film 33 constituting the fixing unit.

  As shown in FIG. 4, the side surface of the fixing cover 42 (cover member) has a length corresponding to at least the length of the fixing film 33 in the longitudinal direction, and includes a plurality of openings formed through the fixing cover 42. A slit 43 is provided. The air 20 inside the fixing device 30 can be exhausted from the slit 43.

  In the fixing device 30 of the present embodiment, the upstream side of the fixing nip portion N in the conveyance path 14 of the recording material S is covered with the inlet guide 37. Further, the side surface on the pressure roller 32 side constituting the fixing unit with respect to the conveyance path 14 of the recording material S is covered with the fixing cover 41. Further, the side surface on the heating unit 31 side and the lower surface of the fixing device 30 are covered with the fixing cover 42 with respect to the conveyance path 14 of the recording material S. Further, the upper surface on the downstream side of the fixing nip portion N is covered with the conveyance guides 38 and 39 and the decurling roller 40. Thereby, the internal space of the fixing device 30 of the present embodiment is configured in a substantially sealed state except for the opening of the slit 43 of the fixing cover 42.

  The inlet guide 37, the fixing cover 41, the fixing cover 42, the conveyance guides 38 and 39, and the decurling roller 40 constituting the fixing device 30 of the present embodiment are cover members that cover the fixing film 33 and the pressure roller 32 serving as fixing means. Configured as Further, a part of the cover member is constituted by conveyance guides 38 and 39 for conveying the recording material S. In addition, a part of the cover member is configured by a decurling roller 40 serving as a conveyance rotating body that conveys the recording material S.

<Air flow in the image forming apparatus body>
Next, the flow of air 20 in the image forming apparatus 1 main body will be described with reference to FIGS. 5 and 6. FIG. 5A is a perspective explanatory view seen from the front side of the image forming apparatus 1 showing a state in which the fixing device 30 of the present embodiment is mounted on the image forming apparatus 1 main body. FIG. 5B is a perspective explanatory view seen from the front side of the image forming apparatus 1 showing a state in which the fixing device 30 of the present embodiment is mounted on the main body of the image forming apparatus 1. FIG. 6 is a cross-sectional explanatory diagram illustrating the flow of air 20 in the fixing device 30 of the present embodiment.

  As shown in FIGS. 5A and 5B, the main body of the image forming apparatus 1 is positioned at a position facing a slit 43 formed of an opening provided through the fixing cover 42 of the fixing apparatus 30 shown in FIG. A ventilation duct 50 is provided. The fixing device 30 is detachably attached to the main body of the image forming apparatus 1. As shown in FIG. 5B, when the fixing device 30 is attached to the main body of the image forming apparatus 1, the slit 43 (opening) provided in the fixing cover 42 and the ventilation duct 50 are communicated.

  One end portion in the longitudinal direction of the ventilation duct 51 communicates with one end portion in the longitudinal direction of the ventilation duct 50. The ventilation duct 51 is provided on the back side of the main body of the image forming apparatus 1. At the other end in the longitudinal direction of the ventilation duct 51, an intake fan 52 made of a sirocco fan serving as a suction means is provided. In the sirocco fan, vertically long and slender plate-like blades are attached in a cylindrical shape, and the wind direction flows in a centrifugal direction perpendicular to the rotation axis.

  As shown in FIG. 5B, the intake fan 52 (suction means) made of a sirocco fan is rotated so that the interior of the fixing device 30 can be seen from the slit 43 (opening) provided in the fixing cover 42 via the ventilation ducts 51 and 50. The air 20 is sucked. The sucked air 20 can be exhausted to a portion where the water vapor is not affected inside the main body of the image forming apparatus 1.

  As shown in FIG. 6, the recording material S such as paper is heated in the fixing nip N, and the water contained therein is evaporated to generate water vapor. The downstream side of the fixing nip N is covered with a decurling roller 40 and conveyance guides 38 and 39. For this reason, the water vapor generated in the fixing nip N is guided by the flow of the air 20 shown in FIG. 5B, and the main body of the image forming apparatus 1 from the slit 43 provided in the fixing cover 42 through the ventilation ducts 50 and 51. It is exhausted to the part where water vapor is not affected. Thereby, it is possible to prevent water droplets from adhering to the transport roller shaft and the transport guides 38 and 39 in the main body of the image forming apparatus 1.

  The internal space of the fixing device 30 is covered with an inlet guide 37, fixing covers 41 and 42, conveying guides 38 and 39, and a decurling roller 40, and is substantially sealed except for the opening of the slit 43 of the fixing cover 42. Yes. For this reason, the water vapor generated in the fixing nip portion N is exhausted from the slit 43 which is substantially the only opening inside the fixing device 30 by the intake air by the intake fan 52. Thereafter, it is possible to efficiently exhaust air to the portion where the water vapor is not affected inside the main body of the image forming apparatus 1 through the ventilation ducts 50 and 51.

  As a result, it is possible to prevent water droplets from adhering to the pressure roller 32 and water droplets from adhering to the decurling roller 40 and the conveyance guides 38 and 39 downstream of the fixing nip portion N. Further, it is possible to prevent jamming of the recording material S due to the slip of the fixing film 33 and the recording material S, an image defect, or an image defect due to water droplets. Note that the size, number, arrangement, etc. of the slits 43 provided in the fixing cover 42 can be changed as appropriate, and are not limited to the configuration of the present embodiment.

  In the internal space of the fixing device 30, the downstream side of the fixing nip portion N is covered with a decurling roller 40 serving as a cover member, conveyance guides 38 and 39, and fixing covers 41 and 42. Thereby, a substantially sealed state can be formed except for the slit 43 (opening) of the fixing cover 42 (cover member). In the fixing nip portion N, water vapor generated by evaporation of water contained in the recording material S such as paper during heat fixing can be efficiently exhausted outside the fixing device 30 through the slit 43.

  Therefore, slipping of the fixing film 33 and the recording material S due to water droplets adhering to the surface of the pressure roller 32 can be prevented. Further, it is possible to prevent image defects due to water droplets adhering to the conveyance guides 38 and 39 in the vicinity of the fixing nip portion N and the decurling roller 40 (conveyance roller) downstream of the fixing nip portion N. As a result, water vapor in the vicinity of the fixing nip N is efficiently exhausted to the outside of the fixing device 30, and jamming of the recording material S due to slippage of the fixing film 33 and the recording material S, image defects, and image defects due to water droplets can be prevented. .

  Next, the configuration of the second embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. In addition, what was comprised similarly to the said 1st Embodiment attaches | subjects the same member name even if the same code | symbol or a code | symbol differs, and abbreviate | omits description. FIG. 7 is an explanatory perspective view showing the configuration of the fixing device 30 of the present embodiment. The fixing device 30 of this embodiment has the same configuration except that the fixing cover 44 (cover member) shown in FIG. 7 is used instead of the fixing cover 42 (cover member) of the first embodiment. Therefore, the sectional view of the fixing device 30 of the present embodiment is substantially the same as the sectional view of the fixing device 30 of the first embodiment shown in FIG.

  In the fixing device 30 of this embodiment, the side surface on the pressure roller 32 side of the conveyance path 14 of the recording material S is covered with a fixing cover 41 with reference to FIG. Further, the side surface on the heating unit 31 side and the lower surface of the fixing device 30 with respect to the conveyance path 14 of the recording material S are covered with a fixing cover 44 shown in FIG. As shown in FIG. 7, the fixing cover 44 is provided with a slit 45 including an opening penetrating the fixing cover 44 at a position facing the fixing film 33 shown in FIG. 3.

  Similarly to the fixing device 30 of the present embodiment as shown in FIG. 3, the upstream side of the fixing nip portion N is covered with the inlet guide 37. Further, the side surface on the pressure roller 32 side with respect to the conveyance path 14 of the recording material S is covered with a fixing cover 41. Further, the side surface on the heating unit 31 side and the lower surface of the fixing device 30 with respect to the conveyance path 14 of the recording material S are covered with a fixing cover 44 shown in FIG. Further, the upper surface on the downstream side of the fixing nip N is covered with the conveyance guides 38 and 39 and the decurling roller 40.

  The inlet guide 37, the fixing cover 41, the fixing cover 44, the conveyance guides 38 and 39, and the decurling roller 40 constituting the fixing device 30 of the present embodiment are cover members that cover the fixing film 33 and the pressure roller 32 serving as fixing means. Configured as Further, a part of the cover member is constituted by conveyance guides 38 and 39 for conveying the recording material S. In addition, a part of the cover member is configured by a decurling roller 40 serving as a conveyance rotating body that conveys the recording material S. As a result, the internal space of the fixing device 30 of the present embodiment is also substantially hermetically sealed except for the slit 45 formed by the opening penetrating the fixing cover 44.

<Air flow in the image forming apparatus body>
Next, the flow of the air 20 in the image forming apparatus 1 main body of the present embodiment will be described with reference to FIG. FIG. 8A is a perspective explanatory view seen from the front side of the image forming apparatus 1 showing how the fixing device 30 of the present embodiment is mounted on the main body of the image forming apparatus 1. FIG. 8B is a perspective explanatory view seen from the front side of the image forming apparatus 1 showing a state in which the fixing device 30 of the present embodiment is mounted on the main body of the image forming apparatus 1.

  As shown in FIG. 8A, the main body of the image forming apparatus 1 of the present embodiment has two intake fans 46 facing the slits 45 (openings) provided in the fixing cover 44 (cover member) of the fixing device 30. Are arranged. The intake fan 46 is configured as a suction unit that sucks the air 20 from the slit 45 (opening). The intake fan 46 of this embodiment is configured by an axial fan. The axial fan flows linearly while the wind direction swirls along the rotation axis of the motor.

  The fixing device 30 of this embodiment is also detachably attached to the main body of the image forming apparatus 1. As shown in FIG. 8B, the air 20 inside the fixing device 30 opens the slit 45 (opening) of the fixing cover 44 by the rotation of the intake fan 46 with the fixing device 30 attached to the main body of the image forming apparatus 1. Sucked through. The sucked air 20 is efficiently exhausted to a portion where the water vapor is not affected inside the main body of the image forming apparatus 1.

  A drain container 28 is provided on the exhaust side of each intake fan 46. Air 20 containing water vapor exhausted by each intake fan 46 collides with the wall surface of the drain container 28. A part of the air is exhausted from the upper opening 28 a of the drain container 28 to a portion where the water vapor is not affected inside the main body of the image forming apparatus 1. Moisture generated by cooling the water vapor is stored in the drain container 28.

  The interior of the fixing device 30 is covered with an upper space by a decurling roller 40 and conveying guides 38 and 39 on the downstream side of the fixing nip N in the conveying path 14. As a result, the water vapor generated in the fixing nip portion N of the fixing device 30 is sucked through the slit 45 of the fixing cover 44 by the rotation of the intake fan 46 and the water vapor is generated inside the image forming apparatus 1 main body. Efficiently exhausts the parts that do not affect. This prevents water droplets from adhering to the decurling roller 40 (conveying roller) and the conveying guides 38 and 39.

  Further, the internal space of the fixing device 30 is substantially sealed by the various cover members described above. For this reason, the water vapor generated in the fixing nip portion N is efficiently exhausted from the slit 45 (opening) of the fixing cover 44, which is substantially the only opening, by the suction of the intake fan 46 to the portion where the water vapor does not affect the image forming apparatus 1 main body. It becomes possible to do.

  As a result, it is possible to prevent water droplets from adhering to the pressure roller 32 and water droplets from adhering to the decurling roller 40 and the conveyance guides 38 and 39 downstream of the fixing nip portion N. Further, it is possible to prevent jamming of the recording material S due to slippage of the fixing film 33 and the recording material S, image defects, and image defects due to water droplets. Other configurations are the same as those in the first embodiment, and the same effects can be obtained.

  Next, the configuration of the third embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. In addition, what was comprised similarly to each said embodiment attaches | subjects the same member name even if the same code | symbol or a code | symbol differs, and abbreviate | omits description. FIG. 9A is an explanatory perspective view illustrating the configuration of the fixing device 30 according to the third embodiment. FIG. 9B is a cross-sectional explanatory diagram illustrating the configuration of the fixing device 30 of the third embodiment. FIG. 10A is a perspective explanatory view seen from the front side of the image forming apparatus 1 showing a state in which the fixing device 30 of the third embodiment is mounted on the image forming apparatus 1. FIG. 10B is a perspective explanatory view seen from the front side of the image forming apparatus 1 showing a state in which the fixing device 30 of the third embodiment is mounted on the image forming apparatus 1.

  The configuration of the fixing device 30 of the present embodiment is that a fixing cover 60 (cover member) shown in FIG. 9B is used instead of the fixing cover 42 (cover member) of the first embodiment shown in FIG. Since the configuration is substantially the same, redundant description is omitted. In the fixing device 30 of this embodiment, the side surface on the pressure roller 32 side with respect to the conveyance path 14 of the recording material S is covered with a fixing cover 41. Further, the side surface on the heating unit 31 side and the lower surface of the fixing device 30 are covered with the fixing cover 60 with respect to the conveyance path 14 of the recording material S.

  The inlet guide 37, the fixing cover 41, the fixing cover 60, the conveyance guides 38 and 39, and the decurling roller 40 constituting the fixing device 30 of the present embodiment are cover members that cover the fixing film 33 and the pressure roller 32 serving as fixing means. Configured as Further, a part of the cover member is constituted by conveyance guides 38 and 39 for conveying the recording material S. In addition, a part of the cover member is configured by a decurling roller 40 serving as a conveyance rotating body that conveys the recording material S. As a result, the internal space of the fixing device 30 of the present embodiment is also substantially hermetically sealed except for the opening 61 that is an opening provided in the fixing cover 60.

  As shown in FIG. 9B, the fixing cover 60 of the present embodiment is disposed with a predetermined amount of space between the fixing film 33 and the fixing film 33 over the entire longitudinal direction of the fixing film 33. As shown in FIG. 9A, one end portion of the fixing cover 60 in the longitudinal direction is provided at one end portion of the ventilation duct 62 provided in the main body of the image forming apparatus 1 shown in FIGS. 10A and 10B. An opening 61 that is connected to and communicates with the opening 63 is provided. At the other end in the longitudinal direction of the ventilation duct 62, an intake fan 52 made of a sirocco fan serving as a suction means is provided. The intake fan 52 (suction unit) sucks the air 20 from the opening 61 (opening) provided in the fixing cover 60 via the ventilation duct 62.

  As shown in FIG. 9B, the internal space of the fixing device 30 of the present embodiment is covered with an inlet guide 37 on the upstream side of the fixing nip portion N in the conveyance path 14 of the recording material S. Further, the side surface on the pressure roller 32 side with respect to the conveyance path 14 of the recording material S is covered with the fixing cover 41. Further, the side surface on the heating unit 31 side and the lower surface of the fixing device 30 are covered with the fixing cover 60 with respect to the conveyance path 14 of the recording material S. Further, the upper surface of the recording material S on the downstream side of the fixing nip N in the conveyance path 14 is covered with conveyance guides 38 and 39 and a decurling roller 40. As a result, the internal space of the fixing device 30 is substantially hermetically sealed except for an opening 61 that is an opening provided in the fixing cover 60 at one end in the longitudinal direction of the fixing cover 60.

<Air flow in the image forming apparatus body>
Next, the flow of air in the image forming apparatus 1 main body of the present embodiment will be described with reference to FIG. As shown in FIG. 10A, in the main body of the image forming apparatus 1 of the present embodiment, the opening 61 is located at a position facing the opening 61 provided at one end in the longitudinal direction of the fixing cover 60 of the fixing device 30. A ventilation duct 62 provided with an opening 63 that is detachably connected to the air is provided.

  The fixing device 30 of the present embodiment is also detachably attached to the image forming apparatus 1 main body. As shown in FIG. 10B, when the fixing device 30 is attached to the main body of the image forming apparatus 1, the opening 61 provided at one end in the longitudinal direction of the fixing cover 60 and the one end of the ventilation duct 62 are provided. The opening 63 formed is connected and communicated. As a result, the fixing cover 60 and the ventilation duct 62 are configured as an integrated ventilation duct.

  An intake fan 52 made of a sirocco fan is connected to the other end of the ventilation duct 62. The air 20 in the fixing device 30 is sucked through the ventilation duct 62 by the rotation of the intake fan 52. Then, the air is efficiently exhausted to a portion where the water vapor is not affected inside the main body of the image forming apparatus 1.

  The internal space of the fixing device 30 of the present embodiment is covered with a decurling roller 40 and conveyance guides 38 and 39 on the downstream side of the fixing nip portion N in the conveyance path 14 of the recording material S. As a result, the water vapor generated at the fixing nip portion N is exhausted to a portion where the water vapor is not affected inside the main body of the image forming apparatus 1 by the flow of the air 20 shown in FIG. This prevents water droplets from adhering to the decurling roller 40 (conveying roller shaft) and the conveying guides 38 and 39.

  Further, the internal space of the fixing device 30 is substantially sealed. For this reason, the water vapor generated in the fixing nip N is efficiently exhausted from the opening 61 of the fixing cover 60, which is substantially the only opening, by suction of the intake fan 52 to a portion where the water vapor is not affected inside the main body of the image forming apparatus 1. It becomes possible.

  As a result, it is possible to prevent water droplets from adhering to the pressure roller 32 and water droplets from adhering to the decurling roller 40 and the conveyance guides 38 and 39 downstream of the fixing nip portion N. It is possible to prevent jamming of the recording material S due to slippage of the fixing film 33 and the recording material S, image failure, and image failure due to water droplets. Other configurations are the same as those in the above embodiments, and the same effects can be obtained.

S ... Recording material 20 ... Air 32 ... Pressure roller (fixing means)
33. Fixing film (fixing means)
37 ... Entrance guides 38, 39 ... Conveying guide 40 ... Decal roller (conveying rotator)
41. Fixing cover 42 ... Fixing cover (cover member)
43 ... Slit (opening)
52. Intake fan (suction means)

Claims (5)

Fixing means for fixing the toner image on the recording material;
A cover member covering the fixing means;
An opening provided in the cover member;
A suction means for sucking air from the opening;
An image forming apparatus comprising: Fixing means for fixing the toner image on the recording material;
A cover member covering the fixing means;
An opening provided in the cover member;
A fixing device having
The fixing device is detachably provided,
A ventilation duct communicating with the opening;
Suction means for sucking air from the opening through the ventilation duct;
An image forming apparatus comprising: Fixing means for fixing the toner image on the recording material;
A cover member covering the fixing means;
An opening provided in the cover member;
A fixing device having
The fixing device is detachably provided,
A suction means for sucking air from the opening facing the opening;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein a part of the cover member is a conveyance guide that conveys a recording material.   4. The image forming apparatus according to claim 1, wherein a part of the cover member is a conveyance rotating body that conveys a recording material. 5.

Images