JP2012047790A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suitably removing ultrafine particles.SOLUTION: An ultrafine particle removal device 250 is provided inside of the image forming apparatus 1. The ultrafine particle removal device 250 has: a suction fan 251; and a duct that includes end edges 261, 262, where openings 263, 264 are formed in positions facing both end faces of a fixing roller 210 in a shaft direction. Suction ports 271, 272 are formed on a surface of an opposite side of a surface facing the both end faces of the fixing roller 210 in the shaft direction in the end edges 261, 262. The duct includes end edges 481, 482 where openings 483, 484 are formed in positions facing both end faces of a pressure roller 220 in a shaft direction.

Description

  The present invention relates to an image forming apparatus. More specifically, the present invention relates to an image forming apparatus that can suitably remove ultra fine particles generated inside the apparatus.

  In an image forming apparatus using an electrophotographic system, toner is applied to an electrostatic latent image formed on a photosensitive drum to form a toner image, the toner image is transferred to a sheet, and the toner image is fixed on a sheet by a fixing device. There is a method to do.

  In a heating-type fixing device that fixes a toner image to a sheet by heating the sheet, a substance generated due to the heating may be scattered inside the image forming apparatus. It is preferable to remove such substances.

  For example, Patent Document 1 discloses an image forming apparatus provided with a volatile organic compound removing unit for removing a volatile organic compound (VOC). This volatile organic compound (VOC) is mainly generated from paper or toner (see paragraph [0003] of Patent Document 1). According to Patent Document 1, first, air is applied to the surface of a sheet by a blowing fan to blow off a volatile organic compound (VOC). Next, the blown air is sucked by a suction fan and volatile organic compounds (VOC) are removed by a photocatalytic filter (see paragraphs [0066] and [0067] of Patent Document 1 and FIGS. 2 and 3). Etc.).

JP-A-2005-70264

  By the way, in recent years, it has been desired to further suppress the generation of ultra fine particles (UFP) due to increasing awareness of environmental problems. Ultrafine particles (UFP) refers to particles having a diameter of 100 nm or less among suspended particulate matter (SPM). It has been found that the ultra fine particles (UFP) are mainly generated from silicone rubber used as an elastic member of a fixing device. When silicone rubber is heated, low molecular siloxane is generated. It has been found that this low molecular siloxane is a major cause of the generation of ultrafine particles (UFP).

  However, in the volatile organic compound removing apparatus that removes the volatile organic compound (VOC), it is somewhat difficult to recover the ultrafine particles (UFP). This is because the cause of generation of ultrafine particles (UFP) is different from the cause of generation of volatile organic compounds (VOC), and their occurrence locations are naturally different. In the volatile organic compound removing device described in Patent Document 1, air is sucked from the entire vicinity of the fixing device, and the efficiency is low in removing ultra-fine particles (UFP) having a light mass (FIG. 3 of Patent Document 1). Etc.).

  The present invention has been made to solve the above-described problems of the prior art. That is, an object of the present invention is to provide an image forming apparatus capable of suitably removing ultra fine particles (UFP).

  In order to solve this problem, an image forming apparatus according to one aspect of the present invention includes an image forming unit that forms a toner image on an image carrier, a transfer unit that transfers the toner image from the image carrier to a sheet, and a toner. And a fixing device that fixes the image on the sheet. The fixing device includes a fixing rotating body including a heating member that heats the sheet in contact with the sheet to which the toner image is transferred, a heating member-side elastic layer that supports the heating member, and a nip together with the heating member. The heating member-side elastic layer includes a pressure rotating member including a pressure member to be formed, a pressure member-side elastic layer that supports the pressure member, and a heat source that heats the heating member. At least a part of the rotating body is exposed at both axial ends. In addition, the image forming apparatus includes a suction unit that sucks air, and a duct that communicates with the suction unit and includes a fixing rotator side end portion at a position facing both end surfaces in the axial direction of the fixing rotator. The fixing rotator-side terminal portion has a fixing rotator-side opening formed along the exposed portion of the heating member-side elastic layer on the surface opposite to both axial end faces of the fixing rotator. In such an image forming apparatus, ultrafine particles emitted from the exposed portion of the heating member side elastic layer can be sucked and removed. In addition, particles having a particle size larger than that of ultrafine particles can be removed.

  In the image forming apparatus described above, at least a part of the pressure member-side elastic layer is exposed at both ends in the axial direction of the pressure rotator, and the duct is in the axial direction of the pressure rotator. The pressurizing rotator side terminal end is provided at a position facing both end surfaces of the pressurizing rotator side, and the pressurizing rotator side end portion is formed on the surface facing the both end surfaces in the axial direction of the pressurizing rotator on the pressurizing member side elastic layer. It is preferable that the pressurizing rotator side opening is formed along the exposed portion. This is because the ultrafine particles released from the exposed portion of the pressure member-side elastic layer can be removed by suction.

  In the image forming apparatus described above, the opening on the fixing rotator side is the position of the nip portion between the fixing rotator and the pressure rotator from the heating start position of the heating member by the heat source toward the downstream side of the rotation of the fixing rotator. It is good to be formed. This is because the ultrafine particles can be sucked from the high temperature portion of the exposed portion of the heating member-side elastic layer, which is where the ultrafine particles are likely to be generated.

  In the image forming apparatus described above, the pressure rotator side opening may be formed from a position of a nip portion between the fixing rotator and the pressure rotator to a position downstream of the pressure rotator. This is because the ultrafine particles can be sucked from the high temperature portion of the exposed portion of the pressure member-side elastic layer, where the ultrafine particles are likely to be generated.

  In the image forming apparatus described above, the opening on the fixing rotator side is the position of the nip portion between the fixing rotator and the pressure rotator from the heating start position of the heating member by the heat source toward the downstream side of the rotation of the fixing rotator. The pressure rotating body side opening may be formed from the position of the nip portion between the fixing rotating body and the pressure rotating body to the position downstream of the pressure rotating body. This is because the ultrafine particles can be sucked from the high temperature portion of the exposed portions of the heating member-side elastic layer and the pressure member-side elastic layer, where ultrafine particles are likely to be generated.

  In the image forming apparatus described above, a suction port is formed on the surface on the opposite side of the fixing rotator side opening at the fixing rotator side end portion, at a position upstream of the fixing rotator in the fixing rotator side opening. In addition, a suction port may be formed on the surface of the pressurizing rotator side end portion on the opposite side of the pressurizing rotator side opening at the most upstream side of the pressurizing rotator in the pressurizing rotator side opening. . Ultra fine particles can be efficiently sucked from the exposed part of the heating member side elastic layer and the pressure member side elastic layer, which is the most likely to generate ultra fine particles, from the high temperature part where the temperature rises greatly. Because.

  In the image forming apparatus described above, the heat source is an induction heating device including a core and an exciting coil, and the fixing rotating body is a fixing belt in which a metal layer heated by the induction heating device is used as a heating member. The pressure roller is preferably a pressure roller in which a release layer having releasability is used as a pressure member. This is because ultrafine particles can be suitably removed from an image forming apparatus including a fixing type fixing device using an induction heating device.

  The image forming apparatus described above includes an external heating roller having a heat source therein, and the fixing rotator is a fixing roller having a release layer that rotates in contact with the external heating roller as a heating member. The rotating body may be a pressure roller in which a release layer having releasability is used as the pressure member. This is because ultrafine particles can be suitably removed from an image forming apparatus having a fixing type fixing device using an external heating roller.

  In the image forming apparatus described above, an external heating roller having a heat source is provided, the fixing rotator is a fixing roller, and the pressure rotator has a release layer having releasability as a pressure member. It is a pressure roller that is used, and the heating member may be a heating belt wound between the fixing rotator and the external heating roller. This is because ultrafine particles can be suitably removed from an image forming apparatus having a fixing type fixing device that performs fixing at the nip portion between the heating belt and the pressure roller.

  The image forming apparatus according to another aspect of the present invention also includes an image forming unit that forms a toner image on an image carrier, a transfer unit that transfers the toner image from the image carrier to a sheet, and a toner image that is fixed to the sheet. A fixing device. The fixing device includes a fixing rotating body including a heating member that heats the sheet in contact with the sheet to which the toner image is transferred, a heating member-side elastic layer that supports the heating member, and a nip together with the heating member. A pressure rotating member including a pressure member to be formed, a pressure member-side elastic layer that supports the pressure member, and a heat source that heats the heating member. At least a part of the pressure rotating body is exposed at both ends in the axial direction. In addition, the image forming apparatus includes a suction unit that sucks air, a duct that communicates with the suction unit, and includes a pressure rotator side end portion at a position facing both end surfaces in the axial direction of the pressure rotator. The pressurizing rotator side end portion is formed by forming the pressurizing rotator side opening along the exposed portion of the pressurizing member side elastic layer. In such an image forming apparatus, ultrafine particles released from the exposed portion of the pressure member-side elastic layer can be sucked and removed. In addition, particles having a particle size larger than that of ultrafine particles can be removed.

  According to the present invention, there is provided an image forming apparatus capable of suitably removing ultra fine particles (UFP).

1 is a schematic configuration diagram for explaining an image forming apparatus according to an embodiment. 1 is a schematic configuration diagram for explaining a fixing device according to a first embodiment; 1 is a perspective cross-sectional view illustrating a structure of a heating belt of an image forming apparatus according to a first embodiment. 1 is a schematic configuration diagram for explaining a fixing roller and an ultrafine particle removing device of a fixing device according to a first embodiment. It is a schematic block diagram for demonstrating the opening part of the fixing device and ultrafine particle removal apparatus which concern on 1st Embodiment. It is a schematic block diagram for demonstrating the opening part of another fixing device which concerns on 1st Embodiment, and an ultrafine particle removal apparatus. It is a schematic block diagram for demonstrating the pressure roller and ultrafine particle removal apparatus of the fixing device which concern on 2nd Embodiment. It is a schematic block diagram for demonstrating the opening part of the fixing device and ultrafine particle removal apparatus which concern on 2nd Embodiment. It is a schematic block diagram for demonstrating the opening part of the fixing device and ultrafine particle removal apparatus which concern on 3rd Embodiment. It is a schematic block diagram for demonstrating the opening part of the fixing device and ultrafine particle removal apparatus which concern on 4th Embodiment. It is a schematic block diagram for demonstrating the opening part of the fixing device and ultrafine particle removal apparatus which concern on 5th Embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. In the present embodiment, the present invention is embodied in an image forming apparatus.

(First embodiment)
1. Image Forming Apparatus The image forming apparatus 1 of the present embodiment is a so-called tandem color printer having an intermediate transfer belt 101 as schematically shown in FIG. The intermediate transfer belt 101 is an endless belt member. Both ends of the intermediate transfer belt 101 are supported by rollers 102 and 103 and rotate in the direction of arrow A in the drawing. Along the lower portion of the intermediate transfer belt 101 in the figure, image forming portions 104Y, 104M, 104C, and 104K for each color of yellow (Y), magenta (M), cyan (C), and black (K) are arranged.

  The image forming units 104Y, 104M, 104C, and 104K for each color have the same configuration. Each has a photosensitive drum 106 as an image carrier and a charging device 107, an exposure device 108, a developing device 109, and a cleaner device 110 arranged around the photosensitive drum 106. A primary transfer device 111 is disposed at a position facing the photosensitive drum 106 with the intermediate transfer belt 101 interposed therebetween. In FIG. 1, the image forming unit 104Y is representatively shown.

  1 shows a paper feed cassette 112 that stores paper P. A paper feed roller 113 that feeds the paper P is provided above the paper feed cassette 112. The paper P is sent upward from the paper feed cassette 112 along the transport path 114. A secondary transfer device 115 is disposed at a position facing the roller 103 with the conveyance path 114 interposed therebetween. The intermediate transfer belt 101, the primary transfer device 111, and the secondary transfer device 115 are transfer units for transferring the toner image onto the paper P. Further, a fixing device 200 is arranged on the downstream side (upper side in the figure). The fixing device 200 has a roller pair of a fixing roller 210 and a pressure roller 220. A paper conveyance switching guide 120 is disposed further downstream of the conveyance path 114 from the fixing device 200.

  A roller pair 116 and a roller pair 118 are arranged further downstream of the conveyance path 114 from the sheet conveyance switching guide 120. The paper transport switching guide 120 is for switching between transporting the paper P to the roller pair 116 or the roller pair 118. A paper discharge tray 117 is provided further downstream of the conveyance path 114 than the roller pair 116. The roller pair 116 is for discharging the paper P to the paper discharge tray 117.

  The roller pair 118 is for reversing the transport direction of the paper P that has been transported along the transport path 114 and for transporting the paper P to the transport path 119. The conveyance path 119 is a path for conveying the paper P on which an image is formed on one side to the location of the secondary transfer device 115 again. In other words, this is a path used to form an image on the opposite side of the sheet P where the image is formed. As described above, the image forming apparatus 1 of the present embodiment is capable of duplex printing.

  Further, the image forming apparatus 1 includes an ultrafine particle removing device 250 inside the main body. The ultrafine particle removing device 250 includes a suction fan 251 and a duct 260. The suction fan 251 is for sucking air inside the duct 260. The duct 260 wraps around to a position facing the side surface of the fixing device 200 as will be described later. The duct 260 has an opening at a position facing the side surface of the fixing device 200.

  Next, the basic operation of the image forming apparatus 1 of this embodiment will be briefly described. When the image forming apparatus 1 receives an image forming instruction, the image forming apparatus 1 generates image data of each color from the image signal. The generated image data of each color is sent to the corresponding image forming units 104Y, 104M, 104C, and 104K. The image forming units 104Y, 104M, 104C, and 104K for each color form electrostatic latent images by charging and exposing the respective photosensitive drums 106 based on the image data. Further, the formed electrostatic latent image is developed to form a toner image.

  The formed toner images are sequentially transferred to the intermediate transfer belt 101 by the primary transfer device 111 and superimposed. The toner image superimposed on the intermediate transfer belt 101 is transferred onto the paper P by the secondary transfer device 115. The paper P carrying the toner image is further conveyed to the fixing device 200 where it is heated and pressurized by the fixing device 200. As a result, the toner image is fixed on the paper P. The paper P on which the toner image is fixed is discharged to the paper discharge tray 117 by the roller pair 116.

  On the other hand, in the case of duplex printing, the paper P on which the toner image is fixed is conveyed to the conveyance path 119 by the roller pair 118. Then, it is conveyed again to the secondary transfer device 115. At this time, the toner image is transferred to the surface opposite to the surface on which the toner image has already been fixed. Thereafter, the toner image is fixed and discharged onto the paper discharge tray 117. The above is the basic operation of the image forming apparatus 1.

2. Fixing Device Here, the fixing device 200 of this embodiment will be described. FIG. 2 is a schematic configuration diagram of the fixing device 200 of the image forming apparatus 1. The fixing device 200 includes a fixing roller 210, a pressure roller 220, an induction heating device 230, and a non-contact type thermometer 240.

  The fixing roller 210 is a fixing rotating body having a cored bar 211 and an elastic layer 212. A heating belt 213 is placed around the fixing roller 210. Its diameter is about 40 mm. The cored bar 211 is a member for suppressing the permanent deformation of the fixing roller 210 and maintaining the durability of the fixing roller 210. Examples of the material include aluminum and SUS. Of course, other steel materials may be used. The elastic layer 212 is a heating member-side elastic layer that is slightly deformed to form a nip portion when pressed by the pressure roller 220. Examples of the material include silicone rubber and silicone sponge. The fixing roller 210 rotates in the direction of arrow B in FIG.

  The heating belt 213 is a heating member for actually heating the paper by contacting the paper on which the toner image is transferred. As shown in FIG. 3, the heating belt 213 includes a heating layer 214, a heat-resistant elastic layer 215, and a heat-resistant release layer 216 from the inside. The heating layer 214 is a metal layer that is heated by electromagnetic induction. An example of the material is nickel. Its thickness is about 40 μm. The heat resistant elastic layer 215 is a heating member side elastic layer having heat resistance. An example of the material is silicone rubber. Its thickness is about 200 μm. The heat-resistant release layer 216 is a release layer having heat resistance. Examples of the material include hard plastics such as PFA (polytetrafluoroethylene perfluoroalkyl vinyl ether, hereinafter referred to as PFA) and PTFE (polytetrafluoroethylene, hereinafter referred to as PTFE). Its thickness is about 30 μm.

  The pressure roller 220 is a pressure rotator including a cored bar 221, an elastic layer 222, and a release layer 223. The diameter is about 35 mm, which is not significantly different from the diameter of the fixing roller 210. The metal core 221 is a member for suppressing the permanent deformation of the pressure roller 220 and maintaining the durability of the pressure roller 220. Examples of the material include aluminum and SUS. Of course, other steel materials may be used. The elastic layer 222 is a pressure member-side elastic layer that is pressed by the fixing roller 210 and slightly deforms to form a nip portion. Examples of the material include silicone rubber and silicone sponge. The release layer 223 is a layer for preventing the paper P after fixing from sticking to the surface of the pressure roller 220. It is also a pressure member for actually pressing the fixing roller 210 or the paper P. The release layer 223 is sufficiently thin. Therefore, the thickness does not appear in FIG. The nip formed between the fixing roller 210 and the pressure roller 220 is about 12 mm. The pressure contact force is about 500N. The pressure roller 220 rotates in the direction of arrow C in FIG.

  The induction heating device 230 is a device that serves as a heat source for heating the heating layer 214 of the heating belt 213 by induction heating. The induction heating device 230 has a core 231 and an excitation coil 232. The material of the core 231 is, for example, MnZn-based ferrite. The exciting coil 232 is a litz wire wound 10 times in the longitudinal direction of the fixing roller 210. The litz wire is a bundle of 114 wires having a diameter of 0.15 mm. When the exciting coil 232 is energized, a magnetic flux is formed around the exciting coil 232. The core 231 allows magnetic flux to pass through the heating belt 213. Note that the bottom core 233 of the core 231 in FIG. 2 is for suppressing leakage of magnetic flux.

  The non-contact type thermometer 240 is a thermometer for measuring the surface temperature of the fixing roller 210 by detecting infrared rays. The surface of the heating belt 213 is kept at a fixing temperature (about 180 ° C.) by using a non-contact thermometer 240.

3. Location of Ultra Fine Particles (UFP) Here, ultra fine particles (UFP) can be generated from the elastic layer 212 of the fixing roller 210 and the heat resistant elastic layer 215 of the heating belt 213. Ultrafine particles (UFP) are generated when these silicone-based members are at a fixing temperature around 180 ° C. Then, ultrafine particles (UFP) are scattered inside the main body of the image forming apparatus 1 from locations where the elastic layer 212 of the fixing roller 210 and the heat-resistant elastic layer 215 of the heating belt 213 are exposed to the outside. The portions where these members are exposed are both end faces in the axial direction of the fixing roller 210 (both end faces in the longitudinal direction of the fixing roller 210).

  Ultra fine particles (UFP) can also be generated from the elastic layer 222 of the pressure roller 220. However, the generated amount is slightly smaller than that of the fixing roller 210 side. This is because the temperature of the elastic layer 222 of the pressure roller 220 is slightly lower than the temperatures of the elastic layer 212 of the fixing roller 210 and the heat resistant elastic layer 215 of the heating belt 213.

4). Ultra Fine Particle Removal Device The ultra fine particle removal device 250 is a device that can remove ultra fine particles (UFP) by sucking ultra fine particles (UFP) together with air. The ultrafine particle removing device 250 is also a device that can remove suspended particulate matter (SPM) having a particle size larger than that of ultrafine particles (UFP). FIG. 4 shows a schematic configuration of the ultrafine particle removing apparatus 250. The ultrafine particle removing device 250 includes a suction fan 251, a dust collection filter 252, and a duct 260. The suction fan 251 is a suction unit that sucks air inside the duct 260. The dust collection filter 252 is a filter for preventing particles containing ultrafine particles from being discharged to the outside when the air inside the duct 260 is discharged to the outside.

  The duct 260 is a flow path for flowing air. The duct 260 is provided with end portions 261 and 262. The end portions 261 and 262 are fixing rotor side end portions located at the furthest position from the suction fan 251 in the duct 260. The end portions 261 and 262 are provided at positions facing both end surfaces of the fixing roller 210 in the axial direction (both end surfaces in the longitudinal direction). Openings 263 and 264 are provided on the surfaces of the end portions 261 and 262 facing both end surfaces of the fixing roller 210 in the axial direction, respectively. The openings 263 and 264 are fixing rotator-side openings that are opened at positions facing both end surfaces of the fixing roller 210 in the axial direction. The openings 263 and 264 are formed along portions where the elastic layer 212 of the fixing roller 210 and the heat-resistant elastic layer 215 of the heating belt 213 are exposed to the outside. The duct 260 is formed from the position where the suction fan 251 is disposed to the position where the end portions 261 and 262 are disposed. That is, the duct 260 communicates with a portion where the suction fan 251 is located.

  As shown in FIG. 4, a suction port 271 is provided at a position opposite to the surface of the terminal portion 261 facing the fixing roller 210. The suction port 271 is a connecting part that allows the terminal part 261 and the other part of the duct 260 to communicate with each other. In addition, a suction port 272 is provided at a position opposite to the surface facing the fixing roller 210 in the end portion 262.

  Here, the opening 263 and the opening 264 are formed at positions and shapes symmetrical with respect to a plane perpendicular to the cylindrical axis of the fixing roller 210. The suction port 271 and the suction port 272 are formed at positions and shapes symmetrical with respect to a plane perpendicular to the cylindrical axis of the fixing roller 210.

  Air flows in the direction of the arrow in FIG. That is, it flows into the openings 263 and 264 from the vicinity of the side surface of the heating belt 213 of the fixing roller 210. Next, after flowing to the location of the suction fan 251 along the duct 260, it is discharged to the outside of the image forming apparatus 1 through the dust collection filter 252. Here, ultrafine particles (UFP) and other particles are captured by the dust collection filter 252. That is, it is not discharged outside the image forming apparatus 1.

  FIG. 5 is a diagram in which the shape and the arrangement of the openings 263 and 264 of the end portions 261 and 262 are overlaid on the arrangement of the fixing device 220 shown in FIG. As shown in FIG. 5, the opening 263 is formed along the circumference of the side surface of the heating belt 213. The opening 263 is indicated by a two-dot chain line in FIG. The opening 263 is formed on the upstream side of the rotation in the nip portion between the fixing roller 210 and the pressure roller 220 from the heating upstream end 265 where the heating belt 213 starts to receive heat from the induction heating device 230 toward the downstream side of the fixing roller 210. Positions 266 are formed. The heating upstream end 265 is a heating start position located on the most upstream side in the region where the heating layer 214 of the heating belt 213 receives the magnetic field formed by the induction heating device 230. As described above, the opening 263 is formed on the side surface of the heating belt 213 over a region where the temperature of the heating belt 213 is high. This is because this region is a region where ultra fine particles (UFP) are likely to be generated.

  The suction port 271 is located on the most upstream side of the rotation of the fixing roller 210 in the opening 263. The location of the suction port 271 is a location where the temperature of the heating belt 213 is high and the rate of temperature rise is also high. For this reason, the amount of ultrafine particles (UFP) generated is particularly large at this location. Since the suction at the place where the ultrafine particles (UFP) are likely to be generated is strong, the ultrafine particles (UFP) are favorably absorbed.

5. Modified example 5-1. Wide opening A modification will now be described. In this embodiment, an opening 263 is provided along the location where the heating belt 213 of the fixing roller 210 is disposed. However, the area of the opening 263 may be widened. FIG. 6 is a schematic configuration diagram showing a fixing device 300 having large openings 361 and 362 toward the center of the fixing roller 210. The openings 361 and 362 are formed along the elastic layer 212 of the fixing roller 210 and the heat-resistant elastic layer 215 of the heating belt 213. Even in this way, ultrafine particles (UFP) can be removed. Moreover, low molecular siloxane can be absorbed by the wide opening 361,362.

6). Summary As described above in detail, the image forming apparatus 1 according to the present embodiment includes the ultrafine particle removing device 250. The duct 260 of the ultrafine particle removing device 250 has openings 263 and 264 formed at positions where the heating belt 213 of the fixing roller 210 is at a high temperature. Thereby, an image forming apparatus capable of suitably removing ultra fine particles (UFP) is realized.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the image forming apparatus is not limited to a color printer. That is, it is not limited to color. It is not limited to a printer. It can also be applied to copiers. Further, the present invention can be applied to an image forming apparatus having a function of receiving a print job from a public line and forming an image, and other apparatuses for forming an image. Also, it can be applied regardless of the type of toner. Further, the present invention is not necessarily applied to an image forming apparatus for duplex printing. Of course, it can be applied regardless of the transfer method.

(Second Embodiment)
A second embodiment will be described. The fixing device according to the present embodiment sucks ultra fine particles (UFP) not only from the side surface of the fixing roller but also from the side surface of the pressure roller by a duct. Therefore, not only the ultra fine particles (UFP) scattered from the side surface of the fixing roller but also the ultra fine particles (UFP) that can be scattered from the side surface of the pressure roller can be removed. Therefore, only the ultrafine particle removing apparatus different from the first embodiment will be described.

1. Ultrafine Particle Removal Device FIG. 7 is a schematic configuration diagram for explaining the pressure roller 220 side of the fixing device 400 of this embodiment. As shown in FIG. 7, the ultrafine particle removing device 450 is provided with terminal portions 481 and 482 at positions facing both end surfaces in the axial direction of the pressure roller 220 (both end surfaces in the longitudinal direction). The terminal portions 481 and 482 are pressure rotating body side terminal portions. The end portions 481 and 482 are opened at positions facing both end surfaces of the pressure roller 220 in the axial direction (both end surfaces in the longitudinal direction). Openings 483 and 484 are formed in the end portions 481 and 482, respectively. The openings 483 and 484 are pressure rotor-side openings that are opened on the side surfaces of the pressure roller 220. Note that terminal portions 261 and 262 are formed on the side surface of the fixing roller 210 as shown in FIG.

  FIG. 8 is a schematic configuration diagram showing the arrangement of openings of the fixing device 400 and the ultrafine particle removing device 450 of the present embodiment. In the fixing device 400 shown in FIG. 8, the duct 460 goes around to the positions of the side surfaces of the fixing roller 210 and the pressure roller 220. Openings 263 and 264 are provided at positions on the side surface of the fixing roller 210. Openings 483 and 484 are provided on the side surfaces of the pressure roller 220.

  The openings 483 and 484 are provided from a position on the upstream side of the nip between the fixing roller 210 and the pressure roller 220 to a position on the downstream side of the pressure roller 220. The part facing the part where the openings 483 and 484 are formed is the part heated by the pressure roller 220 coming into contact with the fixing roller 210. The temperature at that location is higher than the temperature at other locations on the pressure roller 220. That is, it is a place where ultra fine particles (UFP) are easily generated in the pressure roller 220.

  Further, suction ports 491 and 492 are provided at positions on the most upstream side of the pressure roller 220 in the openings 483 and 484. The position of the pressure roller 220 facing these is the place where the temperature is highest in the pressure roller 220 and also the place where the temperature rises most rapidly. That is, in the openings 483 and 484, the ultrafine particles (UFP) are most likely to be generated.

2. Summary As described above in detail, the image forming apparatus according to the present embodiment includes the ultrafine particle removing apparatus 450. The duct 460 of the ultrafine particle removing device 450 has an opening formed at a position facing the side surfaces of the fixing roller 210 and the pressure roller 220. Thereby, an image forming apparatus capable of suitably removing ultra fine particles (UFP) is realized.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the image forming apparatus is not limited to a color printer. That is, it is not limited to color. It is not limited to a printer. It can also be applied to copiers. Further, the present invention can be applied to an image forming apparatus having a function of receiving a print job from a public line and forming an image, and other apparatuses for forming an image. Also, it can be applied regardless of the type of toner. Further, the present invention is not necessarily applied to an image forming apparatus for duplex printing. Of course, it can be applied regardless of the transfer method.

(Third embodiment)
A third embodiment will be described. The image forming apparatus of the present embodiment is different from the first embodiment in the fixing method of the fixing device. The fixing device of the present embodiment has an external heating roller that heats the fixing roller from the outside of the fixing roller. Therefore, the differences will be mainly described.

1. Fixing Device The fixing device 500 of this embodiment has a heating device outside the fixing roller, as shown in FIG. The fixing device 500 includes a fixing roller 510, a pressure roller 220, and an external heating roller 530. The fixing roller 510 includes a cored bar 511 having a heat source, an elastic layer 512, and a release layer 513.

  The external heating roller 530 is an external heating device that heats the fixing roller 510 from the outside. The external heating roller 530 includes a heat source 531, a cored bar 532, a surface layer 533, and a temperature sensor 534. The external heating roller 530 is for applying heat generated by the heat source 531 to the release layer 513 of the fixing roller 510.

2. Ultrafine Particle Removal Device The ducts of the ultrafine particle removal device 550 are provided with end portions 561 and 562. The end portions 561 and 562 are end portions at positions farthest from the suction fan 251. The end portions 561 and 562 are provided at positions facing both ends in the longitudinal direction of the fixing roller 510. The end portions 561 and 562 are opened at positions facing both ends in the longitudinal direction of the fixing roller 510. Openings 563 and 564 are provided in the end portions 561 and 562, respectively. The end portions 561 and 562 are fixing rotator side end portions. The duct is formed from the position where the suction fan 251 is disposed to the position where the end portions 561 and 562 are disposed.

  The openings 563 and 564 are formed from the nip portion between the fixing roller 510 and the external heating roller 530 along the elastic layer 512 of the fixing roller 510 toward the rotation downstream side of the fixing roller 510. The suction ports 571 and 572 are provided at positions facing the nip portion between the fixing roller 510 and the external heating roller 530. This is because this position has the largest temperature rise in the fixing roller 510. That is, it is a place where ultra fine particles (UFP) are likely to be generated.

  The side of the pressure roller 220 will be described. As shown in FIG. 7, the ultrafine particle removing device 550 of this embodiment is provided with terminal portions 481 and 482 at positions facing both ends in the longitudinal direction of the pressure roller 220. The terminal portions 481 and 482 are pressure rotating body side terminal portions. The end portions 481 and 482 are opened at positions facing both end portions of the pressure roller 220 in the longitudinal direction. An opening 483 is formed in the end portion 481. An opening 484 is formed in the end portion 482.

3. Summary As described above in detail, the image forming apparatus according to the present embodiment has the ultrafine particle removing device 550 at a position facing the side surface of the fixing roller 510. The duct 560 of the ultrafine particle removing device 550 has openings 561 and 562 at positions where the release layer 513 of the fixing roller 510 is at a high temperature. In addition, an opening is formed at a position facing the side surface of the pressure roller 220. Thereby, an image forming apparatus capable of suitably removing ultra fine particles (UFP) is realized.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the image forming apparatus is not limited to a color printer. That is, it is not limited to color. It is not limited to a printer. It can also be applied to copiers. Further, the present invention can be applied to an image forming apparatus having a function of receiving a print job from a public line and forming an image, and other apparatuses for forming an image. Also, it can be applied regardless of the type of toner. Further, the present invention is not necessarily applied to an image forming apparatus for duplex printing. Of course, it can be applied regardless of the transfer method.

(Fourth embodiment)
A fourth embodiment will be described. The image forming apparatus of the present embodiment is different from the first embodiment in the fixing method of the fixing device. The fixing device of this embodiment is a belt-type fixing device using a fixing belt. Therefore, the differences will be mainly described.

1. Fixing Device As shown in FIG. 10, the fixing device 600 of this embodiment includes a fixing roller 610, a pressure roller 220, and an external heating roller 630. A heating belt 613 is wound around the fixing roller 610 and the external heating roller 630. The heating belt 613 is a heating member for heating and fixing the image forming surface of the paper P. The structure of the heating belt 613 is the same as the structure of the heating belt 213 shown in FIG. The fixing roller 610 includes a cored bar 611 and an elastic layer 612. The external heating roller 630 includes a heat source 631, a cored bar 632, a surface layer 633, and a temperature sensor 634. The pressure roller 220 includes a cored bar 221, an elastic layer 222, and a release layer 223.

2. Ultrafine particle removal apparatus The ultrafine particle removal apparatus of this embodiment will be described. Terminal portions 661 and 662 are provided in the duct of the ultrafine particle removing device 650. The end portions 661 and 662 are end portions at positions farthest from the suction fan 251. The end portions 661 and 662 are provided at positions facing both ends of the fixing roller 610 in the longitudinal direction. The end portions 661 and 662 are opened at positions facing both ends in the longitudinal direction of the fixing roller 610. The end portions 661 and 662 are provided with openings 663 and 664, respectively. The end portions 661 and 662 are fixing rotator side end portions. The duct is formed from the position where the suction fan 251 is disposed to the position where the end portions 661 and 662 are disposed.

  The side of the pressure roller 220 will be described. As shown in FIG. 7, the ultrafine particle removing device 650 of this embodiment is provided with end portions 481 and 482 at positions facing both ends in the longitudinal direction of the pressure roller 220. The terminal portions 481 and 482 are pressure rotating body side terminal portions. The end portions 481 and 482 are opened at positions facing both end portions of the pressure roller 220 in the longitudinal direction. An opening 483 is formed in the end portion 481. An opening 484 is formed in the end portion 482.

3. Summary As described above in detail, the image forming apparatus according to the present embodiment has the ultrafine particle removing device 650 at a position facing the side surface of the fixing roller 610. The duct of the ultrafine particle removing device 650 has openings 663 and 664 at positions where the heating belt 613 is at a high temperature. Openings 483 and 484 are also formed on the pressure roller 220 side. Thereby, an image forming apparatus capable of suitably removing ultra fine particles (UFP) is realized.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the image forming apparatus is not limited to a color printer. That is, it is not limited to color. It is not limited to a printer. It can also be applied to copiers. Further, the present invention can be applied to an image forming apparatus having a function of receiving a print job from a public line and forming an image, and other apparatuses for forming an image. Also, it can be applied regardless of the type of toner. Further, the present invention is not necessarily applied to an image forming apparatus for duplex printing. Of course, it can be applied regardless of the transfer method.

(Fifth embodiment)
A fifth embodiment will be described. In the fixing device according to this embodiment, ultra fine particles (UFP) are hardly generated from the fixing roller. For this reason, the ultrafine particle removing apparatus of this embodiment has a duct having an opening only on the pressure roller side.

1. Fixing Device As shown in FIG. 11, the fixing device 700 of this embodiment includes a fixing roller 710, a pressure roller 220, and an ultrafine particle removing device 750. The fixing roller 710 includes a heat source 711, a cored bar 712, and a release layer 713. The heat source 711 is, for example, a halogen lamp. The release layer 713 is, for example, a fluorine coat layer. The pressure roller 220 includes a cored bar 221, an elastic layer 222, and a release layer 223.

2. Ultrafine Particle Removal Device The ultrafine particle removal device 750 of this embodiment is provided with terminal portions 481 and 482 at positions facing both ends in the longitudinal direction of the pressure roller 220, as shown in FIG. The terminal portions 481 and 482 are pressure rotating body side terminal portions. The end portions 481 and 482 are opened at positions facing both end portions of the pressure roller 220 in the longitudinal direction. An opening 483 is formed in the end portion 481. An opening 484 is formed in the end portion 482. Note that there is no terminal portion on the fixing roller 710 side. In other words, this embodiment does not have the fixing rotator side termination portion described in the first to fourth embodiments.

3. Summary As described in detail above, the image forming apparatus according to the present embodiment has the ultrafine particle removing device 750 at a position facing the side surface of the pressure roller 220. The duct 760 of the ultrafine particle removing device 750 has openings 483 and 484 at positions where the elastic layer 222 of the pressure roller 220 is at a high temperature. Thereby, an image forming apparatus capable of suitably removing ultra fine particles (UFP) is realized.

  Note that this embodiment is merely an example, and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the image forming apparatus is not limited to a color printer. That is, it is not limited to color. It is not limited to a printer. It can also be applied to copiers. Further, the present invention can be applied to an image forming apparatus having a function of receiving a print job from a public line and forming an image, and other apparatuses for forming an image. Also, it can be applied regardless of the type of toner. Further, the present invention is not necessarily applied to an image forming apparatus for duplex printing. Of course, it can be applied regardless of the transfer method.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 200,300,400,500,600,700 ... Fixing apparatus 210,510,610,710 ... Fixing roller 211,511,611 ... Core metal 212,512,632 ... Elastic layer 213,613 ... Heating Belt 214 ... Heating layer 215 ... Heat resistant elastic layer 216 ... Heat resistant release layer 220 ... Pressure roller 221 ... Core metal 222 ... Elastic layer 223 ... Release layer 230 ... Induction heating device 231 ... Core 232 ... Excitation coil 233 ... Bottom core 240 ... Non-contact type thermometers 250, 450, 550, 650, 750 ... Ultrafine particle removing device 251 ... Suction fan 252 ... Dust collection filter 260 ... Ducts 261, 262, 481, 482 ... End portions 263, 264, 361, 362 , 483, 484 ... openings 271, 272, 491, 492 ... suction port 513 ... release layers 530, 630 ... externally applied Rollers 531,631 ... heat source 532,632 ... metal core 533,633 ... surface layer 534, 634 ... temperature sensor 711 ... heat source 712 ... core metal 713 ... release layer P ... paper

Claims (10)

An image forming unit for forming a toner image on the image carrier;
A transfer unit for transferring a toner image from the image carrier to a sheet;
An image forming apparatus having a fixing device for fixing a toner image to the sheet,
The fixing device includes:
A fixing rotator comprising a heating member that heats the sheet in contact with the sheet onto which the toner image has been transferred, and a heating member-side elastic layer that supports the heating member;
A pressure rotator including a pressure member that forms a nip together with the heating member, and a pressure member-side elastic layer that supports the pressure member;
A heat source for heating the heating member,
The heating member-side elastic layer is at least partially exposed at both axial ends of the fixing rotating body,
A suction part for sucking air;
A duct that communicates with the suction portion and includes a fixing rotator side end portion at a position facing both end surfaces of the fixing rotator in the axial direction;
The fixing rotator side end portion is:
An image forming apparatus, wherein a fixing rotator side opening is formed on a surface of the fixing rotator opposite to both axial end surfaces along an exposed portion of the heating member side elastic layer. The image forming apparatus according to claim 1,
The pressure member side elastic layer is
At least a portion of the pressure rotating body is exposed at both ends in the axial direction;
The duct is provided with a pressure rotator side end portion at a position facing both end faces in the axial direction of the pressure rotator,
The pressurizing rotating body side termination is
An image is characterized in that a pressurizing rotator side opening is formed along the exposed portion of the pressurizing member side elastic layer on a surface opposite to both axial end faces of the pressurizing rotator. Forming equipment. The image forming apparatus according to claim 1,
The fixing rotor side opening is
The image is formed from a heating start position to the heating member by the heat source to a position of a nip portion between the fixing rotator and the pressure rotator toward a rotation downstream side of the fixing rotator. Forming equipment. The image forming apparatus according to claim 2,
The pressure rotor side opening is
An image forming apparatus, wherein the image forming apparatus is formed from a position of a nip portion between the fixing rotator and the pressure rotator to a position downstream of the pressure rotator. The image forming apparatus according to claim 2,
The fixing rotor side opening is
The heat source is formed from the heating start position to the heating member to the position of the nip portion between the fixing rotator and the pressure rotator toward the downstream side of the rotation of the fixing rotator,
The pressure rotor side opening is
An image forming apparatus, wherein the image forming apparatus is formed from a position of a nip portion between the fixing rotator and the pressure rotator to a position downstream of the pressure rotator. An image forming apparatus according to any one of claims 3 to 5, comprising:
A suction port is formed at a position on the opposite side of the fixing rotator-side opening at the fixing rotator-side end portion at a position upstream of the fixing rotator in the fixing rotator-side opening.
A suction port is formed at a position on the opposite side of the pressurizing rotator side opening at the pressurizing rotator side end portion, at a position upstream of the pressurizing rotator in the pressurizing rotator side opening. An image forming apparatus. An image forming apparatus according to any one of claims 1 to 6, comprising:
The heat source is
An induction heating device comprising a core and an exciting coil;
The fixing rotator is
A fixing roller including a fixing belt in which a metal layer heated by the induction heating device is used as the heating member;
The pressure rotating body is:
An image forming apparatus comprising a pressure roller in which a release layer having releasability is used as the pressure member. An image forming apparatus according to any one of claims 1 to 6, comprising:
An external heating roller having the heat source therein;
The fixing rotator is
A fixing roller comprising a release layer that rotates in contact with the external heating roller as the heating member;
The pressure rotating body is:
An image forming apparatus, wherein the pressure member is a pressure roller in which a release layer having releasability is used. An image forming apparatus according to any one of claims 1 to 6, comprising:
An external heating roller having the heat source therein;
The fixing rotator is
A fixing roller,
The pressure rotating body is:
A pressure roller in which a release layer having releasability is used as the pressure member,
The heating member is
An image forming apparatus, wherein the image forming apparatus is a heating belt wound between the fixing rotator and the external heating roller. An image forming unit for forming a toner image on the image carrier;
A transfer unit for transferring a toner image from the image carrier to a sheet;
An image forming apparatus having a fixing device for fixing a toner image to the sheet,
The fixing device includes:
A fixing rotator comprising a heating member that heats the sheet in contact with the sheet onto which the toner image has been transferred, and a heating member-side elastic layer that supports the heating member;
A pressure rotator including a pressure member that forms a nip together with the heating member, and a pressure member-side elastic layer that supports the pressure member;
A heat source for heating the heating member,
The pressure member side elastic layer is
At least a portion of the pressure rotating body is exposed at both ends in the axial direction;
A suction part for sucking air;
A duct that communicates with the suction portion and that includes a pressure rotator side end portion at a position facing both end surfaces of the pressure rotator in the axial direction;
The pressurizing rotating body side termination is
An image forming apparatus, wherein a pressing rotator side opening is formed along an exposed portion of the pressing member side elastic layer.

Images