JP2010117420A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clean image forming apparatus which carries out highly efficient capture of VOC volatilized from toner on heated paper without diffusing the VOC into the apparatus, directly cooling a fixing device and without generating air flow which hinders conveyance of paper. <P>SOLUTION: A paper conveyance device 20 for conveying the paper P on which a toner image has been fixed in a printer 1 includes a VOC capture conveyance roller 30 being a rotating member provided with a cylindrical shaft 31 and a roller 32 being porous members having a plurality of holes 31a and 32a penetrating between inside and outside on surfaces opposed to the paper P, guiding outside air to the inside through the holes 31a and 32a and conveying the paper P by rotational force. Thus, the VOC volatilized from the toner T is sucked at a point approximate to a surface of the paper P heated by the fixing device 13 by the cylindrical shaft 31 and the roller 32 of the VOC capture conveyance roller 30 as a paper conveyance member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  An electrophotographic image forming apparatus such as a copying machine or a printer includes a fixing device that fixes an unfixed toner image transferred onto a sheet. The fixing device includes a fixing member and a pressure member that are pressed against each other to form a fixing nip portion, and a heating unit that heats at least one of these members. A thermal fixing method is widely adopted in which a sheet carrying an unfixed toner image is inserted into a fixing nip heated by a heating unit, whereby unfixed toner is heated and pressurized to be fixed on the sheet surface.

  In the fixing device employing such a thermal fixing method, the temperature is adjusted so that the surface of the heated fixing member and / or the pressure member is 160 to 200 ° C. Therefore, the fixing device and its surroundings are the same. It becomes very hot. When the fixing device becomes hot, the synthetic resin that constitutes the housing, etc., the silicone oil applied to the surface of the fixing member in order to prevent the toner from adhering and improve the peelability of the paper, and the resin component contained in the toner are also hot. Will be exposed to. As a result, volatile organic compounds (hereinafter sometimes referred to as “VOC”) are volatilized from these resins and oils. This VOC has a particularly high rate of volatilization from the toner. The volatilized VOC generates a strange odor and can cause discomfort, so it is necessary to prevent it from diffusing outside the image forming apparatus.

Therefore, various methods have been proposed to prevent the VOC gas from diffusing outside the image forming apparatus, and examples thereof can be seen in Patent Documents 1 and 2. The image forming apparatuses described in Patent Documents 1 and 2 include a suction fan and an exhaust fan for generating an air flow around the fixing device and discharging the air to the outside of the apparatus, and a filter for collecting VOC. ing.
JP 2006-349826 A (Page 6, FIG. 3-4) Japanese Patent Laying-Open No. 2007-264077 (page 6-7, FIG. 1)

  In the image forming apparatuses described in Patent Documents 1 and 2, a fan is used to generate an air flow around the fixing device, and the air is guided to the location of the filter so that the paper is exposed to a high temperature around the fixing device. Trying to collect VOC gas generated from However, in these methods, there is a possibility that the air hitting the surface of the paper does not flow to the exhaust fan as it is and proceeds to the other. As a result, some of the VOC that volatilizes from the sheet may diffuse inside the image forming apparatus and leak outside without passing through a filter.

  These methods are not desirable for a fixing device that needs to maintain a predetermined temperature in order to fix an unfixed toner image because the fixing device is directly cooled. There is a risk that the temperature management of the fixing device may become very complicated, and temperature unevenness may occur. As a result, there is a concern that a problem such as fixing failure may occur.

  Furthermore, these methods apply an air flow to the paper or pass the paper through the air flow, which may hinder paper conveyance. That is, there is a possibility that the paper skews and the edge of the paper is bent. As a result, there is a concern that a paper jam occurs and the paper and the paper transport path are damaged.

  The present invention has been made in view of the above points. In an image forming apparatus having a fixing device that heat-fixes an unfixed toner image on a sheet, VOC that volatilizes from the toner on the heated sheet is diffused into the apparatus. Can clean VOCs without causing odors, without cooling the fixing device directly, or generating an air flow that interferes with paper transport. An object is to provide an image forming apparatus.

  In order to solve the above-described problems, the present invention provides a fixing device that heat-fixes an unfixed toner image on a sheet, a sheet conveying device that conveys a sheet after toner image fixing, and air inside the image forming apparatus. An image forming apparatus comprising: an exhaust device that discharges; a duct through which an air flow generated by the exhaust device passes; and a filter that collects a volatile organic compound contained in the air. A rotating member that has a plurality of holes penetrating between the inside and the outside on the surface facing the inside, guides outside air to the inside through the holes, and conveys the paper by a rotational force It was decided to prepare.

  In the image forming apparatus having the above-described configuration, the rotating member, the duct, and the exhaust device are coupled so that the inside thereof communicates.

  Further, in the image forming apparatus having the above configuration, the filter is disposed in the duct.

  In the image forming apparatus having the above-described configuration, the rotating member has a concave-convex shape on the contact surface with the paper, and the concave portion includes the hole.

  Further, in the image forming apparatus having the above configuration, the rotating member is configured by a roller.

  Further, in the image forming apparatus having the above configuration, the rotating member is constituted by a belt.

  In the image forming apparatus having the above-described configuration, the rotating member includes a paddle portion whose front end is in contact with the sheet.

  According to the configuration of the present invention, a fixing device that heats and fixes an unfixed toner image on a paper, a paper transport device that transports the paper after toner image fixing, and an exhaust device that discharges air inside the image forming apparatus to the outside. And a duct through which an air flow generated by the exhaust device passes, and a filter that collects a volatile organic compound contained in the air, wherein the paper transport device is a surface facing the paper A porous member having a plurality of holes penetrating between the inside and the outside, and a rotating member for guiding the outside air to the inside through the holes and conveying the paper by a rotational force; Therefore, the VOC that is volatilized from the toner on the paper is sucked by the porous member of the rotating member as the paper transporting member at a location near the surface of the paper heated by the fixing device. Door can be. Therefore, in this method, VOCs volatilized from the toner on the paper do not diffuse into the image forming apparatus, the fixing device is directly cooled, or an air flow that impedes paper conveyance is not generated. In this way, it is possible to provide a clean image forming apparatus capable of performing highly efficient collection of VOCs volatilized from the toner on the paper and preventing the generation of off-flavors.

  In addition, since the rotary member, the duct, and the exhaust device are coupled so that the inside thereof communicates, the VOC that volatilizes from the toner on the paper can be sucked more effectively. . Therefore, it becomes possible to collect VOC more efficiently.

  In addition, since the filter is disposed in the duct, VOC sucked from the toner on the paper can easily pass through the filter. Therefore, it is possible to further improve the VOC collection efficiency.

  In addition, since the rotating member has a concave-convex shape on the contact surface with the paper, and the concave portion is provided with the hole, the rotating member surface is prevented from coming into close contact with the toner. The location can be made to correspond to the location of the toner with as wide an area as possible. As a result, a larger amount of VOC that volatilizes from the toner on the paper can be sucked. Therefore, the collection efficiency of VOC can be further increased.

  In addition, since the rotating member is constituted by a roller, it is possible to suck VOCs volatilized from the toner on the paper while transporting the paper with a simpler construction. Thereby, it is possible to obtain an image forming apparatus capable of performing highly efficient collection of VOCs and achieving cost reduction.

  In addition, since the rotating member is constituted by a belt, the contact area with the paper can be expanded. As a result, the VOC that volatilizes from the toner on the paper can be sucked for a long time. Therefore, it is possible to further improve the VOC collection efficiency.

  Further, since the rotating member is provided with a paddle portion whose tip is in contact with the paper on the surface thereof, the effect of preventing the portion without a hole on the surface of the rotating member from coming into contact with the toner is improved. Can correspond to the location of the toner in a wide area. As a result, a larger amount of VOC that volatilizes from the toner on the paper can be sucked. Therefore, the collection efficiency of VOC can be improved.

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

  First, an image output operation of the image forming apparatus according to the first embodiment of the present invention will be described while explaining the outline of the structure with reference to FIGS. FIG. 1 is a left side view of a schematic vertical section showing a schematic structure of a printer as an example of an image forming apparatus, FIG. 2 is a graph showing temperature dependence of VOC volatilization amount from toner, and FIG. 3 is a graph showing toner temperature after fixing. It is a graph which shows a time change. In FIG. 1, the right side is the front side of the printer, and the left side is the back side.

  As shown in FIG. 1, a paper feed cassette 3 is provided below the inside of the main body 2 of the printer 1. The paper P is stacked and accommodated inside the paper feed cassette 3. A paper feeding device 4 for the paper feeding cassette 3 is disposed above the downstream portion of the paper feeding cassette 3 in the paper conveyance direction. The sheet feeding device 4 feeds the sheet P toward the upper right of the sheet feeding cassette 3 in FIG. The paper feed cassette 3 can be pulled out / stored by being slid horizontally to the front side of the main body 2, that is, rightward in FIG.

  As shown in FIG. 1, a manual paper feed tray 5 is provided at the center of the front surface of the main body 2 of the printer 1. The manual paper feed tray 5 is rotatable in a vertical plane along the paper transport direction around a support shaft provided at the lower end and extending substantially horizontally in the horizontal direction. The manual feed tray 5 can be opened and closed with its upper end at the front side of the printer 1, that is, rightward in FIG. 1. By opening and unfolding, the paper P or the like is placed on the upper surface. It becomes a form that can be done.

  The manual paper feed tray 5 can handle paper of a size that is not in the paper feed cassette 3, a thick paper, an OHP sheet, and the like that is to be fed into the apparatus by hand. The paper placed on the manual paper feed tray 5 is sent out into the main body 2 by the paper feed device 6 for the manual paper feed tray 5 disposed on the left side of the manual paper feed tray 5 in FIG. When not in use, the manual paper feed tray 5 is closed as shown in FIG.

  A paper feed path 7, a registration roller 8, an image forming unit 9, and a transfer roller 10 are disposed downstream of the paper feed cassette 3 and the manual feed tray 5 in the paper feed direction. The paper P sent out from the paper feed cassette 3 or the manual paper feed tray 5 passes through the paper feed paper conveyance path 7 and reaches the position of the registration roller 8. The registration roller 8 corrects the oblique feeding of the paper P, measures the timing of the toner image formed by the image forming unit 9, and feeds the paper P to the transfer roller 10.

  Image data signals such as characters, graphics, and patterns from an external computer (not shown) are transmitted to the printer 1 and controlled by the optical scanning device 11 provided above the image forming unit 9 based on the image data. Laser light L (a chain line in the figure) is irradiated. As a result, in the image forming unit 9, an electrostatic latent image of the original image is formed on the photosensitive drum 12, which is an image carrier, and a toner image is developed from the electrostatic latent image. The toner image is transferred onto the paper P sent in synchronization by the registration roller 8 at a transfer nip portion formed by the contact between the photosensitive drum 12 and the transfer roller 10.

  A fixing device 13 is provided downstream of the image forming unit 9 and the transfer roller 10 in the sheet conveyance direction. The paper P carrying the unfixed toner image by the transfer roller 10 is sent to the fixing device 13 where the toner image is heated and pressed by the heat roller and the pressure roller to be fixed.

  Downstream of the fixing device 13, a paper transport device 20 that transports the paper P after the toner image fixing further downstream is provided. Here, as shown in FIG. 2, it can be seen that the VOC that volatilizes from the toner increases as the temperature rises, and particularly increases rapidly from about 120 ° C. Further, as shown in FIG. 3, it can be seen that the toner temperature on the sheet after fixing is lowered from about 140 ° C. to about 60 ° C. in only about one second. Therefore, in order to collect as many VOCs as possible, the sheet conveying device 20 constituting a part of the VOC collecting mechanism is arranged close to the downstream of the fixing device 13 as shown in FIG.

  A discharge paper transport path 14, a paper discharge port 15, and a paper discharge unit 16 are disposed downstream of the paper transport device 20. The paper P discharged from the fixing device 13 and passed through the location of the paper transport device 20 is sent upward through the paper transport path 14 for paper discharge, and a paper discharge portion provided on the upper surface of the main body 2 from the paper discharge port 15. 16 is discharged.

  Next, the structure of the sheet conveying device 20 downstream of the fixing device 13 will be described with reference to FIGS. 4 and 5 in addition to FIG. FIG. 4 is a vertical sectional front view showing the periphery of the sheet conveying apparatus, and FIG. 5 is a partially enlarged vertical sectional front view of a VOC collecting and conveying roller of the sheet conveying apparatus. In addition, the white arrow in FIG.4 and FIG.5 has shown the distribution route and distribution direction of air.

  As shown in FIGS. 1 and 4, the sheet conveying device 20 includes a VOC collecting and conveying roller 30 and a conveying roller 21 that are rotating members. The printer 1 also includes an exhaust fan 17, which is an exhaust device, a duct 18, and a filter 19.

  The VOC collecting and conveying roller 30 is disposed on the upper side of the sheet conveying path downstream of the fixing device 13. The VOC collecting and conveying roller 30 is in pressure contact with the conveying roller 21 disposed on the lower side thereof to form a conveying nip portion, and conveys the paper P further downstream by its rotational force. The conveyance speed of the paper P by the VOC collection conveyance roller 30 and the conveyance roller 21 is the same as the conveyance speed of the fixing device 13 and is, for example, 250 mm / s. And the VOC collection conveyance roller 30 is provided with the cylindrical axial part 31 and the roller part 32 as a porous member, as shown in FIG.4 and FIG.5.

  The cylindrical shaft portion 31 is made of, for example, a metal material such as aluminum, and has a cylindrical shape with a circular cross section with one end closed. The other end of the cylindrical shaft portion 31 is coupled to the duct 18 so that the inside thereof communicates so that air flows. The surface of the cylindrical shaft portion 31 is provided with a plurality of holes 31a penetrating in the radial direction between the inside and the outside. The cylindrical shaft portion 31 is supported by the main body 2 so as to be rotatable about an axis extending substantially horizontally in the paper width direction perpendicular to the paper transport direction.

  The roller portion 32 is made of a material such as foamed silicone, porous metal, or porous ceramic, and has a cylindrical shape with a circular cross section. A cylindrical shaft portion 31 is inserted inside the roller portion 32 so that the axes thereof coincide with each other. Further, as shown in FIG. 5, the surface of the roller portion 32 facing the paper P penetrates in the radial direction between the inside and the outside so as to communicate with the hole 31 a of the cylindrical shaft portion 31. A plurality of holes 32a are provided. Furthermore, the contact surface of the roller portion 32 with the paper P has an uneven shape, and the recess 32b is provided with a hole 32a. The surfaces of the VOC collecting / conveying roller 30 and the conveying roller 21 facing the paper P are coated with a release layer (for example, a fluororesin) to which the toner after fixing is difficult to adhere.

  The exhaust fan 17 and the duct 18 are coupled in the order of the exhaust fan 17, the duct 18, and the cylindrical shaft portion 31 of the VOC collecting / conveying roller 30, and communicate with each other so that air flows therethrough. As the filter 19, for example, a photocatalyst such as titanium oxide or activated carbon capable of collecting VOC contained in the air is used, and is disposed inside the duct 18. Further, the exhaust fan 17 is provided at a location above the fixing device 13 and in the vicinity of the side surface of the printer 1 in order to exhaust the air inside the printer 1 to the outside.

  When the exhaust fan 17 shown in FIG. 4 is driven, as shown in FIG. 5, VOCs volatilized from the toner T on the paper P together with air from the plurality of holes 32 a on the surface of the roller portion 32 of the VOC collecting and conveying roller 30. Sucked. Then, as shown in FIG. 4, the air containing VOC passes through the hole 31 a of the cylindrical shaft portion 31, the inside of the cylindrical shaft portion 31, and the inside of the duct 18 and reaches the location of the filter 19. Here, the filter 19 collects VOC contained in the air. Thereafter, clean air from which the VOC has been removed is discharged from the location of the exhaust fan 17 to the outside of the printer 1.

  Next, the effect when VOC is collected from the toner on the fixed paper using the VOC collecting mechanism will be described with reference to FIG. FIG. 6 is a table showing the influence of the presence or absence of the VOC collecting mechanism according to the first embodiment of the present invention on the VOC emission amount to the outside of the printer.

The printer 1 equipped with the exhaust fan 17, the duct 18, the filter 19 and the paper conveying device 20 according to the present invention is installed in a SUS chamber (volume 1 m ³ , inner surface electrolytic polishing finish), and the outside air environment is 23 ± 2. The temperature was set to 50 ° C. and 5 ± 5% Rh, and the chamber was set to ventilate at 67 L / min. After ventilation for about 1 hour, a printing operation was performed for 10 minutes, and the air in the chamber was continuously sampled at 100 mL / min with a TENAX (registered trademark) collection tube. Sampling was continuously performed for about 2 hours after printing was stopped. Then, the sampled TENAX (registered trademark) collection tube is desorbed by a heat desorption apparatus, and the collected VOC is measured by a GC-MS apparatus to estimate the amount of VOC discharged to the outside of the printer 1. It was.

  Further, as a comparative example, the amount of VOC discharged to the outside of the printer was measured by the same method using a printer not equipped with the VOC collecting mechanism according to the present invention.

  According to FIG. 6, the printer with the VOC collection mechanism according to the present invention can reduce the amount of VOC discharged to the outside of the printer to about 2/3 compared with the printer without the VOC collection mechanism. I can see that

  As described above, the fixing device 13 that heat-fixes the unfixed toner image on the paper P, the paper transport device 20 that transports the paper P after the toner image is fixed, and the exhaust that exhausts the air inside the printer 1 to the outside. In a printer 1 comprising an exhaust fan 17 that is a device, a duct 18 through which an air flow generated by the exhaust fan 17 passes, and a filter 19 that collects volatile organic compounds (VOC) contained in the air. The sheet conveying apparatus 20 is provided with a porous member (a cylindrical shaft portion 31 and a roller portion 32) having a plurality of holes 31a and 32a penetrating between the inside and the outside on the surface facing the sheet P. Since the outside air is guided to the inside through the holes 31a and 32a and the rotating member (VOC collecting and conveying roller 30) for conveying the sheet P by the rotational force is provided, the sheet conveying member The rotating member (VOC collecting / conveying roller 30) has a porous member (cylindrical shaft portion 31, roller portion 32) on the surface of the paper P in the vicinity of the surface of the paper P heated by the fixing device 13. VOC that volatilizes from the toner T can be sucked. Therefore, in this method, the VOC that volatilizes from the toner T on the paper P does not diffuse into the printer 1, directly cools the fixing device 13, and does not generate an air flow that impedes paper conveyance. . In this way, it is possible to provide a clean printer 1 that can perform highly efficient collection of VOC that volatilizes from the toner T on the paper P and prevents the generation of a strange odor.

  In addition, since the VOC collecting and conveying roller 30, the duct 18, and the exhaust fan 17, which are rotating members, are coupled so as to communicate with each other, the VOC that volatilizes from the toner T on the paper P can be more effectively reduced. Can be aspirated. Therefore, it becomes possible to collect VOC more efficiently.

  Since the filter 19 is disposed in the duct 18, the VOC sucked from the toner on the paper P can easily pass through the filter 19. Therefore, it is possible to further improve the VOC collection efficiency.

  Further, since the contact surface of the VOC collecting / conveying roller 30 is uneven, and the concave portion 32b is provided with a hole 32a, the surface of the VOC collecting / conveying roller 30 is in close contact with the toner T. Therefore, the location of the hole 32a on the surface can be made to correspond to the location of the toner T with the widest possible region. As a result, it is possible to suck more VOC that volatilizes from the toner T on the paper P. Therefore, the collection efficiency of VOC can be further increased.

  In addition, since the rotating member of the sheet conveying device 20 is configured by a roller (VOC collecting / conveying roller 30), the VOC that volatilizes from the toner T on the sheet P while conveying the sheet P with a simpler configuration. It is possible to suck. As a result, it is possible to obtain a printer 1 that can perform highly efficient collection of VOCs and can achieve cost reduction.

  Next, a detailed configuration of the image forming apparatus according to the second exemplary embodiment of the present invention will be described with reference to FIGS. 7 is a left side view of a schematic vertical section of a printer as an image forming apparatus, FIG. 8 is a front view of a vertical section showing the periphery of the paper transport apparatus of the printer, and FIG. It is a cross-sectional front view. White arrows in FIGS. 8 and 9 indicate air flow paths and flow directions. Since the basic configuration of this embodiment is the same as that of the first embodiment described with reference to FIGS. 1 to 6, the same reference numerals are used for the same components as those of the first embodiment. The description is omitted.

  In the printer 1 according to the second embodiment, as illustrated in FIGS. 7 and 8, the paper transport device 20 includes a VOC collection transport belt 40 and a transport belt 22 as rotating members.

  The VOC collecting and conveying belt 40 is disposed on the upper side of the sheet conveying path downstream of the fixing device 13. The VOC collecting / conveying belt 40 is an endless belt wound around two support rollers 41 arranged in the paper conveying direction and having an axis extending substantially horizontally in the paper width direction. The VOC collecting / conveying belt 40 is in pressure contact with the endless conveying belt 22 that is similarly wound around the two support rollers 23, and forms a conveying nip portion. The paper P is conveyed further downstream by force.

  The VOC collecting / conveying belt 40 is made of a metal material such as stainless steel. Then, on the surface of the VOC collecting / conveying belt 40 facing the paper P, as shown in FIGS. 8 and 9, a plurality of holes 40a penetrating between the inside and the outside are provided by etching. . Further, the contact surface of the VOC collecting / conveying belt 40 with the paper P has an uneven shape, and a hole 40a is provided in the recessed portion 40b. The surfaces of the VOC collecting / conveying belt 40 and the conveying belt 22 facing the paper P are coated with a release layer (for example, a fluororesin) to which the toner after fixing is difficult to adhere.

  As shown in FIGS. 7 and 8, an air intake section 42 is provided between the two support rollers 41 that support the VOC collecting / conveying belt 40. As shown in FIG. 8, the air intake portion 42 has a hollow rectangular parallelepiped box shape, and is coupled to the duct 18 at one end in the paper width direction so that the inside thereof communicates to allow air to flow. . The bottom of the intake section 42 is close to the lower inner surface of the VOC collecting and conveying belt 40, and an opening 42a is provided at this location. The opening 42a is sized to cover a region corresponding to the numerous holes 40a of the VOC collecting / conveying belt 40 located below the opening 42a.

  When the exhaust fan 17 shown in FIG. 8 is driven, VOCs volatilized from the toner T on the paper P are sucked together with air from the plurality of holes 40a on the surface of the VOC collecting / conveying belt 40, as shown in FIG. . Then, as shown in FIG. 8, the air containing VOC passes through the opening 42 a of the intake portion 42, the inside of the intake portion 42, and the inside of the duct 18, and reaches the location of the filter 19. Here, the filter 19 collects VOC contained in the air. Thereafter, clean air from which the VOC has been removed is discharged from the location of the exhaust fan 17 to the outside of the printer 1.

  Next, the effect when VOC is collected from the toner on the fixed paper using the VOC collecting mechanism will be described with reference to FIG. FIG. 10 is a table showing the influence of the presence or absence of the VOC collection mechanism according to the second embodiment of the present invention on the VOC discharge amount to the outside of the printer. The VOC measurement method and the comparison method are the same as those in the first embodiment.

  According to FIG. 10, the printer with the VOC collection mechanism according to the present invention can reduce the amount of VOC discharged to the outside of the printer to about ½ compared with the printer without the VOC collection mechanism. I can see that

  In this way, since the rotating member of the sheet conveying device 20 is constituted by the belt (VOC collecting / conveying belt 40), the contact area with the sheet P can be expanded. Thereby, the VOC that volatilizes from the toner T on the paper P can be sucked for a long time. Therefore, it is possible to further improve the VOC collection efficiency.

  Next, a detailed configuration of the image forming apparatus according to the third embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a left side view of a schematic vertical section of a printer as an image forming apparatus, FIG. 12 is a front view of a vertical section showing the periphery of the paper transport apparatus of the printer, and FIG. 13 is a partially enlarged vertical view of a VOC collection and transport paddle of the paper transport apparatus It is a section left side view. White arrows in FIGS. 12 and 13 indicate air flow paths and flow directions. Since the basic configuration of this embodiment is the same as that of the first embodiment described with reference to FIGS. 1 to 6, the same reference numerals are used for the same components as those of the first embodiment. The description is omitted.

  In the printer 1 according to the third embodiment, as shown in FIGS. 11 and 12, the paper transport device 20 includes a VOC collection transport paddle 50 and a transport roller 21 as rotating members.

  The VOC collection transport paddle 50 is disposed on the upper side of the paper transport path downstream of the fixing device 13. The VOC collecting / conveying paddle 50 is brought into pressure contact with the conveying roller 21 disposed on the lower side thereof to form a conveying nip portion, and conveys the paper P further downstream by its rotational force. And the VOC collection conveyance paddle 50 is provided with the cylindrical axial part 51 as a porous member, and the several paddle part 52 as shown in FIG.12 and FIG.13.

  The cylindrical shaft portion 51 is made of, for example, a metal material such as aluminum and has a cylindrical shape with a circular cross section with one end closed. The other end of the cylindrical shaft portion 51 is coupled to the duct 18 so that the inside thereof communicates so that air flows. On the surface of the cylindrical shaft portion 51, a plurality of holes 51a penetrating in the radial direction between the inside and the outside are provided. The cylindrical shaft portion 51 is supported by the main body 2 so as to be rotatable about an axis extending substantially horizontally in the paper width direction perpendicular to the paper transport direction.

  The paddle portion 52 is made of a metal material such as aluminum, for example, like the cylindrical shaft portion 51, and extends radially outward from the surface of the cylindrical shaft portion 51. With respect to the paper width direction, the paddle portion 52 extends substantially the same length as the transport roller 21 and is formed in a long plate shape. A plurality of paddle portions 52 are arranged in the circumferential direction of the cylindrical shaft portion 51 at predetermined angles. The VOC collecting and conveying paddle 50 conveys the paper P with the tips of the paddle portions 52 provided on the surface thereof contacting the paper P. The plurality of holes 51 a of the cylindrical shaft portion 51 are provided between the adjacent paddle portions 52. Further, the surface of the VOC collecting / conveying paddle 50 and the conveying roller 21 facing the paper P is coated with a release layer (for example, fluororesin) to which the toner after fixing is difficult to adhere.

  At both ends of the paddle portion 52 in the paper width direction, circular flange portions 53 having an axis line that coincides with the axis line of the cylindrical shaft portion 51 are provided. The flange portion 53 has a diameter that is substantially the same as the diameter of the VOC collection and conveyance paddle 50 at the distal end in the radial direction of the paddle portion 52. As a result, the flange portion 53 closes the air circulation space created by the adjacent paddle portions 52 at the both ends of the paddle portion 52 in the sheet width direction.

  When the exhaust fan 17 shown in FIG. 12 is driven, as shown in FIG. 13, adjacent paddle portions 52 in which VOCs volatilized from the toner T on the paper P abut on the paper P on the surface of the VOC collecting and transporting paddle 50. The air is sucked together with air from the plurality of holes 51a. Then, as shown in FIG. 12, the air containing VOC passes through the inside of the cylindrical shaft portion 51 and the inside of the duct 18 and reaches the location of the filter 19. Here, the filter 19 collects VOC contained in the air. Thereafter, clean air from which the VOC has been removed is discharged from the location of the exhaust fan 17 to the outside of the printer 1.

  Next, the effect when VOC is collected from the toner on the fixed paper using the VOC collecting mechanism will be described with reference to FIG. FIG. 14 is a table showing the influence of the presence or absence of the VOC collecting mechanism according to the third embodiment of the present invention on the VOC emission amount to the outside of the printer. The VOC measurement method and the comparison method are the same as those in the first embodiment.

  According to FIG. 14, the printer with the VOC collection mechanism according to the present invention can reduce the amount of VOC discharged to the outside of the printer to about 2/3 compared with the printer without the VOC collection mechanism. I can see that

  In this way, the VOC collecting and transporting paddle 50 that is a rotating member of the paper transporting device 20 includes the paddle portion 52 whose tip is in contact with the paper P on the surface thereof. It is possible to enhance the action of preventing the portion without the hole from coming into contact with the toner T, and the portion of the hole 51a can be made to correspond to the portion of the toner T with a wide area. As a result, it is possible to suck more VOC that volatilizes from the toner T on the paper P. Therefore, the collection efficiency of VOC can be improved.

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

  For example, the printer 1 is an image forming apparatus for monochrome printing that uses only black toner in the above-described embodiment, but is not limited to such a model, and includes an intermediate transfer belt and superimposes a plurality of colors. The image forming apparatus may be a tandem type or rotary rack type color printing capable of forming an image.

  The exhaust fan 17 is coupled to the duct 18 so as to communicate with the inside. However, the exhaust fan 17 is not connected to the duct 18 and may be configured to exhaust the air inside the printer 1 to the outside. I do not care. Similarly, the duct 18 is directly connected to the cylindrical shaft portion 31 of the VOC collection and conveyance roller 30, the intake portion 42 inside the VOC collection and conveyance belt 40, and the cylindrical shaft portion 51 of the VOC collection and conveyance paddle 50. There may be no configuration.

  The filter 19 may be disposed on the downstream side of the exhaust fan 17 in the air flow direction.

  The present invention can be used in general image forming apparatuses.

It is a model vertical cross-section left side view of the printer according to the first embodiment of the present invention. 6 is a graph showing the temperature dependence of the amount of VOC volatilization from toner. 6 is a graph showing a change in toner temperature with time after fixing. FIG. 2 is a vertical cross-sectional front view showing the periphery of the paper transport device of the printer of FIG. 1. FIG. 5 is a partially enlarged vertical sectional front view of a VOC collecting / conveying roller of the paper conveying apparatus shown in FIG. 4. 5 is a table showing the effect of the presence or absence of the VOC collection mechanism shown in FIG. 4 on the amount of VOC discharged to the outside of the printer. It is a model vertical section left side view of a printer concerning a 2nd embodiment of the present invention. FIG. 8 is a vertical sectional front view showing the periphery of the sheet conveying device of the printer of FIG. 7. FIG. 9 is a partially enlarged vertical sectional front view of a VOC collecting and conveying belt of the sheet conveying apparatus shown in FIG. 8. It is a table | surface which shows the influence which the presence or absence of the VOC collection | recovery mechanism shown in FIG. 8 has on the VOC discharge | release amount outside a printer. It is a model vertical cross-section left side view of a printer according to a third embodiment of the present invention. FIG. 12 is a vertical sectional front view showing the periphery of the sheet conveying device of the printer of FIG. 11. FIG. 13 is a partially enlarged vertical cross-sectional left side view of the VOC collecting / conveying paddle of the paper conveying apparatus shown in FIG. 12. 13 is a table showing the effect of the presence or absence of the VOC collection mechanism shown in FIG. 12 on the amount of VOC discharged outside the printer.

Explanation of symbols

1 Printer (image forming device)
2 Body 13 Fixing device 17 Exhaust fan (exhaust device)
18 Duct 19 Filter 20 Paper transport device 30 VOC collection transport roller (rotating member)
31 Cylindrical shaft (porous member)
31a hole 32 roller part (porous member)
32a hole 32b recess 40 VOC collecting and conveying belt (rotating member, porous member)
40a hole 40b recess 50 VOC collection conveyance paddle (rotary member)
51 Cylindrical shaft (porous member)
51a hole 52 paddle part

Claims (7)

A fixing device that heats and fixes an unfixed toner image on the paper, a paper transport device that transports the paper after the toner image is fixed, an exhaust device that exhausts the air inside the image forming device to the outside, and the exhaust device generates In an image forming apparatus comprising a duct through which an air flow passes, and a filter that collects a volatile organic compound contained in the air,
In the paper conveying device, a porous member having a plurality of holes penetrating between the inside and the outside is provided on the surface facing the paper, through which the outside air is guided to the inside, and the rotational force An image forming apparatus comprising a rotating member that conveys the sheet.   The image forming apparatus according to claim 1, wherein the rotating member, the duct, and the exhaust device are coupled so as to communicate with each other.   The image forming apparatus according to claim 1, wherein the filter is disposed in the duct.   4. The image forming apparatus according to claim 1, wherein the rotating member has a concave-convex shape on a contact surface with the paper, and the hole is provided in the concave portion. 5.   The image forming apparatus according to claim 1, wherein the rotating member is configured by a roller.   The image forming apparatus according to claim 1, wherein the rotating member is formed of a belt.   4. The image forming apparatus according to claim 1, wherein the rotating member includes a paddle portion whose front end is in contact with a sheet on the surface of the rotating member. 5.

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