JP2017194602A - Fine particle removal device, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fine particle removal device that can remove fine particles for a long period with a simple configuration.SOLUTION: A fine particle removal device comprises: a discharge duct that opens in a source of fine particles; and alkaline fine particles that, when a side of the source is upstream side of the discharge duct, are arranged to be in contact with the fine particles moving from the upstream side to the downstream side of the discharge duct, wherein the alkaline fine particles have Dof 1 μm or more and Dof 90 μm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fine particle removing apparatus, an image forming apparatus, and an image forming method.

  In recent years, it has been pointed out that ultrafine particles having a particle diameter of less than 100 nm are discharged from an image forming apparatus employing an electrophotographic method such as a printer, a copier, a facsimile machine, or a composite machine thereof. In such an image forming apparatus, ultrafine particles are removed by using a predetermined apparatus (see, for example, Patent Documents 1 and 2).

  Patent Document 1 describes an image forming apparatus having electrostatic dust collecting means for electrostatically collecting generated ultra fine particles or cyclone dust collecting means for collecting generated ultra fine particles by a cyclone method. Yes. The image forming apparatus described in Patent Document 1 electrostatically collects ultrafine particles after ionizing them by using electrostatic dust collecting means. Moreover, in the image forming apparatus described in Patent Document 1, ultrafine particles are aggregated and collected by using a cyclone dust collecting means. Furthermore, the image forming apparatus described in Patent Document 1 also describes that ultrafine particles can be adsorbed and removed by using a filter carrying an adsorbent together.

  Further, in Patent Document 2, a gas containing a gaseous substance before ultrafine particles is passed through an adsorption layer containing activated carbon particles, thereby adsorbing the gaseous substances on the activated carbon particles to remove ultrafine particles. ing. As described above, the image forming apparatus described in Patent Document 2 suppresses the generation of ultrafine particles themselves, thereby suppressing the discharge of ultrafine particles from the image forming apparatus.

JP 2010-02803 A JP 2013-33197 A

  However, in the image forming apparatus described in Patent Document 1, it is necessary to install electrostatic dust collecting means or cyclone dust collecting means, so that there is a problem that space saving cannot be achieved and the structure of the apparatus is complicated. It was. Further, in the image forming apparatus described in Patent Document 2, since it is necessary to chemically adsorb the gaseous substance to the activated carbon, the adsorptive capacity is lowered according to the amount of the gaseous substance generated. There was a problem that generation of fine particles could not be suppressed.

  Accordingly, a first object of the present invention is to provide a fine particle removing apparatus capable of removing fine particles generated with a simple configuration over a long period of time. A second object of the present invention is to provide an image forming apparatus having the particulate removing device. Furthermore, a third object of the present invention is to provide an image forming method in which fine particles are removed so as not to participate in image formation.

The present invention provides, as one means for solving the first problem described above, an exhaust duct opened toward a particulate generation source, and the exhaust duct when the generation source side is an upstream side of the exhaust duct. A fine particle removing device, wherein the fine particles have a D ₁₀ of 1 μm or more and a D ₉₀ of 90 μm or less. I will provide a.

  According to the present invention, as a means for solving the second problem described above, a fixing process of heating and pressurizing a recording medium carrying a toner image through a nip formed by a pair of fixing members is performed. And a fixing device for fixing the toner image on the recording medium, and a particulate removing device of the present invention, wherein an upstream end of the exhaust duct of the particulate removing device opens toward the fixing member. An image forming apparatus is provided.

  Further, according to the present invention, as one means for solving the above-mentioned third problem, a nip portion formed by a pair of fixing members, at least one of which is formed of an elastic body, a recording medium carrying a toner image. An image forming method including a step of fixing the toner image on the recording medium by heating and pressurizing through the air, the step of sucking air into an exhaust duct opened toward the fixing member, and the sucked air A step of contacting fine particles therein with alkali fine particles in the exhaust duct to aggregate or ionize the fine particles, and a step of discharging the air after the fine particles have been aggregated or ionized from the exhaust duct. An image forming method is provided.

  The present invention can provide a fine particle removing apparatus capable of removing fine particles generated with a simple configuration over a long period of time and an image forming apparatus having the fine particle removing apparatus. Further, the present invention can provide an image forming method in which fine particles are removed so as not to be affected.

FIG. 1 is a diagram showing a configuration of a fine particle removing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

(Configuration of particulate removal device)
FIG. 1 is a diagram showing a configuration of the particulate removing device 200.

  As shown in FIG. 1, the particulate removal device 200 includes an exhaust duct 210, alkaline particulates 220, a humidifier 230, a capture filter 240, and a blower 250.

  The exhaust duct 210 is arranged so that the upstream side thereof opens toward the generation source of fine particles. Specifically, the exhaust duct 210 is disposed at a position where substantially all the fine particles can be sucked by inhaling air. The material of the exhaust duct 210 is not particularly limited. The material of the exhaust duct 210 preferably has heat resistance and good thermal conductivity. The material of the exhaust duct 210 is, for example, a metal material such as aluminum or iron. In the present embodiment, “fine particles” refers to particles having a particle diameter in the range of 10 to 1000 nm. Moreover, the kind of fine particle is not specifically limited. Examples of the fine particles include siloxane molecules generated by friction of a fixing member in an image forming apparatus described later, components generated by heating a volatile substance partially contained in the toner, and the like. Therefore, the “particle generation source” includes a fixing member when the particles are siloxane molecules.

  The exhaust duct 210 includes an exhaust duct main body 212, an intake port 213, and an exhaust port 214. One (upstream end) opening of the exhaust duct body 212 is an intake port 213, and the other (downstream end) opening is an exhaust port 214. The cross-sectional shape of the exhaust duct body 212 is not particularly limited. The cross-sectional shape of the exhaust duct body 212 may be circular or polygonal. In the present embodiment, the cross-sectional shape of the exhaust duct body 212 is a rectangle. Further, the cross-sectional dimension of the exhaust duct body 212 is not particularly limited. What is necessary is just to set suitably the cross-sectional dimension of the exhaust duct main body 212 by the installation place of the exhaust duct 210, the quantity of the particulates to remove, etc.

  The intake port 213 is an opening on the source side of the exhaust duct body 212. The intake port 213 is formed so that a cross-sectional dimension increases toward the generation source. The cross-sectional dimension of the opening end of the intake port 213 is not particularly limited. The cross-sectional dimension of the opening end of the intake port 213 is about 0.5 to 3.0 times the dimension when the fine particle generation source is viewed in plan. In addition, it is preferable that it is larger than the dimension when the generation source of fine particles is viewed in plan. If the cross-sectional dimension of the opening end of the intake port 213 is larger than the dimension when the generation source is viewed in plan, it is preferable from the viewpoint of reducing the leakage of fine particles from the intake port 213. Moreover, it is preferable that the intake port 213 is opened near the generation source. More specifically, the distance between the intake port 213 and the generation source can be represented by the shortest distance from the opening center of the intake port 213 to the generation source.

  The cross-sectional dimension of the opening end portion of the intake port 213 described above and the shortest distance described above can be appropriately adjusted according to the strength of the intake air. Specifically, in the case of strong intake, even if the cross-sectional dimension of the opening end of the intake port 213 is small and the shortest distance is long, substantially all fine particles can be sucked. On the other hand, in the case of weak intake air, it is preferable that the cross-sectional dimension of the opening end portion of the intake port 213 is larger and the shortest distance is shorter from the viewpoint of sucking substantially all the fine particles.

  The exhaust port 214 is an opening on the exhaust side of the exhaust duct body 212. In the present embodiment, the exhaust port 214 is formed so that the cross-sectional dimension increases toward the exhaust region. The opening position of the exhaust port 214 can be appropriately selected according to the purpose of removing the fine particles. For example, when fine particles are harmful to the generation source and the surrounding area, the exhaust port 214 opens at a position away from the generation area and the surrounding area. On the other hand, when the aggregated particles and ionized substances are harmless to the generation source and the surrounding area, the exhaust port 214 may be opened near the generation area and the surrounding area.

The alkaline fine particles 220 are arranged so as to come into contact with fine particles moving from the upstream side of the exhaust duct 210 to the downstream side when the source side is the upstream side of the exhaust duct 210. The alkaline fine particles 220 are fine particles exhibiting alkalinity that aggregate or ionize the fine particles. _{D 10} of the alkaline particles 220 are at 1μm or _{more, D 90} is 90μm or less. Incidentally, _{D 10} of the alkaline particles 220 are at 2μm or _more, and more preferably _{D 90} is 30μm or less.

If _{D 10} of the alkaline particles 220 is less than 1 [mu] m, it becomes difficult carrier by carrier 221 to be described later. On the other hand, when the D ₉₀ of the alkaline fine particles 220 exceeds 90 μm, the total surface area of the alkaline fine particles 220 becomes small, and a desired effect cannot be obtained. In addition, it is considered that the alkaline fine particles 220 having a D ₉₀ of more than ₉₀ μm change the air flow in the exhaust duct 210, and thus the performance is deteriorated.

Here, “D ₁₀ ” means the particle diameter when the cumulative volume in the volume-based particle size distribution is 10%. “D ₉₀ ” means the particle diameter when the cumulative volume in the volume-based particle size distribution is 90%. Incidentally, D ₁₀ and D ₉₀ of the alkaline particles is within the predetermined range, to increase the total surface area of the alkaline particles, believed to have the effect of increasing the chance of contact between particles. Further, if D ₁₀ and D ₉₀ of the alkaline particles within a predetermined range, the particle diameter of the fine particles flying, the ratio of the particle diameter of the alkaline particles, considered or not to have produced a preferable effects.

  The kind of the alkaline fine particles 220 is not particularly limited. Examples of the alkaline fine particles 220 include potassium carbonate, potassium hydroxide, sodium hydroxide, sodium hydrogen carbonate, and potassium hydrogen carbonate. The alkaline fine particles 220 are preferably potassium carbonate from the viewpoint of high catalytic function. The alkaline fine particles 220 described above may be used alone or in combination of two or more.

  The particle diameter of the alkaline fine particles 220 can be determined, for example, by image processing of an image taken with a transmission electron microscope, and can be adjusted by, for example, classification or mixing of classified products.

  The alkaline fine particles 220 may be arranged directly on the exhaust duct body 212 or may be carried (held) by the carrier 221. The structure of the carrier 221 is not particularly limited as long as the alkaline fine particles 220 can be carried. Examples of the carrier 221 include fibrous materials such as aramid fibers, glass fibers, cellulose fibers, nylon fibers, vinylon fibers, polyester fibers, polyolefin fibers, and rayon fibers, and nonwoven fabrics composed of the fibrous materials. It is.

  The alkaline fine particles 220 may be fixed to the above-described fibrous substance, or may be accommodated in the nonwoven fabric in a particle shape. In the present embodiment, the alkaline fine particles 220 are accommodated in a non-woven fabric (support 221) made of a fibrous material. Further, the carrier 221 holding the alkaline fine particles 220 is disposed so as to block the exhaust path in the exhaust duct body 212. At this time, the carrier 221 is made of a fibrous material and has pores, so that the exhaust duct 210 is not completely blocked. Therefore, the fine particles passing through the exhaust duct 210 contact the alkaline fine particles 220 and pass through the carrier 221.

  The humidifier 230 is disposed upstream of the alkaline fine particles 220 in the exhaust duct 210. The humidifier 230 humidifies the fine particles in the exhaust duct 210 and promotes the aggregation of the fine particles. The configuration of the humidifying device 230 is not particularly limited as long as the function described above can be exhibited. Examples of the configuration of the humidifier 230 include a configuration in which water vapor is sprayed by a spray method, a humidifying filter, and the like. In the present embodiment, the humidifier 230 is a humidification filter.

  The configuration of the humidifying filter is not particularly limited as long as the above function can be exhibited. As an example of the configuration of the humidifying filter, one constituted by a shape holding member, water absorbing and water retaining fiber material can be used. Examples of the shape holding member include a metal net, a hard plastic material, a net-like hard plastic material, and the like. Examples of the water-absorbing and water-retaining fiber materials include those obtained by knitting a non-woven fabric made of rayon, cotton or the like into a net or small lattice. And it is preferable that the shape retention member and the water absorption and water retention fiber material are overlapped in the moving direction of the fine particles in the exhaust duct 220. Accordingly, even when humidifying, the humidifying filter can be uniformly humidified without distortion, and an antifungal effect can be obtained.

  For example, the humidifying filter may be formed as a single unit by a shape holding member made of a hard plastic material being overlapped on the water absorbing and water retaining fiber material by sewing. The humidifying filter may have a structure in which both sides of a shape holding member made of a net-like hard plastic material are stacked and overlapped so as to be sandwiched between water absorbing and water retaining fiber materials. In this case, it is preferable that the shape holding member and the water absorption and water retention fiber material are overlapped with an adhesive. Thus, by disposing the humidifier 230 on the upstream side of the alkaline fine particles 220, the humidified fine particles come into contact with the alkaline fine particles.

  The capture filter 240 is disposed downstream of the alkaline fine particles 220 in the exhaust duct 210. The capture filter 240 captures one or both of the aggregated particles of fine particles and the ionized product of the fine particles. The configuration of the capture filter 240 is not particularly limited as long as the above function can be exhibited. Examples of the capture filter 240 include a nonwoven fabric, a woven fabric, an activated carbon filter, and the like. Here, the “aggregated particles of fine particles” mean particles aggregated by contact between the fine particles and the alkaline fine particles 220. The “particle ionized product” means a particle ionized by contact between the particle and the alkaline particle 220.

  The blower 250 generates an air flow from the upstream side to the downstream side of the exhaust duct 210. The blower 250 may be disposed on the upstream side of the exhaust duct 210 or may be disposed on the downstream side. The blower 250 arranged on the upstream side of the exhaust duct 210 sends air from the upstream side of the exhaust duct 210 toward the downstream side. On the other hand, the blower 250 disposed on the downstream side of the exhaust duct 210 sucks air from the downstream side of the exhaust duct 210 to generate an air flow from the upstream side to the downstream side. In the present embodiment, blower 250 is arranged on the downstream side of exhaust duct 210.

  Here, the mechanism of action of the present invention will be described. In the present invention, it was found that the alkaline fine particles 220 aggregate or ionize the fine particles. The alkaline fine particles 220 transfer charges to the flying fine particles. More specifically, when the fine particles are an organic compound, the alkaline fine particles 220 promote the cleavage of the fine particles. As a result, the fine particles are combined with surrounding molecules to increase the apparent molecular weight and particle diameter. In this manner, the alkaline fine particles 220 aggregate fine particles (organic compounds) by bonding with other molecules. On the other hand, when the fine particles are inorganic compounds, the alkaline fine particles 220 ionize the fine particles. Thereby, it is presumed that the fine particles are easily attached to the capture filter by electrostatic force.

  The fine particle removal apparatus 200 described above can be installed in all apparatuses that can generate fine particles, and can appropriately remove fine particles from the apparatus. In the following description, the image forming apparatus 100 equipped with the fine particle removing apparatus 200 will be described.

(Configuration of image forming method)
FIG. 2 is a diagram showing a configuration of a color tandem type image forming apparatus 100 according to an embodiment of the present invention. This image forming apparatus is a multifunction machine having functions such as a scanner, a copy, and a printer, and is an apparatus called an MFP (Multi Function Peripheral).

  The image forming apparatus 100 is an annular intermediate transfer member that moves in the circumferential direction and is wound around two rollers 102 (left side in FIG. 2) and 106 (right side in FIG. 2) in the center of the main body casing 101. The intermediate transfer belt 108 is provided. The intermediate transfer belt 108 is supported by the rollers 102 and 106 and is driven to rotate in the arrow X direction.

  Below the intermediate transfer belt 108, in order from the left side in FIG. 2, an image forming unit 110Y as a printing unit corresponding to each color toner of yellow (Y), magenta (M), cyan (C), and black (K), 110M, 110C, and 110K are arranged side by side.

  Each of the image forming units 110Y, 110M, 110C, and 110K has the same configuration except for the color of the toner handled by each of the image forming units 110Y, 110M, 110C, and 110K. Specifically, for example, the yellow image forming unit 110Y includes a photosensitive drum 190, a charging device 191, an exposure device 192, a developing device 193 that performs development using toner, and a cleaner device 195. It is configured. A primary transfer roller 194 is disposed at a position facing the photosensitive drum 190 with the intermediate transfer belt 108 interposed therebetween. At the time of image formation, first, the surface of the photosensitive drum 190 is uniformly charged by the charging device 191, and then the surface of the photosensitive drum 190 is exposed according to an image signal input from an external device (not shown) by the exposure device 192. Thus, a latent image is formed. Next, the developing device 193 develops the latent image on the surface of the photosensitive drum 190 to become a toner image. This toner image is transferred to the intermediate transfer belt 108 by applying a voltage between the photosensitive drum 190 and the primary transfer roller 194. Transfer residual toner on the surface of the photosensitive drum 190 is removed by a cleaner device 195.

  As the intermediate transfer belt 108 moves in the arrow X direction, four color toner images are formed as an output image on the intermediate transfer belt 108 by the image forming units 110Y, 110M, 110C, and 110K.

  A cleaning device 125 that removes residual toner from the surface of the intermediate transfer belt 108 and a toner collection box 126 that collects toner removed by the cleaning device 125 are provided on the left side of the intermediate transfer belt 108 in FIG. . Further, a secondary transfer roller 112 as a secondary transfer member is provided on the right side of the intermediate transfer belt 108 in FIG. 2 with a conveyance path 124 for the paper 90 (recording medium) interposed therebetween. A transport roller 120 is provided in a position corresponding to the upstream side of the secondary transfer roller 112 in the transport path 124. An optical density sensor 115 as a toner density sensor for detecting a toner pattern on the intermediate transfer belt 108 is provided.

  In FIG. 2, a fixing device 130 serving as a fixing unit that fixes toner on a sheet 90 is provided in the upper right part of the main body casing 101. The fixing device 130 has a pair of fixing members extending perpendicularly to the paper surface in FIG. A pair of fixing members is a heating roller 132 and a pressure roller 131. The heating roller 132 is heated to a predetermined target temperature (for example, a fixing temperature within a range of 180 to 200 ° C.) by a heater 133 as a heating source. The pressure roller 131 is urged toward the heating roller 132 by a spring (not shown). Thereby, the pressure roller 131 and the heating roller 132 form a nip portion for fixing. The sheet 90 on which the toner image has been transferred passes through the nip portion, whereby the toner image is fixed on the sheet 90. The temperatures of the pressure roller 131 and the heating roller 132 are detected by temperature sensors 135 and 136 made of thermistors, respectively.

  The heating roller 132 is provided so as to cover a cored bar 301 as a cylindrical base material, a rubber layer (elastic body) 302 provided so as to cover the outer peripheral surface of the cored bar 301, and an outer peripheral surface of the rubber layer 302. The surface layer 303 is provided. In the internal space of the cored bar 301, a heater 133 is provided as a heating source for heating the heating roller 132 to a predetermined target temperature (in this example, a fixing temperature within a range of 180 to 200 ° C.).

  The core metal 301 is made of a metal material such as aluminum or iron. In the present embodiment, the thickness of the cored bar 301 is about 0.1 to 5 mm, but is preferably about 0.1 to 1.5 mm in consideration of weight reduction and warm-up time. Moreover, in this Embodiment, the outer diameter of the metal core 301 is set to about 10-50 mm.

  The rubber layer 302 is preferably formed of a silicone rubber material. The silicone rubber material is preferable in terms of heat resistance against the fixing temperature and elasticity for ensuring the size of the area where the paper 90 is pressed against (the length of the nip portion). In addition, any material that can be used for the rubber layer 302 may be any material that has heat resistance to the fixing temperature, and includes acrylic rubber, fluorine-based rubber material, and the like. The thickness of the rubber layer 302 is preferably in the range of 0.05 to 2 mm. In the present embodiment, the rubber layer 302 has a thickness of about 0.2 to 0.4 mm.

  The surface layer 303 has heat resistance with respect to the fixing temperature, releasability that assists the separation of the paper sheet 90 that has passed through the nip portion, and a property that prevents the fine particles generated from the rubber layer 302 from permeating (gas barrier property). Examples of the material of the surface layer 303 include fluorine-based resins such as tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), and ethylenetetrafluoroethylene (ETFE). The thickness of the surface layer 303 is preferably in the range of 5 to 100 μm. In the present embodiment, the thickness of the surface layer 303 is set to about 30 to 40 μm.

  With respect to the direction along the central axis of the core metal 301, that is, the width direction of the sheet 90 to be pressed against the heating roller 132, the end of the rubber layer 302 and the end of the surface layer 303 are respectively from the end of the core metal 301. Are also arranged at the same position on the inside.

  Further, the upstream end of the above-described exhaust duct 210 is opened in the fixing member (heating roller 132). In the present embodiment, the downstream end of the exhaust duct 210 opens to the outside of the image forming apparatus 100 so that the air flow does not affect image formation. Note that the downstream end of the exhaust duct 210 may open to the inside of the image forming apparatus 100.

  Further, at the lower part of the main body casing 101, paper feed cassettes 116A and 116B are provided in two stages as paper feed ports accommodating paper 90 as a print medium (recording medium) on which an output image is to be formed. Each of the paper feed cassettes 116 </ b> A and 116 </ b> B is provided with a paper feed roller 118 for feeding the paper 90 and a paper feed sensor 117 for detecting the sent paper 90. For simplicity, a state in which the sheet 90 is stored only in the sheet feeding cassette 116A is shown.

  In the main body casing 101, a control unit 400 including a CPU (Central Processing Unit) that controls the operation of the entire image forming apparatus is provided.

  At the time of image formation, the sheet 90 is fed one sheet at a time from the sheet feeding cassette 116 </ b> A to the conveyance path 124 by the sheet feeding roller 118 under the control of the control unit 400. The sheet 90 sent to the transport path 124 is sent to the toner transfer position between the intermediate transfer belt 108 and the secondary transfer roller 112 by the transport roller 120 at a timing by the registration sensor 114. On the other hand, as described above, the four color toner images are formed on the intermediate transfer belt 108 by the image forming units 110Y, 110M, 110C, and 110K.

  The four-color toner images on the intermediate transfer belt 108 are transferred by the secondary transfer roller 112 to the sheet 90 sent to the toner transfer position described above. The sheet 90 on which the toner image is transferred is conveyed through a nip formed by the pressure roller 131 and the heating roller 132 of the fixing device 130, and is subjected to heating and pressure. As a result, the toner image is fixed on the sheet 90. Then, the paper sheet 90 on which the toner image is fixed is discharged by a paper discharge roller 121 to a paper discharge tray section 122 provided on the upper surface of the main body casing 101 through a paper discharge path 127. In this example, a switchback conveyance path 128 is provided for feeding the paper sheet 90 to the toner transfer position again in the case of duplex printing.

(Image forming method)
An image forming method according to an embodiment of the present invention includes a step of sucking in-machine air into an exhaust duct opened toward a fixing member, and contacting the fine particles in the sucked in-machine air with alkali fine particles 220 in the exhaust duct. A step of aggregating or ionizing the fine particles, a step of discharging the in-machine air after the fine particles are agglomerated or ionized to at least one of the inside and outside of the image forming apparatus 100, and a fixing step. It includes an exposure process, a development process, and a transfer process.

  In order to perform the image forming method according to the present embodiment, an apparatus configured similarly to the image forming apparatus 100 described above can be used.

  In the charging step, the photosensitive drum is charged by a charging device or the like. The photoreceptor drum is, for example, a negatively charged organic photoreceptor having photoconductivity. The organic photoreceptor includes, for example, a conductive support, a charge generation layer, a charge transport layer, and a surface layer.

  In the exposure step, the charged photosensitive drum is irradiated with light by an exposure device or the like to form an electrostatic latent image.

  In the development process, toner is supplied to the photosensitive drum on which the electrostatic latent image is formed, and a toner image corresponding to the electrostatic latent image is formed. The developing step can be performed using, for example, a known developing device in an electrophotographic image forming apparatus. Here, the “toner image” refers to a state where toner is gathered in an image form.

  In the transfer step, the toner image formed on the photosensitive drum is transferred to a recording medium such as paper. The transfer step can be performed using, for example, a known transfer unit. The transfer unit includes, for example, an intermediate transfer belt to which a toner image is transferred, and a cleaning device that removes toner remaining on the photosensitive drum. As described above, the image forming method is substantially an intermediate transfer method.

  In the fixing step, the toner image transferred to the recording medium is fixed to the recording medium by a known fixing device or the like.

  In the step of sucking the in-machine air into the exhaust duct opened toward the fixing member, for example, the in-machine air is sucked into the exhaust duct 210 by driving the blower 250.

  The step of agglomerating or ionizing the fine particles is performed by sucking in-machine air into the exhaust duct 210. Specifically, when the fine particles moving through the exhaust duct 210 come into contact with the alkaline fine particles 220 disposed in the exhaust duct 210, the fine particles are aggregated or ionized. The mechanism by which the fine particles aggregate or ionize is as described above.

  In the step of discharging the in-machine air after the fine particles are aggregated or ionized to at least one of the inside and outside of the image forming apparatus 100, the step of sucking the internal air into the exhaust duct 210 and the step of aggregating or ionizing the fine particles This is performed later, and fine particles are removed from the vicinity of the fixing member.

  Therefore, in the image forming method according to the present embodiment, the fine particles are removed from the apparatus. Thus, electrophotographic image formation can be performed in a clean environment.

As is apparent from the above description, the particulate removing device described above has the exhaust duct 210 that opens toward the particulate generation source, and the upstream side of the exhaust duct 210 when the generation source side is the upstream side of the exhaust duct 210. Alkali fine particles 220 arranged so as to come into contact with the fine particles moving downstream from the surface, D ₁₀ of the alkaline fine particles 220 is 1 μm or more, and D ₉₀ is 90 μm or less. Therefore, the particulate removing device can remove particulates generated with a simple configuration over a long period of time.

Further, _{D 10} of the alkaline particles 220 are at 2μm or _{more, D 90} it is 30μm or less, more effectively remove particles.

  Further, as the alkaline fine particles 220, one or two or more fine particles selected from the group consisting of potassium carbonate, potassium hydroxide, sodium hydroxide, sodium hydrogen carbonate and potassium hydrogen carbonate can be used.

  In addition, it is more effective from the viewpoint of promoting the aggregation of the fine particles that the humidifying device for humidifying the fine particles moving through the exhaust duct 210 is further arranged upstream of the alkaline fine particles 220 in the exhaust duct 210. It is.

  Further, the alkaline fine particles 220 are held in a non-woven fabric made of a fibrous material, and capture one or both of fine particles aggregated particles and fine particle ionized products downstream of the alkaline fine particles 220 in the exhaust duct 210. It is more effective from the viewpoint of appropriately capturing the agglomerated particles of fine particles and the ionized product of the fine particles to further arrange the capture filter for the purpose.

  Further, the arrangement of the blower that generates the airflow from the upstream side to the downstream side of the exhaust duct 210 is more effective from the viewpoint of appropriately discharging the fine particles and the air from which the fine particles have been removed.

  Further, as is apparent from the above description, the above-described image forming apparatus performs the toner image by a fixing process in which the recording medium carrying the toner image is heated and pressed while passing through the nip portion formed by the pair of fixing members. Is fixed on a recording medium (paper 90) and the above-described fine particle removing device, and the upstream end of the exhaust duct 210 of the fine particle removing device 200 opens toward the fixing member. Therefore, it is effective from the viewpoint of removing fine particles generated with a simple configuration over a long period of time and forming an image in a clean environment.

  In addition, it is more effective from the viewpoint of properly removing silicone-derived siloxane molecules that at least one of the pair of fixing members is formed of a material containing a silicone material.

  Further, as is apparent from the above description, the above-described image forming method allows a recording medium carrying a toner image to pass through a nip portion formed by a pair of fixing members, at least one of which is formed of an elastic body. An image forming method including a step of fixing a toner image on a recording medium by heating and pressurizing, the step of sucking into an exhaust duct 210 opened toward a fixing member, and exhausting fine particles in the sucked air The step of contacting the alkali fine particles 220 in the duct 210 to aggregate or ionize the fine particles and the step of discharging the air after the fine particles are aggregated or ionized from the exhaust duct 210 are included. Therefore, it is effective from the viewpoint of removing fine particles generated with a simple configuration over a long period of time and forming a high-quality image in a clean environment.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

1. Preparation of image forming apparatus <No. Preparation of image forming apparatus 1>
An image forming apparatus having a configuration as shown in FIG. 2 was used as the image forming apparatus. Specifically, a modified machine of a commercially available full-color multifunction peripheral (Bizhub (registered trademark) C754e; Konica Minolta Co., Ltd.) was used as the image forming apparatus. Moreover, potassium carbonate was used as alkaline fine particles. The alkaline fine particles had D ₁₀ = 1.5 μm and D ₉₀ = 30 μm. The alkaline fine particles were accommodated in a non-woven fabric (support) made of polyethylene terephthalate (PET).

  Specifically, the alkaline fine particles were accommodated in a non-woven fabric formed in a bag shape so as to be 30% with respect to the capacity of the bag. And the nonwoven fabric which accommodated the alkaline fine particle was arrange | positioned so that the exhaust path of an exhaust duct might be plugged up. In addition, the capacity | capacitance of alkaline particulates is the quantity spread to the whole in a bag, when it inhales by an exhaust duct. Thereby, the alkaline fine particles were arranged on the entire cross section of the exhaust passage. In addition, a trapping filter, a humidifier, and a blower are arranged in the fine particle removing device, and a silicone rubber elastic body is used as a material for the fixing member.

<No. Preparation of image forming apparatus 2>
A 3.5μm is _{D 10} of the alkaline _particles, except that _{D 90} of a 85 .mu.m, No. No. 1 is the same as the image forming apparatus 1. 2 image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 3>
Except that potassium hydroxide was used as the alkaline fine particles, No. 1 was used. No. 1 is the same as the image forming apparatus 1. 3 image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 4>
No. 1 except that sodium carbonate was used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. 4 image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 5>
No. 1 except that sodium hydroxide was used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. 5 image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 6>
No. 1 except that calcium hydroxide was used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. 6 image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 7>
No. 1 except that potassium carbonate with D ₁₀ = 1.1 μm and D ₉₀ = 25 μm was used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. 7 image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 8>
No. 1 except that potassium carbonate with D ₁₀ = 60 μm and D ₉₀ = 88 μm was used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. Eight image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 9>
Except that it was arranged as a disk-shaped pellet (diameter 5 mm, thickness 2 mm) in which alkaline fine particles were compression-molded, and no trapping filter was provided. No. 1 is the same as the image forming apparatus 1. Nine image forming apparatuses were prepared. In addition, the pellet was arrange | positioned with the density of 100 mg / cm < ² > on the surface of the nonwoven fabric formed in the bag shape.

<No. Preparation of image forming apparatus 10>
No. except that the humidifier was not arranged. No. 1 is the same as the image forming apparatus 1. Ten image forming apparatuses were prepared.

<No. Preparation of 11 Image Forming Apparatus>
No. except that fluororubber was used as the material of the fixing member. No. 1 is the same as the image forming apparatus 1. Eleven image forming apparatuses were prepared.

<No. Preparation of 12 image forming apparatuses>
No. 1 except that sodium hydrogen carbonate was used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. Twelve image forming apparatuses were prepared.

<No. Preparation of 13 image forming apparatuses>
No. 1 except that potassium hydrogen carbonate was used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. Thirteen image forming apparatuses were prepared.

<No. Preparation of image forming apparatus 14>
No. 1 except that potassium carbonate and sodium hydrogen carbonate were used as the alkaline fine particles. No. 1 is the same as the image forming apparatus 1. Fourteen image forming apparatuses were prepared. In addition, the mixture ratio of potassium carbonate and sodium hydrogencarbonate is 1: 1.

<No. Preparation of 15 image forming apparatuses>
No. except that the alkaline fine particles were not arranged and the capture filter and the humidifier were not arranged. No. 1 is the same as the image forming apparatus 1. Fifteen image forming apparatuses were prepared.

<No. Preparation of 16 image forming apparatuses>
No. except that no alkaline fine particles were arranged, no capture filter and humidifier were arranged, and the fixing member was made of fluororubber. No. 1 is the same as the image forming apparatus 1. Sixteen image forming apparatuses were prepared.

<No. 17 Preparation of Image Forming Apparatus>
Except that ascorbic acid was used in place of the alkaline fine particles, and that no humidifier was provided, no. No. 1 is the same as the image forming apparatus 1. Seventeen image forming apparatuses were prepared.

<No. Preparation of 18 image forming apparatuses>
Except that potassium carbonate of D ₁₀ = 0.2 μm, D ₉₀ = 20 μm was used as the alkaline fine particles, and no humidifier was disposed. No. 1 is the same as the image forming apparatus 1. Eighteen image forming apparatuses were prepared.

<No. Preparation of 19 image forming apparatuses>
Except that potassium carbonate of D ₁₀ = 75 μm, D ₉₀ = 156 μm was used as the alkaline fine particles, and no humidifier was provided. No. 1 is the same as the image forming apparatus 1. Nineteen image forming apparatuses were prepared.

Table 1 shows the types of alkaline fine particles used, D ₁₀ and D ₉₀ , the arrangement method of the alkaline fine particles, the configuration of the fine particle removing apparatus, and the material of the fixing member.

2. Evaluation No. 1-No. 19 image forming apparatuses were installed in a stainless steel chamber having a volume of 1 m ^{3, and} the inside of the chamber was set to ventilate 67 L / min. After the inside of the chamber was ventilated for about 1 hour, a printing operation was performed at a rate of 60 sheets / minute for 10 minutes, and fine particles discharged from each image forming apparatus were sampled during the printing operation. A toner having a volume average particle diameter of 8 μm was used. The fine particles discharged into the chamber were continuously measured with a fine particle measuring instrument (CPC3007; TSI). The total number of fine particles within the range of particle diameter of 10 to 1000 nm observed from the start of printing to the time corresponding to 3 ventilation after the end of printing was measured. And, according to the following criteria, No. 1 to 19 image forming apparatuses were evaluated.
A: The number of fine particles is 7.0 × 10 ⁵ or less.
A: The number of fine particles is more than 7.0 × 10 ^{5 and not} more than 8.0 × 10 ⁶ .
○: The number of fine particles is more than 8.0 × 10 ⁶ and 1.0 × 10 ⁷ or less.
X: The number of fine particles is more than 1.0 × 10 ⁷ and 1.0 × 10 ⁸ or less.
XX: The number of fine particles is more than 1.0 × 10 ⁸ and 1.0 × 10 ¹⁰ or less.
XXX: The number of fine particles is more than 1.0 × 10 ¹⁰ .

  Table 2 shows the image forming apparatus No. The measured number of fine particles and the evaluation results are shown.

  As shown in Table 2, No. in which alkaline fine particles are not arranged. 15, no. 16 and No. 16 in which acidic fine particles are arranged. In the image forming apparatus 17, a very large amount of fine particles was measured. This is considered to be because the fine particles were exhausted as they were without being aggregated or ionized because the alkaline fine particles were not arranged. Moreover, the particle diameter of the alkaline fine particles is too small. In 18 image forming apparatuses, many fine particles were measured. This is presumably because the particle diameter was too small to be supported by the support and the alkaline fine particles were also discharged. Furthermore, the particle diameter of the alkaline fine particles is too large. In 19 image forming apparatuses, a lot of fine particles were measured. This is presumably because the particle diameter was too large, the total surface area of the alkaline fine particles was reduced, and the effect was not exhibited.

Further, as shown in Table 2, No. 10 having alkaline fine particles having D ₁₀ of 1 μm or more and D ₉₀ of 90 μm or less. 1-No. In 14 image forming apparatuses, discharge of fine particles was suppressed. No. 1-No. 5, no. 12-No. As can be seen from the evaluation results of the image forming apparatus No. 14, discharge of fine particles was suppressed regardless of the type of alkaline fine particles.

  According to the present invention, it is possible to remove fine particles appropriately generated over a long period of time in any apparatus or image forming apparatus that generates fine particles. Therefore, according to the present invention, application of an electrophotographic image forming apparatus that can be used in a clean environment is expected.

90 Paper 100 Image forming apparatus 101 Main casing 102, 106 Roller 108 Intermediate transfer belt 110Y, 110M, 110C, 110K Image forming unit 112 Secondary transfer roller 114 Registration sensor 115 Optical density sensor 116A, 116B Paper feed cassette 118 Paper feed roller DESCRIPTION OF SYMBOLS 120 Conveyance roller 121 Discharge roller 122 Discharge tray part 124 Conveyance path 125 Cleaning device 126 Toner collection box 127 Discharge path 128 Switchback conveyance path 130 Fixing device 131 Pressure roller 132 Heating roller 133 Heater 135, 136 Temperature sensor 190 Photosensitive Body drum 191 Charging device 192 Exposure device 193 Development device 194 Primary transfer roller 195 Cleaner device 200 Particulate removal device 210 Exhaust gas DOO 212 exhaust duct body 213 inlet 214 outlet 220 alkaline particles 221 bearing member 230 humidifier 240 retaining filter 250 fan 301 core metal 302 rubber layer 303 surface 400 controller

Claims (9)

An exhaust duct that opens toward the source of particulates;
When the source side is the upstream side of the exhaust duct, alkaline fine particles arranged so as to come into contact with the fine particles moving from the upstream side to the downstream side of the exhaust duct,
The _{D 10} of the alkaline particles are at 1μm or _{more, D 90} is 90μm or less,
Particulate removal device. The fine particle removing apparatus according to claim 1, wherein D _{10 of the} alkaline fine particles is 2 μm or more and D ₉₀ is 30 μm or less.   The fine particles according to claim 1 or 2, wherein the alkaline fine particles are one or more fine particles selected from the group consisting of potassium carbonate, potassium hydroxide, sodium hydroxide, sodium hydrogen carbonate, and potassium hydrogen carbonate. Removal device.   The particulate removal according to any one of claims 1 to 3, wherein a humidifying device for humidifying the particulate moving in the exhaust duct is further arranged upstream of the alkaline particulate in the exhaust duct. apparatus. The alkaline fine particles are held in a nonwoven fabric composed of a fibrous material,
The capture filter for capturing one or both of the aggregated particles of the fine particles and the ionized product of the fine particles is further disposed downstream of the alkaline fine particles in the exhaust duct. The fine particle removing apparatus according to one item.   The particulate removing device according to any one of claims 1 to 5, further comprising a blower that generates an air flow from an upstream side to a downstream side of the exhaust duct. A fixing device for fixing the toner image on the recording medium by a fixing process in which the recording medium carrying the toner image is heated and pressed while passing through a nip formed by a pair of fixing members;
The fine particle removal apparatus according to any one of claims 1 to 6, and
An upstream end of the exhaust duct of the particulate removing device opens toward the fixing member,
Image forming apparatus.   The image forming apparatus according to claim 7, wherein at least one of the pair of fixing members is formed of a material including a silicone material. A process of fixing the toner image on the recording medium by heating and pressurizing the recording medium carrying the toner image through a nip formed by a pair of fixing members, at least one of which is formed of an elastic body. An image forming method comprising:
Inhaling into an exhaust duct that opens toward the fixing member;
Contacting the fine particles in the sucked air with the fine alkali particles in the exhaust duct to aggregate or ionize the fine particles;
Exhausting the air after the fine particles have been aggregated or ionized from the exhaust duct,
Image forming method.

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