JP2011118258A - Image forming apparatus - Google Patents

Abstract

An image forming apparatus capable of generating ions stably over a long period of time without expanding the space required for installation.
An image forming apparatus 100 has an ion generation function, and includes a housing 101, a plurality of transport paths 51, 52, and 53, and an ion generation unit 10. The ion generating unit 10 is disposed in a space sandwiched between portions of the plurality of transport paths 51, 52, and 53 that run parallel to each other. The ion generation unit 10 includes a duct 11, an ion generation device 12, and a fan 13. The duct 11 forms a flow path for intake and exhaust in the width direction of the sheet with respect to the outside of the housing 101. The ion generator 12 is disposed in the duct. The airflow generator generates an airflow in the duct.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus equipped with an ion generation unit having an ion generation function.

  It is no exaggeration to say that image forming apparatuses such as copiers and printers are indispensable devices in offices, and are actually installed in most offices. Furthermore, in recent years, image forming apparatuses are becoming widespread in ordinary households and hospitals, and are extremely familiar to us.

  Incidentally, some image forming apparatuses supply air sucked from the periphery of the image forming apparatus to a process unit or a fixing unit of the image forming apparatus and then discharge the air outside the image forming apparatus. As one of such image forming apparatuses, harmful substances contained in the airflow discharged to the outside of the apparatus are removed and cleaned and negative ions are supplied, and harmful substances generated inside the apparatus are discharged to the outside of the apparatus. There is an image forming apparatus provided with an air purifying unit for preventing this (see, for example, Patent Document 1).

JP 2005-4144 A

  In the technique described in Patent Document 1 described above, an ion generating unit having electrodes is formed around the image forming unit in order to remove toner powder, dust, ozone, and the like generated by the image forming operation of the image forming unit. It is forced to be placed in the vicinity of the image forming portion inside the airflow. In the fixing unit included in the image forming unit, silicon is used as a sheet release agent. As a result, the ion generation efficiency of the ion generation unit decreases due to the influence of silicon or the like generated around the image forming unit, and the ability to purify the air around the image forming device as the image forming apparatus is used for a longer period of time. There was a problem of lowering.

  On the other hand, it is conceivable to prevent a decrease in ion generation efficiency due to the influence of silicon or the like by increasing the distance between the ion generation unit and the image formation unit. However, when a unit having an air cleaning function is arranged outside the image forming apparatus in order to increase the distance between the ion generating unit and the image forming unit, an extra space for installing such a unit is required. In particular, there is a problem that a space necessary for installing the image forming apparatus is increased.

  An object of the present invention is to provide an image forming apparatus capable of stably generating ions over a long period of time without expanding the space required for installation.

  The image forming apparatus according to the present invention has an ion generation function, and includes an image forming unit, a paper feeding unit, a paper discharge unit, a plurality of conveyance paths, an ion generating unit, and a housing. The housing includes an image forming unit, a paper feeding unit, a plurality of conveyance paths, and an ion generation unit. The image forming unit performs image forming processing on the sheet at the image forming position based on the image data. The paper feed unit accommodates paper supplied to the image forming position. The paper discharge unit accommodates paper on which an image is formed. The conveyance path is a plurality of conveyance paths including a main conveyance path through which a sheet from the paper feeding unit to the paper discharge unit via the image forming position is conveyed, and at least two of the plurality of conveyance paths At least some of them run parallel to each other. The ion generation unit is disposed in a space sandwiched between portions of the plurality of transport paths that run parallel to each other. The ion generation unit includes a duct, an ion generation device, and an airflow generation device. The duct forms a flow path that sucks and exhausts air from the outside of the housing in a direction orthogonal to the sheet conveyance direction within the plane of the sheet conveyed through the plurality of conveyance paths. The ion generator is disposed in the duct. The airflow generation device generates an airflow in the duct.

  In this configuration, the ion generating device of the ion generating unit stored inside the image forming apparatus is disposed in a duct whose respective end portions communicate with the outside of the housing. For this reason, the ion generator is positioned in a space in the housing that is isolated from the space to which the image forming unit belongs, and the influence of silicon or the like generated from the image forming unit is prevented from reaching the ion generating device. The

  Further, the radius of curvature in the vicinity of the branch points of the plurality of transport paths cannot be made too small in order to prevent paper jams. For this reason, an empty space is formed between the plurality of conveyance paths. Since the ion generation unit is arranged by effectively using the vacant space sandwiched between multiple transport paths, the ion generation unit will not protrude outside the housing, and as a result, the ion generation unit is installed. However, the space necessary for installing the image forming apparatus does not increase.

  Furthermore, since the duct is configured to suck and exhaust air in the width direction of the sheet with respect to the outside of the housing, the duct does not cross the conveyance path, and the configuration is simplified.

  In the above-described configuration, the plurality of conveyance paths include a main conveyance path and a duplex printing conveyance path in which a sheet passing through the image formation position is reversed and conveyed to the image formation position again. Is configured so as to be able to be pulled out and stored with respect to the housing, and at least a part of the duct of the ion generating unit can be configured to be fixed to the apparatus main body including the housing.

  When a paper jam occurs in the duplex printing conveyance path, the jammed sheet can be easily removed by pulling out the duplex printing conveyance path. In addition, since at least a part of the duct is fixed to the apparatus main body and is not pulled out together with the double-sided printing conveyance path, positional deviation between the duct and the housing is prevented.

  The duplex printing conveyance path includes a sub conveyance path that branches from the main conveyance path between the image forming position and the paper discharge unit and merges with the main conveyance path before reaching the image formation position in the main conveyance path, and a sub conveyance. And a switchback transport path that inverts the front and back of the paper that is branched from the path and performs double-sided printing, and the ion generation unit is configured to be disposed between the sub-transport path and the switchback transport path Can do. Even when a fixing device that thermally fixes an image on a sheet at a part of the image forming position is disposed in the vicinity of the ion generation unit, a sub-transport path or a switchback transport path is provided between the ion generation unit and the fixing device. Therefore, the influence of the heat generated from the fixing device on the ion generation unit is suppressed.

  Furthermore, it is preferable that the ion generation unit is disposed at a position closer to the junction point to the main conveyance path than the branch point from the main conveyance path of the duplex printing conveyance path. Since a fixing device for thermally fixing an image to the paper is disposed near the branch point from the main transport path of the duplex printing transport path, the fixing point to the main transport path from the branch point from the main transport path of the duplex print transport path is arranged. By disposing the ion generation unit at a position close to the junction, the influence of heat generated from the fixing device on the ion generation unit is suppressed.

  Further, the housing has an exhaust opening through which air passing through the periphery of the image forming position is exhausted, and the ion generation unit has a surface different from the surface of the housing provided with the exhaust opening, It is preferable to have a duct inlet. Since the air exhaust opening through the periphery of the image forming position and the air inlet of the ion generation unit are provided on different surfaces of the housing, the air discharged from the exhaust opening is sucked into the ion generation unit. Is prevented. This prevents the influence of silicon or the like generated from the image forming unit from affecting the ion generator.

  Further, the housing may have an exhaust opening on the back surface or side surface, and the ion generation unit may be configured to suck air from the front surface of the housing and exhaust air to the back surface. This also prevents the influence of silicon or the like generated from the image forming unit from reaching the ion generator.

  Further, the housing has an exhaust opening on the side surface, and the ion generation unit can be configured to suck air from the back surface of the housing and exhaust it to the front surface. This also prevents the influence of silicon or the like generated from the image forming unit from reaching the ion generator.

  Further, the ion generation unit is configured to suck in from the front of the housing and exhaust to the back, protrude from the back of the housing by a minimum interval to be provided on the back of the housing, and is exhausted from the duct. An auxiliary duct that guides air upward may be further provided. By providing the auxiliary duct, the air containing the ions exhausted from the duct is blown out from a high position and easily travels to the surroundings. Further, by installing the image forming apparatus so as to attract the auxiliary duct to the wall surface of the installation place of the image forming apparatus, the minimum interval that should be provided between the wall surface and the back surface of the housing is easily and reliably provided.

  According to the present invention, ions can be stably generated over a long period of time without expanding the space required for installation.

1 is a schematic front sectional view of an image forming apparatus according to an embodiment of the present invention. 1 is a schematic diagram of a right side cross-sectional view of an image forming apparatus. 2 is a schematic diagram of a right side cross-sectional view of an image forming apparatus with a front lid opened. (A) is a perspective view of an ion generation unit, (B) is a perspective view of an ion generation unit in a state where a duct is divided. It is a figure which shows the attachment state of the ion generation unit in an image forming apparatus. 6 is a schematic diagram of a right side cross-sectional view of an image forming apparatus according to another embodiment. It is a perspective view of the ion generation unit with which the image forming apparatus concerning other embodiments is equipped. 6 is a schematic front sectional view of an image forming apparatus according to another embodiment. (A) is a perspective view of an ion generation unit provided in the image forming apparatus shown in FIG. 7, and (B) is a perspective view of the ion generation unit in a state where a duct is divided.

  As shown in FIG. 1, the image forming apparatus 100 according to the embodiment of the present invention includes a scanner unit 200, an image forming unit 300, and a paper feeding unit 400.

  The scanner unit 200 includes an automatic document feeder (ADF) 201, a first document table 202, a second document table 203, a first mirror base 204, a second mirror base 205, a lens 206, and a solid-state imaging device (CCD: Charge Coupled Device) 207.

  The ADF 201 conveys documents one by one from the document tray 211 to the discharge tray 212 via the second document table 203. The ADF 201 is rotatable about the back side so that the top surface of the first document table 202 can be opened and closed. By rotating the ADF 201 so that the front side moves upward, the upper surface of the first document table 202 is exposed, so that the document can be placed on the first document table 202 by manual operation.

  Both the first platen 202 and the second platen 203 are made of hard glass plates. The first mirror base 204 and the second mirror base 205 are movable in the horizontal direction below the first document table 202 and the second document table 203. The moving speed of the second mirror base 205 is ½ of the moving speed of the first mirror base 204. The first mirror base 204 is equipped with a light source and a first mirror. The second mirror base 205 is equipped with a second mirror and a third mirror.

  When reading an image of a document conveyed by the ADF 201, the first mirror base 204 is stopped below the second document table 203. The light from the light source is emitted toward the image surface of the document passing over the second document table 203, and the reflected light on the image surface of the document is reflected toward the second mirror base 205 by the first mirror.

  When reading an image of a document placed on the first document table 202, the first mirror base 204 and the second mirror base 205 move horizontally below the first document table 202. The light from the light source is emitted toward the image surface of the document placed on the first document table 202, and the reflected light on the image surface of the document is reflected toward the second mirror base 205 by the first mirror.

  Regardless of whether or not the ADF 201 is used, the reflected light on the image surface of the document is incident on the CCD 207 via the lens 206 by the second mirror and the third mirror with a constant optical path length.

  The CCD 207 outputs an electrical signal corresponding to the amount of reflected light on the image surface of the document. This electrical signal is sent to an image processing unit (not shown) and subjected to various image processing, and then temporarily stored in a storage unit provided in the image forming apparatus 100, and in response to an output instruction from the control unit. 300 is input as image data.

  The image forming apparatus 100 includes a plurality of transport paths for transporting paper, that is, a main transport path 51, a sub transport path 52, and a switchback transport path 53. The main transport path 51 is configured so as to reach the paper discharge tray 38 constituting the paper discharge unit from the paper supply unit 400 via the image forming position. At least a part of at least two of the plurality of transport paths 51, 52, 53 are running in parallel with each other. Details of the sub transport path 52 and the switchback transport path 53 will be described later.

  The image forming unit 300 includes a photosensitive drum 31, a charger 32, an exposure device 33, a developing device 34, a transfer belt 35, a cleaner 36, and a fixing device 37 that constitute the process unit 30.

  The photosensitive drum 31 has a photosensitive layer on its surface and rotates in a predetermined direction. The charger 32 uniformly charges the surface of the photosensitive drum 31 to a predetermined potential.

  The exposure device 33 irradiates the surface of the photosensitive drum 31 with light based on the image data. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 31 by the photoconductive action in the photosensitive layer. The exposure device 33 scans the laser beam modulated based on the image data in the axial direction of the photosensitive drum 31 through a polygon mirror.

  The developing device 34 supplies toner to the surface of the photosensitive drum 31 and visualizes the electrostatic latent image into a toner image.

  The transfer belt 35 is stretched in a loop between a plurality of rollers below the photosensitive drum 31, and has a predetermined electric resistance value. Inside the loop-shaped movement path of the transfer belt 35, there is provided a transfer roller 35A that presses against the photosensitive drum 31 with the transfer belt interposed therebetween. A predetermined transfer voltage is applied to the transfer roller 35A. The transfer roller 35 </ b> A forms a transfer electric field at a transfer position that is a region facing the photosensitive drum 31 in the main conveyance path 51. A toner image carried on the photosensitive drum 31 is transferred onto a sheet passing between the transfer belt 35 and the photosensitive drum 31.

  The cleaner 36 removes residual toner from the surface of the photosensitive drum 31 after the transfer of the toner image to the paper.

  A fixing device 37 is disposed on the downstream side of the transfer region along the main conveyance path 51. The fixing device 37 includes a heating roller 37A and a pressure roller 37B. The fixing device 37 fixes the unfixed toner image adhering to the sheet conveyed through the main conveyance path 51 to the sheet by heat and pressure at a fixing position where the heating roller 37A and the pressure roller 37B are in pressure contact with each other. . The transfer position and the fixing position constitute an image forming position.

  The paper on which the image is formed is stored in the paper discharge tray 38.

  In the vicinity of the fixing device 37, an exhaust fan 39 that exhausts the gas around the process unit 30 to the outside of the image forming apparatus 100 is provided.

  The paper feed unit 400 includes paper feed cassettes 401, 402, 403, 404 and a manual feed tray 405. Each of the paper feed cassettes 401, 402, 403, and 404 accommodates a plurality of sheets of paper of the same size, such as plain paper, photographic paper, and OHP film. In the manual feed tray 405, paper of a different size from the paper stored in the paper feed cassettes 401, 402, 403, 404 (such as a less frequently used size) or paper stored in the paper feed cassettes 401, 402, 403, 404 is stored. A paper having a paper quality different from that of the paper is placed.

  The paper feed unit 400 feeds paper one by one from one of the paper feed cassettes 401, 402, 403, 404 or the manual feed tray 405. The sheet fed from the sheet feeding unit 400 is transported to the image forming position of the process unit 30 via the main transport path 51.

  The sub-transport path 52 branches from the main transport path 51 between the image forming position and the paper discharge tray 38 and joins the main transport path 51 just before reaching the image forming position in the main transport path 51. The switchback transport path 53 is configured to be branched from the sub transport path 52 and to reverse the front and back of the sheet on which double-sided printing is performed. By the sub transport path 52 and the switchback transport path 53, the sheet that has passed through the image forming position is reversed and turned to the image forming position. The sub conveyance path 52 and the switchback conveyance path 53 constitute a duplex printing conveyance path.

  The sub transport path 52 and the switchback transport path 53 run in parallel with each other in almost all areas. Further, the area including the image forming position in the main transport path 51 and almost all the areas of the sub-transport path 52 and the switchback transport path 53 run in parallel with each other.

  The sub-conveying path 52 and the switchback conveying path 53 are configured as a drawer unit 54 surrounded by a broken line in FIG. 1 together with the fixing device 37, and are drawn out from the apparatus main body including the casing 101 of the image forming apparatus 100. It is configured to be retractable. A slide rail is attached to each of the drawer unit 54 and the apparatus main body. By sliding the slide rail, the drawer unit 54 is pulled out and stored linearly in the front-rear direction. Therefore, when a paper jam occurs in the sub transport path 52, the switchback transport path 53, and the main transport path 51 near the fixing device 37, the jammed paper can be easily removed by pulling out the drawer unit 54. Become.

  The downstream side of the branch point between the main transport path 51 and the sub transport path 52 and the branch point between the sub transport path 52 and the switchback transport path 53 are curved. The radius of curvature of the curved portion needs to be large enough to transport the paper without damaging the paper (paper folds, dents, etc., or even paper jam). For this reason, a space is created between the plurality of transport paths 51, 52, 53.

  The ion generation unit 10 is arranged in a space between the plurality of transport paths 51, 52, 53 that run parallel to each other. Since the ion generation unit 10 is disposed by effectively using the empty space sandwiched between the plurality of transport paths 51, 52, 53, the ion generation unit 10 protrudes outside the housing 101 of the image forming apparatus 100. As a result, even if the ion generating unit 10 is installed, the space necessary for installing the image forming apparatus 100 does not increase.

  For example, the ion generation unit 10 is disposed between the sub-transport path 52 and the switchback transport path 53. For this reason, even when the fixing device 37 is disposed in the vicinity of the ion generation unit 10, the sub-transport path 52 or the switchback transport path 53 (in this embodiment, between the ion generation unit 10 and the fixing device 37). Since the sub-transport path 52) is arranged, the influence of the heat generated from the fixing device 37 on the ion generation unit 10 is suppressed.

The ion generation unit 10 is configured to ionize water vapor in the air by corona discharge to generate approximately the same amount of positive ions and negative ions. In this embodiment, the positive ion has a plurality of water molecules attached around the hydrogen ion (H ⁺ ), and is represented as H ⁺ (H ₂ O) _m (m is a natural number). On the other hand, a negative ion is accompanied by a plurality of water molecules around an oxygen ion (O ₂ ⁻ ), and is expressed as O ₂ ⁻ (H ₂ O) _n (n is a natural number). When these positive ions and negative ions adhere to the surface of bacteria floating around the image forming apparatus 10, they chemically react to generate hydrogen peroxide H ₂ O ₂ or hydroxyl radicals / OH which are active species. Since these hydrogen peroxide H ₂ O ₂ or hydroxyl radical / OH exhibits extremely strong activity, it can sterilize airborne bacteria in the air.

  In this embodiment, the ion generation unit 10 takes in air from the back side of the housing 101 and exhausts it to the front side.

  The housing 101 includes an image forming unit 300, a paper feeding unit 400, a plurality of transport paths 51, 52, 53, and an ion generation unit 10.

  As shown in FIGS. 2 and 3, the front lid 102, which is a front side portion of the housing 101 and faces the image forming unit 300 and the conveyance paths 51, 52, 53, is a front-rear direction with the lower end portion as an axis. It can be opened and closed freely. By opening the front lid 102, the image forming unit 300 and the conveyance paths 51, 52, and 53 are exposed to the outside of the housing 101.

  The ion generation unit 10 includes a duct 11, an ion generation device 12, a fan 13 that functions as an airflow generation device, and a filter 14. The duct 11 is a flow path that sucks and exhausts air from the outside of the housing 101 in a direction (paper width direction) orthogonal to the paper conveyance direction within the surface of the paper conveyed through the plurality of conveyance paths 51, 52, and 53. Is forming. Both ends of the duct 11 are open to the outside of the housing 101, and the duct 11 isolates the space inside the housing 101 and outside the duct 11 from the internal space of the duct 11. .

  The ion generator 12 is disposed in the duct 11. The fan 13 is rotated by a driving source (not shown) to generate an air flow in the duct 11. In this embodiment, a cross flow fan is used as the fan 13. The cross flow fan sucks and exhausts air in the radial direction.

  The fan 13 is preferably disposed on the upstream side of the ion generator 12 in the air blowing direction in the duct 11. This is to prevent the activity of ions generated from the ion generator 12 from being reduced by passing through the fan.

  The filter 14 is provided in the vicinity of the end portion on the intake side which is the air intake side in the duct 11. The filter 14 is configured to capture dust such as dust, toner, and paper dust that is about to enter the duct 11. The filter 14 is generally sufficient to have a general function for capturing dust, but a filter having a silicon adsorption function is preferably used.

  The ion generation device 12 of the ion generation unit 10 stored inside the image forming apparatus 100 is disposed in a duct 11 having each end communicating with the outside of the housing 101. For this reason, the ion generator 12 is positioned in a space in the casing 101 that is isolated from the space to which the image forming unit 300 belongs, and the influence of silicon or the like generated from the image forming unit 300 is affected. Is prevented. Therefore, the ion generation unit 10 can generate ions stably over a long period of time.

  Further, since the duct 11 is configured to suck and exhaust air in the width direction of the sheet with respect to the outside of the housing 101, the duct 11 does not cross the transport paths 51, 52, and 53, and the duct 11 and The configuration of the transport paths 51, 52, 53 is simplified.

  The ion generation unit 10 includes an independent foaming sealing member 15 such as urethane foam on the outer surface facing the front lid 102. The seal member 15 has a first hole portion that communicates with an opening provided on the side of the duct 11 that faces the front lid 102. The front lid 102 also has a second hole communicating with the opening of the duct 11 and the first hole of the seal member 15. By closing the front lid 102, air leakage between the front lid 102 and the duct 11 is prevented, and the space to which the image forming unit 300 belongs in the housing 101 is isolated from the space in the duct 11. The The seal member 15 can be attached to the front lid 102 instead of being provided in the ion generation unit 10.

  In FIG. 4A and FIG. 4B, the description of the filter 14 and the seal member 15 is omitted. As shown in FIGS. 4A and 4B, the duct 11 has an upstream duct 111 containing an ion generator 12, a fan 13, and a filter 14 in the air blowing direction in the duct 11, and a downstream side. It is divided into a side duct 112. The upstream duct 111 is fixed to the apparatus main body, while the downstream duct 112 is fixed to the drawer unit 54.

An independent foaming sealing member 16 such as urethane foam is attached to a surface of the upstream duct 111 that faces the downstream duct 112, and air leakage between the upstream duct 111 and the downstream duct 112 is prevented. It is peeling off.

  As shown in FIG. 5A, an exhaust opening 103 is provided on one side surface of the casing 101 for exhausting air that passes around the image forming position such as the fixing position and the transfer position. An exhaust fan 39 is disposed in the vicinity of the opening 103. The exhaust opening 103 is preferably provided on the side surface closer to the fixing device 37. The inlet 18 of the ion generation unit 10 is provided on a different surface from the surface of the housing 101 provided with the exhaust opening 103. Therefore, it is possible to prevent the air discharged from the exhaust opening 103 from being sucked into the ion generation unit 10 and to prevent the influence of silicon or the like generated from the image forming unit 300 from affecting the ion generation device 12. Is done. In FIG. 5A, for convenience of description, air is described as passing through the periphery of the fixing device 37, but is configured so as to also pass through the periphery of the transfer position.

  As shown in FIG. 5B, the housing 101 may have an exhaust opening 103 on the back surface, and the ion generation unit 10A may be configured to suck air from the front surface of the housing 101 and exhaust air to the back surface. it can. Also in the image forming apparatus 100A configured in this way, the influence of silicon or the like generated from the image forming unit 300 is prevented from reaching the ion generating apparatus 12. The casing 101 may have an exhaust opening 103 on the side surface, and the ion generation unit 10A may be configured to take in air from the front surface of the housing 101 and exhaust it to the back surface. In FIG. 5B, for convenience of explanation, the same reference numerals are used for the same structures as those in FIG. In FIG. 6, the same reference numerals are used for the same configuration as the image forming apparatus 100 for the image forming apparatus 100 </ b> A for convenience of explanation.

  As shown in FIG. 6, the ion generation unit 10 </ b> A can be configured to further include an auxiliary duct 17. The auxiliary duct 17 protrudes from the back surface of the housing 101 by a minimum interval to be provided on the back surface of the housing 101, and guides the air exhausted from the duct 11 upward.

  By providing the auxiliary duct 17, the air containing the ions exhausted from the duct 11 is blown out from a high position and easily travels to the surroundings. Further, since the image forming apparatus 100A is often installed such that the back surface of the housing 101 is along the wall surface, the image forming apparatus 100A is installed so that the auxiliary duct 17 hits the wall surface of the installation place of the image forming apparatus 100A. Thus, the minimum gap that should be provided between the wall surface and the back surface of the housing 101 is easily and reliably provided.

  As shown in FIG. 7, the ion generation unit 10 </ b> B can be configured to perform intake and exhaust on the same surface of the housing 101. In FIG. 7, for convenience of explanation, the same reference numerals are used for the same configuration as the ion generation unit 10 for the ion generation unit 10 </ b> B. In the ion generation unit 10B, the duct 11B is curved in a U shape in plan view.

  As an example, the ion generation unit 10 </ b> B performs intake and exhaust on the front surface of the housing 101. In this case, two holes of a size corresponding to the cross-sectional area of both ends of the duct 11B are formed in the housing 101. Seal members are disposed between both ends of the duct 11 </ b> B and the front lid 102.

  Also by the image forming apparatus 100B including the ion generation unit 10B configured as described above, ions can be stably generated over a long period of time without expanding the space necessary for installation.

  An image forming apparatus 100C according to still another embodiment will be described with reference to FIG. For convenience of explanation, the same reference numerals are used for members similar to those of the image forming apparatus 100.

  The image forming apparatus 100 </ b> C includes an image forming unit 300 and a paper feeding unit 400. In the image forming apparatus 100C, the main transport path 51C and the sub transport path 52C extend in the vertical direction, and the transfer position and the fixing position are aligned in the vertical direction along the main transport path 51C. The sheet on which the image is formed is stored in a paper discharge tray 38C disposed on the upper surface of the image forming apparatus 100C.

  The image forming apparatus 100 </ b> C includes an external paper feed conveyance path 55 that can receive a paper feed from a paper feed device 500 that can accommodate a large volume of paper.

  In the image forming apparatus 100 </ b> C, as shown by being surrounded by a broken line in FIG. 8, members including one first surface of the main transport path 51 </ b> C, the sub transport path 52 </ b> C, and the transfer belt 35 are unitized as a slide unit 56. . The slide unit 56 is configured to be freely drawn out and stored in a straight line to the side of the housing 101 (leftward in FIG. 8) so that the first surface of the main transport path 51C is in contact with the opposing second surface. Has been. By pulling out the slide unit 56, it becomes easy to remove the paper jammed in the main conveyance path 51C including the image forming position such as the transfer position and the fixing position.

  In the image forming apparatus 100C, the ion generation unit 10C is disposed in a space sandwiched between the main transport path 51C and the sub transport path 52C.

  The ion generating unit 10C is preferably arranged at a position closer to the junction point to the main transport path 51C than the branch point from the main transport path 51C of the sub transport path 52C. Since the fixing device 37 is disposed in the vicinity of the branch point from the main transport path 51C of the sub transport path 52C, the junction point to the main transport path 51C is more than the branch point from the main transport path 51C of the sub transport path 52C. By disposing the ion generation unit 10C at a position close to, the influence of heat generated from the fixing device 37 on the ion generation unit 10C is suppressed.

  As shown in FIG. 9, the ion generation unit 10C includes a duct 11C, an ion generation device 12, a fan 13, and independent foaming seal members 161C and 162C.

  The duct 11C is configured to be divided into three parts, that is, a central duct 111C and end ducts 112C and 113C in the paper width direction. The duct 11 </ b> C is divided so that the size in the width direction of the sheet of the central duct 111 </ b> C becomes smaller toward the upstream side in the pull-out direction of the slide unit 56.

  Seal members 161C and 162C are mounted on the surfaces of the end ducts 112C and 113C on the center duct 111C side. Air leakage between the center duct 111C and the end ducts 112C and 113C is prevented by the seal members 161C and 162C.

  The end ducts 112 </ b> C and 113 </ b> C are fixed to the apparatus main body including the housing 101 </ b> C, and the central duct 111 </ b> C is fixed to the slide unit 56.

  Conveying rollers 511C and 512C of the main conveying path 51C are arranged on the upstream side of the ion generating unit 10C in the drawing direction of the slide unit 56. The conveyance rollers 511C and 512C are pivotally supported by a frame 513C on the first surface side of the main conveyance path 51C.

  The distance between the upstream end portions of the end ducts 112C and 113C in the pull-out direction of the slide unit 56 is made larger than the dimension of the frame 513C in the sheet width direction. Therefore, when the slide unit 56 is pulled out, the transport rollers 511C and 512C and the frame 513C do not collide with the end ducts 112C and 113C, but move between the end ducts 112C and 113C and are pulled out together with the center duct 111C. It is.

  Therefore, the ion generation unit 10C can be mounted without hindering the maintenance work of the image forming apparatus 100C and without increasing the space necessary for installation, and ions can be stably generated over a long period of time. Can do.

  The description of the above-described embodiment is an example in all respects and should be considered as not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10, 10A, 10B, 10C Ion generating unit 11, 11B, 11C Duct 111 Upstream duct 112 Downstream duct 111C Central duct 112C, 113C End duct 17 Auxiliary duct 18 Inlet 30 Process section 37 Fixing device 51, 51C Main Transport path 52, 52C Sub-transport path 53 Switchback transport path 54 Drawer unit 56 Slide unit 100, 100A, 100B, 100C Image forming apparatus 101, 101C Housing 103 Exhaust opening 300 Image forming section 400 Paper feed section

Claims (8)

An image forming apparatus having an ion generation function,
An image forming unit that performs image forming processing on a sheet at an image forming position based on image data;
A paper feeding unit for accommodating paper fed to the image forming position;
A paper discharge unit for storing paper on which an image is formed;
A plurality of conveyance paths including a main conveyance path through which a sheet from the sheet feeding unit to the paper discharge unit via the image forming position is conveyed, and at least two of the plurality of conveyance paths A plurality of conveyance paths at least partially running parallel to each other;
An ion generating unit disposed in a space sandwiched between portions of the plurality of transport paths that run parallel to each other;
A housing containing the image forming unit, the paper feeding unit, the plurality of transport paths, and the ion generation unit;
The ion generation unit includes:
A duct that forms a flow path for sucking and exhausting the outside of the housing in a direction orthogonal to a sheet conveyance direction within a plane of the sheet conveyed through the plurality of conveyance paths;
An ion generator disposed in the duct;
An image forming apparatus comprising: an air flow generating device that generates an air flow in the duct. The plurality of transport paths are
The main transport path;
A double-sided printing conveyance path in which a sheet passing through the image formation position is reversed and conveyed to the image formation position again.
The double-sided printing conveyance path is configured to be able to be pulled out and stored with respect to the casing,
The image forming apparatus according to claim 1, wherein at least a part of the duct among the ion generation units is fixed to an apparatus main body including the housing. The double-sided printing conveyance path is
A sub-transport path that branches from the main transport path between the image forming position and the paper discharge unit and merges with the main transport path before reaching the image forming position in the main transport path;
A switchback conveyance path that reverses the front and back of the paper that is branched from the sub-conveyance path to perform double-sided printing,
The image forming apparatus according to claim 2, wherein the ion generation unit is disposed between the sub-transport path and the switchback transport path.   4. The image forming apparatus according to claim 2, wherein the ion generation unit is disposed at a position closer to a joining point to the main transport path than a branch point from the main transport path of the double-sided printing transport path. The housing has an exhaust opening through which air passing through the periphery of the image forming position is exhausted,
5. The image forming apparatus according to claim 1, wherein the ion generation unit has an intake port of the duct on a surface different from a surface of the housing in which the exhaust opening is provided. The housing has the exhaust opening on a back surface or a side surface,
The image forming apparatus according to claim 5, wherein the ion generation unit is configured to intake air from a front surface of the housing and exhaust air to a back surface. The housing has the exhaust opening on a side surface,
The image forming apparatus according to claim 5, wherein the ion generation unit is configured to intake air from a back surface of the housing and exhaust air to the front surface. The ion generation unit is configured to inhale from the front of the housing and exhaust to the back,
The auxiliary duct which further protrudes from the back surface of the said housing | casing by the minimum space | interval which should be provided in the back surface of the said housing | casing, and guides the air exhausted from the said duct upwards. Image forming apparatus.

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