Static eliminator

Abstract

To provide a static eliminator in which the temperature rise of the static eliminating means is suppressed by a fan.SOLUTION: First ionizer 52 for static elimination of sheets is covered with an enclosure member 62, and air is caused to flow by a fan into an air passage space 70 of the enclosure member 62 to cool the first ionizer 52.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a static eliminator that eliminates static electricity from a sheet on which an image has been formed by an image forming unit. [Background technology]

[0002] In image forming systems, problems can occur, such as sheets being electrostatically attracted to the transport guide, causing transport problems, or when sheets discharged outside the device are stacked, electrostatic forces generated between sheets causing stacking problems.

[0003] To address these problems, a static eliminator has been proposed as described in Patent Document 1. The static eliminator disclosed in Patent Document 1 has two components: a contact type static eliminator that comes into contact with the paper being transported, and a non-contact type static eliminator that is provided downstream in the transport direction from the contact type static eliminator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-167169 A Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the problem caused by the temperature rise of the non-contact type static electricity removing means is not taken into consideration. [Means for solving the problem]

[0006] The static elimination device of the present invention is characterized by having a conveying path through which a sheet on which an image has been formed by an image forming means passes, a non-contact static elimination means for eliminating static electricity from the sheet conveyed along the conveying path, and a fan for generating an air flow in a space in which at least a portion of the non-contact static elimination means is disposed. Effect of the Invention

[0007] The fan prevents the temperature of the charge removing means from increasing. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is a schematic diagram of a non-contact static electricity removing unit as viewed from the sheet transport direction. [Diagram 5] 5 is a schematic diagram of a non-contact static electricity removing unit as viewed from a direction perpendicular to the sheet conveying direction. FIG. [Figure 6] FIG. 1 is a schematic diagram of an image forming system. [Figure 7] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The dimensions, materials, shapes, and relative positions of components described in the following embodiments are not intended to limit the scope of application of the present technology unless otherwise specified.

[0010] <Image forming system> FIG. 6 is an overall view of the hardware configuration of the image forming system 1000 according to the present embodiment. The image forming system 1000 includes an image forming apparatus 100, an inserter 200, a static eliminator 57, and a large-capacity stacker 400. The image forming apparatus 100 forms an image on a sheet based on an instruction from an external device. The inserter 200 conveys a sheet conveyed from the image forming apparatus 100 to the static eliminator 57. The inserter 200 also feeds an insertion sheet from a feed tray 201, and is capable of inserting the insertion sheet between a plurality of sheets conveyed from the image forming apparatus 100. The static eliminator 57 neutralizes the sheet conveyed from the image forming apparatus 100 via the inserter 200. The large-capacity stacker 400 is a large-capacity stacker that stacks the sheets conveyed from the static eliminator 57. The sheet conveyed from the image forming apparatus 100 through the inserter 200 and the static eliminator 57 is discharged onto a discharge tray 401 of the large-capacity stacker 400 .

[0011] Although the image forming system 1000 in this embodiment includes the image forming apparatus 100, the inserter 200, the static eliminator 57, and the large-capacity stacker 400, the configuration of the image forming system 1000 is not limited to this. For example, the image forming system 1000 may further include another finisher downstream of the large-capacity stacker 400. The image forming system 1000 may also be configured such that the static eliminator 57 is directly connected to the image forming apparatus 100, and does not include the inserter 200 or the large-capacity stacker 400. The image forming system 1000 may also be configured such that the static eliminator 300 is integrally provided inside the housing 110 (FIG. 2) of the image forming apparatus 1.

[0012] <Image forming device> 1 is a schematic cross-sectional view of an image forming apparatus 100. The image forming apparatus 100 in this embodiment is a tandem type multifunction machine (having the functions of a copier, printer, and facsimile machine) that employs an intermediate transfer method. The image forming apparatus 100 can form a full-color image on a sheet (transfer material, sheet material, recording medium, media) P such as paper using an electrophotographic method in response to an image signal transmitted from an external device, for example.

[0013] The image forming apparatus 100 has, as a plurality of image forming units (stations), four image forming units 10Y, 10M, 10C, and 10K that form images of yellow (Y), magenta (M), cyan (C), and black (K), respectively. These image forming units 10Y, 10M, 10C, and 10K are arranged in a row along the moving direction of an image transfer surface of an intermediate transfer belt 7, which is arranged substantially horizontally, as described below. Elements in the image forming units 10Y, 10M, 10C, and 10K that have the same or corresponding functions or configurations may be generally described by omitting the suffixes Y, M, C, and K that indicate that the elements are for any of the colors. The image forming unit 10 has photosensitive drums 1 (1Y, 1M, 1C, 1K), chargers 2 (2Y, 2M, 2C, 2K), exposure devices 3 (3Y, 3M, 3C, 3K), developing devices 4 (4Y, 4M, 4C, 4K), primary transfer rollers 5 (5Y, 5M, 5C, 5K), and cleaning devices 6 (6Y, 6M, 6C, 6K).

[0014] The photosensitive drum 1 carrying the toner image is driven to rotate in the direction of the arrow R1 in FIG. 2 (counterclockwise) by a driving force transmitted from a drum drive motor (not shown). The surface of the rotating photosensitive drum 1 is uniformly charged to a predetermined potential of a predetermined polarity (negative polarity in this embodiment) by a charger 2 as a charging means. During charging, a predetermined charging voltage is applied to the charger 2 by a charging power source (not shown). The surface of the charged photosensitive drum 1 is scanned and exposed by an exposure device 3 as an exposure means in response to an image signal, and an electrostatic latent image is formed on the photosensitive drum 1. In this embodiment, the exposure device 3 is configured as a laser scanner device that irradiates the photosensitive drum 1 with a laser beam modulated in response to image information. The electrostatic image formed on the photosensitive drum 1 is developed by a developer 4 as a developing means, which supplies toner as a developer, and a toner image is formed on the photosensitive drum 1. In this embodiment, toner charged to the same polarity as the charging polarity of the photosensitive drum 1 adheres to the exposed portion on the photosensitive drum 1, which has been uniformly charged and then exposed to light, thereby lowering the absolute value of the potential. The developing unit 4 has a developing roller, which is a rotatable developer carrier, that carries the developer and transports it to a developing position facing the photosensitive drum 1. The developing roller is rotationally driven, for example, by a driving force transmitted from a drive system of the photosensitive drum 1. During development, a predetermined developing voltage is applied to the developing roller by a developing power source (not shown).

[0015] An intermediate transfer belt 7, which is a rotatable intermediate transfer body formed of an endless belt as a second image carrier that carries a toner image, is disposed so as to face the four photosensitive drums 1Y, 1M, 1C, and 1K. The intermediate transfer belt 7 is stretched around a plurality of tension rollers, including a drive roller 22, an upstream auxiliary roller 23a, a downstream auxiliary roller 23b, a tension roller 25, a secondary transfer pre-roller 24, and an inner roller 21, and stretched with a predetermined tension (tension). The drive roller 22 transmits a driving force to the intermediate transfer belt 7. The tension roller 25 applies a predetermined tension to the intermediate transfer belt 7 and controls the tension of the intermediate transfer belt 7 to be constant. The secondary transfer pre-roller 24 forms a surface of the intermediate transfer belt 7 in the vicinity of the upstream of the secondary transfer nip N2 with respect to the rotation direction of the intermediate transfer belt 7. The inner roller 21 functions as an opposing member of the outer roller 9. The upstream auxiliary roller 23a and the downstream auxiliary roller 23b form an image transfer surface that is disposed substantially horizontally. The driving roller 22 is driven to rotate by a driving force transmitted from a belt driving motor (not shown). As a result, the intermediate transfer belt 7 receives a driving force from the driving roller 22 and rotates in the direction of the arrow r2 in FIG. 2 (clockwise). In this embodiment, the intermediate transfer belt 7 is driven to rotate at a peripheral speed of 150 to 470 mm / sec. Among the multiple tension rollers, the tension rollers other than the driving roller 22 are rotated in accordance with the rotation of the intermediate transfer belt 7. On the inner peripheral surface side of the intermediate transfer belt 7, primary transfer rollers 5Y, 5M, 5C, and 5K, which are roller-shaped primary transfer members as primary transfer means, are arranged in correspondence with the photosensitive drums 1Y, 1M, 1C, and 1K. The primary transfer roller 5 presses the intermediate transfer belt 7 toward the photosensitive drum 1 to form a primary transfer nip N1 as a primary transfer portion, which is a contact portion between the photosensitive drum 1 and the intermediate transfer belt 7. Further, on the inner peripheral surface side of the intermediate transfer belt 7, a pressing member 26 is provided upstream of the inner roller 21 and downstream of the pre-secondary transfer roller 24 in the rotation direction of the intermediate transfer belt 7. The pressing member 26 comes into contact with the inner peripheral surface of the intermediate transfer belt 7 and presses the intermediate transfer belt 7 from the inner peripheral surface side to the outer peripheral surface side.

[0016] The toner image formed on the photosensitive drum 1 as described above is primarily transferred onto the rotating intermediate transfer belt 7 at the primary transfer nip N1 by the action of the primary transfer roller 5. During the primary transfer, a primary transfer voltage, which is a DC voltage of a polarity opposite to the normal charging polarity of the toner (positive polarity in this embodiment) is applied to the primary transfer roller 5 by a primary transfer power source (not shown). For example, when a full-color image is formed, the toner images of each color of yellow, magenta, cyan, and black formed on each photosensitive drum 1 are primarily transferred in sequence so as to be superimposed on the same image forming area on the intermediate transfer belt 7. In this embodiment, the primary transfer nip N1 is an image forming position where a toner image is formed on the intermediate transfer belt 7. The intermediate transfer belt 7 is an example of a rotatable endless belt that transports the toner image carried at the image forming position.

[0017] An outer roller 9, which is a secondary transfer member, is disposed at a position facing the inner roller 21 on the outer peripheral surface side of the intermediate transfer belt 7. The outer roller 9 is pressed against the inner roller 21 via the intermediate transfer belt 7 to form a secondary transfer nip N2 as a secondary transfer portion, which is a contact portion between the intermediate transfer belt 7 and the outer roller 9. The toner image formed on the intermediate transfer belt 7 as described above is secondarily transferred onto a sheet being conveyed while being sandwiched between the intermediate transfer belt 7 and the outer roller 9 by the action of the outer roller 9 in the secondary transfer nip N2. During the secondary transfer, a secondary transfer voltage, which is a constant voltage controlled DC voltage of a polarity opposite to the normal charging polarity of the toner (positive polarity in this embodiment), is applied to the outer roller 9 by the secondary transfer power source 18. In this embodiment, for example, a secondary transfer voltage of +1 to +7 kv is applied, and a secondary transfer current of +40 to +120 μa is caused to flow, so that the toner image on the intermediate transfer belt 7 is secondarily transferred onto the sheet. In this embodiment, the inner roller 21 is electrically grounded (connected to ground). Alternatively, the inner roller 21 may be used as a secondary transfer member, to which a secondary transfer voltage having the same polarity as the normal charging polarity of the toner is applied, and the outer roller 9 may be used as a counter electrode, which is electrically grounded.

[0018] The sheet is conveyed to the secondary transfer nip N2 in synchronization with the toner image on the intermediate transfer belt 7. That is, a sheet stored in a recording material cassette 11 serving as a recording material storage unit is conveyed to the registration rollers 8 by a feed roller or the like and stopped temporarily. The sheet P is then sent to the secondary transfer nip N2 by the registration rollers 8 being rotationally driven so that the toner image on the intermediate transfer belt 7 coincides with a desired image forming area on the sheet P at the secondary transfer nip N2. A conveyance guide 14 for guiding the sheet P to the secondary transfer nip N2 is provided downstream of the registration rollers 8 and upstream of the secondary transfer nip N2 in the sheet conveyance direction of the sheet P.

[0019] The sheet P onto which the toner image has been transferred is transported by a pre-fixing transport section 41 to a fixing device 40 as a fixing means. The fixing device 40 applies heat and pressure to the sheet P carrying the unfixed toner image while sandwiching and transporting the sheet P between a pair of fixing rotors, thereby fixing (melting and bonding) the toner image onto the surface of the sheet P. Thereafter, the sheet P onto which the toner image has been fixed is transported to the inserter 200 by a pair of exit rollers 42.

[0020] Meanwhile, the toner remaining on the photosensitive drum 1 after the primary transfer is removed from the photosensitive drum 1 and collected by a cleaning device 6 serving as a cleaning means. Also, the toner remaining on the intermediate transfer belt 7 after the secondary transfer and the adhering matter such as paper powder adhering from the sheet P are removed from the intermediate transfer belt 7 and collected by a belt cleaning device 12 serving as an intermediate transfer body cleaning means. In this embodiment, the belt cleaning device 12 electrostatically collects and cleans the adhering matter such as the secondary transfer residual toner on the intermediate transfer belt 7.

[0021] In this embodiment, an intermediate transfer belt unit 20 serving as a belt conveying device is configured by including the intermediate transfer belt 7 stretched around a plurality of tension rollers, the primary transfer rollers 5, the belt cleaning device 12, and a frame supporting these. The intermediate transfer belt unit 20 is supported detachably on the housing 110 of the image forming apparatus 100 for maintenance or replacement. Here, the intermediate transfer belt 7 may be one made of a resin-based material having a single layer or multi-layer structure, or one having a multi-layer structure with an elastic layer made of an elastic material.

[0022] In this embodiment, the primary transfer roller 5 is configured by providing an elastic layer made of ion-conductive foamed rubber on the outer periphery of a metal core material. In this embodiment, the primary transfer roller 5 has an outer diameter of 15 to 20 mm, and an electrical resistance of 1×10 when measured by applying a voltage of 2 kV in an environment of 23° C. and 50% rh. 5 ~1×10 8 It is ω.

[0023] In this embodiment, the outer roller 9 is configured by providing an elastic layer of ion-conductive foamed rubber on the outer periphery of a metal core material. In this embodiment, the outer roller 9 has an outer diameter of 20 to 25 mm, and an electrical resistance of 1×10 when measured by applying a voltage of 2 kV in an environment of 23° C. and 50% rh. 5 ~1×10 8 The outer roller 9 is in contact with the inner roller 21 with a predetermined pressure across the intermediate transfer belt 7, forming a secondary transfer nip N2.

[0024] In this embodiment, the inner roller 21 is configured by providing an elastic layer of electronically conductive rubber on the outer periphery of a metal core material. In this embodiment, the inner roller 21 has an outer diameter of 20 to 22 mm, and an electrical resistance of 1×10 when measured by applying a voltage of 50 V in an environment of 23° C. and 50% rh. 5 ~1×10 8ω. The secondary transfer pre-roller 24 may have a configuration similar to that of the inner roller 21. In this embodiment, the rotation axes of the tension rollers of the intermediate transfer belt 7 including the inner roller 21 and the outer roller 9 are substantially parallel to each other.

[0025] <Outline of the static eliminator> Next, the static eliminator 57 according to this embodiment will be described with reference to FIG. 2. FIG. 2 is a schematic cross-sectional view of the static eliminator 57. In the image forming system 1000, the static eliminator 57 is disposed downstream of the image forming apparatus 100 and the inserter 200. The sheet p may become charged by the image forming process of the image forming apparatus 100 described above. In such a case, multiple sheets p discharged onto the discharge tray 401 may stick together due to static electricity, which may lead to stacking failure. Therefore, in this embodiment, the static eliminator 57 is configured to eliminate static electricity from the sheet p on which an image is formed by the image forming apparatus 100.

[0026] The static eliminator 57 has, inside the housing 157, a static elimination roller pair 50 as a contact static elimination section that eliminates static electricity from the sheet in a state of contact with the sheet (contact state), and a non-contact static elimination section 56 that eliminates static electricity from the sheet without contacting the sheet (non-contact state). The static eliminator 57 also has an entrance roller pair 43 that receives the sheet from the inserter 200 and conveys it along the conveying path T, and an exit roller pair 44 that discharges the sheet, which has been neutralized by the static elimination roller pair 50 and the non-contact static elimination section 56, to the large-capacity stacker 400. The entrance roller pair 43 and the exit roller pair 44 are an example of a conveying section in this embodiment.

[0027] The pair of static electricity removing rollers 50 is composed of a static electricity removing roller 71 which rotates in contact with the lower surface of the sheet, and an opposing static electricity removing roller 72 which rotates in contact with the upper surface of the sheet. The opposing static electricity removing roller 72 is an example of a first static electricity removing roller, and the static electricity removing roller 71 is an example of a second static electricity removing roller. The static electricity removing roller 71 is composed of an elastic layer of ion conductive foamed rubber provided on the outer periphery of a metal core material. In this embodiment, the static electricity removing roller 71 has an outer diameter of 20 to 25 mm, and an electrical resistance of 1×10 when measured by applying a voltage of 2 kV in an environment of 23° C. and 50% rh. 5 ~1×10 8 ω, which is the same member as the outer roller 9 described above. The discharge counter roller 72 has an outer diameter of 20 to 25 mm, and forms a discharge nip portion together with the discharge roller 71. The sheet conveyed from the image forming apparatus 100 is first roughly removed of the electrostatic charge by the discharge nip portion of the discharge roller pair 50. A discharge voltage, which is a constant voltage controlled DC voltage of the opposite polarity (negative polarity in this embodiment) to the secondary transfer member (outer roller 9) by the discharge power source 55, is applied to the discharge roller 71 by the discharge power source 55, which is a high voltage application means for discharging. The sheet that has passed the discharge roller pair 50 is then discharged by the non-contact discharge unit 56 provided downstream of the discharge roller pair 50. The non-contact discharge unit 56 removes the charge of the sheet that has not been completely discharged by the discharge roller pair 50. Non-contact static electricity removing unit 56 includes a first ionizer 52, which is a non-contact static electricity removing means, arranged above sheet 7 to be conveyed, and a second ionizer 152 (second static electricity removing means) arranged below sheet 7. Non-contact static electricity removing unit 56 further includes a first conveying guide 53 and a second conveying guide 54 arranged below first conveying guide 53.

[0028] Fig. 3(A) is a top view of the first transport guide 53. Fig. 3(B) is a perspective view of the first transport guide 53 and the second transport guide 54. The first transport guide 53 is provided with an opening 82 so that ions generated from the ion generating unit 61 (electrode needle) of the first ionizer 52 can reach the transported sheet without being physically blocked. Similarly to the first transport guide 53, the second transport guide 54 is provided with an opening 83 so that ions generated from the ion generating unit 161 (electrode needle) of the second ionizer 152 can reach the transported sheet without being physically blocked.

[0029] The sheet conveyed from the image forming apparatus 100 is first roughly cleaned of electrostatic charge by the pair of static electricity removal rollers 50. As described above, the high voltage applied to the static electricity removal roller 71 by the static electricity removal power source 55 is applied with a polarity opposite to that applied to the outer roller 9. Next, the sheet 7 is cleaned of any charges that could not be completely removed in the static electricity removal nip portion by the non-contact static electricity removal section 56 further downstream, and is discharged outside the static electricity removal device 57. Also, the positional relationship between the pair of static electricity removal rollers 50 and the first and second conveying guides 53 and 54 is configured to be close to each other this time, but the distance therebetween is not specified.

[0030] <Configuration for Cooling First Ionizer 52 and Second Ionizer 152> 4 and 5 show the details of non-contact static electricity removing unit 56. Fig. 4 is a view seen from the sheet conveying direction D side. Fig. 5 is a view seen from a direction perpendicular to conveying direction D. A first ionizer 52 is disposed above first conveying guide 53, and a second ionizer 152 is disposed below second conveying guide 54.

[0031] The first ionizer 52 includes an ionizer control unit 60 and an ion generating unit (ion irradiation unit) 61 that generates ions. The first ionizer 52 generates ions by applying a high voltage to the ion generating unit 61, which is an electrode needle. The length of the first ionizer 52 in the sheet width direction (the front-rear direction of the static electricity removal device 57) perpendicular to the conveying direction D is longer than the length of the first ionizer 52 in the conveying direction D in which the sheet is conveyed. A plurality of ion generating units 61, which are arranged below the first ionizer 52, are provided lined up in the sheet width direction as shown in FIG.

[0032] The surrounding member 62 surrounding the periphery of the first ionizer 52 is disposed inside the housing 157 (see FIG. 2) of the static eliminator 57. As shown in FIG. 5, the surrounding member 62 has a first side portion 62a facing one side surface of the first ionizer 52 and a second side portion 62b facing the other side surface of the first ionizer 52. The surrounding member 62 has an upper portion 62c that connects the first side portion 62a and the second side portion 62b and is positioned above the first ionizer 52. The surrounding member 62 has a first wall portion 62h that is disposed closer to the first conveying guide 53 in the vertical direction than the first side portion 62a and upstream in the conveying direction D than the ion generating unit 61 and extends vertically. The surrounding member 62 has a first connection portion 62s that connects the first wall portion 62h and the first side portion 62a. The surrounding member 62 includes a second wall portion 62k extending in the vertical direction, disposed closer to the first transport guide 53 than the second side portion 62b in the vertical direction and downstream in the transport direction D than the ion generation portion 61. The surrounding member 62 includes a second connection portion 62j that connects the second wall portion 62k and the second side portion 62b.

[0033] 4, the surrounding member 62 includes a back wall 62r disposed on one side in the sheet width direction relative to the first ionizer 52 (the back side of the static eliminator 57), and a first fan 65 that sends air to the ionizer control unit 60 of the first ionizer 52 is disposed on the back wall 62r. ​​The surrounding member 62 includes a front wall 62f disposed on the other side in the sheet width direction relative to the first ionizer 52 (the front side of the static eliminator 57). An opening is formed in the front wall 62f to allow air to pass through.

[0034] The first fan 65 is configured to take in outside air and generate an airflow that flows along the seat width direction (the longitudinal direction of the first ionizer 52) in the space in which the ionizer control unit 60 is disposed. The air blown from the first fan 65 and passing through the ionizer control unit 60 passes through an opening in the front wall 62f.

[0035] 5, one end of a sealing member 63, which is an insulator made of resin, is attached to the first connection portion 62s of the surrounding member 62. The sealing member 63 is a flexible, in other words, elastically deformable, resin sheet. The sealing member 63 is installed so that the other folded end abuts against the first ionizer 52 in a deformed state. Note that a sealing member 63 whose end abuts against the first ionizer 52 is also attached to the second connection portion 62j.

[0036] The seal member 63 and the upper portion 62c, first side portion 62a, and second side portion 62b of the enclosing member 62 define an air passing space (first space) 70 through which air passes from a fan 65 for cooling the ionizer control unit 60. The ionizer control unit 60, which is a part of the first ionizer 52, is disposed in the air passing space 70. Thus, the ionizer control unit 60 is cooled by the airflow generated by the first fan 65 in the air passing space 70.

[0037] The seal member 63 as a partition member spatially separates the ion generating section 61 from the air passing space 70 , and regulates air flowing through the air passing space 70 from flowing into the ion generating section 61 .

[0038] A resin sheet 64 is attached to the inner surfaces of the first wall portion 62h and the second wall portion 62k. The resin sheet 64 is an example of a defining member that defines a space (hereinafter referred to as an ion passing space) that connects the ion generating unit 61 and the transport path T. Ions generated by the ion generating unit 61 pass through the ion passing space and are irradiated onto a sheet passing through the transport path T.

[0039] The lower side of the surrounding member 62 is open, and the ion generation unit 61 and the first transport guide 53 communicate with each other. The ion generation unit 61 and the transport path T communicate with each other via an opening 82 of the first transport guide 53.

[0040] The second ionizer 152 has the same configuration as the first ionizer 52. That is, the second ionizer 152 includes an ionizer control unit 160 and an ion generating unit (ion irradiation unit) 161. The second ionizer 152 generates ions by applying a high voltage to the ion generating unit 161, which is an electrode needle. The length of the second ionizer 152 in the sheet width direction (the front-rear direction of the static electricity removal device 57) perpendicular to the conveying direction D is longer than the length of the second ionizer 152 in the conveying direction D in which the sheet is conveyed. The ion generating units 61 arranged below the second ionizer 152 are arranged side by side in the sheet width direction as shown in FIG.

[0041] The second ionizer 152 is surrounded by an enclosing member 162 having the same configuration as the enclosing member 62 for the first ionizer 52. That is, the enclosing member 162 surrounding the periphery of the second ionizer 152 is disposed inside the housing of the static eliminator 57. The enclosing member 162 has a first side portion 162a facing one side surface of the second ionizer 152 and a second side portion 162b facing the other side surface of the second ionizer 152. The enclosing member 162 has a lower portion 162c that connects the first side portion 162a and the second side portion 162b and is positioned lower than the second ionizer 152.

[0042] Furthermore, the surrounding member 162 has a first wall portion 162h that is disposed closer to the second transport guide 54 in the vertical direction than the first side portion 162a and upstream in the transport direction D than the ion generation unit 161, and extends in the vertical direction. The surrounding member 162 has a first connection portion 162s that connects the first wall portion 162h and the first side portion 162a. The surrounding member 162 has a second wall portion 162k that is disposed closer to the second transport guide 54 in the vertical direction than the second side portion 162b and downstream in the transport direction D than the ion generation unit 161, and extends in the vertical direction. The surrounding member 162 has a second connection portion 162j that connects the second wall portion 162k and the second side portion 162b.

[0043] As shown in FIG. 4, the surrounding member 162 has a back wall 162r disposed on one side of the second ionizer 152 in the sheet width direction (the back side of the static eliminator 57). A second fan 165 that blows air toward the ionizer control unit 160 of the second ionizer 152 is disposed on the back wall 162r. The surrounding member 162 has a front wall 162f disposed on the other side of the second ionizer 152 in the sheet width direction (the front side of the static eliminator 57). An opening through which air can pass is formed in the front wall 162f. The second fan 165 is configured to take in outside air and generate an airflow that flows in the sheet width direction along the ionizer control unit 160. The air that is blown from the second fan 165 and passes through the ionizer control unit 160 passes through the opening in the front wall 162f.

[0044] 5, one end of a sealing member 163, which is an insulator made of resin, is attached to the first connecting portion 162s of the enclosing member 162. The sealing member 163 is installed so that the other bent end abuts against the second ionizer 152. Note that a sealing member 163 whose end abuts against the second ionizer 152 is also attached to the second connecting portion 162j.

[0045] The seal member 163, and the lower portion 162c, first side portion 162a, and second side portion 162b of the surrounding member 162 define an air passing space 170 through which air from a second fan 165 for cooling the ionizer control unit 160 passes.

[0046] The seal member 163 as a partition member spatially separates the ion generating unit 161 from the air passing space 170, and regulates the air flowing through the air passing space 170 from flowing into the ion generating unit 161. The seal member 163 is a flexible resin sheet, and is disposed so as to abut against the second ionizer 152.

[0047] A resin sheet 164 is attached to the inner surfaces of the first wall portion 162h and the second wall portion 162k. The resin sheet 164 provided on the first wall portion 162h and the second wall portion 162k constitutes a defining member that defines an ion passing space that connects the ion generation portion 161 and the transport path T.

[0048] The upper side of the surrounding member 162 is open, and the ion generation unit 161 and the second transport guide communicate with each other. The ion generation unit 161 and the transport path T communicate with each other via an opening 83 of the second transport guide .

[0049] The ionizer control units 60, 160 adjust the voltage according to the set amount of static electricity removal and control the electric charge generated from the ion generating units 61, 161, but in order to operate normally, the temperature must be kept below a certain level. The ionizer of this embodiment must be kept at a temperature below 40°.

[0050] In the static eliminator 57, the sheet 7 heated by the fixing device 40 is continuously transported. Therefore, the temperature in the static eliminator 57 increases due to the sheet, and depending on the usage environment (ambient temperature), it may exceed the usage temperature range of the ionizer control units 60 and 160. Therefore, in order to ensure normal operation, the ionizer control units 60 and 161 need to be cooled.

[0051] Therefore, in this embodiment, the ionizer control unit 60 is cooled by sending outside air to the ionizer control unit 60 by the first fan 65. Also, the ionizer control unit 160 is cooled by sending outside air to the ionizer control unit 160 by the second fan 165.

[0052] However, blowing air to the ionizer with a fan raises the following concerns. That is, if outside air from the fan flows into the space between the ion generating unit and the sheet in the transport path T, it is possible that the ions generated by the ion generating unit will be carried away by the airflow from the fan. In this case, there is a concern that the ions will not reach the sheet, making it impossible to properly neutralize the static electricity from the sheet.

[0053] Therefore, in this embodiment, the ion generating units 61, 161 and the ionizer control units 60, 161 are spatially separated by the seal members 63, 161. Specifically, the seal member 63 separates the air passing space 70 through which the air from the first fan 65 passes, from the ion generating unit 61. Even in a state in which the ionizer control unit 60 is cooled by the air flowing through the air passing space 70, the seal member 63 can suppress the airflow of the fan 65 from adversely affecting the charge elimination of the sheet by the first ionizer 52. In other words, the seal member 63 can prevent the ion generating unit 61 from being adversely affected by the air while ensuring the normal operation of the ionizer control unit 60. The seal member 163 in contact with the second ionizer 152 also exerts the same effect as the seal member 63.

[0054] As described above, the sealing members 63, 163 are flexible resin sheets, one end of which is attached to the surrounding members 62, 162, and the other folded end is installed so as to abut against the ionizers 52, 152. As a result, even if the position of the ionizers 52, 152 relative to the surrounding members 62, 162 varies, the sealing members 63, 163 deform in accordance with the variation in position, so that the air passage spaces 70, 170 are reliably defined.

[0055] If a conductor is present in the vicinity, the ions generated from the ion generating unit 61 are absorbed by the conductive material and do not reach the sheet 7, and therefore cannot be properly neutralized. Here, since the surrounding member 62 in the embodiment is made of metal, a resin sheet (insulating member) 64 is attached to the surface of the first wall portion 62h and the second wall portion 62k. The seal member 63 and the conveying guide 53 are also made of resin insulators. Therefore, in this embodiment, the members around the ion generating unit 61 are made of insulators. Therefore, the ions can reliably reach the sheet 7 and can be properly neutralized. Although the first ionizer 52 has been described, the same applies to the periphery of the ion generating unit 153 of the second ionizer 152.

[0056] In the above embodiment, the resin sheet 64, which is an insulator, is attached to the surrounding member 62, which is a conductor, to prevent the conductor from being exposed. However, the first wall portion 62h and the second wall portion 62k of the surrounding member 62 may be made of an insulating material.

[0057] The configuration, operation, and effects of the above embodiment will be summarized below.

[0058] (1) Air is blown to the first ionizer 52 by the first fan 65. This prevents the first ionizer 52 from rising in temperature, and prevents malfunctions caused by the rise in temperature of the first ionizer 52. In particular, when a sheet that has passed through the fixing device 40 passes through the static eliminator, the ionizer may be heated by the high-temperature sheet that has passed through the fixing device 40. If the ionizer is disposed inside the housing of the static eliminator, the rise in temperature of the ionizer is of even greater concern. In this embodiment, the air from the first fan 65 can maintain the temperature of the first ionizer 52 at or below a temperature at which the first ionizer 52 can stably operate.

[0059] (2) A seal member 63 that restricts air from the first fan 65 from flowing to the ion generating unit 61 of the first ionizer 52 is disposed as a restricting unit. If air from the first fan 65, which is used to prevent the first ionizer 52 from rising in temperature, flows into the ion generating unit 61, there is a concern that the ions will be carried by the air and the static elimination ability of the sheet will decrease. In this embodiment, the flow of air to the ion generating unit 61 is restricted by the seal member 63, so that the static elimination ability can be prevented from decreasing. In the above embodiment, the seal member 63 that can elastically deform and contacts the first ionizer 52 to effectively restrict the flow of air to the ion generating unit 61 is shown as an example of the restricting unit. However, the restricting unit is not limited to the seal member 63. For example, the connection portion 62j of the enclosure member 61 may be closer to the first ionizer 52 to serve as the restricting unit.

[0060] (3) A part of the surrounding member 62 constitutes a duct through which the air sent by the first fan 65 passes. Therefore, the first ionizer 52 can be cooled by the first fan 65 efficiently.

[0061] (4) The first fan 65 and the surrounding member 62 are disposed so that air from the first fan 65 flows along the longitudinal direction of the first ionizer 52. Therefore, the first ionizer 52 can be efficiently cooled by the first fan 65.

[0062] (5) The seal member 63 is disposed as a partition between the air passing space 70, which is a space through which the air blown by the first fan 65 flows, and the ion passing space in which the ion generating unit 61 is disposed. This makes it possible to prevent a decrease in static electricity removal capacity caused by the air from the first fan 65. Note that the partition is not limited to the elastically deformable seal member 63. For example, the connection portion 62j of the enclosing member 61 may be disposed closer to the first ionizer 52 to serve as the partition.

[0063] (6) The defining member that defines the ion passing space that connects the ion generating unit 61 and the transport path T through which the sheet passes is an insulator. Therefore, the ions generated in the ion generating unit 61 can reliably reach the sheet passing through the transport path T.

[0064] Although the above (1) to (6) have been described with respect to the first ionizer 52, the second ionizer 152 also provides the same functions and effects as the first ionizer 52.

[0065] In the embodiment described above, a configuration in which the rear wall 62r of the surrounding member 62 and the rear wall of the housing 157 are separate has been exemplified, but the rear wall of the surrounding member 62 may also serve as the rear wall of the housing 157. A configuration in which the front wall 62f of the surrounding member 62 and the front side of the housing 157 are separate has been exemplified, but the front wall 62f of the surrounding member 62 may also serve as the front wall of the housing 157. The surrounding member 162 for the second ionizer 152 may also be configured such that the rear wall 162r of the surrounding member 62 also serves as the rear wall of the housing 157, similarly to the surrounding member 62.

[0066] In the above-described embodiment, the surrounding member 62 is described as one member. However, the surrounding member may be formed by combining a plurality of members. For example, the member including the first side portion 62a, the second side portion 62b, and the upper portion 62c, the member including the first connecting portion 62s and the second connecting portion 62j, and the member including the first wall portion 62h and the second wall portion 62k may be separate members. In this case, the member including the first connecting portion 62s and the second connecting portion 62j and the member including the first wall portion 62h and the second wall portion 62k may be insulating members. The surrounding member 162 for the second ionizer 152 may also be formed by combining a plurality of members, similar to the surrounding member 62.

[0067] In the illustrated embodiment, one end of the seal member 63 is attached to the first connecting portion 62s, and the other end of the seal member abuts against the first ionizer 52. However, one end of the seal member 63 may be attached to the first ionizer 52, and the other end of the seal member may abut against the surrounding member 62. Similarly, one end of the seal member 163 for the second ionizer 152 may be attached to the second ionizer 152, and the other end of the seal member may abut against the surrounding member 162.

[0068] Also, the elastically deformable seal member 63 has been exemplified as the partition. However, for example, a resin plate that connects the first ionizer 52 and the surrounding member 62 (or the surrounding member 162) in an undeformed state and separates the air passing space 170 from the ion passing space in which the ion generating unit 61 is disposed may be provided as the partition. Similarly, a resin plate may be provided as the partition instead of the seal member 163 for the second ionizer 152.

[0069] In the above embodiment, the first fan 65 is disposed on the back wall 62r as a blower fan, and the first fan 65 blows air toward the ionizer control unit 60 of the first ionizer 52. That is, the first ionizer 52 is disposed downstream of the first fan 65 in the air blowing direction of the first fan 65. Here, as in the modified example shown in FIG. 7, the first exhaust fan 265 as another fan may be disposed on the front wall 62f, and the second exhaust fan 365 may be disposed on the front wall 162f. The first exhaust fan 265 also generates an airflow in the air passing space 70 like the first fan 65. The second exhaust fan 365 also generates an airflow in the air passing space 170 like the second fan 165.

[0070] It is also possible to provide only the first exhaust fan 265 to prevent the temperature of the first ionizer 52 from rising, without providing the first fan 65. It is also possible to provide only the second exhaust fan 365 to prevent the temperature of the second ionizer 152 from rising, without providing the second fan 165.

[0071] Although an electrophotographic type image forming apparatus for forming an image on a sheet has been exemplified, an inkjet type image forming apparatus may also be used. [Explanation of symbols]

[0072] 14 Image forming device 52 First Ionizer 57 Static eliminator 60 Ionizer control unit 61 Ion generating unit 62 Enclosure 63 Sealing material 65 First Fan 70 Air passage space

Claims

1. a conveying path through which a sheet on which an image is formed by an image forming means passes; a non-contact static elimination unit that includes an ion generating unit that generates ions and a control unit that controls the ion generating unit, and that eliminates static electricity from the sheet conveyed through the conveyance path without coming into contact with the sheet; a surrounding member surrounding the control unit; a partition member that separates a first space in which the control unit is surrounded by the surrounding member from a second space in which the ion generation unit is disposed; a fan that generates an airflow in the first space; A static eliminator comprising:

2. The static eliminator according to claim 1 , wherein the surrounding member surrounds the ion generating section.

3. the surrounding member and the partition portion are a duct, 2. The static eliminator according to claim 1, wherein the fan is disposed so that the air blown by the fan flows through the duct.

4. It has a housing, 4. The static eliminator according to claim 3, wherein the non-contact static eliminator and the duct are disposed inside the housing.

5. 2. The static eliminator according to claim 1, wherein the air from the fan is caused to flow along the longitudinal direction of the non-contact static eliminator.

6. 6. The static eliminator according to claim 5, wherein the partition is an elastically deformable sealing member, and the sealing member is in contact with the surrounding member and the non-contact static eliminator.

7. The static eliminator according to claim 6, wherein the sealing member is a sheet-like member, one end of the sealing member being attached to the enclosing member and the other end being arranged so as to abut against the non-contact static eliminator.

8. The static eliminator according to claim 1 , wherein a defining member defining the space connecting the ion generating section and the transport path comprises an insulator.

9. a transport guide that forms the transport path and has an opening through which ions generated by the ion generation unit pass, 9. The static eliminator according to claim 8, wherein the regulating member is disposed between the ion generating unit and the conveying guide in the thickness direction of the sheet being conveyed.

10. 2. The static eliminator according to claim 1, wherein the fan is a blower fan that blows air toward the control unit.

11. another fan that generates an airflow in the non-contact first space, The static eliminator according to claim 10, wherein the control unit is disposed between the blower fan and the other fan.

12. a second non-contact type charge eliminating means for eliminating charges from the sheet being conveyed through the conveyance path; 2. The static eliminator according to claim 1, further comprising a second fan for blowing air to the second static eliminator.

13. 2. The static eliminator according to claim 1, further comprising a pair of static eliminator rollers for eliminating static electricity from the sheet being transported along the transport path.

14. The static eliminator according to claim 1 , wherein the control unit includes a board for controlling the ion generating unit and a housing for supporting the board.

15. The enclosing member includes an upper portion and a side portion, and has an open lower portion on which the conveying path is disposed, 2. The static eliminator according to claim 1, wherein the first space is defined by the partition, the upper portion of the surrounding member, and the side portion of the surrounding member.

16. an image forming means for forming an image on a sheet; The static eliminator according to any one of claims 1 to 13, which eliminates static electricity from a sheet on which an image has been formed by the image forming unit; An image forming system comprising:

17. The image forming means includes a transfer section that transfers a toner image onto a sheet, and a fixing section that fixes the toner image transferred onto the sheet onto the sheet using heat.

17. The image forming system according to claim 16, further comprising:

Images