Static elimination device

Abstract

To prevent a recording medium from winding around one of static elimination rolls when static elimination is performed by passing the recording medium between a roll pair constituted by the two static elimination rolls.SOLUTION: A static elimination roll unit 54 includes two static elimination rolls 61 and 62 and a peeling member 63. These two static elimination rolls 61 and 62 are configured so that voltages of different potentials are applied thereto, and static elimination is performed by passing a sheet therethrough to reduce the amount of charge on the sheet. The peeling member 63 is provided in contact with the surface of one static elimination roll 61 of the two static elimination rolls 61 and 62, and configured to peel off the paper adhering to the static elimination roll 61 according to the rotation of the static elimination roll 61.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a static eliminator. [Background technology]

[0002] Patent document 1 discloses a discharge device having a first contact-type discharge means for discharging a high-resistance charged medium, the first contact-type discharge means having a discharge member that contacts the charged medium being transported and discharges the majority of the charge on the charged medium, and a second non-contact-type discharge means that is provided downstream of the first contact-type discharge means in the transport direction of the charged medium and discharges in a non-contact manner the remaining charge on the charged medium after it has been discharged by the first contact-type discharge means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-167169 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a static elimination device that can prevent a recording medium from becoming wrapped around one of the static elimination rolls when static elimination is performed by passing the recording medium between a roll pair consisting of two static elimination rolls. [Means for solving the problem]

[0005] The static elimination device according to a first aspect of the present invention includes two static elimination rolls to which voltages of different potentials are applied, and which reduce and eliminate the charge on a recording medium as the recording medium passes through the two static elimination rolls; The electrostatic elimination roll further includes a peeling member that is provided in contact with the surface of one of the two electrostatic elimination rolls and peels off the recording medium adhered to the electrostatic elimination roll as the electrostatic elimination roll rotates.

[0006] The static elimination device of the second aspect of the present invention is the static elimination device of the first aspect, wherein the two static elimination rolls are arranged above and below each other in the vertical direction, and the peeling member is arranged in contact with at least the static elimination roll arranged on the lower side in the vertical direction.

[0007] A third aspect of the static elimination device of the present invention is the static elimination device of the first aspect, in which power is supplied to one of the two static elimination rolls, and the peeling member is provided in contact with at least the static elimination roll on the non-power supply side.

[0008] A static eliminator of a fourth aspect of the present invention is the static eliminator of any one of the first to third aspects, wherein a tip of the peeling member is abutted against a surface downstream in the forward rotation direction of the static elimination roll so that the angle between the tip and the surface is an acute angle.

[0009] A static elimination device of a fifth aspect of the present invention is a static elimination device of any one of the first to third aspects, wherein the peeling member is positioned so as to peel off the recording medium adhering to the surface of the static elimination roll as the static elimination roll rotates.

[0010] A static eliminator according to a sixth aspect of the present invention is the static eliminator according to any one of the first to fifth aspects, wherein a plurality of the peeling members are provided in the width direction of a transport path along which a recording medium is transported.

[0011] A static elimination device of a seventh aspect of the present invention is a static elimination device of any one of the first to sixth aspects, wherein the peeling member is configured to abut against the surface of the static elimination roll by being urged in the surface direction of the static elimination roll by an elastic member.

[0012] The static eliminator of an eighth aspect of the present invention is the static eliminator of the first aspect, further comprising a control unit that controls rotation of the two static eliminator rolls, The control unit performs a forward operation to rotate the two charge-eliminating rolls in a forward direction in which the recording medium passes between the two charge-eliminating rolls and is transported to a subsequent stage, before performing a reverse operation to rotate the charge-eliminating roll provided with the peeling member in a reverse direction that is opposite to the forward rotation direction.

[0013] A ninth aspect of the static elimination device of the present invention is the static elimination device of the eighth aspect, wherein the control unit controls the static elimination roll to perform a reverse operation not only at the start of a printing process on a recording medium, but also after a printing process on a recording medium based on one printing instruction has been completed.

[0014] A static eliminator of a tenth aspect of the present invention is the static eliminator of the eighth or ninth aspect, wherein the control unit controls the static eliminator roll to perform a reverse rotation operation, stop the operation of the static eliminator roll, and then perform a forward rotation operation of the static eliminator roll.

[0015] An eleventh aspect of the static eliminator of the present invention is the static eliminator of the eighth or ninth aspect, wherein when the control unit performs a forward rotation operation after performing a reverse rotation operation of the static elimination roll, the rotation speed of the static elimination roll during the forward rotation operation is controlled to gradually increase until it reaches a steady rotation.

[0016] A twelfth aspect of the static elimination device of the present invention is a static elimination device according to any one of the first to eleventh aspects, in which the two static elimination rolls and the peeling member are arranged in a static elimination roll unit configured to be insertable and removable from the static elimination device main body.

[0017] The static eliminator of a thirteenth aspect of the present invention is the static eliminator of the twelfth aspect, further comprising a guide plate for guiding the insertion position of the static eliminator roll unit when the static eliminator roll unit is inserted into the static eliminator body.

[0018] The static eliminator according to a fourteenth aspect of the present invention is the static eliminator according to any one of the first to thirteenth aspects, further comprising a plurality of static elimination roll pairs each including the two static elimination rolls.

[0019] A static elimination device according to a fifteenth aspect of the present invention includes a static elimination roll and a static elimination belt to which voltages of different potentials are applied, and which reduce and eliminate the charge on a recording medium by passing the recording medium; The electrostatic elimination roll is provided with a peeling member that is provided in contact with the surface of one of the electrostatic elimination roll and the electrostatic elimination belt and peels off the recording medium adhered to the electrostatic elimination roll or the electrostatic elimination belt as the electrostatic elimination roll rotates or the electrostatic elimination belt turns. Effect of the Invention

[0020] According to the first aspect of the static elimination device of the present invention, when a recording medium is passed between a pair of rolls consisting of two static elimination rolls to eliminate static electricity, it is possible to prevent the recording medium from becoming wrapped around one of the static elimination rolls.

[0021] According to the static elimination device of the second aspect of the present invention, it is possible to prevent the recording medium from being wrapped around the static elimination roll that is more likely to have the recording medium wrapped around it.

[0022] According to the static elimination device of the third aspect of the present invention, it is possible to prevent the recording medium from being wound around the static elimination roll that is more likely to have the recording medium wound around it.

[0023] According to the static eliminator of the fourth aspect of the present invention, the recording medium adhered to the static eliminator roll can be peeled off as the static eliminator roll rotates.

[0024] According to the static eliminator of the fifth aspect of the present invention, the recording medium adhered to the static eliminator roll can be peeled off as the static eliminator roll rotates.

[0025] According to the static eliminator of the sixth aspect of the present invention, even when static electricity is eliminated from recording media of different widths, the recording media adhered to the static eliminator roll can be peeled off.

[0026] According to the static eliminator of the seventh aspect of the present invention, the peeling member can be brought into contact with the surface of the static elimination roll without providing a gap.

[0027] According to the static elimination device of the eighth aspect of the present invention, even if the tip of the peeling member adheres to the surface of the static elimination roll, it is possible to prevent the tip of the peeling member from bending and preventing the recording medium adhering to the static elimination roll from being properly peeled off.

[0028] According to the static eliminator of the ninth aspect of the present invention, it is possible to reduce the possibility that the tip of the peeling member will adhere to the surface of the static elimination roll due to the influence of discharge products generated by corona discharge.

[0029] According to the static eliminator of the tenth aspect of the present invention, the load on the mechanism for rotating the static eliminator roll can be reduced.

[0030] According to the static eliminator of the eleventh aspect of the present invention, the possibility that the tip of the peeling member will bend can be reduced.

[0031] According to the static eliminator of the twelfth aspect of the present invention, it becomes possible to easily replace the static eliminator roll.

[0032] According to the static eliminator of the thirteenth aspect of the present invention, it is possible to reduce the user's effort in inserting the static eliminator roll unit into the static eliminator body.

[0033] According to the static eliminator of the fourteenth aspect of the present invention, static elimination of the recording medium can be performed by a plurality of pairs of static elimination rolls.

[0034] According to the static elimination device of the 15th aspect of the present invention, when static elimination is performed by passing a recording medium between a static elimination means constituted by a static elimination roll and a static elimination belt, it is possible to prevent the recording medium from becoming wrapped around the static elimination roll or the static elimination belt. [Brief description of the drawings]

[0035] [Figure 1] 1 is a diagram showing a configuration of an image forming system 10 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view for explaining the appearance of the static eliminator 50 shown in FIG. [Diagram 3] 3 is a diagram for explaining the structure of the static eliminator 50 shown in FIG. 2. FIG. [Figure 4] FIG. 2 is a perspective view of a static elimination roll unit 54. [Diagram 5] 13 is a diagram showing a state in which a static elimination roll unit 54 is detached from the main body of the static eliminator 50. FIG. [Figure 6] 5 is a cross-sectional view of the static elimination roll unit 54 shown in FIG. [Figure 7] 13 is an enlarged perspective view of the peeling member 63 and its periphery. FIG. [Figure 8] 4 is a diagram for explaining details of the process of eliminating static electricity from a sheet by the static elimination roll unit 54 shown in FIG. 3. FIG. [Figure 9] 13 is a diagram showing a state in which a sheet wraps around a static elimination roll 61 when a peeling member 63 is not provided in a static elimination roll unit 54. FIG. [Figure 10] 13 is a diagram for explaining how a peeling member 63 prevents a paper sheet from wrapping around a discharging roll 61. FIG. [Figure 11] 13 is a diagram for explaining how a peeling member 63 prevents a paper sheet from wrapping around a discharging roll 61. FIG. [Figure 12] 13 is a diagram for explaining a state in which the charge eliminating rolls 61 and 62 suddenly rotate in the normal direction from a stopped state. FIG. [Figure 13] 11 is a diagram for explaining rotation control when the control unit 56 causes the static elimination rolls 61 and 62 to transition from a stopped state to a rotating state. FIG. [Figure 14] 13 is a perspective view of a static elimination roll unit 54a using one plate-shaped peeling member 64. FIG. [Figure 15] 15 is a cross-sectional view of the static elimination roll unit 54a shown in FIG. 14. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[0037] FIG. 1 is a diagram showing a system configuration of an image forming system 10 according to an embodiment of the present invention.

[0038] As shown in FIG. 1, an image forming system 10 according to one embodiment of the present invention is composed of an image forming device 20, a post-processing device 30, an interposer 40, a static elimination device 50, an inspection device 60, a stacker 70, and a post-processing device 80.

[0039] The image forming device 20 has a function of storing recording media such as printing paper and executing a process of forming an image on the stored printing paper. Note that the recording media includes not only printing paper but also films on which images can be printed. However, the following description will be given of the case where printing paper (hereinafter abbreviated to paper) is used as the recording medium.

[0040] The post-processing device 30 performs post-processing such as cooling, curl correction, inserting slip sheets or punching the paper on which an image has been formed by the image forming device 20, and conveys the paper to an interposer 40 at a downstream stage.

[0041] The interposer 40 is an interleaf inserting device that inserts a set interleaf sheet into the middle of the conveying path.

[0042] The static eliminator 50 performs static elimination to reduce the amount of charge on the charged paper. A specific structure for eliminating static electricity from the paper by the static eliminator 50 will be described later.

[0043] The inspection device 60 receives the paper on which an image has been printed from the image forming device 20 from the previous stage, and inspects the image printed on this paper, that is, judges whether or not there is an abnormality in the image printed on the paper. Specifically, the inspection device 60 receives image data of the image printed on the paper from the image forming device 20, reads the image of the paper conveyed from the image forming device 20, and compares the image of the received image data with the read image to judge whether the image printed on the conveyed paper is normal or abnormal.

[0044] When a sheet of paper on which an image has been printed by the image forming device 20 is conveyed to the stacker 70, the stacker 70 stores the sheet of paper therein.

[0045] The post-processing device 80 performs post-processing on the paper on which an image is formed by the image forming device 20. Specifically, the post-processing device 80 has at least one or more functions of a folding function, a cutting function, a bookbinding function, a binding function, a stacking function, an alignment function, a punching function, and a paper discharge function for the paper on which an image is formed by the image forming device 20. Here, the folding function is a function of performing folding processing on the paper. The cutting function is a function of cutting the top and bottom and the fore-edge of the paper formed as a booklet. The bookbinding function is also called a booklet function, and is a function of bundling multiple sheets of paper to generate a booklet. The binding function is also called a staple function, and is a function of binding multiple sheets of paper using staples. The stacking function is a function of sequentially stacking the transported paper on a tray. The alignment function is also called a tamper / jogger fence function, and is a function of aligning the width direction of the paper. The punching function is also called a punch function, and is a function of forming punch holes at predetermined positions in the paper.

[0046] Since the image forming system 10 of this embodiment is configured as described above, the paper on which an image has been printed in the image forming device 20 is transported in the following order: post-processing device 30, interposer 40, static elimination device 50, inspection device 60, stacker 70, and post-processing device 80, where various processes are performed.

[0047] Here, in the image forming device 20, a charged photoconductor is irradiated with a laser beam or the like to form an electrostatic latent image, the formed electrostatic latent image is developed with a coloring material such as toner, the developed image is transferred to paper, and then a fixing process is performed to perform printing. Therefore, the paper or the like on which an image is formed in the image forming device 20 is often charged. In particular, when a high-resistance dielectric such as a resin film is used as a recording medium, the amount of charge charged on the recording medium is likely to be large. And, if the surface of the recording medium is charged with a negative charge, for example, a positive charge is induced on the back side of the recording medium due to dielectric polarization. As a result, the recording media are attracted to each other due to electrostatic attraction, and if the recording media are to be post-processed in the post-processing device 80 while still being charged, a situation occurs in which the recording media are charged and adhere to each other due to overlapping on the paper discharge tray, or a discharge phenomenon occurs between the recording media and the human body.

[0048] Furthermore, if a recording medium such as paper that is still charged passes through the inspection device 60, noise may be generated during the inspection, which may result in erroneous inspection results.

[0049] Therefore, in the image forming system 10 of this embodiment, a static eliminator 50 for eliminating static electricity to reduce the electric charge on the recording medium is provided at the rear stage of the image forming apparatus 20.

[0050] Next, the appearance of the static eliminator 50 shown in Fig. 1 will be described with reference to the perspective view of Fig. 2. As shown in Fig. 2, the static eliminator 50 is configured to be connectable to other devices in the previous and subsequent stages, and is structured to receive paper conveyed from the device in the previous stage, perform static elimination processing, and then convey the paper to the device in the subsequent stage. Since the image forming system 10 of this embodiment is configured as shown in Fig. 1, the static eliminator 50 receives paper conveyed from the interposer 40 in the previous stage, performs static elimination processing, and then conveys the paper after static elimination to the inspection device 60 in the subsequent stage.

[0051] Next, the structure of the static eliminator 50 shown in Fig. 2 will be described with reference to Fig. 3. Fig. 3 is a see-through diagram of the inside of the static eliminator 50 shown in Fig. 2 as viewed from the front.

[0052] As shown in FIG. 3, the static eliminator 50 includes pairs of transport rolls 51 to 53, a static elimination roll unit 54, a non-contact static elimination unit 55, and a control unit 56.

[0053] The static eliminator 50 is configured to transport paper transported from a previous device to a subsequent device by transport roll pairs 51 to 53. A static eliminator unit 54 is disposed between the transport roll pair 51 and the transport roll pair 52, and a non-contact static eliminator unit 55 is disposed between the transport roll pair 52 and the transport roll pair 53.

[0054] The static elimination roll unit 54 has two static elimination rolls 61, 62 inside and functions as a contact type static eliminator that directly contacts the paper and applies an electric charge to it, thereby obtaining a relatively large amount of static elimination. However, there is a large variation in the surface potential of the paper after static elimination, and static elimination tends to be uneven.

[0055] The non-contact static electricity eliminating unit 55 is, for example, a corotron or scorotron static electricity eliminator, and has a function of eliminating electric charges without contacting the paper by, for example, using an AC voltage to cause corona discharge and supplying the generated ions to the paper. With this non-contact static electricity eliminating unit 55, it is not possible to ensure a large amount of static electricity elimination, but the variation in the surface potential after static elimination is small, making it possible to eliminate static electricity uniformly.

[0056] In the static elimination device 50 of this embodiment, two static eliminators with different characteristics, namely, static elimination roll unit 54 and non-contact static elimination unit 55, are used to eliminate static electricity from the paper transported from the previous device, and then the paper is transported to the subsequent device.

[0057] The control unit 56 controls the operations of the transport roll pairs 51 to 53, the static elimination roll unit 54, and the non-contact static elimination unit 55 to perform static elimination processing on the paper.

[0058] As described above, the static elimination roll unit 54 is provided with the two static elimination rolls 61 and 62, and the control unit 56 controls the rotation of the two static elimination rolls 61 and 62.

[0059] The paper is conveyed while being sandwiched between the two charge eliminating rolls 61, 62, and charge is eliminated. The charge eliminating roll unit 54 is configured to be detachable from the main body of the charge eliminating device 50.

[0060] Fig. 4 shows a perspective view of the static elimination roll unit 54. As shown in Fig. 4, the static elimination roll unit 54 includes two static elimination rolls 61, 62 arranged above and below in the vertical direction, and a plurality of peeling members 63 provided in contact with at least the static elimination roll 61 arranged on the lower side in the vertical direction.

[0061] The peeling members 63 are arranged in a line in the width direction of the transport path along which the paper is transported.

[0062] In this manner, the two static elimination rolls 61 and 62 and the plurality of peeling members 63 are disposed in a static elimination roll unit configured so as to be insertable into and removable from the main body of the static eliminator 50.

[0063] Fig. 5 shows how the static elimination roll unit 54 is attached to and detached from the main body of the static elimination device 50. As shown in Fig. 5, the static elimination device 50 is provided with a guide plate 57 for guiding the insertion position of the static elimination roll unit 54 when inserting the static elimination roll unit 54 into the main body of the static elimination device 50. This guide plate 57 is configured so that a portion of it protrudes from an attachment opening for attaching the static elimination roll unit 54. Therefore, when inserting the static elimination roll unit 54 into the static elimination device 50, the user can easily attach the static elimination roll unit 54 to the main body of the static elimination device 50 by placing a lower portion of the static elimination roll unit 54 on this guide plate 57.

[0064] Next, a cross-sectional view of the static elimination roll unit 54 shown in FIG. 4 is shown in FIG.

[0065] The static elimination roll unit 54 includes two static elimination rolls 61, 62 and a peeling member 63. The two static elimination rolls 61, 62 are configured to have different potential voltages applied thereto, and to reduce the amount of charge on the paper as the paper passes therethrough, thereby eliminating static electricity.

[0066] The peeling member 63 is provided in contact with the surface of one of the two charge removal rolls 61, 62, and is configured to peel off the paper adhering to the charge removal roll 61 as the charge removal roll 61 rotates.

[0067] The peeling member 63 is composed of a movable part 71, a support part 72, and a spring 73 which is an elastic body.

[0068] The support portion 72 is fixed to a housing of the static elimination roll unit 54, and movably supports the movable portion 71. The movable portion 71 is movably supported by the support portion 72, and is biased in the surface direction of the static elimination roll 61 by a spring 73. The movable portion 71 is configured to come into contact with the surface of the static elimination roll 61 by being biased in the surface direction of the static elimination roll 61 by the spring 73.

[0069] The tip of the movable part 71, which is the tip of the peeling member 63, is provided in contact with the downstream surface of the static electricity removing roll 61 in the forward rotation direction so as to form an acute angle with the surface. The peeling member 63 is disposed at a position such that the paper adhering to the surface of the static electricity removing roll 61 is peeled off as the static electricity removing roll 61 rotates.

[0070] The peeling member 63 has the above-mentioned configuration and functions to peel off the paper adhered to the charge eliminating roll 61 as the charge eliminating roll 61 rotates.

[0071] 7 shows an enlarged perspective view of the periphery of the peeling member 63. Referring to FIG. 7, it can be seen that a movable part 71 rotatably attached to a support part 72 is biased by a spring 73.

[0072] Next, details of the process of removing static electricity from a sheet by the static elimination roll unit 54 shown in Fig. 3 will be described with reference to Fig. 8. Note that in Fig. 8, only the movable part 71 of the peeling member 63 is illustrated and described in schematic form, and the peeling member 63 is not shown in its entirety.

[0073] The pair of charge removal rolls 61, 62 arranged as shown in Figure 8 are configured so that a driving force from a drive motor is transmitted to one charge removal roll 62, and the other charge removal roll 61 is brought into contact with the charge removal roll 62 so as to be driven.

[0074] A static elimination power supply is connected to the static elimination roll 62, and for example, a static elimination bias Va is applied from the static elimination power supply. In this embodiment, a positive DC voltage is used as the static elimination bias Va. The other static elimination roll 61 is grounded.

[0075] In the static electricity removing roll unit 54, a static electricity removing bias Va is applied to one of the static electricity removing rolls 62, so that the static electricity removing roll unit 54 applies a positive charge to the charged surface of the paper as the paper passes by. As a result, the non-polar negative charge on the surface of the paper is removed by the amount of charge applied to the paper. Then, as the charge on the surface of the paper decreases, the dielectrically polarized positive charge on the back surface of the paper also decreases.

[0076] 8, in the static elimination roll unit 54 of the present embodiment, power is supplied to one static elimination roll 62 of the two static elimination rolls 61, 62, and a plurality of peeling members 63 are provided in contact with at least the static elimination roll 61 on the non-power supply side. Here, a static elimination bias Va is applied to the static elimination roll 62, so that the static elimination roll 62 is a static elimination roll on the power supply side. Also, no static elimination bias Va is applied to the static elimination roll 61, so that the static elimination roll 61 is a static elimination roll on the non-power supply side.

[0077] A tip of a movable part 71 constituting a part of the peeling member 63 is disposed so as to abut against the surface of the static elimination roll 61. The peeling member 63 functions to peel off the paper adhering to the static elimination roll 61 as the static elimination roll 61 rotates.

[0078] The peeling member 63 is provided to prevent the paper from wrapping around the grounded discharge roll 61 after discharging, causing a paper jam. Figure 9 shows how the paper wraps around the discharge roll 61 when the discharge roll unit 54 does not have the peeling member 63.

[0079] 9 shows how, when static electricity is removed from the paper S, a positive charge is applied to the paper from the static electricity removal roll 62 at a positive potential to which a static electricity removal bias Va is applied, causing the paper S to become charged, and the potential difference between the paper S and the static electricity removal roll 61 on the ground side, which serves as the counter electrode, becomes large, causing the paper S to wrap around the static electricity removal roll 61. Note that such wrapping around the static electricity removal roll 61 is likely to occur when static electricity is removed from so-called weak paper, such as thin paper.

[0080] If the sheet S wraps around the static elimination roll 61 in this way, the sheet S after static elimination will not reach the transport roll pair 52, causing a sheet jam.

[0081] Next, how the peeling member 63 prevents the paper from wrapping around the charge removing roll 61 will be described with reference to FIGS.

[0082] 10, when the peeling member 63 is provided, a tip portion of a movable portion 71 of the peeling member 63 is in direct contact with the surface of the static elimination roll 61. The tip portion of the movable portion 71 is disposed so as to form an acute angle with the downstream surface of the static elimination roll 61. Therefore, even if the paper S adheres to the static elimination roll 61 after passing between the two static elimination rolls 61 and 62 as shown in FIG. 10, the tip portion of the paper S is separated from the surface of the static elimination roll 61 by the movable portion 71.

[0083] As a result, the paper S reaches the transport roll pair 52 normally, as shown in FIG. 11, and is transported to a downstream device without causing a paper jam.

[0084] Next, a description will be given of the rotation control of the static elimination rolls 61, 62. As described above, in the static elimination device 50, the rotation control of the static elimination rolls 61, 62 is performed by the control unit 56 shown in FIG.

[0085] Then, before performing a forward rotation operation in which the two charge removal rolls 61, 62 are rotated in the forward direction in which the paper passes between the two charge removal rolls 61, 62 and is transported to the subsequent stage, the control unit 56 performs a reverse operation in which the charge removal roll 61, on which the peeling member 63 is provided, is rotated in a reverse direction that is opposite to the forward rotation direction.

[0086] The control unit 56 controls the neutralization roll 61 to perform the reverse rotation operation not only when the print process for the paper starts, but also after the print process for the paper based on one print job, which is a print instruction, is completed.

[0087] At this time, the control unit 56 controls the charge removing roller 61 so that after the charge removing roller 61 has performed the reverse rotation operation, the operation of the charge removing roller 61 is temporarily stopped, and then the charge removing roller 61 is rotated in the normal direction.

[0088] Furthermore, when the charge removal roller 61 rotates in the forward direction after the reverse direction, the control unit 56 controls the rotation speed of the charge removal roller 61 during the forward direction to gradually increase until the rotation speed reaches a steady state.

[0089] The reason why the control unit 56 does not rotate the two charge eliminating rolls 61 and 62 in the normal direction from a stopped state when eliminating static electricity from the paper will be described with reference to FIG.

[0090] FIG. 12 shows a state in which the charge eliminating rolls 61 and 62 suddenly rotate in the normal direction from a stopped state.

[0091] In the static eliminator 50 of this embodiment, the tip of the movable part 71 constituting the peeling member 63 is in contact with the static eliminator roll 61 while being biased in the direction of the surface of the static eliminator roll 61. Therefore, if printing is not performed for a long period of time in the image forming system 10, the tip of the movable part 71 continues to be in contact with the surface of the static eliminator roll 61. In addition, the static eliminator 50 may generate discharge products such as nitrogen oxides due to corona discharge.

[0092] If the tip of the movable part 71 continues to be in contact with the surface of the de-ionization roll 61 for a long period of time in the presence of such discharge products, the tip of the movable part 71, which is part of the peeling member 63, may adhere (or become fixed) to the surface of the de-ionization roll 61 due to the influence of the discharge products.

[0093] Fig. 12(A) shows how the tip of the movable part 71 is stuck to the surface of the static elimination roll 61. Referring to Fig. 12(A), it can be seen that the tip of the movable part 71 biased by the spring 73 is stuck to the surface of the static elimination roll 61. In Fig. 12, for ease of understanding, a mark is provided at the position on the surface of the static elimination roll 61 where the movable part 71 is stuck.

[0094] Fig. 12(B) shows the state when the static elimination rolls 61, 62 are rotated in the forward direction in this state. In Fig. 12(B), it can be seen that the tip of the movable part 71 is bent because the static elimination roll 61 rotates in the forward direction with the tip of the movable part 71 still attached to the surface of the static elimination roll 61. If static elimination processing is performed with the tip of the movable part 71 in this bent state, the peeling member 63 will not function normally and paper jams will occur.

[0095] Therefore, in the static eliminator 50 of this embodiment, when the static eliminator rolls 61, 62 are shifted from a stopped state to a rotating state, the control unit 56 controls the rotation by a method as shown in FIG.

[0096] First, when the control unit 56 tries to rotate the two static electricity removing rolls 61, 62 that are in a stopped state as shown in Fig. 13(A), it rotates them in the reverse direction opposite to the forward rotation direction as shown in Fig. 13(B). Then, the binding between the movable part 71 and the surface of the static electricity removing roll 61 is released. After that, the control unit 56 rotates the static electricity removing rolls 61, 62 in the forward rotation direction that was originally intended. Then, as shown in Fig. 13(C), the tip of the movable part 71 is maintained in normal contact with the surface of the static electricity removing roll 61 without being bent.

[0097] In this way, the control unit 56 controls the two charge removal rolls 61, 62 to rotate in the forward direction, after performing a reversing operation to rotate them in a reverse direction opposite to the forward rotation direction, and then rotate them in the forward rotation direction.

[0098] Here, in the de-electrification roll unit 54 described above, a configuration is provided in which a plurality of peeling members 63 each consisting of a movable portion 71 and a support portion 72 are provided, but the peeling members can also be configured using other structures.

[0099] For example, Fig. 14 shows a static elimination roll unit 54a using one plate-shaped peeling member 64. The peeling member 64 shown in Fig. 14 is made of, for example, a Mylar film, and is arranged so that its tip portion comes into contact with the surface of the static elimination roll 61, similar to the peeling member 63.

[0100] A cross-sectional view of the static elimination roll unit 54a shown in Fig. 14 is shown in Fig. 15. Referring to Fig. 15, it can be seen that the plate-shaped peeling member 64 is disposed with respect to the static elimination roll 61 at an angle so as to peel off the paper being conveyed thereto. The plate-shaped peeling member 64 also peels off the paper adhering to the surface of the static elimination roll 61, similar to the peeling member 63 described above.

[0101] In addition, in the present embodiment, the static elimination device 50 has been described using a single static elimination roll pair consisting of two static elimination rolls 61, 62, but multiple such static elimination roll pairs may be provided within the static elimination device 50.

[0102] In addition, in the static eliminator 50 of this embodiment, a configuration in which the static elimination of paper is performed by a static elimination roll pair consisting of two static elimination rolls 61 and 62 has been described, but the present invention is not limited to such a configuration. For example, the present invention can be similarly applied to a static elimination device having a static elimination roll and a static elimination belt to which voltages of different potentials are applied and which reduce the amount of charge on the paper by passing the paper through them to eliminate static electricity. In this case, a peeling member may be provided in contact with the surface of one of the static elimination roll and the static elimination belt, and the paper attached to the static elimination roll or the static elimination belt may be peeled off as the static elimination roll or the static elimination belt rotates. [Explanation of symbols]

[0103] 10. Image forming system 20 Image forming device 30 Aftertreatment device 40 Interposer 50 Static eliminator 51~53 Transport roll pair 54, 54a Static electricity removal roll unit 55 Non-contact static elimination unit 56 Control section 57 Information Board 60 Inspection Equipment 61, 62 Antistatic roll 63 Peeling member 64 Peeling member 70 Stacker 71 Moving parts 72 Support part 73 Spring 80 Aftertreatment device

Claims

1. Two static elimination rolls to which voltages of different potentials are applied, and which reduce and eliminate the charge on a recording medium as the recording medium passes through the static elimination rolls; a peeling member provided in contact with a surface of one of the two static elimination rolls and configured to peel off the recording medium attached to the static elimination roll as the static elimination roll rotates; A static elimination device comprising:

2. 2. The static elimination device according to claim 1, wherein the two static elimination rolls are disposed vertically above and below each other, and the peeling member is provided so as to abut at least against the static elimination roll disposed on the lower side in the vertical direction.

3. 2. The static elimination device according to claim 1, wherein power is supplied to one of the two static elimination rolls, and the peeling member is provided in contact with at least the static elimination roll on the non-power supply side.

4. 4. The static eliminator according to claim 1, wherein a tip of the peeling member is in contact with a surface of the static elimination roll on a downstream side in a forward rotation direction of the static elimination roll such that an acute angle is formed between the tip of the peeling member and a surface of the static elimination roll on a downstream side in a forward rotation direction of the static elimination roll.

5. 4. The static eliminator according to claim 1, wherein the peeling member is disposed at a position such that the recording medium adhering to the surface of the static eliminator roll is peeled off as the static eliminator roll rotates.

6. The static eliminator according to claim 1 , wherein a plurality of the peeling members are provided in a width direction of a transport path along which the recording medium is transported.

7. 7. The static eliminator according to claim 1, wherein the peeling member is configured to be biased in a surface direction of the static elimination roll by an elastic member so as to come into contact with the surface of the static elimination roll.

8. A control unit for controlling the rotation of the two static elimination rolls is further provided. The control unit performs a reverse operation to rotate the discharge roll provided with the peeling member in a reverse direction opposite to the forward rotation direction before performing a forward rotation operation to rotate the two discharge rolls in a forward rotation direction in which the recording medium passes between the two discharge rolls and is transported to a subsequent stage.

9. The static elimination device according to claim 8 , wherein the control unit controls the static elimination roll to perform a reverse rotation operation not only when a printing process for a recording medium starts, but also after a printing process for a recording medium is completed based on one printing instruction.

10. The static eliminator according to claim 8 or 9, wherein the control unit controls the static eliminator roll so that, after performing the reverse rotation operation of the static eliminator roll, the operation of the static eliminator roll is stopped and then the static eliminator roll is rotated in the normal direction.

11. The static elimination device according to claim 8 or 9, wherein the control unit controls the rotation speed of the static elimination roll during the forward rotation operation to gradually increase until the rotation reaches a steady state when the static elimination roll performs a reverse rotation operation and then a forward rotation operation.

12. The static eliminator according to claim 1 , wherein the two static eliminator rolls and the peeling member are disposed in a static eliminator roll unit configured so as to be insertable into and removable from a static eliminator body.

13. The static eliminator according to claim 12 , further comprising a guide plate for guiding an insertion position of the static eliminator roll unit when the static eliminator roll unit is inserted into the static eliminator body.

14. An electrostatic elimination device described in any one of claims 1 to 13, wherein a plurality of electrostatic elimination roll pairs each consisting of the two electrostatic elimination rolls are provided.

15. a static elimination roll and a static elimination belt to which voltages of different potentials are applied, and which reduce and eliminate the charge on a recording medium as the recording medium passes through the static elimination roll and the static elimination belt; a peeling member provided in contact with a surface of one of the static elimination roll and the static elimination belt, and peeling off a recording medium attached to the static elimination roll or the static elimination belt as the static elimination roll rotates or the static elimination belt turns; A static elimination device comprising:

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