Static elimination device and image forming system, charge adjustment device

Abstract

This improves usability when configuring settings related to static electricity removal and charge adjustment for the sheet. [Solution] The static elimination device 300 includes a thumb rotary switch 54a for setting the voltage applied to the static elimination roller 51b. The image forming apparatus 100 includes a static elimination level button 157 for setting the voltage applied to the static elimination roller 51b. The mode setting unit 153 can select between a first mode in which the setting on the thumb rotary switch 54a is applied as the voltage applied to the static elimination roller 51b, and a second mode in which the setting on the static elimination level button 157 is applied as the voltage applied to the static elimination roller 51b.

Description

Technical Field

[0001] The present invention relates to a static eliminator for eliminating static electricity from a sheet, an image forming apparatus including the same, and a charge adjusting device for adjusting the charge of the sheet.

Background Art

[0002] In an image forming apparatus, during image formation, a sheet may be charged, and the sheets may stick to each other due to the electrostatic force generated between the discharged sheets, resulting in a stacking defect. Therefore, in Patent Document 1, an image forming apparatus including a static eliminator for eliminating static electricity from a sheet has been proposed. The static eliminator described in Patent Document 1 includes a switch for switching ON / OFF of static elimination by a static elimination roller.

[0003] Also, as a device for suppressing the sticking of sheets to each other, in Patent Document 2, a charge adjusting device has been proposed that applies a voltage every other sheet being conveyed and charges the sheets so that the surfaces of the stacked sheets have the same polarity.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, various settings related to printing are often made using the control panel located on the image forming apparatus itself. Therefore, it is desirable that settings related to static elimination and charge adjustment can also be set from the control panel located on the image forming apparatus itself. However, in an image forming system, if settings related to static elimination and charge adjustment can be made using both the control panel on the image forming apparatus itself and the control panel on the static elimination device, there is a possibility that the settings in these multiple control panels will not match. In such cases, it can lead to user confusion and a decrease in usability.

[0006] Therefore, the present invention aims to improve usability when setting up static discharge and charge adjustment for sheets. [Means for solving the problem]

[0007] One aspect of the present invention is an image forming system comprising: an image forming apparatus for forming an image on a sheet; and a static elimination device having a static elimination member for eliminating static electricity from the sheet on which the image formed by the image forming apparatus, wherein the static elimination device has a first setting means for setting a voltage applied to the static elimination member; the image forming apparatus has a second setting means for setting a voltage applied to the static elimination member; and a third setting means for selecting a first mode in which the setting in the first setting means is applied as the voltage applied to the static elimination member; and a second mode in which the setting in the second setting means is applied as the voltage applied to the static elimination member.

[0008] Another aspect of the present invention is a static elimination device connected to an image forming apparatus that forms an image on a sheet, characterized by comprising: a static elimination member for eliminating static electricity from a sheet on which an image has been formed by the image forming apparatus; and a third setting means for selecting a first mode in which a setting in a first setting means of the static elimination device is applied as the voltage applied to the static elimination member; and a second mode in which a setting in a second setting means of the image forming apparatus is applied as the voltage applied to the static elimination member.

[0009] Another aspect of the present invention is a charge adjustment device connected to an image forming apparatus that forms an image on a sheet, characterized in that it comprises: a charge supply member that supplies charge to a sheet on which an image has been formed by the image forming apparatus; and a third setting means for selecting a first mode in which a setting in a first setting means of the charge adjustment device is applied as the voltage applied to the charge supply member; and a second mode in which a setting in a second setting means of the image forming apparatus is applied as the voltage applied to the charge supply member. [Effects of the Invention]

[0010] According to the present invention, it is possible to improve usability when making settings related to static discharge and charge adjustment of the sheet. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view of an image forming system. [Figure 2] This is the copy settings screen on the control panel of an image forming apparatus. [Figure 3] This is a schematic cross-sectional view of the static elimination device. [Figure 4] This is the control panel for the static elimination device. [Figure 5] This is the static elimination setting screen on the control panel of an image forming apparatus. [Figure 6] This is a block diagram of an image forming system. [Figure 7] This is a flowchart of the CPU of the image forming apparatus according to the first embodiment. [Figure 8] This is a flowchart of the CPU of the static elimination device according to the first embodiment. [Figure 9] This is a modified example of the control panel for an anti-static device. [Figure 10] This is a flowchart of the CPU of the image forming apparatus according to the second embodiment. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings.

[0013] [First Embodiment] FIG. 1 shows a schematic diagram of an image forming system 400 according to the first embodiment. The image forming system 400 includes an image forming apparatus 100 (image forming apparatus main body, printer) and a static eliminator 300 connected to the image forming apparatus 100. The image forming system 400 forms an image on a sheet S and discharges it as a product. The sheet S, which is a recording material (recording medium), can use various sheet materials of different sizes and materials, such as paper like plain paper and thick paper, sheet materials with surface treatment like coated paper, sheet materials with special shapes like envelopes and index paper, plastic sheet materials, cloth, etc. Examples of plastic sheet materials are synthetic paper mainly made of synthetic resin and sheets for overhead projectors (OHT).

[0014] The static eliminator 300 is a device (static eliminator) having a static elimination function for removing (reducing) the charge of the sheet S discharged from the image forming system 400. The static eliminator 300 can also be said to be a charge adjustment device for adjusting the charged state of the sheet S discharged from the image forming system 400. The static eliminator 300 may have functions other than the static elimination function (for example, a decurler function for correcting the curl of the sheet S). In addition, the static eliminator 300 of the present embodiment is arranged as an independent device connected to the image forming apparatus 100.

[0015] The image forming system 400 may include optional devices other than the static eliminator 300. Examples of optional devices are a high-capacity feeder (optional feeder) for supplying the sheet S to the image forming apparatus 100, and a sheet processing apparatus (finisher) for performing processing such as binding on the sheet S on which an image is formed by the image forming apparatus 100. Also, another device such as an inserter may be connected between the image forming apparatus 100 and the static eliminator 300. In such a case, the devices upstream of the static eliminator 300 can be collectively interpreted as an image forming apparatus.

[0016] <Image Forming Apparatus> The configuration of the image forming apparatus 100 will be described with reference to FIG. 1. The image forming apparatus 100 includes an image forming unit 101 which is an intermediate transfer type electrophotographic mechanism. The image forming unit 101 includes four process units 11Y, 11M, 11C, and 11K each having a photosensitive drum 1Y, 1M, 1C, 1K, respectively, and a transfer unit 15 having an intermediate transfer belt 6 and a secondary transfer roller 9.

[0017] Each process unit includes a photosensitive drum as an image carrier (latent image carrier), and a charging device, an exposure device, and a developing device as process parts that act on the photosensitive drum to perform each step of the electrophotographic process. That is, the process unit 11Y includes the photosensitive drum 1Y, the charging device 2Y, the exposure device 3Y, and the developing device 4Y. The process unit 11M includes the photosensitive drum 1M, the charging device 2M, the exposure device 3M, and the developing device 4M. The process unit 11C includes the photosensitive drum 1C, the charging device 2C, the exposure device 3C, and the developing device 4C. The process unit 11K includes the photosensitive drum 1K, the charging device 2K, the exposure device 3K, and the developing device 4K.

[0018] Each of the photosensitive drums 1Y, 1M, 1C, 1K is rotationally driven in a predetermined rotation direction A. The process units 11Y, 11M, 11C, 11K have substantially the same configuration except that the toners as developers accommodated in the developing devices 4Y, 4M, 4C, 4K are different.

[0019] The transfer unit 15 includes an intermediate transfer belt 6 as an intermediate transfer body, a secondary transfer roller 9 as a transfer means (secondary transfer means), primary transfer rollers 5Y, 5M, 5C, 5K, a plurality of rollers 20, 21, 22, 23, 24, 25, and a belt cleaner 12. The intermediate transfer belt 6 is stretched over the plurality of rollers 20, 21, 22, 23, 24, 25. The primary transfer rollers 5Y, 5M, 5C, 5K are positioned on the inner surface side of the intermediate transfer belt 6 and corresponding to the photosensitive drums 1Y, 1M, 1C, 1K. A primary transfer section is formed between the primary transfer rollers 5Y, 5M, 5C, 5K and the corresponding photosensitive drums 1Y, 1M, 1C. Roller 20 is a tension roller that applies appropriate tension to the intermediate transfer belt 6. Roller 22 is a drive roller that rotates the intermediate transfer belt 6 in a predetermined rotational direction G. The secondary transfer roller 9 is in contact with the outer surface of the intermediate transfer belt 6 and is positioned to sandwich the intermediate transfer belt 6 together with the opposing roller 21 (secondary transfer opposing roller). A secondary transfer section T2 is formed as a nip between the secondary transfer roller 9 and the intermediate transfer belt 6, which is the transfer section on which the toner image is transferred to the sheet S.

[0020] The image forming apparatus 100 is equipped with a transfer power supply 10 as a voltage application means for forming a bias electric field for transferring a toner image to the secondary transfer section T2. ​​In this embodiment, the secondary transfer roller 9, which is the outer roller of the secondary transfer section T2, is electrically connected to the transfer power supply 10, and a predetermined transfer voltage is applied from the transfer power supply 10. The transfer voltage is a voltage with the opposite polarity to the normal charging polarity of the toner used for image formation. On the other hand, the opposing roller 21, which is the inner roller of the secondary transfer section T2, is electrically connected to the ground potential (metal frame, etc.) of the image forming apparatus 100. Alternatively, the inner roller of the secondary transfer section T2 may be connected to the transfer power supply 10, and the outer roller of the secondary transfer section T2 may be connected to the ground potential GND. In this case, a transfer voltage with the same polarity as the normal charging polarity of the toner is applied to the inner roller.

[0021] The image forming apparatus 100 further includes a storage section 63 (storage compartment, cassette) for storing the sheet S, a feeding unit 64 for feeding the sheet S, and a registration roller 8 for registering (aligning) the sheet S. The image forming apparatus 100 also includes a pre-fixing transport device 41 for transporting the sheet S after it has passed through the secondary transfer section T2, a fixing device 40 for fixing a toner image onto the sheet S, and a pair of discharge rollers 42 as a discharge unit for discharging the sheet S to the outside of the image forming apparatus 100.

[0022] The feeding unit 64 includes, for example, a pickup roller 65 that feeds the uppermost sheet S from the storage section 63 in the sheet feeding direction, and a pair of separation rollers 66 that separates and transports the fed sheets S one by one. The pair of separation rollers includes a transport roller that feeds the uppermost sheet S in the sheet feeding direction, and a separation roller that contacts the transport roller and forms a separation nip together with the transport roller. The separation roller prevents double feeding of sheets S by applying frictional force to the sheets S at the separation nip, thereby preventing sheets S other than the uppermost sheet S from passing through the separation nip. The separation roller is an example of a separation member that separates the sheets S, and for example, a pad-shaped elastic member (rubber pad) may be used as the separation member.

[0023] The fixing device 40 is a thermal fixing device that has a fixing nip and heats the toner image on the sheet S while gripping and transporting the sheet S with the fixing nip. The fixing device 40 has a heating member that contacts the surface of the sheet S on which the toner image is formed, a pressurizing member that forms a fixing nip together with the heating member, and a heat source that heats the heating member. The heating member and the pressurizing member can be, for example, a belt member stretched over a plurality of rollers, or a rigid roller member. The heat source can be, for example, a halogen lamp or an IH induction heating mechanism.

[0024] Furthermore, the image forming apparatus 100 is equipped with an operation panel 102 (operation unit), which is the user interface of the image forming system 400. The operation panel 102 includes a display unit 103, which is a resistive touch panel that displays information to the user and accepts user input. By operating the operation panel 102, the user can set setting information and execution conditions for image forming operations for the image forming system 400. The setting information is, for example, attribute information such as the size, material, and brand of the sheet S stored in the storage unit 63. The execution conditions for image forming operations are, for example, the value of the transfer voltage.

[0025] Figure 2 shows the copy settings screen displayed on the display unit 103 of the operation panel 102. To configure settings related to static elimination by the static elimination device 300, the user presses the static elimination setting button 151. When the static elimination setting button 151 is pressed, the display unit 103 transitions from the copy settings screen to the static elimination settings screen, which will be described later. The display unit 103 also displays a status line 152, which displays messages related to information that should be notified to the user. The status line 152 is an area where the displayed content is retained and continues to be displayed even when the display screen transitions. In the example in Figure 2, the message "The paper is running low." is displayed to notify the user that the paper in the storage unit 63 is running low. The user can understand the status of the image forming system 400 by checking the status line 152.

[0026] When a user inputs an instruction to perform image formation, the control unit of the image forming apparatus 100 starts an image formation job, which is a series of tasks that transport sheets S one by one, form images, and output the resulting product. Hereinafter, the series of operations by the image forming apparatus 100 in which an image is formed on one sheet S will be referred to as the image formation operation. The image formation job includes an image formation operation on at least one sheet S.

[0027] In the image formation operation, toner images of each color are created in process units 11Y, 11M, 11C, and 11K. Specifically, the photosensitive drums 1Y, 1M, 1C, and 1K are rotated, and the charging devices 2Y, 2M, 2C, and 2K uniformly charge the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1K. The exposure devices 3Y, 3M, 3C, and 3K expose the photosensitive drums 1Y, 1M, 1C, and 1K based on the image information input along with the execution instruction, forming an electrostatic latent image on the surface of the photosensitive drums 1Y, 1M, 1C, and 1K. The developing devices 4Y, 4M, 4C, and 4K supply yellow, magenta, cyan, and black toners, respectively, to the photosensitive drums 1Y, 1M, 1C, and 1K, and develop the electrostatic latent image into toner images of each color.

[0028] In this embodiment, an inverted development method is used. Specifically, the charging device charges the surface of the photosensitive drum to the same polarity as the normal charging polarity of the toner. Then, the potential of the exposed area, which has been exposed by the exposure device, decreases, and toner adheres to the exposed area during development.

[0029] The toner images created in each process unit 11Y, 11M, 11C, and 11K are first transferred from the photosensitive drums 1Y, 1M, 1C, and 1K to the intermediate transfer belt 6 in the primary transfer section. A transfer voltage with the opposite polarity to the normal charging polarity of the toner is applied to the primary transfer rollers 5Y, 5M, 5C, and 5K by constant voltage control.

[0030] In this embodiment, the primary transfer rollers 5Y, 5M, 5C, and 5K are conductive rollers having a core metal and a conductive elastic layer formed on the outer circumference of the core metal. The elastic layer is formed of, for example, ion-conductive foamed rubber. Ion-conductive foamed rubber is a foamed rubber material in which a conductive agent that exhibits ion conductivity is dispersed. The conductive agent and foamed rubber material can be materials known as transfer roller materials. Each primary transfer roller can preferably have, for example, an outer diameter of 15 to 20 mm and a resistance value of 1E+5 to 1E+8 Ω when a voltage of 2 kV is applied under environmental conditions of 23°C and 50% RH.

[0031] The intermediate transfer belt 6 is driven to rotate at a predetermined peripheral speed (process speed) equal to the peripheral speed of the photosensitive drums 1Y, 1M, 1C, and 1K. In this embodiment, the peripheral speed is 150 to 470 mm / sec. As the intermediate transfer belt 6 rotates, toner images of other colors are transferred on top of the toner image transferred in the upstream primary transfer section, thereby forming a full-color toner image on the intermediate transfer belt 6. The full-color toner image is carried on the intermediate transfer belt 6 and transported toward the secondary transfer section T2.

[0032] In parallel with the creation of the toner image in the image forming unit 101, the feeding unit 64 feeds sheets S one by one to the image forming unit 101. The fed sheets S are transported to the secondary transfer unit T2 by the registration roller 8 in synchronization with the timing at which the toner image on the intermediate transfer belt 6 is transported to the secondary transfer unit T2. Then, in the secondary transfer unit T2, the toner image is transferred (secondary transfer) from the intermediate transfer belt 6 to the sheets S.

[0033] In this embodiment, the secondary transfer roller 9 is a conductive roller having a core metal and a conductive elastic layer formed on the outer circumference of the core metal. The elastic layer is formed of, for example, ion-conductive foamed rubber. Ion-conductive foamed rubber is a foamed rubber material in which a conductive agent that exhibits ion conductivity is dispersed. The conductive agent and foamed rubber material can be materials known as transfer roller materials. The secondary transfer roller 9 can preferably have an outer diameter of 20 to 25 mm and a resistance value of 1E+5 to 1E+8 Ω when a voltage of 2 kV is applied under environmental conditions of 23°C and 50% RH.

[0034] Furthermore, the opposing roller 21 is a conductive rubber roller having a core metal and an elastic layer of electronically conductive foamed rubber formed on the outer circumference of the core metal. Electronically conductive foamed rubber is a foamed rubber material in which a conductive agent that exhibits electronic conductivity is dispersed. The conductive agent and foamed rubber material can be materials known as those used for transfer rollers. For example, the opposing roller 21 can preferably have an outer diameter of 20 to 22 mm and a resistance value of 1E+5 to 1E+8 Ω when a voltage of 50 V is applied under environmental conditions of 23°C and 50% RH.

[0035] During secondary transfer, a transfer voltage with the opposite polarity to the toner's normal charging polarity is applied to the secondary transfer roller 9 from the transfer power supply 10 via constant voltage control. The transfer voltage is, for example, +1 to +7 kV and is automatically adjusted so that a current of +40 to +120 μA flows from the secondary transfer roller 9 to the opposing roller 21. The application of the transfer voltage creates a bias electric field in the secondary transfer section T2, where the potential of the secondary transfer roller 9 is opposite to the toner's normal charging polarity relative to the intermediate transfer belt 6. This bias electric field causes an electrostatic force to act on the toner on the intermediate transfer belt 6, moving it towards the secondary transfer roller 9. As a result, the toner is transferred from the intermediate transfer belt 6 to the sheet S as it passes through the secondary transfer section T2, and a toner image is transferred to the sheet S.

[0036] Furthermore, a transport guide 11 is provided immediately before the secondary transfer section T2 to improve the positional accuracy of the sheet S relative to the intermediate transfer belt 6. In addition, any remaining toner on the intermediate transfer belt 6 that is not transferred to the sheet S is collected by the belt cleaner 12 and reused for image formation.

[0037] The sheet S, having passed through the secondary transfer section T2, is transported to the fuser 40 by the pre-fixing transport device 41, where it undergoes toner image fixing treatment by the fuser 40. Fixing treatment is a process in which the toner image on the sheet S is heated and pressurized while the sheet S is being transported while being held between the nip sections of the fuser 40. The pre-fixing transport device 41 transports the sheet S by supporting it on an endless rubber belt, for example. The rubber belt can be made of ethylene propylene diene rubber (EPDM) with a width of 100 to 110 mm and a thickness of 1 to 3 mm. The rubber belt also has holes with a diameter of 3 to 7 mm, and by generating negative pressure inside the rubber belt using a fan, the sheet S can be stably supported on the rubber belt.

[0038] The sheet S that has passed through the fixing device 40 is discharged toward the static elimination device 300 by the discharge roller pair 42.

[0039] The intermediate transfer type image forming unit 101 described above is an example of an image forming means for forming an image on the sheet S, and the image forming means may be, for example, a direct transfer type electrophotographic unit. In this case, the toner image formed on the photosensitive drum, which acts as an image carrier, is directly transferred from the photosensitive drum to the sheet S at the transfer nip (transfer section) where the photosensitive drum and the transfer roller face each other. At the transfer nip, a bias electric field is formed in which the potential of the transfer roller is opposite to the normal charging polarity of the toner relative to the photosensitive drum.

[0040] <Static eliminator> Figure 2 is a schematic diagram of the static elimination device 300 in this embodiment. The static elimination device 300 comprises a pair of static elimination rollers 51 as a contact-type static eliminator, an ionizer unit 52 as a non-contact-type static eliminator, and a high-voltage substrate 55 (high-voltage power supply).

[0041] The static elimination roller pair 51 includes a static elimination opposing roller 51a that contacts the first surface Sa of the sheet S, and a static elimination roller 51b that contacts the second surface Sb of the sheet S opposite to the first surface Sa. The static elimination roller 51b is a contact-type static elimination member that contacts the conveyed sheet S and eliminates static electricity from the sheet S. The static elimination opposing roller 51a is in contact with the static elimination roller 51b, and a static elimination nip is formed as a nip portion between the static elimination roller 51b and the static elimination opposing roller 51a. The static elimination roller pair 51 eliminates static electricity from the sheet S while conveying it in the sheet conveying direction Cv by gripping the sheet S with the static elimination nip.

[0042] The static elimination opposing roller 51a is connected to the ground potential GND. The static elimination opposing roller 51a is electrically connected, for example, to the metal frame of the static elimination device 300. The static elimination roller 51b is connected to the high-voltage substrate 55. The high-voltage substrate 55 is a voltage applying means that applies a voltage (static elimination voltage) to the static elimination roller 51b for static elimination of the sheet S.

[0043] Furthermore, the static elimination roller 51b may be arranged to contact the first surface Sa of the sheet S, and the static elimination opposing roller 51a may be arranged to contact the second surface Sb of the sheet S. In that case, the voltage applied to the static elimination roller 51b will have the opposite polarity to the voltage applied to the static elimination roller 51b in this embodiment.

[0044] In this embodiment, the static elimination roller 51b is a conductive roller having a core metal and a conductive elastic layer formed on the outer circumference of the core metal. The elastic layer is formed of, for example, ion-conductive foamed rubber. Ion-conductive foamed rubber is a foamed rubber material in which a conductive agent that exhibits ion conductivity is dispersed. Known materials can be used for the conductive agent and the foamed rubber material. The static elimination roller 51b can preferably be one with an outer diameter of 20 to 25 mm and a resistance value of 1E+5 to 1E+8 Ω when a voltage of 2 kV is applied under environmental conditions of 23°C and 50% RH. The static elimination opposing roller 51a is made of stainless steel (SUS) and is a roller with an outer diameter of 20 to 25 mm. Note that the static elimination roller 51b may be a roller made of a metal material such as stainless steel.

[0045] The ionizer unit 52 includes a first ionizer 52a facing the first surface of the sheet S and a second ionizer 52b facing the second surface of the sheet S. The ionizer unit 52 is a non-contact static elimination unit positioned downstream of the static elimination roller pair 51 in the sheet transport direction Cv. Each of the first ionizer 52a and the second ionizer 52b has an electrode needle, and by applying a voltage to the electrode needle, a corona discharge is generated from the needle tip, ionizing the air around the needle tip. The generated ions then neutralize the charge on the surface of the sheet S, thereby eliminating static electricity from the sheet S.

[0046] In this embodiment, the ionizer section 52 has a first ionizer 52a and a second ionizer 52b arranged above and below the sheet transport path. The transport guides 53a and 53b that form the sheet transport path of the ionizer section 52 are made of a resin synthesized from, for example, PC (polycarbonate) and ABS (acrylonitrile-butadiene-styrene). The volume resistivity of the transport guides 53a and 53b is, for example, 1 × 10¹⁴ Ω·cm. Furthermore, as shown in Figure 3, each of the transport guides 53a and 53b has multiple holes formed in it to prevent ions emitted from the first ionizer 52a and the second ionizer 52b from being physically shielded.

[0047] The first ionizer 52a and the second ionizer 52b described above are examples of non-contact type static eliminators, and other non-contact type static eliminators may be used. For example, a Corotron type or Scorotron type static eliminator that eliminates static electricity from the sheet by corona discharge from a discharge wire may be used. Furthermore, non-contact type static eliminators do not necessarily need to be provided on both sides of the transport path; for example, the static elimination device 300 may have only the first ionizer 52a as a non-contact type static eliminator. Also, if the sheet S can be sufficiently eliminated by the static elimination roller 51b, the non-contact type static eliminator may be omitted.

[0048] The sheet S, which has been transported from the image forming apparatus 100 to the static elimination device 300, first has most of its charge removed (roughly removed) by the static elimination nip of the static elimination roller pair 51. Specifically, the static elimination voltage is set to have the opposite polarity to the transfer voltage applied to the secondary transfer roller 9. The value of the static elimination voltage is set in the range of -1kV to -6kV.

[0049] Immediately after passing through the secondary transfer section T2 (Figure 1), the first surface Sa of the sheet S, which was in contact with the intermediate transfer belt 6, is normally negatively charged, and the second surface Sb, which was in contact with the secondary transfer roller 9, is positively charged. When a static elimination voltage opposite to the transfer voltage is applied to the static elimination roller 51b, a current flows between the static elimination roller 51b and the static elimination opposing roller 51a, supplying positive charge to the first surface Sa and the second surface Sb of the sheet S. In this way, by applying a static elimination voltage to the static elimination roller 51b, a current flows through the sheet S in the static elimination nip, reducing the amount of charge carried on the first surface Sa and the second surface Sb of the sheet S.

[0050] The sheet S, having passed through the static elimination roller pair 51, is further statically removed in the ionizer section 52. Specifically, the ions irradiated from the first ionizer 52a and the second ionizer 52b neutralize the residual charge on the first surface Sa and the second surface Sb of the sheet S, further reducing the amount of charge on the sheet S. The sheet S, having passed through the ionizer section 52, is discharged to the outside of the static elimination device 300 by the discharge roller pair 56 and loaded onto the discharge tray 57.

[0051] <Static elimination settings via the control panel of the static elimination device> The static elimination device 300 has an operating unit 54 for setting the magnitude of the voltage applied to the static elimination roller 51b. Figure 4 shows the operating unit 54. The operating unit 54 has a thumb rotary switch 54a and a selector switch 54b, which are hardware keys. Hereinafter, settings related to static elimination, such as the static elimination level, which indicates the value of the voltage applied to the static elimination roller 51b by the high-voltage circuit board 55, and the ON / OFF setting of voltage application to the static elimination roller 51b, will be referred to as "static elimination settings".

[0052] The thumb rotary switch 54a is a switch for manually setting the voltage value applied to the static elimination roller 51b by the high-voltage circuit board 55. The thumb rotary switch 54a displays a static elimination level, which is a numerical value corresponding to the voltage applied to the static elimination roller 51b. The higher the static elimination level, the higher the voltage applied to the static elimination roller 51b. The user can change the static elimination level by operating the thumb rotary switch 54a. The thumb rotary switch 54a is an example of a first setting means for setting the static elimination voltage, which is located in the static elimination device 300.

[0053] The selector switch 54b is a switch for manually switching the voltage application to the static elimination roller 51b between "ON" and "OFF". When the selector switch 54b is "ON", a voltage corresponding to the set static elimination level is applied to the static elimination roller 51b, and when the selector switch 54b is "OFF", no voltage is applied to the static elimination roller 51b. By operating the selector switch 54b, the user can switch static elimination ON / OFF without changing the setting (static elimination level) of the thumb rotary switch 54a. The selector switch 54b is an example of a fourth setting means for switching static elimination ON / OFF.

[0054] In this embodiment, when the selector switch 54b is set to "OFF", no voltage is applied to the static elimination roller 51b, but voltage is applied to the first ionizer 52a and the second ionizer 52b. For example, even sheets that do not require static elimination by the static elimination roller pair 51 may become slightly charged due to friction with the transport guide. In such cases, by eliminating the static charge from the sheets using the first ionizer 52a and the second ionizer 52b, it is possible to suppress the repulsion of the discharged sheets against each other and improve the stackability of the sheets.

[0055] The operating unit 54 may not have a selector switch 54b. In such a configuration, the voltage application to the static elimination roller 51b can be turned OFF by setting the static elimination level to "00" using the thumb rotary switch 54a.

[0056] <Static elimination settings via the control panel of the image forming apparatus> In this embodiment, various settings related to the print job can be made using the operation panel 102 of the image forming apparatus 100. Therefore, the magnitude of the voltage applied to the static elimination roller 51b can also be set from the operation panel 102 of the image forming apparatus 100. Figure 5 shows the static elimination setting screen displayed on the display unit 103 of the operation panel 102. When the static elimination setting button 151 in Figure 2 is pressed, the screen on the display unit 103 transitions from the copy setting screen to the static elimination setting screen.

[0057] The static elimination setting screen displays a mode setting section 153 and a voltage setting section 154. The voltage setting section 154 has software keys, a static elimination level button 157 and an ON / OFF button 158. The static elimination level button 157 is a button for setting the value of the voltage applied to the static elimination roller 51b by the high-voltage substrate 55. The static elimination level button 157 displays the static elimination level, which is a numerical value corresponding to the voltage applied to the static elimination roller 51b. After pressing the static elimination level button 157, the user can set the static elimination level to any value using the numeric keypad. The user can change the static elimination level by operating the static elimination level button 157. In other words, the static elimination level button 157 has the same function as the thumb rotary switch 54a described above. The static elimination level button 157 is an example of a second setting means for setting the static elimination voltage provided by the image forming apparatus 100.

[0058] The ON / OFF button 158 is a button for manually switching the voltage application to the static elimination roller 51b between "ON" and "OFF". By operating the ON / OFF button 158, the user can switch static elimination ON / OFF without changing the setting of the static elimination level button 157. In other words, the ON / OFF button 158 has the same function as the selector switch 54b described above. The ON / OFF button 158 is an example of a fourth setting means for switching static elimination ON / OFF.

[0059] The mode setting unit 153 is for selecting which static elimination setting to apply (reflect) to the static elimination operation: the operating unit 54 (thumb rotary switch 54a) of the static elimination device 300, or the operating panel 102 (voltage setting unit 154) of the image forming apparatus 100. The mode setting unit 153 displays a static elimination device button 155 and an image forming apparatus button 156, and either the static elimination device button 155 or the image forming apparatus button 156 is selected. In this embodiment, the button selected in the mode setting unit 153 is displayed brightly, and the unselected button is displayed grayed out. In the example in Figure 5, the image forming apparatus button 156 is selected, so the static elimination device button 155 is grayed out. The mode setting unit 153 is an example of a third setting means for setting a first mode in which the value of the thumb rotary switch 54a is applied as the voltage value applied to the static elimination roller 51b, and a second mode in which the value of the static elimination level button 157 is applied.

[0060] When the static elimination device button 155 is selected, the static elimination setting by the operation unit 54 of the static elimination device 300 is applied to the static elimination operation. That is, a voltage corresponding to the static elimination level set by the thumb rotary switch 54a is applied to the static elimination roller 51b, and when the selector switch 54b is set to "OFF", no voltage is applied to the static elimination roller 51b. Furthermore, when the static elimination device button 155 is selected, the static elimination setting by the operation panel 102 of the image forming apparatus 100 is not applied, but the setting information of the voltage setting unit 154 is retained.

[0061] On the other hand, when the image forming apparatus button 156 is selected, the static elimination setting on the operation panel 102 of the image forming apparatus 100 is applied to the static elimination operation. That is, a voltage corresponding to the static elimination level set by the static elimination level button 157 is applied to the static elimination roller 51b, and when the ON / OFF button 158 is set to "OFF", no voltage is applied to the static elimination roller 51b. Furthermore, when the image forming apparatus button 156 is selected, the static elimination setting on the operation unit 54 of the static elimination device 300 is not applied.

[0062] Thus, the user can select by the mode setting unit 153 whether to apply the static elimination setting from the operation unit 54 of the static elimination device 300 or the operation panel 102 of the image forming apparatus 100 to the static elimination operation. In other words, the mode setting unit 153 allows the user to select between a first mode in which the static elimination setting from the operation unit 54 of the static elimination device 300 is applied, and a second mode in which the static elimination setting from the operation panel 102 of the image forming apparatus 100 is applied.

[0063] The status line 152 displays the settings of the mode setting unit 153. In the example in Figure 5, the image forming apparatus button 156 is selected, so the message "Static elimination setting: Image forming apparatus takes priority." is displayed.

[0064] <System Control Configuration> Figure 6 is a block diagram showing the control configuration of an image forming system 400, which consists of an image forming apparatus 100 and a static elimination device 300. The image forming apparatus 100 has an image forming control unit 200 for controlling the image forming operation described above. The image forming control unit 200, which is the control means, includes a CPU 201, a ROM 202, and a RAM 203. The CPU 201 is an execution means that reads and executes the control program. The RAM 203 is the workspace for the CPU 201 when executing the control program. The ROM 202 is an example of a storage unit that stores various information such as setting information related to the control of the image forming apparatus 100. An operation panel 102 is connected to the CPU 201, and the CPU 201 can control the screen displayed on the display unit 103.

[0065] The static elimination device 300 has a static elimination control unit 210 that controls the static elimination operation described above. The static elimination control unit 210 includes a CPU 211, a ROM 212, and a RAM 213. The CPU 211 is an execution means that reads and executes a control program. The RAM 213 is the workspace for the CPU 211 when executing the control program. The ROM 212 is an example of a storage unit that stores various information such as setting information related to the control of the static elimination device 300. The CPU 211 of the static elimination control unit 210 is connected to the CPU 201 of the image forming control unit 200 by a communication cable, and can operate in cooperation as an image forming system 400 through bidirectional communication.

[0066] Furthermore, the CPU 211 is connected to an operating unit 54 (thumb rotary switch 54a and selector switch 54b), a high-voltage board 55, and an ionizer unit 52. The CPU 211 controls the high-voltage board 55 based on the settings of the operating unit 54 of the static elimination device 300 or the operating panel 102 of the image forming apparatus 100. At this time, the CPU 201 determines, based on the mode setting unit 153 described above, which static elimination setting, the operating unit 54 of the static elimination device 300 or the operating panel 102 of the image forming apparatus 100, to apply to the static elimination operation.

[0067] <Flowchart> Next, we will explain the processing of print jobs. Figure 7 is a flowchart showing the processing performed by the CPU 201 of the image forming apparatus 100.

[0068] First, the CPU 201 checks whether the current static elimination setting has priority for the image forming apparatus 100 or the static elimination device 300 (S100). That is, the CPU 201 determines which static elimination setting to apply to the static elimination operation: the operation unit 54 of the static elimination device 300 or the operation panel 102 of the image forming apparatus 100. This determination is made based on the setting in the mode setting unit 153.

[0069] If the static elimination setting on the operation panel 102 of the image forming apparatus 100 takes precedence (image forming apparatus in S100), the CPU 201 acquires the static elimination setting set on the operation panel 102 of the image forming apparatus 100 (S101). Then, the CPU 201 displays "Image forming apparatus setting takes precedence" on the status line 152 of the display unit 103 (S102). On the other hand, if the static elimination setting on the operation unit 54 of the static elimination device 300 takes precedence (static elimination device in S100), the CPU 201 displays "Static elimination device setting takes precedence" on the status line 152 of the display unit 103 (S103).

[0070] Next, the CPU 201 determines whether a print job has started (S104). If a print job has not started (NO in S104), the CPU 201 continues to monitor whether the static elimination settings have been changed (S100). If a print job has started (YES in S104), the CPU 201 notifies the static elimination device 300 of the start of the print job (S105) and notifies the CPU 211 of the static elimination settings (S106). Specifically, if the static elimination settings on the operation panel 102 of the image forming apparatus 100 take precedence, the static elimination level of the static elimination level button 157 and the setting status of the ON / OFF button 158 are notified to the CPU 211. Also, if the static elimination settings on the operation unit 54 of the static elimination device 300 take precedence, this fact is notified to the CPU 211. Based on the information notified here, the static elimination device 300 operates. The flowchart of the processes executed by the CPU 211 of the static elimination device 300 will be described later.

[0071] The CPU 201 determines whether the static elimination device 300 has started its static elimination operation (S107). If the static elimination device 300 has started its static elimination operation (YES in S107), the image forming apparatus 100 starts paper transport and image formation operations (S108). The image forming apparatus 100 operates until the print job is completed (S109), and when the print job is completed (YES in S109), the image forming apparatus 100 terminates its paper transport and image formation operations (S110). The CPU 201 then notifies the static elimination device 300 that the print job has ended (S111). The CPU 201 then determines whether the static elimination device 300 has finished its static elimination operation (S112), and after confirming the completion of the static elimination operation (YES in S112), terminates the flowchart process.

[0072] Next, we will describe the processes performed by the CPU 211 of the static elimination device 300 in a print job. Figure 10 is a flowchart of the processes performed by the CPU 211 of the static elimination device 300.

[0073] The CPU 211 first obtains the settings of the thumb rotary switch 54a and the selector switch 54b (S201). The CPU 211 determines whether the static elimination setting of the static elimination device 300 has been changed (S202), and if it has been changed (YES in S202), it notifies the image forming apparatus 100 of the change in the static elimination setting (S203). If the static elimination setting has not been changed (NO in S202), the CPU 211 proceeds to the next process. The CPU 211 determines whether it has received notification from the image forming apparatus 100 that a print job has started (S204), and if it has not received notification that a print job has started (NO in S204), it continues to monitor whether the static elimination setting has been changed (S201).

[0074] When a print job start notification is received (YES in S204), the CPU 211 determines which static elimination setting takes precedence: that of the static elimination device 300 or the image forming apparatus 100 (S205). That is, the CPU 211 determines which static elimination setting—that of the operation unit 54 of the static elimination device 300 or that of the operation panel 102 of the image forming apparatus 100—should be applied to the static elimination operation. This determination is made based on the notification from the CPU 201 in S106.

[0075] If the image forming apparatus 100 takes priority (image forming apparatus in S205), the CPU 211 obtains the static elimination settings set on the operation panel 102 of the image forming apparatus 100 (S206) and sets them on the high-voltage substrate 55 and the ionizer unit 52 (S207). If the static elimination device 300 takes priority (static elimination device in S205), the CPU 211 sets the values ​​obtained from the thumb rotary switch 54a and the selector switch 54b on the high-voltage substrate 55 and the ionizer unit 52 (S208). Then, the CPU 211 notifies the image forming apparatus 100 to start the static elimination operation (S209) and starts the static elimination operation (S210). The static elimination device 300 continues the static elimination operation until the print job is completed (NO in S211), and stops the static elimination operation when it receives notification that the print job is complete (YES in S211) (S212). Then, the CPU 211 notifies the image forming apparatus 100 that the static elimination operation is complete (S213). In this way, the CPU 211 of the static elimination device 300 controls the static elimination operation according to the operation instructions of the CPU 201 of the image forming apparatus 100.

[0076] Incidentally, in this embodiment, static elimination settings can be made on both the operation unit 54 of the static elimination device 300 and the operation panel 102 of the image forming apparatus 100. Therefore, there may be discrepancies between the static elimination settings made on the operation unit 54 of the static elimination device 300 and the static elimination settings made on the operation panel 102 of the image forming apparatus 100. For example, the static elimination level of the thumb rotary switch 54a may be "10," while the static elimination level of the static elimination level button 157 may be "15." Another example is when the selector switch 54b is "OFF" and the ON / OFF button 158 is "ON." Such discrepancies in static elimination settings can cause confusion for the user, making it difficult to actually set the voltage applied to the static elimination roller 51b.

[0077] Therefore, the static elimination setting screen in this embodiment is provided with the mode setting unit 153 described above. This mode setting unit 153 allows the user to arbitrarily set whether to apply the static elimination setting of the operation unit 54 of the static elimination device 300 or the operation panel 102 of the image forming apparatus 100. As a result, it is possible to improve the usability when the user performs static elimination settings.

[0078] Furthermore, the settings configured in the mode setting unit 153 are displayed on the status line 152. Specifically, the status line 152 displays whether the first mode, which applies the value of the thumb rotary switch 54a, or the second mode, which applies the value of the static elimination level button 157, is selected. This display on the status line 152 is retained even when the display screen transitions from the static elimination setting screen to another screen. Therefore, the user can check the settings of the mode setting unit 153 at any time, further improving usability.

[0079] <Variation> Next, a modified example of the first embodiment will be described. Figure 9 shows a modified example of the operation unit 54 of the static elimination device 300. The operation unit 54 shown in Figure 9 has a mode switch 54c instead of a selector switch 54b.

[0080] The mode switch 54c is used to select whether to apply the static elimination setting of the operation unit 54 of the static elimination device 300 or the operation panel 102 of the image forming apparatus 100 to the static elimination operation. In other words, the mode switch 54c has the same function as the mode setting unit 153 described above. The mode switch 54c is an example of a third setting means for setting a first mode in which the value of the thumb rotary switch 54a is applied as the voltage value applied to the static elimination roller 51b, and a second mode in which the value of the static elimination level button 157 is applied.

[0081] When "Static Eliminator" is selected in mode switch 54c, the static elimination setting by the operation unit 54 of the static eliminator 300 is applied. That is, a voltage corresponding to the static elimination level set by the thumb rotary switch 54a is applied to the static elimination roller 51b, and when the selector switch 54b is set to "OFF", no voltage is applied to the static elimination roller 51b. Furthermore, when "Static Eliminator" is selected in mode switch 54c, the static elimination setting by the operation panel 102 of the image forming apparatus 100 is not applied.

[0082] On the other hand, if "image forming apparatus" is selected in mode switch 54c, the static elimination settings on the operation panel 102 of the image forming apparatus 100 are applied. That is, a voltage corresponding to the static elimination level set by the static elimination level button 157 is applied to the static elimination roller 51b, and if the ON / OFF button 158 is set to "OFF", no voltage is applied to the static elimination roller 51b. Furthermore, if "image forming apparatus" is selected in mode switch 54c, the static elimination settings on the operation unit 54 of the static elimination device 300 are not applied.

[0083] Thus, the user can select by the mode switch 54c whether to apply the static elimination settings of the control panel 54 of the static elimination device 300 or the control panel 102 of the image forming apparatus 100 to the static elimination operation. In other words, the user can select by the mode switch 54c whether to apply the static elimination settings of the control panel 54 of the static elimination device 300 or the static elimination settings of the control panel 102 of the image forming apparatus 100.

[0084] Even in this modified configuration, the user can arbitrarily set whether to apply the static elimination settings of the control unit 54 of the static elimination device 300 or the control panel 102 of the image forming apparatus 100. This improves the usability for the user when setting static elimination parameters.

[0085] Furthermore, since the mode switch 54c is provided on the exterior of the static elimination device 300, the user can easily confirm which static elimination setting, the static elimination setting of the static elimination device 300 or the static elimination setting of the image forming apparatus 100, is prioritized. Also, if the mode switch 54c is provided on the operation unit 54 of the static elimination device 300, it is preferable not to provide (delete) the mode setting unit 153 on the static elimination setting screen in order to prevent user confusion. In the first embodiment, it is sufficient if either the image forming apparatus 100 or the static elimination device 300 has means (third setting means) for switching between the first mode and the second mode. [Second Embodiment] Next, a second embodiment of the present invention will be described. In the first embodiment, an example was described in which a mode setting unit 153 is provided for selecting between a first mode to which the static elimination setting by the operation unit 54 of the static elimination device 300 is applied, and a second mode to which the static elimination setting by the operation panel 102 of the image forming apparatus 100 is applied. In addition, an example was described in which a mode switch 54c is provided on the operation unit 54 of the static elimination device 300 instead of the mode setting unit 153.

[0086] On the other hand, in the second embodiment, an example will be described in which the CPU 201 automatically switches between a first mode in which the static elimination setting by the operation unit 54 of the static elimination device 300 is applied, and a second mode in which the static elimination setting by the operation panel 102 of the image forming apparatus 100 is applied. In the second embodiment, the basic configuration of the image forming system 400 is the same as in the first embodiment, so the explanation will be omitted.

[0087] Figure 10 is a flowchart showing the processing performed by the CPU 201 of the image forming apparatus 100 according to the second embodiment. The basic flow is the same as in Figure 7 of the first embodiment, but a flow (S304-S308) that automatically switches priorities has been added.

[0088] First, the CPU 201 checks whether the current static elimination setting has priority for the image forming apparatus 100 or the static elimination device 300 (S300). That is, the CPU 201 determines which static elimination setting to apply to the static elimination operation: the operation unit 54 of the static elimination device 300 or the operation panel 102 of the image forming apparatus 100. This determination is made based on the setting in the mode setting unit 153.

[0089] If the static elimination setting on the operation panel 102 of the image forming apparatus 100 takes precedence (image forming apparatus in S300), the CPU 201 acquires the static elimination setting set on the operation panel 102 of the image forming apparatus 100 (S301). Then, the CPU 201 displays "Image forming apparatus setting takes precedence" on the status line 152 of the display unit 103 (S302). On the other hand, if the static elimination setting on the operation unit 54 of the static elimination device 300 takes precedence (static elimination device in S300), the CPU 201 displays "Static elimination device setting takes precedence" on the status line 152 of the display unit 103 (S303).

[0090] Next, the CPU 201 monitors whether the static elimination setting has been changed on the operation panel 102 of the image forming apparatus 100 (S304). If the static elimination setting has been changed on the operation panel 102 of the image forming apparatus 100 (YES in S304), the CPU 201 retrieves the static elimination setting of the image forming apparatus 100 (S305) and notifies the operation panel 102 that the setting of the image forming apparatus 100 takes precedence (S306). At this time, if the static elimination device button 155 was selected in the mode setting unit 153, the image forming apparatus button 156 is selected.

[0091] If the static elimination setting has not been changed on the operation panel 102 of the image forming apparatus 100 (NO in S304), the CPU 201 monitors whether the static elimination setting has been changed on the operation unit 54 of the static elimination device 300 (S307). This can be confirmed by notification from the CPU 211 of the static elimination device 300. If the static elimination setting has been changed on the operation unit 54 of the static elimination device 300 (YES in S307), the operation panel 102 is notified that the setting of the static elimination device 300 takes precedence (S308). At this time, if the image forming apparatus button 156 was selected on the mode setting unit 153, the static elimination device button 155 is selected. If the static elimination setting has not been changed on the operation unit 54 of the static elimination device 300 (NO in S307), the CPU 201 proceeds to the next process.

[0092] Next, CPU201 determines whether the print job has started (S309). If the print job has not started (NO in S309), CPU201 continues to monitor whether the static elimination settings have been changed (S304). If the print job has started (YES in S309), CPU201 notifies the static elimination device 300 of the start of the print job (S310) and notifies CPU211 of the static elimination settings (S311).

[0093] The CPU 201 determines whether the static elimination device 300 has started its static elimination operation (S312). If the static elimination device 300 has started its static elimination operation (YES in S312), the image forming apparatus 100 starts paper transport and image formation operations (S313). The image forming apparatus 100 operates until the print job is completed (S314), and when the print job is completed (YES in S314), the image forming apparatus 100 terminates its paper transport and image formation operations (S315). The CPU 201 then notifies the static elimination device 300 that the print job has ended (S316). The CPU 201 then determines whether the static elimination device 300 has finished its static elimination operation (S317), and after confirming the completion of the static elimination operation (YES in S317), terminates the flowchart process.

[0094] In the flowchart described above, the CPU 201 switches from a first mode in which the static elimination setting by the operation unit 54 is applied to a second mode in which the static elimination setting by the operation panel 102 is applied, based on the change in the static elimination setting on the operation panel 102. The CPU 201 also switches from a first mode in which the static elimination setting by the operation panel 102 is applied to a second mode in which the static elimination setting by the operation unit 54 is applied, based on the change in the static elimination setting on the operation unit 54. As a result, the user does not need to switch modes using the mode setting unit 153, improving operability. In this embodiment, the CPU 201 functions as a third setting means for selecting between the first mode and the second mode.

[0095] In the second embodiment as well, the user can set whether to apply the static elimination setting of the operation unit 54 of the static elimination device 300 or the operation panel 102 of the image forming apparatus 100. This improves the usability when the user makes static elimination settings. In the second embodiment, since the CPU 201 automatically switches between the first mode and the second mode, the mode setting unit 153 and mode switch 54c described in the first embodiment do not necessarily need to be provided.

[0096] In the second embodiment as well, the status line 152 displays whether the static elimination setting of the image forming apparatus 100 or the static elimination setting of the static elimination device 300 is prioritized. This display on the status line 152 is retained even when transitioning from the static elimination setting screen to another screen. Therefore, the user can check the setting of the mode setting unit 153 at any time, further improving usability.

[0097] [Other embodiments] In the embodiments described above, a static elimination device 300 for removing static electricity from the sheet S was explained. The static elimination device 300 also functions as a charge adjustment device that adjusts the charged state of the sheet S by supplying charge to the sheet S via a static elimination roller 51b, which is a charge supply member. The charge adjustment device does not necessarily reduce the amount of charge on the sheet S (does not remove static electricity). For example, the charge adjustment device may adjust the amount of charge on each surface of the sheet S so that, when the sheets S are stacked after processing by the charge adjustment device, the opposing surfaces of overlapping sheets are charged with the same polarity. Specifically, the charge adjustment device applies a voltage to every other sheet of a plurality of sheets so that the electrostatic polarity of the sheet surface is reversed. In this case, since the opposing surfaces of overlapping sheets are charged with the same polarity, the sheets sticking together due to electrostatic force can be reduced.

[0098] Furthermore, by applying the control described in each embodiment to the control of the voltage applied to the static elimination roller pair 51, which acts as a charge supply unit, the charged state of the sheet S can be adjusted more appropriately. Specifically, a mode setting unit 153 is provided to switch between a first mode in which the setting in the operation unit 54 is applied as the voltage applied to the static elimination roller 51b, and a second mode in which the setting in the operation panel 102 is applied as the voltage applied to the static elimination roller 51b. This makes it possible to improve the usability of the charge adjustment device when the user makes charge adjustment settings.

[0099] Furthermore, in the embodiments described above, a static elimination roller 51b, which is a roller member, was described as an example of a contact-type static elimination member that comes into contact with the sheet S. The contact-type static elimination member is not limited to this, and may also be a brush member in which conductive fibers or elongated conductive sheet pieces come into contact with the sheet S.

[0100] Furthermore, in the embodiments described above, it was explained that the sheet S is charged mainly in the transfer section of the electrophotographic process. However, this is not limited to this, and in image forming systems other than electrophotographic methods, such as inkjet methods, the sheet S may be charged by frictional charging or peeling charging due to friction or peeling with transport guides, transport rollers, or transport belts. For this reason, this technology may also be applied to image forming systems other than electrophotographic methods.

[0101] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions. [Explanation of Symbols]

[0102] 51 Static Elimination Roller Pair 54 Operation section 54a Thumb rotary switch 100 Image forming apparatus 102 Control Panel 153 Mode setting section 154 Voltage setting section 300 Static eliminator

Claims

1. An image forming apparatus that forms an image on a sheet, A static elimination device having a static elimination member for removing static electricity from a sheet imaged by the aforementioned image forming apparatus, Equipped with, The static elimination device has a first setting means for setting the voltage applied to the static elimination member, The image forming apparatus has a second setting means for setting the voltage applied to the static elimination member, The system includes a third setting means for selecting a first mode in which the setting in the first setting means is applied as the voltage applied to the static elimination member, and a second mode in which the setting in the second setting means is applied as the voltage applied to the static elimination member. An image forming system characterized by the following:

2. The first setting means and the third setting means are hardware keys provided in the static elimination device. The image forming system according to claim 1.

3. The image forming apparatus has a display unit that displays information, The second setting means and the third setting means are software keys displayed on the display unit. The image forming system according to claim 1.

4. The system includes a fourth setting means for setting whether or not to apply voltage to the static elimination member without changing the voltage value set by the first setting means and the second setting means. The image forming system according to claim 2 or 3, characterized in that it is the same as described above.

5. The static elimination member is a pair of static elimination rollers that eliminate static electricity from the sheet while nipping and transporting it. The static elimination device is positioned downstream of the pair of static elimination rollers in the sheet transport direction and has a non-contact static elimination unit that eliminates static electricity from the sheet without contacting it. Even if the setting by the fourth setting means is set so that no voltage is applied to the static elimination roller pair, voltage is still applied to the non-contact static elimination unit. The image forming system according to feature 4.

6. The image forming apparatus has a display unit that displays information, The second setting means is a software key displayed on the static elimination setting screen of the display unit, The display unit is capable of showing which of the first mode or the second mode is set, even when the display screen transitions from the static elimination setting screen to another screen. The image forming system according to claim 1.

7. The third setting means is a control means that switches from the second mode to the first mode based on the voltage applied to the static elimination member being set by the first setting means, and switches from the first mode to the second mode based on the voltage applied to the static elimination member being set by the second setting means. The image forming system according to claim 1.

8. A static eliminator connected to an image forming apparatus that forms an image on a sheet, A static elimination member for removing static electricity from a sheet imaged by the image forming apparatus, A third setting means for selecting a first mode in which the setting in the first setting means of the static elimination device is applied as the voltage applied to the static elimination member, and a second mode in which the setting in the second setting means of the image forming apparatus is applied as the voltage applied to the static elimination member, Equipped with, A static elimination device characterized by the following features.

9. A charge adjustment device connected to an image forming apparatus that forms an image on a sheet, A charge supply member that supplies charge to a sheet imaged by the image forming apparatus, A third setting means for selecting a first mode in which the setting in the first setting means of the charge adjustment device is applied as the voltage applied to the charge supply member, and a second mode in which the setting in the second setting means of the image forming apparatus is applied as the voltage applied to the charge supply member, Equipped with, A charge adjustment device characterized by the following features.

Images