Paper discharge device and image forming system

Abstract

To provide a paper discharge device and an image forming system capable of coexisting with a CD matching member and further improving discharged paper aligning performance.SOLUTION: An image forming system of the invention includes: a paper discharge member (paper discharge roller 31) that discharges paper on which an image has been formed by an image forming device 10; a paper stacking section (paper discharge tray 32) that stacks the paper discharged by the paper discharge member; a CD alignment member 33 that aligns the paper stacked on the paper stacking section in the width direction; and a static elimination section 34 that non-contactly eliminates charge from the paper discharged to the paper stacking section. The charge eliminating section 34 is positioned outside the movable range of the CD alignment member 33.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a paper discharge device and an image forming system. [Background technology]

[0002] Electrophotographic image forming apparatuses that form images on paper are known. Electrophotographic image forming apparatuses develop an electrostatic latent image formed on a photosensitive member with toner, transfer the toner image to paper in a transfer unit, and fix the toner image in a fixing unit.

[0003] In the electrophotographic image forming apparatus, the paper discharged onto the paper discharge tray is charged with static electricity because charged toner is transferred onto the paper by the action of an electric field. To improve the alignment of discharged paper, it is necessary to remove static electricity from the paper discharged onto the paper discharge tray. For example, Patent Document 1 discloses a configuration in which a static eliminator is disposed near the downstream side of the paper discharge roller. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-39141 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if a CD alignment member or the like is installed on the paper discharge tray to further improve the alignment of discharged paper, it becomes impossible to place the static eliminator near the downstream side of the paper discharge roller.

[0006] An object of the present invention is to provide a paper discharge device and an image forming system that can coexist with a CD alignment member and further improve paper discharge alignment. [Means for solving the problem]

[0007] The invention described in claim 1 has been made to achieve the above object, In the paper ejection device, a paper discharge member that discharges paper on which an image has been formed by the image forming device; a paper stacking section for stacking the paper discharged by the paper discharge member; a CD alignment member that aligns the sheets loaded in the sheet loading section in the width direction; a charge eliminating unit that eliminates charge on the paper discharged to the paper stacking unit in a non-contact manner; Equipped with The charge eliminating unit is characterized in that it is arranged outside the movable range of the CD alignment member.

[0008] The invention described in claim 2 is the paper discharge device described in claim 1, The static eliminator is configured to be movable so that the distance between the static eliminator and the topmost sheet stacked on the sheet stacking section is within a predetermined range.

[0009] The invention described in claim 3 is the paper discharge device described in claim 2, The sheet stacking device is characterized by including a detection unit that detects the distance between the static eliminator and the topmost sheet stacked on the sheet stacking unit.

[0010] The invention described in claim 4 is the paper discharge device described in claim 3, The static eliminator is configured to be movable so that the distance detected by the detector can be maintained within a predetermined range.

[0011] The invention described in claim 5 is the paper discharge device described in claim 4, The static eliminator is characterized by further comprising a control unit that controls movement of the static eliminator so that the distance detected by the detection unit can be maintained within a predetermined range.

[0012] The invention described in claim 6 is the paper discharge device described in claim 3, The detection position of the detection unit and the static elimination position of the static elimination unit are the same.

[0013] The invention described in claim 7 is the paper discharge device described in claim 3, The present invention is characterized by comprising an output control unit that outputs an alarm when the distance detected by the detection unit falls below a predetermined threshold.

[0014] The invention described in claim 8 is the paper discharge device described in claim 1, The static eliminator is configured to be movable to a retracted position.

[0015] The invention described in claim 9 is the paper discharge device described in claim 1, The static elimination unit is characterized in that the static elimination position in the transport direction of the paper is adjustable.

[0016] The invention described in claim 10 is the paper discharge device described in claim 9, The image forming apparatus is characterized by including an adjustment unit that adjusts the neutralization position of the neutralization unit in accordance with the stiffness of the paper.

[0017] The invention described in claim 11 is the paper discharge device described in claim 1, The static eliminator is an ionizer that emits positive ions and negative ions toward the surface of the paper.

[0018] The invention described in claim 12 is In an image forming system, an image forming device that forms an image on a sheet; a paper discharge device according to any one of claims 1 to 11, which discharges paper on which the image has been formed by the image forming device; The present invention is characterized by comprising: [Effects of the Invention]

[0019] According to the present invention, it is possible to coexist with a CD alignment member, and it is possible to further improve the alignment of discharged sheets. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram showing a schematic configuration of an image forming system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a functional block diagram showing a control structure of the image forming system according to the present embodiment. [Figure 3A] FIG. [Figure 3B] FIG. [Figure 4] FIG. 2 is a diagram illustrating a detailed configuration of a paper discharge device. [Figure 5] 10 is a graph showing the correspondence relationship between the distance between the static eliminator and the paper and the amount of static elimination. [Figure 6] 6 is a flowchart illustrating an example of control of the image forming system according to the present embodiment. [Figure 7A] 10A and 10B are diagrams for explaining the detection position of the detection unit and the static elimination position of the static eliminator when the detection unit detects a position directly below. [Figure 7B] 10A and 10B are diagrams illustrating an example of a state in which the detection position of the detection unit and the static elimination position of the static eliminator are made to coincide with each other. [Figure 8] FIG. 10 is a diagram illustrating an example of a state in which the static eliminator is moved to a retreat position. [Figure 9] 10A and 10B are diagrams illustrating an example of adjusting the neutralization position of the neutralization unit. [Figure 10] 10 is a graph showing the correspondence relationship between the stiffness of paper and the appropriate static elimination position by the static elimination unit. [Figure 11] FIG. 1 is a diagram for explaining the principle of a pulse AC type ionizer. [Figure 12] 10A and 10B are diagrams illustrating an example of how a charged sheet is neutralized by a neutralization unit. [Figure 13A] FIG. 10 is a diagram showing a detailed configuration of a paper discharge device according to a first modified example. [Figure 13B] 13B is a diagram showing an example of a state in which the support member is rotated upward from the state in FIG. 13A. FIG. [Figure 13C] 13C is a diagram showing an example of a state in which the stay is rotated upward from the state shown in FIG. 13B. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0022] As shown in FIG. 1, the image forming system 1 according to this embodiment includes an image forming apparatus 10 and a post-processing apparatus 20.

[0023] The image forming device 10 forms an image on a sheet based on print data. As shown in Figures 1 and 2, the image forming device 10 includes a control unit 11, an image reading unit 12, an image forming unit 13, a storage unit 14, an operation panel 15, and a communication unit 16.

[0024] The control unit 11 includes a CPU, RAM, ROM, etc. First, the CPU reads out various processing programs stored in the ROM in response to an instruction signal and loads the programs into the RAM. The instruction signal is received as an operation signal input from the operation unit 152 or via the communication unit 16. Next, the CPU comprehensively controls the operation of the image forming apparatus 10 in cooperation with the various programs loaded into the RAM.

[0025] The image reading unit 12 reads an image of a document placed on a document table or an automatic document feeder (ADF), not shown, and obtains an image signal. Specifically, the image reading unit 12 scans and exposes the image of the document using the optical system of a scanning exposure device, reads the reflected light using a line image sensor, and obtains an image signal. The image signal is subjected to processes such as A / D conversion, shading correction, and compression, and then input to the control unit 11 as image data. Note that the image data input to the control unit 11 is not limited to that read by the image reading unit 12. For example, it may be image data received from an external device (not shown) via the communication unit 16.

[0026] The image forming unit 13 forms an image made up of four colors, C, M, Y, and K, on ​​a sheet of paper in accordance with the pixel values ​​of the four colors of each pixel of the image-processed original image. The image forming unit 13 includes four writing units 131, an intermediate transfer belt 132, a secondary transfer roller 133, a fixing unit 134, and the like.

[0027] The four writing units 131 are arranged in series (tandem) along the belt surface of the intermediate transfer belt 132 and form images of the respective colors of C, M, Y, and K. The writing units 131 have the same configuration except for the colors of the images they form. Each writing unit 131 includes an optical scanning unit 131a, a photosensitive member 131b, a developing unit 131c, a charging unit 131d, a cleaning unit 131e, and a primary transfer roller 131f.

[0028] When forming an image, in each writing unit 131, first, the photoconductor 131b is charged by the charging unit 131d. Next, a light beam emitted from the optical scanning unit 131a is scanned over the photoconductor 131b based on the original image to form an electrostatic latent image. When the developing unit 131c supplies a color material such as toner and performs development, an image (toner image) is formed on the photoconductor 131b. The images formed on the photoconductors 131b of the four writing units 131 are sequentially superimposed and primarily transferred onto the intermediate transfer belt 132 by the respective primary transfer rollers 131f. As a result, images of each color are formed on the intermediate transfer belt 132. The intermediate transfer belt 132 is an image carrier that rotates while being wound around multiple rollers. After the primary transfer, the cleaning unit 131e removes color material remaining on the photoconductors 131b.

[0029] In the image forming unit 13, paper is fed in time with the image on the rotating intermediate transfer belt 132 reaching the position of the secondary transfer roller 133. In the image forming unit 13, paper is fed from the manual feed tray T1 or the paper feed tray T2. One of the pair of secondary transfer rollers 133 presses against the intermediate transfer belt 132. The other of the pair constitutes one of the multiple rollers that wrap around the intermediate transfer belt 132. Next, the image is secondarily transferred from the intermediate transfer belt 132 onto the paper by the pressure of the secondary transfer roller 133. Next, the paper is transported to the fixing unit 134, where it is fixed, and then transported to the downstream post-processing device 20. The fixing process is a process in which the fixing roller 134a applies heat and pressure to the paper to fix the image to the paper. When forming images on both sides of the paper, the paper is transported to the inversion path 135, where the paper surface is inverted, and then the paper is again fed to the position of the secondary transfer roller 133.

[0030] The storage unit 14 is a non-volatile storage means configured by an HDD, an SSD, etc. The storage unit 14 stores various programs, various setting data, etc. in a manner that allows the control unit 11 to read and write the data.

[0031] The operation panel 15 includes a display unit 151 that displays various information to the user, and an operation unit 152 that accepts operation inputs from the user. The display unit 151 is configured with a color liquid crystal display or the like, and displays an operation screen and the like in accordance with a display control signal input from the control unit 11. The operation screen includes, for example, various setting screens, various buttons, and the operating status of each function. The operation unit 152 includes a touch panel provided on the screen of the display unit 151 and various hard keys arranged around the screen of the display unit 151. When a button displayed on the screen is pressed with a finger, a touch pen, or the like, the operation unit 152 first detects the X and Y coordinates of the pressed point of force as a voltage value. Next, the operation unit 152 outputs an operation signal associated with the detected position to the control unit 11. Note that the touch panel is not limited to a pressure-sensitive type and may be, for example, an electrostatic type or an optical type. Furthermore, when a hard key is pressed, the operation unit 152 outputs an operation signal associated with the pressed key to the control unit 11. The user can operate the operation unit 152 to make settings related to image formation, issue paper transport instructions, and stop the device. Settings related to image formation include, for example, image quality settings, magnification settings, application settings, output settings, and paper settings.

[0032] The communication unit 16 has a communication IC, a communication connector, etc., and is an interface that connects the image forming apparatus 10 to a communication network. The communication unit 16 transmits and receives various information to and from external devices connected to the communication network using a predetermined communication protocol under the control of the control unit 11. The communication unit 16 can also input and output various information via USB.

[0033] The post-processing device 20 is connected to the rear stage of the image forming device 10. The post-processing device 20 includes a control unit 21, a post-processing unit 22, a conveying unit 23, and a paper discharge device 30.

[0034] The control unit 21 includes a CPU, a ROM, a RAM, etc., and controls the overall operation of each unit of the post-processing device 20.

[0035] The post-processing section 22 performs designated post-processing on the paper conveyed from the image forming apparatus 10. The post-processing includes, for example, stapling, cutting, and punching (punching holes).

[0036] The conveying section 23 is composed of multiple pairs of rollers. The conveying section 23 conveys the paper conveyed from the image forming device 10 to the post-processing section 22. The conveying section 23 also conveys the paper that has been subjected to post-processing in the post-processing section 22 to the paper discharge device 30.

[0037] 3A and 3B are diagrams that schematically show the configuration of the paper discharge device 30. Fig. 3A is a front view of the paper discharge device 30. Fig. 3B is a top view of the paper discharge device 30. The paper discharge device 30 includes a paper discharge roller 31, a paper discharge tray 32, a CD alignment member 33, and a static eliminator . The paper discharge rollers 31 (paper discharge member) discharge the paper P on which the image has been formed by the image forming apparatus 10 onto the paper discharge tray 32. The paper discharge tray 32 (paper stacking section) stacks the paper P discharged by the paper discharge roller 31.

[0038] The CD alignment member 33 is provided downstream of the paper discharge roller 31 in the transport direction of the paper P. The CD alignment member 33 is a pair of plate-like members formed in a blade shape in a side view. The CD alignment member 33 is configured so that each of the pair of plate-like members can move in the width direction (a direction perpendicular to the transport direction of the paper P) according to the paper size. The CD alignment member 33 aligns the paper P stacked on the paper discharge tray 32 in the width direction by moving in the width direction according to the paper size. The CD alignment member 33 is rotatably attached to the housing of the post-processing device 20. The CD alignment member 33 is normally located above the paper discharge tray 32 (see the solid line in FIG. 3A ). When the job is completed, the CD alignment member 33 rotates upward and moves to a retracted position (see the dashed line in FIG. 3A ). The retracted position is a position that does not get in the way when removing paper from the paper discharge tray 32.

[0039] The static eliminator 34 is provided downstream of the paper discharge roller 31 in the transport direction of the paper P. The static eliminator 34 non-contactly eliminates static electricity from the paper P discharged onto the paper discharge tray 32. As shown in FIG. 3A , the static eliminator 34 is disposed outside the movable range of the CD alignment member 33.

[0040] Generally, the greater the distance between the static eliminator 34 and the paper, the less effective the static elimination, so it is preferable to place them as close as possible. However, if the distance between the static eliminator 34 and the paper is too close, direct discharge occurs, so it is most preferable to use them at the closest distance possible that does not cause direct discharge. Note that as paper is stacked on the paper output tray 32, depending on the type of paper, the center may gradually bulge in a convex direction, bringing the distance between the static eliminator 34 and the paper closer. In this case, direct discharge may occur.

[0041] Therefore, the paper discharge device 30 is provided with a detection unit SE1 that detects the distance between the static eliminator 34 and the topmost (uppermost) paper sheet stacked on the paper discharge tray 32. This makes it possible to monitor the distance between the static eliminator 34 and the paper sheet, thereby always maintaining an appropriate distance.

[0042] FIG. 4 shows the detailed configuration of the paper discharge device 30. The static eliminator 34 and the detector SE1 are attached to the housing of the post-processing device 20 via a support member 35 and a stay 36. The support member 35 is fixed to the housing of the post-processing device 20 . The stay 36 is connected to the support member 35 so as to be folded back. The stay 36 is fixed to the support member 35.

[0043] The static eliminator 34 and the detection unit SE1 are attached to a stay 36. The static eliminator 34 is attached to be able to move up and down relative to the stay 36. The static eliminator 34 and the detection unit SE1 are attached to be able to rotate relative to the stay 36. The static eliminator 34 is configured to be movable so that the distance to the uppermost sheet P1 stacked on the paper output tray 32 is within a predetermined range. Specifically, the static eliminator 34 is configured to be movable so that the distance detected by the detector SE1 can be maintained within the predetermined range. The static eliminator 34 moves up and down relative to the stay 36, thereby adjusting the distance between the static eliminator 34 and the paper P1.

[0044] It is also possible to lower the discharge tray 32 to increase the distance between the static eliminator 34 and the paper. However, lowering the discharge tray 32 affects the paper stacking performance, so it is preferable to move the static eliminator 34.

[0045] FIG. 5 is a graph showing the correspondence relationship between the distance between the static eliminator 34 (ionizer) and the paper P1 and the amount of static elimination. If the distance between the static eliminator 34 and the paper P1 is less than 50 mm, direct discharge occurs, and the amount of static elimination is therefore 0. Therefore, it is preferable to exclude distances less than 50 mm from the predetermined range. If the distance between the static eliminator 34 and the paper P1 is 50 mm or more, the static elimination effect decreases as the distance increases, so it is preferable to exclude distances of, for example, 100 mm or more from the predetermined range. From the above, the predetermined range is preferably 50 to 100 mm. The above is just an example, and it is preferable that the distance between the static eliminator 34 and the paper P1 be set within a range that provides a sufficient static elimination effect depending on the type of static eliminator 34.

[0046] In this embodiment, the control unit 21 controls the movement of the static eliminator 34 so that the distance detected by the detector SE1 can be maintained within a predetermined range. The movement control of the static eliminator 34 will be described below with reference to the flowchart in Fig. 6. The control in Fig. 6 is started when a static elimination mode capable of eliminating static electricity from the paper discharged by the paper discharge roller 31 is turned on.

[0047] First, the control unit 21 determines whether or not the job has been completed (step S101). If the control unit 21 determines that the job has ended (step S101: YES), it ends the process. On the other hand, if the control unit 21 determines that the job has not been completed (step S101: NO), the process proceeds to the next step S102.

[0048] In step S102, the control unit 21 acquires the distance detected by the detection unit SE1. The distance detected by the detection unit SE1 is the distance between the static eliminator 34 and the top sheet stacked on the paper output tray 32.

[0049] Next, the control unit 21 determines whether the distance acquired in step S101 is within a predetermined range (step S103). If the control unit 21 determines that the difference is within the predetermined range (step S103: YES), the process proceeds to step S101. On the other hand, if the control unit 21 determines that the value is not within the predetermined range (step S103: NO), the control unit 21 proceeds to the next step S104.

[0050] In step S104, control unit 21 moves static eliminator 34. Specifically, control unit 21 moves static eliminator 34 so that the distance between static eliminator 34 and the topmost sheet stacked on paper output tray 32 is within a predetermined range. Then, the process proceeds to step S103. As described above, in this embodiment, the distance between the static eliminator 34 and the topmost sheet stacked on the paper discharge tray 32 can be automatically maintained at an appropriate level.

[0051] 7A and 7B are diagrams illustrating the detection position of the detection unit SE1 and the charge removal position of the charge removal unit 34. For convenience of explanation, in FIGS. 7A and 7B, illustrations other than the charge removal unit 34, the detection unit SE1, and the paper P1 are omitted. As shown in FIG. 7A, when the detection unit SE1 detects the position directly below, the distance between the detection unit SE1 and the paper P1 is longer than the distance between the charge removal unit 34 and the paper P1. In other words, the detection unit SE1 cannot accurately detect the distance between the charge removal unit 34 and the paper P1. 7B, in this embodiment, the detection position of detection unit SE1 and the charge removal position of charge removal unit 34 are made to coincide with each other. Specifically, detection unit SE1 is rotated to make the detection position of detection unit SE1 and the charge removal position of charge removal unit 34 coincide with each other. This makes it possible to accurately detect the distance between the charge removal unit 34 and the paper at the charge removal position.

[0052] The control unit 21 outputs an alarm when the distance detected by the detection unit SE1 is less than a predetermined threshold. That is, the control unit 21 functions as an output control unit of the present invention. The predetermined threshold is, for example, 55 mm. Methods for outputting an alarm include displaying an alarm on the display unit 151, illuminating a PATLITE (registered trademark) (not shown), and the like.

[0053] FIG. 8 shows an example of the state in which the static eliminator 34 has been moved to the retreat position. 8, the static eliminator 34 is configured to be movable to a retracted position. The retracted position is a position that does not get in the way when removing paper from the paper output tray 32. The static eliminator 34 moves to the retracted position when not using the static eliminator 34 or when removing paper from the paper output tray 32.

[0054] 9 shows an example of adjusting the neutralization position of the neutralization unit 34. For convenience of explanation, the CD alignment member 33, the support member 35, the stay 36, and the detection unit SE1 are omitted from FIG. As shown in Fig. 9, the static elimination unit 34 is configured so that the static elimination position in the transport direction of the paper P can be adjusted. Specifically, the static elimination unit 34 is rotatably attached to the stay 36. The static elimination position is preferably a position before the paper P discharged by the paper discharge roller 31 comes into contact with the paper discharge tray 32 or a paper P that has already been discharged. This is because if static elimination is performed after the leading edge of the paper P being discharged comes into contact with the paper discharge tray 32 or a paper P that has already been discharged, the static elimination effect will be reduced due to electrostatic induction.

[0055] The control unit 21 adjusts the neutralization position in the sheet conveyance direction of the neutralization unit 34 in accordance with the stiffness of the sheet. That is, the control unit 21 functions as an adjustment unit of the present invention. 10 is a graph showing the correspondence relationship between the stiffness of the paper and the appropriate static elimination position by the static eliminator 34. The horizontal axis represents the stiffness of the paper, and the vertical axis represents the distance from the paper discharge outlet by the paper discharge roller 31. Generally, the lower the stiffness of the paper, the closer the position where the leading edge of the paper lands from the paper discharge outlet of the paper discharge roller 31. Therefore, as shown in FIG. 10, it can be seen that the lower the stiffness of the paper, the closer the distance from the paper discharge outlet is to the appropriate static elimination position by the static elimination unit 34. The control unit 21 determines the static elimination position based on a table that shows the correspondence between the paper type (stiffness) and the static elimination position. This allows the paper to be neutralized at an appropriate position depending on the stiffness of the paper.

[0056] The static eliminator 34 is an ionizer that emits positive ions and negative ions toward the surface of the paper. Specifically, the static eliminator 34 is a pulse AC type ionizer.

[0057] FIG. 11 is a diagram for explaining the principle of a pulse AC type ionizer. As shown in Figure 11, the pulsed AC method alternately generates positive and negative ions from all of the electrode needles 34a of the static eliminator 34. This allows a large amount of ions to be generated. Pulsed AC ionizers can quickly eliminate static electricity from paper P. Pulsed AC ionizers can eliminate static electricity from paper P regardless of whether the paper P is positively or negatively charged. In the example shown in Figure 11, it can be seen that the positive and negative charges on the paper P are canceled out by the oppositely charged ions released from the ionizer.

[0058] FIG. 12 shows an example of how the static electricity is removed from the charged paper P by the static eliminator . In the example shown in FIG. 12, it can be seen that the charged paper P is neutralized by passing through the neutralization section .

[0059] As described above, the image forming system 1 according to this embodiment includes a paper discharge member (paper discharge roller 31), a paper stacking unit (paper discharge tray 32), a CD alignment member 33, and a static elimination unit 34. The paper discharge member discharges paper sheets on which images have been formed by the image forming device 10. The paper stacking unit stacks the paper sheets discharged by the paper discharge member. The CD alignment member 33 aligns the paper sheets stacked on the paper stacking unit in the width direction. The static elimination unit 34 non-contactly eliminates static from the paper sheets discharged onto the paper stacking unit. The static elimination unit 34 is positioned outside the movable range of the CD alignment member 33. Therefore, according to the image forming system 1 of this embodiment, it is possible to enable the static eliminator 34 and the CD alignment member to coexist, thereby further improving the alignment of discharged sheets.

[0060] The static eliminator 34 is movable so that the distance between it and the topmost sheet stacked in the sheet stacking section is within a predetermined range. Therefore, even if the center of the paper bulges, the distance between the static eliminator 34 and the paper can be kept appropriate, thereby suppressing the occurrence of direct discharge while maintaining the static elimination effect.

[0061] The static eliminator 34 also includes a detector SE1 that detects the distance between the static eliminator 34 and the topmost sheet of paper stacked in the paper stacking section. The static eliminator 34 is configured to be movable so that the distance detected by the detector SE1 can be maintained within a predetermined range. Therefore, the distance between the static eliminator 34 and the paper can be monitored and always maintained at an appropriate distance, thereby suppressing the occurrence of direct discharge while maintaining the static elimination effect.

[0062] Also, the control unit 21 controls the movement of the static eliminator 34 so that the distance detected by the detector SE1 can be maintained within a predetermined range. Therefore, the distance between the static eliminator 34 and the paper can be automatically maintained at an appropriate level, and the occurrence of direct discharge can be suppressed while maintaining the static elimination effect without imposing a burden on the user.

[0063] Furthermore, the detection position of the detection unit SE1 and the charge removal position of the charge removal unit 34 are the same. Therefore, the distance between the static eliminator 34 and the paper at the static elimination position can be detected accurately, and the occurrence of direct discharge can be more reliably suppressed while maintaining the static elimination effect.

[0064] The device also includes an output control unit (control unit 21) that outputs an alarm when the distance detected by the detection unit SE1 is less than a predetermined threshold. Therefore, if the distance between the static eliminator 34 and the paper is too close, the situation can be notified to the user, and the occurrence of direct discharge can be more reliably suppressed.

[0065] The static eliminator 34 is configured to be movable to a retracted position. Therefore, it is possible to prevent the sheet from getting in the way when removing the sheets from the sheet stacking section, and the sheet can be removed smoothly from the sheet stacking section.

[0066] The static elimination unit 34 is configured to be able to adjust the static elimination position in the paper transport direction, and is also provided with an adjustment unit (control unit 21) that adjusts the static elimination position of the static elimination unit 34 depending on the stiffness of the paper. Therefore, the paper can be neutralized at an appropriate position depending on the stiffness of the paper, and the neutralization effect can be maintained more reliably.

[0067] The static eliminator 34 is an ionizer that emits positive ions and negative ions toward the surface of the paper. Therefore, it is possible to eliminate static electricity from paper whether it is positively or negatively charged. In addition, because it can generate a large amount of ions, static electricity can be eliminated efficiently in a short time.

[0068] Although the present invention has been specifically described above based on the embodiments thereof, the present invention is not limited to the above embodiments and can be modified within the scope of the present invention.

[0069] (Variation 1) For example, in the above embodiment, the support member 35 is fixed to the housing of the post-processing device 20, and the stay 36 is fixed to the support member 35, but the present invention is not limited to this. 13A, 13B, and 13C show a detailed configuration of the paper discharge device 30A according to the first modification. The static eliminator 34 and the detector SE1 are attached to the housing of the post-processing device 20 via a support member 35A and a stay 36A. The support member 35A is attached to the housing of the post-processing device 20 so as to be rotatable. The stay 36A is connected to the support member 35A so as to be folded back. The stay 36A is rotatably supported by the support member 35A.

[0070] The static eliminator 34 and the detector SE1 are attached to a stay 36A. The detector SE1 is attached to the stay 36A so as to be rotatable. The static eliminator 34 is configured to be movable so that the distance to the top sheet P1 stacked on the sheet output tray 32 is within a predetermined range. Specifically, the static eliminator 34 is configured to be movable so that the distance detected by the detector SE1 is maintained within the predetermined range. FIG. 13A shows the initial position of the sheet output device 30A. From the state shown in FIG. 13A, the distance between the static eliminator 34 and the sheet P1 can be adjusted by rotating the support member 35A and the stay 36A up and down. For example, to increase the distance between the static eliminator 34 and the sheet P1, first rotate the support member 35A upward (see FIG. 13B). Next, rotate the stay 36A upward (see FIG. 13C). This increases the distance between the static eliminator 34 and the sheet P1. To decrease the distance between the static eliminator 34 and the sheet P1, rotate the support member 35A and the stay 36A downward.

[0071] (Other variations) Furthermore, in the above embodiment, the control unit 21 controls the movement of the static eliminator 34 so that the distance detected by the detector SE1 can be maintained within a predetermined range, but this is not limited to this. For example, the user may manually move the static eliminator 34 so that the distance detected by the detector SE1 can be maintained within the predetermined range. Furthermore, the detector SE1 may not be provided as long as the distance between the static eliminator 34 and the topmost sheet can be maintained within the predetermined range.

[0072] Furthermore, in the above embodiment, a pulse AC type ionizer is used as the static eliminator 34, but this is not limiting. That is, the ionizer to be used may be selected appropriately depending on the usage situation. Note that known types of voltage application methods to the electrode needles of the ionizer include DC, AC, high-frequency AC, pulse DC, and SSDC. The type may be selected appropriately depending on specifications such as the type of paper and the required static elimination speed. Furthermore, an air blow type may be used instead of an ionizer as the static eliminator 34. However, in the case of an air blow type, there is a risk that the air may cause the paper to become unsteady or the alignment may become poor, so it is more preferable to use an ionizer.

[0073] In the above embodiment, the control unit 21 of the post-processing device 20 controls the movement of the static eliminator 34, but the present invention is not limited to this. For example, the control unit 11 of the image forming device 10 may control the movement of the static eliminator 34.

[0074] In the above embodiment, the post-processing device 20 is provided with the paper discharge device 30, but the present invention is not limited to this. For example, the image forming device 10 may be provided with the paper discharge device 30.

[0075] In addition, the detailed configuration and operation of each device constituting the image forming system can be modified as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0076] 1. Image forming system 10 Image forming device 11 Control section 12 Image reading unit 13 Image forming unit 131 Writing section 131a Optical scanning unit 131b Photoreceptor 131c Development section 131d Charging part 131e Cleaning Department 131f Primary transfer roller 132 Intermediate transfer belt 133 Secondary transfer roller 134 Fixing section 134a Fuser roller 135 Reverse Route 14 Storage section 15 Operation panel 151 Display section 152 Operation section 16 Communications Department 20 Aftertreatment device 21 Control unit (output control unit, adjustment unit) 22 Post-processing section 23 Conveyor 30, 30A paper ejection device 31 Paper discharge roller (paper discharge member) 32 Paper output tray (paper stacking area) 33 CD alignment member 34 Static elimination unit 35, 35A Support member 36, 36A Stay

Claims

1. a paper discharge member that discharges paper on which an image has been formed by the image forming device; a paper stacking section for stacking the paper discharged by the paper discharge member; a CD alignment member that aligns the sheets loaded in the sheet loading section in the width direction; a charge eliminating unit that eliminates charge on the paper discharged to the paper stacking unit in a non-contact manner; Equipped with The paper ejection device is characterized in that the charge removal unit is disposed outside the movable range of the CD alignment member.

2. 2. The paper discharge device according to claim 1, wherein the static eliminator is configured to be movable so that the distance between the static eliminator and the topmost paper sheet stacked on the paper stacking section is within a predetermined range.

3. 3. The paper discharge device according to claim 2, further comprising a detection unit that detects the distance between the static eliminator and the topmost paper sheet stacked on the paper stacking unit.

4. 4. The paper discharge device according to claim 3, wherein the static eliminator is configured to be movable so that the distance detected by the detector can be maintained within a predetermined range.

5. The paper discharge device according to claim 4 , further comprising a control unit that controls movement of the static eliminator so that the distance detected by the detector can be maintained within a predetermined range.

6. 4. The paper discharge device according to claim 3, wherein the detection position of the detection unit and the charge removal position of the charge removal unit are the same.

7. 4. The paper ejection device according to claim 3, further comprising an output control unit that outputs an alarm when the distance detected by the detection unit is less than a predetermined threshold value.

8. 2. The paper discharge device according to claim 1, wherein the static eliminator is configured to be movable to a retracted position.

9. 2. The paper discharge device according to claim 1, wherein the charge eliminating section is configured so that a charge eliminating position in the paper transport direction is adjustable.

10. The paper discharge device according to claim 9, further comprising an adjustment unit that adjusts the neutralization position of the neutralization unit in accordance with the stiffness of the paper.

11. 2. The paper discharge device according to claim 1, wherein the charge eliminating unit is an ionizer that emits positive ions and negative ions toward the surface of the paper.

12. an image forming device that forms an image on a sheet; a paper discharge device according to any one of claims 1 to 11, which discharges paper on which the image has been formed by the image forming device; An image forming system comprising:

Images