Static elimination device and image forming apparatus

Abstract

To improve static elimination performance without limiting the static elimination range of the guide plate, and to ensure the strength of the guide plate without reducing the paper-passability of the guide plate. [Solution] The static eliminator 500 includes a needle-shaped electrode 502 and a guide member 503 that guides the recording medium 9, and the guide member 503 is positioned outside the range of the discharge irradiation angle 2α formed by applying a voltage to the needle-shaped electrode 502.

Description

Technical Field

[0001] The present invention relates to a charge removing device and an image forming apparatus.

Background Art

[0002] In recent years, in an electrophotographic image forming apparatus, a technique has been proposed in which a guide plate for guiding a sheet in an ionizer charge removing unit using a needle electrode is composed of an insulating member having an opening.

[0003] For example, Patent Document 1 discloses a charge removing device and an image forming system that improve the conveyance accuracy of a recording material while maintaining charge removing performance (see Patent Document 1).

[0004] The abstract of this Patent Document 1 discloses that "The charge removing device includes a conveyance guide part which is an example of a guide part, a first ionizer and a second ionizer which are examples of ionizers. The conveyance guide part guides a sheet which is an example of a recording material. The first ionizer and the second ionizer remove the charge of the sheet guided by the conveyance guide part with the generated ions. The conveyance guide part is at least made of an insulating material on the surface. The conveyance guide part has a first guide member that guides the first surface side of the sheet and a second guide member that is arranged opposite to the first guide member and guides the second surface side of the sheet S." (see the abstract of Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the static elimination device described in Patent Document 1 had the problem that the static elimination range of the ionizer was limited by the insulating material around the opening, resulting in reduced static elimination performance. In addition, increasing the opening of the guide plate to improve static elimination performance resulted in reduced paper passability and a decrease in the strength of the guide plate.

[0007] In addressing these challenges, the present invention aims to improve static elimination performance without limiting the static elimination range provided by the guide plate, and to ensure the strength of the guide plate without reducing its paper-passability. [Means for solving the problem]

[0008] In other words, the above-mentioned problems of the present invention are solved by the following configuration. (1) Needle-shaped electrode and It has a guide member that guides the recording medium, The guide member is The needle-shaped electrode is positioned outside the range of the discharge irradiation angle formed by applying a voltage to the needle-shaped electrode, Static eliminator. (2) The discharge irradiation angle 2α is, If the distance between the static elimination needles is D and the discharge distance is L, Satisfying tanα≧D / (2L), (1) The static elimination device described above. (3) The thickness H of the guide member is If the discharge distance L is taken as the surface of the recording medium that is irradiated, Satisfying 2[mm]≦H≦L, (1) The static elimination device described above. (4) The aperture diameter of the needle electrode is If h is the distance from the surface on which the recording medium is irradiated to the lower end of the guide member, Satisfying d≧D×(Lh) / L, (2) The static elimination device described above. (5) The guide member is The recording medium is positioned such that the amount of charge on it after static discharge is 100[V] or less. (1) The static elimination device described above. (6) The guide member is formed in a comb shape having a horseshoe-shaped opening. The static eliminator according to (1). (7) The guide member is formed in a comb shape having a rectangular horseshoe-shaped opening. The static eliminator according to (1). (8) The guide member has a protruding portion in the conveyance direction of the recording medium, and each of the protruding portions <� is disposed at the center between the needle electrodes. The static eliminator according to (1). (9) The guide member has a protruding portion in the conveyance direction of the recording medium, and each of the protruding portions is formed to be narrower in the conveyance direction of the recording medium. The static eliminator according to (1). (10) The cross-sectional shape of the guide member is formed to be narrower in the direction of the surface irradiated by the recording medium. The static eliminator according to (1). (11) The discharge distance L from the needle electrode to the recording medium is 50 [mm] ≦ L ≦ 100 [mm], The static eliminator according to (1). (12) The static eliminator further includes a lower guide member that guides the lower side of the recording medium, and the lower guide member is formed of an insulating member, and the portion facing the recording medium is non-opening. The static eliminator according to (1). (13) A needle electrode and <� a guide member that guides the recording medium, and the guide member is disposed outside the range of the discharge irradiation angle formed by applying a voltage to the needle electrode. An image forming apparatus including the same. (14) The static eliminator One or more are arranged at the subsequent stage of the fixing unit that fixes an image on the recording medium. The image forming apparatus according to (13). (15) The charge removing device One or more are arranged at the preceding stage of the image forming unit that transfers an image to the recording medium. The image forming apparatus according to (13). [Effect of the Invention]

[0009] According to the present invention, the charge removing device and the image forming apparatus can improve the charge removing performance without restricting the charge removing range by the guide plate, and can secure the strength of the guide plate without degrading the paper passing property of the guide plate. [Brief Description of the Drawings]

[0010] [Figure 1] It is a diagram for explaining a configuration example of an image forming system according to the present embodiment. [Figure 2] It is a functional block diagram for explaining the configuration of an image forming system according to the present embodiment. [Figure 3A] It is a block diagram showing a configuration of the charge removing device as viewed from the paper passing direction of the charge removing device. [Figure 3B] [[ID=ID=32]]It is a cross-sectional view showing a cross-section in the paper passing direction of the charge removing device. [Figure 4] It is a graph for explaining a position where a guide member of a charge removing device according to the second embodiment is arranged. [Figure 5] It is a top view of a guide member of a charge removing device according to the third embodiment (Part 1). [Figure 6] It is a top view of a guide member of a charge removing device according to the third embodiment (Part 2). [Figure 7] It is a top view of a guide member of a charge removing device according to the third embodiment (Part 3). [Figure 8] It is a top view of a guide member of a charge removing device according to the third embodiment (Part 4). [Figure 9A] It is a top view of a guide member of a charge removing device according to the fourth embodiment (Part 1). [Figure 9B]Cross-sectional view AA of the guide member of the static elimination device according to the fourth embodiment (part 1). [Figure 10A] This is a top view (part 2) of the guide member of the static elimination device according to the fourth embodiment. [Figure 10B] A cross-sectional view of the guide member BB of the static elimination device according to the fourth embodiment (part 2). [Figure 11A] This is a top view (part 3) of the guide member of the static elimination device according to the fourth embodiment. [Figure 11B] A cross-sectional view of the CC of the guide member of the static elimination device according to the fourth embodiment (part 3). [Figure 12] This is an explanatory diagram showing the configuration of the static elimination device according to the fifth embodiment. [Figure 13A] This is a top view of the upper guide member of the guide member of the static elimination device according to the sixth embodiment. [Figure 13B] This is a top view of the lower guide member of the static elimination device according to the sixth embodiment. [Modes for carrying out the invention]

[0011] The embodiments for carrying out the present invention will be described in detail below. The embodiments described below are merely examples for realizing the present invention. Therefore, they should be modified or changed as appropriate depending on the configuration of the apparatus to which the present invention is applied and various conditions, and the present invention is not limited to the embodiments described below. Furthermore, the same reference numerals are used for identical components, and descriptions are omitted as appropriate.

[0012] <This embodiment> [Outline configuration of the image forming system] Figure 1 is a diagram illustrating an example of the configuration of the image forming system 600 according to this embodiment. As shown in Figure 1, the image forming system 600 is configured to include, from the upstream side along the transport direction 700 of the recording medium 9, a paper feed device 100, an image forming device 200, a non-loading unit 300, a loading unit 400, and a static eliminator 500. Figure 2 is a functional block diagram illustrating the configuration of the image forming system 600 according to this embodiment.

[0013] Here, the recording medium 9 is, for example, printing paper. However, the recording medium is not limited to printing paper, and may also be recording materials such as OHP (Over Head Projector) sheets, fabric, or film.

[0014] As shown in Figure 1, the paper feeder 100 holds the recording medium 9. The paper feeder 100 supplies the recording medium 9 to the image forming apparatus 200. The paper feeder 100 has multiple rollers (not shown) inside its housing, and transports the recording medium 9 to the image forming apparatus 200 at a constant speed via these rollers. The paper feeder 100 is also connected to an operation display unit 10.

[0015] As shown in Figure 2, the operation display unit 10 comprises a display unit 11 and an operation unit 12. The display unit 11 has a display screen as a setting unit and displays various information on the screen. The operation unit 12 accepts various instructions from the user.

[0016] As shown in Figure 2, the image forming apparatus 200 is configured to include an image forming unit 210 and a fixing unit 220.

[0017] The image forming unit 210 forms toner images on the recording medium 9. The image forming unit 210 forms toner images of each color by an electrophotographic process and transfers the formed toner images to the recording medium 9. In this way, the image forming unit 210 forms a color image in which the toner images of each color are superimposed. Note that this embodiment is not limited to an electrophotographic process as long as an image can be transferred to the recording medium 9.

[0018] As shown in Figure 2, the fuser unit 220 is configured to include a heating roller 221 and a pressure roller 222. The heating roller 221 and the pressure roller 222 constitute a pair of rollers. The fuser unit 220 heats the recording medium 9 with the heating roller 221 to fix the toner image. In this way, the fuser unit 220 fixes the toner image transferred to the recording medium 9.

[0019] The heating roller 221 is heated to a predetermined temperature by a fixing heater, which acts as a heat source. The pressure roller 222 is pressed against or separated from the heating roller 221 at predetermined timings, under the control of the control unit 230. The recording medium 9 on which the toner image has been transferred is subjected to heat and pressure as it passes through the nip between the heating roller 221 and the pressure roller 222, causing the toner image to melt and fix.

[0020] The control unit 230 is composed of, for example, a CPU (Central Processing Unit) and RAM (Random Access Memory), which are not shown. The CPU of the control unit 230 reads various programs stored in the memory unit 240, loads them into the RAM, and executes various processes according to the loaded programs. The control unit 230 receives instructions from the user via the operation unit 12 through the paper feed device 100, and executes printing by controlling the image forming unit 210 and the fuser unit 220.

[0021] The storage unit 240 is composed of, for example, an HDD (Hard Disk Drive) or semiconductor non-volatile memory. The storage unit 240 stores various programs, including system programs and processing programs executed by the control unit 230, as well as data necessary for the execution of these programs.

[0022] When the image forming apparatus 200 transfers a toner image onto the recording medium 9, it transports the recording medium 9 with the transferred toner image to the non-loading unit 300.

[0023] The non-loaded unit 300 is composed of non-loaded units 310 to 330. When it is not necessary to specify any of the non-loaded units 310 to 330, they are collectively referred to as non-loaded unit 300. The non-loaded unit 300 does not need to include all of the non-loaded units 310 to 330, and can be provided as appropriate.

[0024] Each of the non-loading units 310 to 330 performs the corresponding processing as needed. For example, non-loading unit 310 corrects the curl of the recording medium 9 on which the toner image is formed. Non-loading unit 320 detects the position of the image on the recording medium 9 on which the toner image is formed. Non-loading unit 330 folds the recording medium 9 on which the toner image is formed. In this case, non-loading unit 330 can fold it in various ways, such as a tri-fold, a quad-fold, or a gatefold.

[0025] As shown in Figure 1, the non-loading unit 300 transports the recording medium 9, which has been transported from the image forming apparatus 200, to the loading unit 400.

[0026] The loading unit 400 is comprised of loading unit 410 and loading unit 420. Loading unit 410 binds folded recording media 9 and loads the bound media. On the other hand, recording media 9 that are not bound in loading unit 410 pass through loading unit 410 and are transported to loading unit 420. Loading unit 420 loads recording media 9 that have not been folded.

[0027] As shown in Figure 1, the static elimination device 500 is composed of static elimination devices 510 to 540. When it is not necessary to specify one of the static elimination devices 510 to 540, it is collectively referred to as the static elimination device 500. Furthermore, the static elimination device 500 does not need to be equipped with all of the static elimination devices 510 to 540; they can be installed in predetermined locations as appropriate.

[0028] For example, one or more static eliminators 510 are positioned before the image forming unit 210 of the image forming apparatus 200, which transfers a color image onto the recording medium 9. Also, one or more static eliminators 520 are positioned after the fixing unit 220 of the image forming apparatus 200, which fixes the color image onto the recording medium 9. In this embodiment, the image forming apparatus 200 may also be equipped with static eliminators 510 and 520.

[0029] The static elimination device 500 eliminates static electricity from the recording medium 9. The static elimination device 500 generates ions (charges) in the air and removes static electricity by adding these ions to the charged recording medium 9. Each static elimination device 510 to 540 eliminates static electricity from the transported recording medium 9 and transports the de-staticized recording medium 9 to the next device.

[0030] In this embodiment, as shown in Figure 2, the control unit 230 controls the image forming apparatus 200 comprehensively, thereby controlling the image forming system 600. However, the paper feed device 100 and the static elimination device 500 may each be configured to have their own control units.

[0031] Furthermore, the image forming apparatus 200 may be an MFP (Multi-Function Peripheral) that, in addition to image forming functions, also has copying, scanning, facsimile, and other functions.

[0032] <First Embodiment> [Configuration of the static elimination device] Next, the configuration of the static elimination device 500 of the image forming system 600 in the first embodiment will be described.

[0033] Figure 3A is a block diagram showing the configuration of the static elimination device 500 as viewed from the paper feeding direction 701. Figure 3B is a cross-sectional view showing the static elimination device 500 in the paper feeding direction 701. The paper feeding direction 701 is, for example, the direction in which paper is transported from the paper feed device 100 to the image forming apparatus 200, and also the direction in which paper is transported from the image forming apparatus 200 to the non-loaded unit 300.

[0034] As shown in Figure 3A, the static elimination device 500 comprises an ionizer 501, a needle-shaped electrode 502, a guide member 503, and a recording medium 9. Also, as shown in Figure 3B, the guide member 503 comprises an upper guide member 5031, a lower guide member 5032, and a recording medium 9.

[0035] The guide member 503 in Figure 3A schematically represents the upper guide member 5031 in Figure 3B. That is, the upper side (ionizer 501 side) of the guide member 503 is open to the recording medium 9 by the upper guide member 5031. On the other hand, the lower guide member 503 is guided to the recording medium 9 from below by the lower guide member 5032. The lower guide member 5032 is made of an insulating material and has a closed portion facing the recording medium 9.

[0036] The guide member 503 guides the recording medium 9. The guide member 503 is positioned outside the range of the discharge irradiation angle formed by applying voltage to the needle-shaped electrode 502. In this case, given the static elimination needle spacing D, discharge distance L, and discharge irradiation angle 2α, the conditions under which angle α can take are expressed by the following equation (1).

[0037] tanα≧D / (2L) ···(1) Here, 2α: discharge irradiation angle L: Discharge distance D: Static elimination needle interval

[0038] Furthermore, the conditions under which the thickness H of the guide member 503 can be expressed by the following equation (2), where L is the discharge distance.

[0039] 2 [mm] ≤ H ≤ L ···(2) Here, H: thickness of the guide member L: Discharge distance

[0040] Furthermore, the conditions under which the aperture diameter d of the needle electrode 502 can be set are expressed by the following equation (3), where h is the distance from the surface to which the recording medium 9 is irradiated to the lower end of the guide member 503.

[0041] d≧D×(Lh) / L ···(3) Here, d: aperture diameter of the needle-shaped electrode 502 h: Distance from the surface to which the recording medium 9 is illuminated to the lower end of the guide member 503

[0042] Furthermore, as shown in Figure 3A, the guide member 503 has a protruding portion in the paper feeding direction 701 of the recording medium 9 shown in Figures 5 to 11B, via the upper guide member 5031 shown in Figure 3B. Each protruding portion of the guide member 503 is positioned in the center between the needle-shaped electrodes 502.

[0043] As described above, the static elimination device 500 according to the first embodiment includes a needle-shaped electrode 502 and a guide member 503 that guides the recording medium 9. The guide member 503 is positioned outside the range of the discharge irradiation angle formed by applying a voltage to the needle-shaped electrode 502.

[0044] As a result, the static elimination device 500 according to the first embodiment can improve static elimination performance without limiting the static elimination range by the guide member 503, and can ensure the strength of the guide member 503 without reducing the paper-passability of the guide member 503.

[0045] Furthermore, the conditions under which the discharge irradiation angle 2α can take place are, given by the spacing of the static elimination needles D and the discharge distance L, tanα≧D / (2L), as shown in equation (1).

[0046] Furthermore, the conditions under which the thickness H of the guide member 503 can be given by the discharge distance L are 2 [mm] ≤ H ≤ L, as shown in equation (2).

[0047] Furthermore, the conditions under which the aperture diameter d of the needle electrode 502 can be set are d ≥ D × (Lh) / L, where h is the distance from the surface of the recording medium 9 that is irradiated to the lower end of the guide member 503.

[0048] The guide member 503 has a protruding portion in the transport direction 700 (paper feeding direction 701) of the recording medium 9 shown in Figures 5 to 11B, provided by the upper guide member 5031, and each protruding portion may be positioned in the center between the needle-shaped electrodes 502.

[0049] <Second Embodiment> [Configuration of the static elimination device] Next, the static elimination device 500 according to the second embodiment will be described.

[0050] Figure 4 is a graph illustrating the position of the guide member 503 of the static elimination device 500 according to the second embodiment.

[0051] Figure 4 shows that the guide member 503 is positioned such that the charge of the recording medium 9 after static discharge is 100V or less, with the horizontal axis representing the opening diameter d [mm] of the guide member 503 and the vertical axis representing the charge amount [V].

[0052] Figure 4 shows the charge amount [V] of the recording medium 9 after static discharge. For example, if the discharge distance L is 60 [mm], the static discharge needle spacing D is 70 [mm], and the distance h is 2 [mm], and equations (1) and (3) are satisfied, the guide member 503 is placed at a position where the charge amount is 100 [V] or less without the guide member 503.

[0053] As described above, the guide member 503 of the static elimination device 500 according to the second embodiment is positioned so that the amount of charge on the recording medium 9 after static elimination is 100[V] or less.

[0054] As a result, the static elimination device 500 according to the second embodiment can maintain its static elimination performance based on experimental results by positioning the guide member 503 at a position where the amount of charge on the recording medium 9 is 100[V] or less.

[0055] <Third Embodiment> [Configuration of the static elimination device] Next, the configuration of the guide member 503 of the static elimination device 500 according to the third embodiment will be described.

[0056] Figure 5 is a top view of the guide member 504 of the static elimination device 500 according to the third embodiment (Part 1).

[0057] As shown in Figure 5, the guide member 504 is formed in a comb-tooth shape with a horseshoe-shaped opening. The opening diameter d1 is greater than or equal to the opening diameter d in equation (3), and the horseshoe-shaped opening side is in the paper feeding direction 701.

[0058] Figure 6 is a top view of the guide member 505 of the static elimination device 500 according to the third embodiment (part 2).

[0059] As shown in Figure 6, the guide member 505 is formed in a comb-like shape with a rectangular horseshoe-shaped opening. The opening diameter d2 is greater than or equal to the opening diameter d in equation (3), and the opening side of the rectangular horseshoe shape is in the paper feeding direction 701.

[0060] As described above, the guide members 504 and 505 of the static elimination device 500 according to the third embodiment have a horseshoe shape on the downstream side. Since the guide members 504 and 505 are open on the downstream side in the paper feeding direction 701 of the recording medium 9, it is possible to prevent the leading edge of the recording medium 9 from getting caught and thus prevent jams from occurring. Therefore, the guide members 504 and 505 can improve the transportability of the recording medium 9.

[0061] Although Figures 5 and 6 describe the guide members 504 and 505 formed in a comb-tooth shape with a horseshoe-shaped opening, the third embodiment is not limited to the shape of the guide members 504 and 505.

[0062] Figure 7 is a top view of the guide member 5051 of the static elimination device 500 according to the third embodiment (part 3). Figure 8 is a top view of the guide member 5052 of the static elimination device 500 according to the third embodiment (part 4).

[0063] As shown in Figures 7 and 8, the guide members 5051 and 5052 are formed in a comb-like shape with a rectangular horseshoe-shaped opening. Because the guide members 5051 and 5052 have, for example, a rectangular horseshoe-shaped opening, the tip of the recording medium 9 is prevented from colliding with the guide member 503. Furthermore, since the opening of the guide member 5052 is wider than that of the guide member 5051, a margin can be secured for the installation position of the needle-shaped electrode 502.

[0064] <Fourth Embodiment> [Configuration of the static elimination device] Next, the configuration of the guide member 506 of the static elimination device 500 according to the fourth embodiment will be described.

[0065] Figure 9A is a top view (part 1) of the guide member 506 of the static elimination device 500 according to the fourth embodiment. Figure 9B is a cross-sectional view (part 1) of the guide member 506 of the static elimination device 500 according to the fourth embodiment.

[0066] As shown in Figures 9A and 9B, the guide member 506 has protruding portions in the transport direction 700 of the recording medium 9. Each protruding portion of the guide member 506 is formed to be narrow in the transport direction 700 of the recording medium 9. The transport direction 700 is the same direction as the paper feeding direction 701.

[0067] Furthermore, as shown in Figure 9B, the cross-sectional shape of the guide member 506 is formed to be narrow in the direction of the surface to which the recording medium 9 is irradiated. The irradiation direction 702 indicates the direction of the surface to which the recording medium 9 is irradiated.

[0068] Figure 10A is a top view of the guide member 507 of the static elimination device 500 according to the fourth embodiment (part 2). Figure 10B is a cross-sectional view BB of the guide member 507 of the static elimination device 500 according to the fourth embodiment (part 2).

[0069] As shown in Figures 10A and 10B, the guide member 507 has protruding portions in the transport direction 700 of the recording medium 9. Each protruding portion of the guide member 507 is formed to be narrow in the transport direction 700 of the recording medium 9. The transport direction 700 is the same direction as the paper feeding direction 701.

[0070] Furthermore, as shown in Figure 10B, the cross-sectional shape of the guide member 507 is formed to be narrow in the direction of the surface to which the recording medium 9 is irradiated. The irradiation direction 702 indicates the direction of the surface to which the recording medium 9 is irradiated.

[0071] Figure 11A is a top view of the guide member 5061 of the static elimination device 500 according to the fourth embodiment (part 3). Figure 11B is a cross-sectional view of the CC of the guide member 5061 of the static elimination device 500 according to the fourth embodiment (part 3).

[0072] As shown in Figures 11A and 11B, the guide member 5061 has protruding portions in the transport direction 700 of the recording medium 9. Each protruding portion of the guide member 5061 is formed to be narrow in the transport direction 700 of the recording medium 9. The transport direction 700 is the same direction as the paper feeding direction 701.

[0073] Furthermore, as shown in Figure 11B, the cross-sectional shape of the guide member 5061 is formed to be narrow in the direction of the surface to which the recording medium 9 is irradiated. The irradiation direction 702 indicates the direction of the surface to which the recording medium 9 is irradiated.

[0074] As described above, the guide members 506, 507, and 5061 of the static elimination device 500 according to the fourth embodiment are open on the downstream side. Furthermore, the protruding portions of the guide members 506, 507, and 5061 are formed into a mortar-like shape by making the cross-sectional shape narrow in the direction of irradiation 702 to which the recording medium 9 is irradiated.

[0075] As a result, the guide members 506, 507, and 5061 not only prevent jams by avoiding the tip of the recording medium 9 getting caught, but also ensure the strength of each protruding part. Therefore, the guide members 506, 507, and 5061 can be improved in terms of transportability, static elimination, and strength.

[0076] <Fifth Embodiment> [Configuration of the static elimination device] Next, the configuration of the static elimination device 500 according to the fifth embodiment will be described.

[0077] Figure 12 is an explanatory diagram showing the configuration of a static elimination device 500 according to the fifth embodiment. As shown in Figure 12, the static elimination device 500 is configured to include an AC high-voltage power supply 550, a needle-shaped electrode 502, a counter electrode 560, and GND.

[0078] The AC high-voltage power supply 550 applies a voltage to the needle-shaped electrode 502. This causes the AC high-voltage power supply 550 to generate a corona discharge between the needle-shaped electrode 502 and the counter electrode 560. When the corona discharge occurs, the static eliminator 500 converts the air around the electrode needle of the needle-shaped electrode 502 into ions. The static eliminator 500 then coats the recording medium 9 with these converted ions, thereby eliminating static electricity from the recording medium 9.

[0079] Here, the conditions under which the discharge distance L from the needle electrode 502 to the recording medium 9 can be expressed by the following equation (4).

[0080] 50[mm]≦L≦100[mm] (4)

[0081] In the static elimination device 500 according to the fifth embodiment, for example, if the discharge distance L from the needle electrode 502 to the recording medium 9 is long, exceeding 300 [mm], ion neutralization occurs, and the static elimination performance deteriorates.

[0082] Therefore, in the fifth embodiment of the static elimination device 500, the discharge distance L from the needle electrode 502 to the recording medium 9 is set to 50 [mm] ≤ L ≤ 100 [mm] as shown in equation (4). This allows the static elimination device 500 to maintain its static elimination performance.

[0083] <Sixth Embodiment> The static elimination device 500 according to the sixth embodiment has a lower guide member 5032 that guides the lower side of the recording medium 9, and the lower guide member 5032 is made of an insulating material and the portion facing the recording medium 9 may be non-opening.

[0084] Figure 13A is a top view of the upper guide member 508 of the guide member 503 of the static elimination device 500 according to the sixth embodiment. Figure 13B is a top view of the lower guide member 509 of the guide member 503 of the static elimination device 500 according to the sixth embodiment.

[0085] As shown in Figure 13B, the guide member 503 of the static elimination device 500 according to the sixth embodiment may have a non-opening lower guide member 5032, similar to the lower guide member 509 in Figure 3B. Furthermore, the guide member 503 of the static elimination device 500 according to the sixth embodiment may have the upper guide member 508 and / or the lower guide member 509 formed of an insulating material.

[0086] <Other Embodiments> Furthermore, the image forming system 600 according to this embodiment includes a static elimination device 500. The static elimination device 500 has a needle-shaped electrode 502 and a guide member 503 that guides the recording medium 9, and the guide member 503 is positioned outside the range of the discharge irradiation angle formed by applying a voltage to the needle-shaped electrode 502. Therefore, this embodiment can be configured as an image forming system 600 equipped with a static elimination device 500.

[0087] Furthermore, the image forming apparatus 200 according to this embodiment may be configured to include a static elimination device 500. In this case, one or more static elimination devices 510 may be placed in front of the image forming unit 210 that transfers an image onto the recording medium 9. Alternatively, one or more static elimination devices 520 may be placed in behind the fixing unit 220 that fixes the image onto the recording medium 9. [Explanation of symbols]

[0088] 10 Operation display section 11 Display section 12 Control section 100 Paper feeder 200 Image forming apparatus 210 Image forming unit 220 Fixing section 221 Heating roller 222 Pressure roller 230 Control Unit 300, 310, 320, 330 Non-loaded units 400, 410, 420 Loading Units 500,510,520,530,540 Static eliminator 501 Ionizer 502 Needle electrode 503 Guide member 504-507 Guide members 5031, 508 Upper guide member 5032, 509 Lower guide member 600 Image Forming Systems

Claims

1. Needle-shaped electrode and It has a guide member that guides the recording medium, The guide member is The needle-shaped electrode is positioned outside the range of the discharge irradiation angle formed by applying a voltage to the needle-shaped electrode, Static eliminator.

2. The aforementioned discharge irradiation angle 2α is If the distance between the static elimination needles is D and the discharge distance is L, Satisfying tanα ≥ D / (2L), The static elimination device according to claim 1.

3. The thickness H of the guide member is If the discharge distance L is taken with reference to the surface of the recording medium that is irradiated, Satisfying 2 [mm] ≤ H ≤ L, The static elimination device according to claim 1.

4. The aperture diameter of the needle-shaped electrode is If h is the distance from the surface on which the recording medium is irradiated to the lower end of the guide member, d ≥ D × (L - h) / L The static elimination device according to claim 2.

5. The guide member is The recording medium is positioned such that the amount of charge on the recording medium after static discharge is 100 [V] or less. The static elimination device according to claim 1.

6. The guide member is It is formed in a comb-like shape with a horseshoe-shaped opening. The static elimination device according to claim 1.

7. The guide member is It is formed in a comb-like shape with a rectangular, horseshoe-shaped opening. The static elimination device according to claim 1.

8. The guide member is The recording medium has a protruding portion in the transport direction, Each of the aforementioned protruding portions is The following are positioned in the center between the aforementioned needle-shaped electrodes: The static elimination device according to claim 1.

9. The guide member is The recording medium has a protruding portion in the transport direction, Each of the aforementioned protruding portions is Formed to be narrow in the direction of transport of the recording medium, The static elimination device according to claim 1.

10. The cross-sectional shape of the guide member is, The recording medium is formed to be narrow in the direction of the surface to which it is illuminated, The static elimination device according to claim 1.

11. The discharge distance L from the needle electrode to the recording medium is 50 [mm] ≤ L ≤ 100 [mm] The static elimination device according to claim 1.

12. The recording medium further includes a lower guide member that guides the lower side of the recording medium, The lower guide member is, It is made of an insulating material, and the portion facing the recording medium is not open. The static elimination device according to claim 1.

13. Needle-shaped electrode and It has a guide member that guides the recording medium, The guide member is A static elimination device is positioned outside the range of the discharge irradiation angle formed by applying voltage to the needle-shaped electrode, An image forming apparatus equipped with this device.

14. The static elimination device is, One or more are placed after the fixing unit that fixes the image onto the recording medium, The image forming apparatus according to claim 13.

15. The static elimination device is, One or more are arranged in front of the image forming unit that transfers an image onto the recording medium, The image forming apparatus according to claim 13.

Images