JP2005231863A - Static eliminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a static eliminator capable of providing satisfactory static eliminating efficiency and preventing occurrence of disorder in unfixed toner image on a recording material. <P>SOLUTION: An electrical conductive nonwoven fabric 71 opposes to the recording material S on which unfixed toner image is transferred and which is conveyed to eliminate static of the recording material S. With respect to the direction F of conveyance of the recording material, only front fringe part 71f and rear fringe part 71r of a face 71a opposing to the recording material in the electrical conductive nonwoven fabric 71 are covered with electrical conductive members 72f, 72r. Side fringe parts on the left and right sides of the electrical conductive nonwoven fabric are arranged outside a region in which toner image is formed on the recording material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention eliminates the charge of a recording material to which an unfixed toner image is transferred in an image forming apparatus such as a printer, a facsimile, or a copying machine that forms a toner image on a recording material such as paper using electrophotographic technology. It is related with the static elimination apparatus used in order to do.

In an image forming apparatus using an electrophotographic technique, a recording material to which an unfixed toner image is transferred and conveyed by a transfer unit is charged.
If this charging is left unattended, troubles such as hindering subsequent smooth conveyance of the recording material occur, and therefore it is necessary to neutralize the recording material.
The static eliminator is configured such that a conductive non-woven fabric formed by processing countless conductive fibers into a sheet shape is opposed to a recording material to which an unfixed toner image is transferred and conveyed, and the ends of the conductive fibers on the facing surface thereof. It is known that the recording material is discharged by discharging between the recording portion and the recording material.
According to such a static eliminator, it is expected that discharge of the recording material is efficiently performed because discharge is performed between the end portions of countless conductive fibers and the recording material. Due to the fluffing of the conductive fibers on the surface facing the material, there is a problem that when the conductive fibers come into contact with the recording material, abnormal discharge occurs and the unfixed toner image on the recording material is disturbed.
Therefore, in order to solve such a problem, the entire surface of the conductive nonwoven fabric facing the recording material is covered with a sheet-like conductive member (see Patent Document 1), and the entire surface of the opposing surface is also formed into a net-like conductivity. The thing covered with the member (refer patent document 2) has already been proposed. In addition, for the purpose of improving conductivity and adhesiveness, a material in which a pressure-sensitive adhesive is attached to the voids of a conductive nonwoven fabric is known (see Patent Document 3).
JP 2001-278486 A Japanese Patent Laid-Open No. 07-2014487 Japanese Patent Laid-Open No. 06-104093

Each of the conventional techniques described above has the following drawbacks. That is,
In the thing of patent document 1, since the opposing surface with the recording material in a conductive nonwoven fabric is covered with the sheet-like conductive member over the whole surface, the discharge between the edge part of an electroconductive fiber and a recording material Cannot be expected, and the static elimination efficiency is extremely low.
In the thing of patent document 2, since the member which covers the opposing surface with the recording material in a conductive nonwoven fabric has a net shape, compared with the thing of patent document 1, the improvement in static elimination efficiency can be expected, Nevertheless, since the entire opposite surface of the conductive nonwoven fabric is still covered, the static elimination efficiency is still low.
As for the thing of patent document 3, since the adhesive has adhered to the space | gap of an electroconductive nonwoven fabric, it is thought that the fuzz of a conductive fiber is suppressed as a result, but static elimination efficiency falls by the insulation of an adhesive. End up.
SUMMARY OF THE INVENTION An object of the present invention is to provide a static eliminator that can obtain good static elimination efficiency and at the same time, is less likely to cause disturbance in an unfixed toner image on a recording material.

In order to achieve the above object, the static eliminator of the present invention is a static eliminator that neutralizes a recording material with a conductive nonwoven fabric facing a recording material to which an unfixed toner image is transferred and conveyed.
With respect to the conveyance direction of the recording material, only the front edge and the rear edge of the conductive nonwoven fabric facing the recording material are covered with a conductive member.
With such a configuration, the following effects can be obtained.
Usually, the conductive non-woven fabric has intense fuzz of conductive fibers at the edge portion, and there is little fuzz at the central portion.
According to this invention, with respect to the recording material conveyance direction, the front edge and the rear edge of the conductive nonwoven fabric facing the recording material are covered with the conductive member. The fluffing of the synthetic fiber is prevented. Therefore, contact between the conductive fibers and the recording material is prevented, abnormal discharge is prevented, and disturbance of the unfixed toner image on the recording material is also suppressed.
At the same time, the front surface and the rear edge of the conductive nonwoven fabric facing the recording material are covered only with the conductive material, and other parts (the central part and the part with less fuzz) are open. Therefore, in this portion, the discharge is satisfactorily discharged between the end portion of the conductive fiber and the recording material, and the recording material is efficiently discharged.
Therefore, according to the present invention, it is possible to prevent the unfixed toner image from being disturbed without reducing the static elimination efficiency.
Preferably, the conductive member is a conductive member that also covers side surfaces (a front surface and a rear surface) of the front edge portion and the rear edge portion.
If comprised in this way, since the fluff of the conductive fiber in the side surface adjacent to the said opposing surface is also suppressed, a contact with a conductive fiber and a recording material will be prevented more reliably.
Desirably, the left and right side edge portions of the conductive nonwoven fabric are arranged outside a region (image forming region) where a toner image is formed on the recording material with respect to the conveyance direction of the recording material.
Assuming that the left and right side edges of the conductive nonwoven fabric are arranged in the image forming region with respect to the conveyance direction of the recording material, the conductive fibers are conductive due to the fuzz of the conductive fibers at the left and right side edges of the conductive nonwoven fabric. Although the fiber end and the recording material may come into contact with each other in the image forming area and the toner image on the recording material may be disturbed, the left and right side edges of the conductive nonwoven fabric should be arranged outside the image forming area. Thus, such a situation can be surely prevented.
Desirably, a conductive plate for applying a voltage to the conductive nonwoven fabric is provided on the non-opposing surface of the conductive nonwoven fabric with respect to the recording material, and at least the conductive nonwoven fabric of the conductive member and the conductive member is provided. The conductive member covering the front edge is electrically connected.
With such a configuration, a static elimination voltage can be efficiently applied to the conductive nonwoven fabric, and the static elimination efficiency can be further improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic side view showing an internal structure of an example of an image forming apparatus using an embodiment of a static eliminator according to the present invention.
This image forming apparatus is a color image forming apparatus capable of forming a full-color image on both sides of an A3 size sheet (recording material). The image forming unit 20 is accommodated in the case 10 and the case 10. And an exposure unit 30 as exposure means, a developing device (developing device) 40 as developing means, an intermediate transfer body unit 50, and a fixing unit (fixing device) 60 as fixing means.
The case 10 is provided with a frame (not shown) of the apparatus main body, and each unit is attached to the frame.

The image carrier unit 20 includes a photoconductor (image carrier) 21 having a photosensitive layer on the outer peripheral surface, and a corona charger (scorotron charger) 22 as a charging unit that uniformly charges the outer peripheral surface of the photoconductor 21. And forming an electrostatic latent image by selectively exposing the outer peripheral surface of the photoconductor 21 uniformly charged by the corona charger 22 with the laser light L from the exposure unit 30, A toner that is a developer is applied to the electrostatic latent image by the developing device 40 to form a visible image (toner image), and the toner image is primarily transferred to the intermediate transfer belt 51 of the intermediate transfer body unit 50 by the primary transfer portion T1. In addition, the secondary transfer unit T2 performs secondary transfer onto a sheet to be transferred.
The image carrier unit 20 includes a cleaning unit (cleaning blade) 23 that removes toner remaining on the surface of the photoconductor 21 after the primary transfer, and a waste toner storage that stores waste toner removed by the cleaning unit 23. As a part, a waste toner storage unit 24 is provided.

In the case 10, a conveyance path 16 that conveys a sheet on which an image is formed on one side by the secondary transfer section T <b> 2 toward a sheet discharge section (discharge tray section) 15 on the top surface of the case 10, and the conveyance path 16 A return path 17 is provided for switching back the sheet conveyed toward the sheet discharge unit 15 and returning it to the secondary transfer unit T2 so as to form an image on the other side.
Under the case 10, there are provided a paper feed tray 18 for laminating and holding a plurality of sheets, and a paper feed roller 19 for feeding the sheets one by one toward the secondary transfer portion T2.

  The developing device 40 is a rotary developing device, and a plurality of developing device cartridges each containing toner are detachably attached to the rotating body main body 41. In this embodiment, a yellow developer cartridge 42Y, a magenta developer cartridge 42M, a cyan developer cartridge 42C, and a black developer cartridge 42K are provided (in the drawing, yellow Only the developing device cartridge 42Y is directly drawn), and the rotating body main body 41 is rotated at a pitch of 90 degrees in the direction of the arrow so that the developing roller 43 is selectively brought into contact with the photosensitive body 21 and the photosensitive body 21 The surface can be selectively developed.

The exposure unit 30 is configured to irradiate the photosensitive member 21 with the laser light L from an exposure window 31 made of plate glass or the like.
The intermediate transfer body unit 50 stabilizes the state of the belt 51 at a unit frame (not shown), a driving roller 54, a driven roller 55, a primary transfer roller 56, and a primary transfer portion T1 that are rotatably supported by the frame. A guide roller 57, a tension roller 58, and the intermediate transfer belt 51 stretched around these rollers are provided, and the belt 51 is circulated and driven in the direction of the arrow in the figure. The primary transfer portion T1 is formed between the photosensitive member 21 and the primary transfer roller 56, and the secondary transfer portion T2 is in a pressure contact portion between the driving roller 54 and the secondary transfer roller 10b provided on the main body side. It is formed.
The secondary transfer roller 10b can be brought into contact with and separated from the drive roller 54 (and therefore with respect to the intermediate transfer belt 51), and a secondary transfer portion T2 is formed when contacting.
Therefore, when forming a color image, a toner image of a plurality of colors is superimposed on the intermediate transfer belt 51 with the secondary transfer roller 10b being separated from the intermediate transfer belt 51, and then a color image is formed. The secondary transfer roller 10b comes into contact with the intermediate transfer belt 51, and the paper is supplied to the contact portion (secondary transfer portion T2), whereby a color image (toner image) is transferred onto the paper. .
The sheet on which the toner image has been transferred passes through the heating roller pair 61 of the fixing unit 60 to melt and fix the toner image, and is discharged toward the paper discharge tray unit 15.
Therefore, the toner image is conveyed without being fixed on the sheet from the secondary transfer portion T2 to the fixing device 60.

2 is an enlarged view around the secondary transfer portion T2 in FIG. 1, FIG. 3 is a schematic enlarged view seen from the direction of arrow III in FIG. 2, and FIG. 4 is an IV-IV enlarged sectional view in FIG.
In FIG. 2, 10g is a paper guide, which is attached to a pair of side frames (not shown), and the side frame is configured to be swingable by a shaft 10h, so that the paper guide 10g can also swing around the shaft 10h. It is. Since the secondary transfer roller 10b is also attached to the pair of side frames, it swings together with the paper guide 10g.
As shown in FIG. 2, when the paper guide 10g and the secondary transfer roller 10b swing and the secondary transfer roller 10b contacts the intermediate transfer belt 51, the secondary transfer portion T2 is formed as described above. When the paper (recording material) S is supplied to the secondary transfer portion T2, the toner image is transferred onto the paper S from the intermediate transfer belt 51, and the paper S on which the unfixed toner image is transferred is guided by the paper guide 10g. Then, it is conveyed toward the fixing unit 60.

2 to 4, reference numeral 70 denotes a static eliminator.
The charge eliminating device 70 is for discharging the recording material S with the conductive non-woven fabric 71 facing the recording material S to which the unfixed toner image is transferred and conveyed. In this regard, only the front edge portion 71f and the rear edge portion 71r of the surface 71a facing the recording material S in the conductive nonwoven fabric 71 are covered with the conductive members 72f and 72r. The static eliminator 70 is attached to the paper guide 10g. Therefore, the static eliminator 70 swings together with the paper guide 10g.

  The conductive members 72f and 72r also cover the side surfaces 71f1 (front surface) and 71r1 (rear surface) of the front edge portion 71f and the rear edge portion 71r. Specifically, as shown in FIG. 4, the conductive members 72 f and 72 r have an L-shaped cross section, and on the inner surface, the leading edge of the conductive nonwoven fabric 71 facing the recording material S on the front surface 71 a. Only the portion 71f and the rear edge portion 71r are covered, and side surfaces 71f1 and 71r1 adjacent to the facing surface 71a are also covered. The conductive members 72f and 72r can be made of, for example, a metal, a conductive synthetic resin plate, a conductive synthetic resin film, or the like.

As shown in FIG. 3, with respect to the conveyance direction F of the recording material S, the left and right side edges 71b and 71b of the conductive nonwoven fabric 71 are arranged outside the region A where the toner image is formed on the recording material S. .
As shown in FIG. 3 and FIG. 4, a conductive plate 73 for applying a voltage to the conductive nonwoven fabric 71 is provided on the non-facing surface 71 c of the conductive nonwoven fabric 71 with respect to the recording material. 73 and the conductive member 72f covering the front edge portion 71f of the conductive nonwoven fabric 71 among the conductive members are electrically connected.
As shown in FIG. 4, the conductive plate 73 is attached to the back surface (non-opposing surface with respect to the recording material) 71 c of the conductive nonwoven fabric 71 by a conductive adhesive tape 74.
As shown in FIG. 3, the left and right end 73a of the conductive plate 73 protrudes (exposes) outward from the conductive non-woven fabric 71, and both or one of the ends 73a is a voltage applying means (not shown). As a result, the charge removal voltage is applied to the conductive nonwoven fabric 71 via the conductive plate 73 and the conductive adhesive tape 74.

According to the static eliminator as described above, the following effects can be obtained.
(A) The static eliminator 70 is a static eliminator that neutralizes the recording material S with the conductive nonwoven fabric 71 facing the recording material to which the unfixed toner image is transferred and conveyed. Regarding the direction F, since only the front edge portion 71f and the rear edge portion 71r of the surface 71a facing the recording material S in the conductive nonwoven fabric 71 are covered with the conductive members 72f and 72r, the following effects are obtained. It is done.
Usually, the conductive non-woven fabric has intense fuzz of conductive fibers at the edge portion, and there is little fuzz at the central portion.
According to the static eliminator 70, with respect to the conveyance direction F of the recording material S, the front edge portion 71f and the rear edge portion 71r of the conductive nonwoven fabric 71 facing the recording material 71a are covered with the conductive members 72f and 72r. Therefore, the fluffing of the conductive fibers at the front edge portion 71f and the rear edge portion 71r is prevented. Therefore, contact between the conductive fibers and the recording material S is prevented, abnormal discharge is prevented, and disturbance of the unfixed toner image on the recording material S is also suppressed.
At the same time, the front surface 71a and the rear edge 71r of the conductive nonwoven fabric 71 facing the recording material S are covered only with the conductive members 72f and 72r, and other portions (in the central portion). Since the portion 71a1 (see FIG. 3 and FIG. 4) is open, a good discharge is generated between the end portion of the conductive fiber and the recording material S in this portion 71a1. S is effectively neutralized. In addition, as shown in FIG. 4, even if the conductive fiber is fluffed in the central portion 71a1 (the conductive fiber that was fluff is indicated by reference numeral 71d), the fluff is small, and the conductive member 72f, Since 72r also serves as a spacer, the situation where the end of the conductive fiber 71d and the recording material S come into contact with each other is extremely unlikely to occur.
Therefore, according to the static eliminator 70, it is possible to prevent the unfixed toner image from being disturbed without reducing the static elimination efficiency.
(B) Since the conductive members 72f and 72r also cover the side surfaces 71f1 (front surface) and 71r1 (rear surface) of the front edge portion 71f and the rear edge portion 71r, they are electrically conductive on the side surfaces 71f1 and 71r1 adjacent to the facing surface 71a. As a result, the fluffing of the conductive fiber is also suppressed, and the contact between the conductive fiber and the recording material is more reliably prevented.
(C) With respect to the conveyance direction F of the recording material S, the left and right side edge portions 71b of the conductive nonwoven fabric 71 are disposed outside the region (image forming region) A where the toner image is formed on the recording material. Furthermore, the following effects can be obtained.
If the left and right side edge portions 71b of the conductive nonwoven fabric 71 are arranged in the image forming area A with respect to the conveyance direction of the recording material S, the conductive fibers in the left and right side edge portions 71b of the conductive nonwoven fabric 71 are assumed. The edge of the conductive fiber and the recording material come into contact with each other in the image forming area A due to the fluffing of the toner, and the toner image on the recording material may be disturbed. By arranging it outside the image forming area A, such a situation can be surely prevented.
(D) A conductive plate 73 for applying a voltage to the conductive nonwoven fabric 71 is provided on the non-facing surface 71c of the conductive nonwoven fabric 71 with respect to the recording material S, and at least conductive among the conductive plate 73 and the conductive member. Since the conductive member 72f covering the front edge portion 71f of the conductive nonwoven fabric 71 is electrically connected, a static elimination voltage can be efficiently applied to the conductive nonwoven fabric 71, and the static elimination efficiency can be further improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the gist of the present invention.

1 is a schematic side view showing an internal structure of an example of an image forming apparatus using an embodiment of a static eliminator according to the present invention. FIG. 2 is an enlarged view around a secondary transfer portion T2 in FIG. The schematic enlarged view seen from the arrow III direction in FIG. IV-IV expanded sectional view in FIG.

Explanation of symbols

  S: recording material, A: area where toner image is formed, 70: static eliminator, 71: conductive non-woven fabric, 71a: surface facing the recording material, 71b: left and right side edges, 71c: non-contact with recording material Opposing surface, 71f: front edge, 71r: rear edge, 71f1: side surface, 71r1: side surface, 72f: conductive member, 72r: conductive member, 73: conductive plate.

Claims (4)

A static eliminator that neutralizes a recording material by making a conductive nonwoven fabric face the recording material to which an unfixed toner image is transferred and conveyed,
In the transport direction of the recording material, only the front edge and the rear edge of the surface of the conductive nonwoven fabric facing the recording material are covered with a conductive member.   The static eliminator according to claim 1, wherein the conductive member is a conductive member that also covers side surfaces of the front edge portion and the rear edge portion.   3. The static eliminator according to claim 1, wherein left and right side edges of the conductive nonwoven fabric are arranged outside a region where a toner image is formed on the recording material with respect to a conveyance direction of the recording material. .   A conductive plate for applying a voltage to the conductive nonwoven fabric is provided on the non-facing surface of the conductive nonwoven fabric with respect to the recording material, and at least the leading edge of the conductive nonwoven fabric among the conductive plate and the conductive member is provided. 4. The static eliminator according to claim 1, wherein the conductive member is electrically connected.

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