JPH05249792A - Destaticizer for image forming device and image forming device using the same - Google Patents

Abstract

PURPOSE:To bring the potential by an electrostatic charge, of a charge acceptor close to a target potential (for instance, almost zero V), without executing high-voltage discharging so as to generate a large amount of ozone, at the time of removing the static electricity of the electrostatic charge of the charge acceptor used in an image forming device. CONSTITUTION:A destaticizer for the image forming device, removing the static electricity due to the electrification of the charge acceptor 1 used in the image forming device, is provided with a semi-conductive platelike discharge electrode 5 arranged opposite to the charge acceptor 1, at a distance of prescribed gap length, and having prescribed volume resistivity, an AC power source for destaticizing 8 applying an alternating current having a peak-to-peak voltage two times or more a discharge starting voltage between the platelike discharge electrode 5 and the charge acceptor 1, and a mobile means, relatively moving the charge acceptor 1 and the platelike discharge electrode 5 in a state where the alternating current is applied to the platelike discharge electrode 5 and the interval of it and the charge acceptor 1 is kept constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a static eliminator for an image forming apparatus and a static eliminator for removing static electricity of a charge receptor used in an image forming apparatus for forming a recorded image such as a color copying machine. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly, to a static eliminator suitable for removing electrostatic charge of a recording sheet conveying member that conveys a recording sheet by electrostatically attracting a recording sheet for recording an image Forming apparatus

[0002]

2. Description of the Related Art FIG. 8 is a view showing an example of a conventional image forming apparatus, which is an image forming apparatus in which four color toner image forming transfer devices are arranged along a recording sheet conveying path, that is, a so-called tandem type full color electrophotographic copying. It shows an outline of the machine. In FIG. 8, the image forming apparatus U includes an endless recording sheet conveying member (that is, a charge receptor) 01 and a conveying unit H that conveys the recording sheet conveying member 01 along a predetermined path. The transport unit H holds a drive roller 02 (a drive device is not shown) that holds the recording sheet transport member 01 in a predetermined shape and supports it in a transportable manner, a plurality of sheet support rollers 03 to 05, and the plurality of sheets. It is composed of a drive means (not shown) for rotationally driving one sheet support roller of the support rollers 02 to 05. Further, one roller 04 of the plurality of support rollers 03 to 05 is configured as a tension roller that keeps the tension of the recording sheet conveying member 01 constant.

Around the recording sheet conveying member 01, along the conveying direction, a recording sheet feeding device 06, a static electricity applying member for attraction 07, a yellow toner image forming transfer device Y, a magenta toner image forming transfer device M, Cyan toner image forming transfer device C, black toner image forming transfer device K, recording sheet peeling member 08, charge eliminating device 09, and cleaner 01
0 is placed. Each of the toner image forming transfer devices Y,
M, C and K are toner image forming devices Y1, M1 and
C1, K1 and toner image transfer device (transfer corotron) Y
It is composed of 2, M2, C2 and K2. Further, the image forming apparatus U includes a plurality of supply trays 011, 012, 013 in which recording sheets S having different sizes are stored, a fixing device 014, and a discharge tray 015.

The recording sheet supply device 06 selectively takes out the recording sheets S from a plurality of supply trays 011, 012, 013 and supplies them to the recording sheet conveying member 01. The recording sheet S is adsorbed and conveyed by the recording sheet conveying member 01 to which the electrostatic adsorption force is applied by the adsorption static electricity imparting member 07. The recording sheet S conveyed by the recording sheet conveying member 01 is transferred by the yellow toner image forming transfer device Y, the magenta toner image forming transfer device M, the cyan toner image forming transfer device C, and the black toner image forming transfer device K. , A yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are sequentially transferred.

The recording sheet S on which the toner images of the four colors are transferred is separated from the recording sheet conveying member 01 by the recording sheet separating member 08, fixed by the fixing device 014, and discharged to the discharge tray 015. The recording sheet conveying member 01 from which the recording sheet S has been peeled off by the recording sheet peeling member 08 has a static eliminator 09 to remove the charged static electricity.

A pair of corotron chargers are generally used as the static eliminator 09 for removing static electricity of the recording sheet conveying member 01. Generally, in the corotron charger, insulating blocks are provided at both ends of a shield case having a substantially U-shaped cross section, and a discharge wire is stretched so as to be located between the insulating blocks and substantially in the center of the shield case. A high voltage of 4 to 10 KV is applied to this discharge wire, a corona discharge is generated between the discharge wire and the recording sheet conveying member (charge receptor) 01, and the ions generated thereby generate the recording sheet conveying member 01. It adheres to and charges this.

Further, the shield case surrounding the discharge wire of the corotron charger maintains a constant spatial distance from the discharge wire, thereby making the electric field formed on the surface of the discharge wire strong and stable. It has the function of However, the corotron charger has the following drawbacks. In the image forming apparatus U such as a color copying machine in which the toner image forming and transferring apparatus shown in FIG. 8 is arranged in tandem, a very large charge removing performance is required, but in the conventional corotron charging apparatus, it is constant. A fairly high voltage must be applied to obtain the static elimination performance. Then, since a thin discharge wire having low mechanical strength is stretched, the discharge wire is easily broken by vibration due to discharge and the like, which is troublesome to replace. Further, since the voltage is high (especially alternating current), noise inside the device becomes severe.

Another problem is that if an attempt is made to bring the discharge wire and the shield case close to each other, a spark discharge is generated between them and the shape of the corotron cannot be reduced. This is because by bringing them closer together,
This is because the spatial impedance becomes low and the current cannot be controlled. Yet another problem is that when discharging, an electric current also flows in the shield case in addition to the charge receptor (recording sheet conveying member), so that an extra discharge current flows, resulting in an increase in the size of the high-voltage power supply and an increase in price. Due to the increase in the electric current, the amount of ozone generated also increases, which may cause pollution of the surrounding environment.

[0009]

In applying such a corotron charger as a charge eliminating member for a recording sheet conveying member of an image forming apparatus U such as the tandem type color copying machine shown in FIG. 8, the charge eliminating ability is required. Has limitations and has the following problems. First of all, if the static elimination potential remains to some extent, a so-called cycle-up phenomenon occurs in which the potential of the recording sheet conveying member gradually increases as the sheet conveying body rotates. When this happens,
Adhesion failure due to insufficient current in the paper suction section, transfer failure in the transfer section, cleaning failure of the sheet conveyance body, and the like occur.

There have been proposed some methods of superposing a direct current component in addition to an alternating current component of the voltage in such a state. However, depending on the environment and the absolute value of the potential entering the static elimination part, the static elimination part may be used. The potential of the carrier that exits from the target does not always reach the target potential (for example, 0 V), and complicated control is required to stabilize it, which results in a considerable increase in cost. Have
In view of such a problem, the present invention aims to solve the following matters (a). (A) When removing the charge static electricity of the charge receptor used in the image forming apparatus, the charge potential of the charge receptor is set to a target potential (for example, approximately the same) without performing high-voltage discharge that generates a large amount of ozone. 0V).

[0011]

Next, the structure of the present invention devised to solve the above problems will be described. The constituent elements of the present invention correspond to those of the embodiments described later. For simplification, the reference numerals of the constituent elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments.

In order to solve the above problems, the first aspect of the present application
The static eliminator for an image forming apparatus of the present invention is a static eliminator for an image forming apparatus that removes electrostatic charge of a charge receptor (1) used in an image forming apparatus. A semi-conductive flat plate discharge electrode (5) having a predetermined volume resistivity, which is arranged with a gap length apart, and a discharge starting voltage between the flat plate discharge electrode (5) and the charge acceptor (1). AC power source for static elimination (8) for applying an alternating current having a peak-to-peak voltage of 2 times or more to the flat plate discharge electrode
And a movement for relatively moving the charge acceptor (1) and the flat plate discharge electrode (5) while keeping the gap constant while the alternating current is applied to the flat plate discharge electrode (5). Means for adjusting the gap length and the volume resistivity of the flat discharge electrode (5) to the charge acceptor (1).
And the flat discharge electrode (5) is set to a value in a range in which uniform discharge is performed.

In the static eliminator for an image forming apparatus according to the second invention of the present application, in the first invention, the volume resistivity of the flat plate discharge electrode (5) is 10 6 to 10 13 Ω.
-Characterized by being set in the range of cm.

In the image forming apparatus (U) of the third invention of the present application, an endless recording sheet conveying member (21) conveyed along a predetermined path by the conveying means, and the recording sheet conveying member (U). 21) a recording sheet feeding device (26) for feeding the recording sheet (S) to the recording sheet feeding device (26), and static electricity for electrostatically attracting the recording sheet (S) fed by the recording sheet feeding device (26). An electrostatic charge imparting member (27) for adsorption imparted to the member (21), an image carrier on which a toner image to be transferred to the recording sheet (S) conveyed by the recording sheet conveying member (21) is formed, and this image. A plurality of toner image forming transfer devices (Y, M, C, K) having a toner image transfer static electricity generating member for transferring the toner image on the carrier to the recording sheet conveyed by the recording sheet conveying member; A recording sheet peeling member (28) for peeling the recording sheet (S) on which the toner images have been transferred by the plurality of toner image forming transfer devices (Y, M, C, K) from the recording sheet conveying member (21); A fixing device (34) for fixing the toner image on the recording sheet (S) peeled by the recording sheet peeling member (28), and recording in which the recording sheet (S) is peeled by the recording sheet peeling member (28). In an image forming apparatus provided with a static eliminator (29) for removing static electricity of the sheet conveying member (21), the static eliminator (29) is disposed in a volume facing the recording sheet conveying member (21). A semi-conductive flat plate discharge electrode (5) having a resistivity of 10 6 to 10 13 Ω · cm, and the start of discharge between the flat plate discharge electrode (5) and the recording sheet conveying member (21). Twice the voltage An alternating current power source (8) for static elimination for applying an alternating current having the above peak-to-peak voltage to the flat plate discharge electrode (5).

[0015]

The static eliminator for an image forming apparatus of the first invention of the present application having the above-mentioned characteristics is provided with a predetermined gap length facing a charge acceptor (1) used in the image forming apparatus and having a predetermined gap. A semi-conductive flat plate discharge electrode (5) having a volume resistivity of is arranged. Then, the flat discharge electrode (5) is supplied with an AC power source (8) for static elimination so that a peak-to-peak voltage which is at least twice as high as the discharge start voltage between the flat discharge electrode (5) and the charge acceptor (1). The alternating current having is applied. By applying the alternating current, a discharge is generated between the flat plate discharge electrode (5) and the charge acceptor (1). During the discharge, the gap length and the volume resistivity of the flat plate discharge electrode (5) are determined by the charge acceptor (1) and the flat plate discharge electrode (5).
It is set to a value within the range in which uniform discharge is performed.

The charge acceptor (1) and the flat plate-shaped discharge electrode (5) are moved relatively by the moving means while keeping the interval (the gap length) constant. The alternating current is applied to the flat discharge electrode (5) during the relative movement. When the charge acceptor (1) and the flat plate discharge electrode (5) move relative to each other, the position of the charge acceptor (1) facing the flat plate discharge electrode (5) moves. Then, the uniform discharge is performed in a portion of the charge acceptor (1) facing the flat plate discharge electrode (5). Since the static electricity of the charge receptor (1) is removed by the uniform discharge, the static electricity of the charge receptor (1) is removed after the charge receptor (1) is moved opposite to the flat discharge electrode (5). Uniform target potential (for example, approximately 0 V)
Is discharged to.

In the charge eliminating device for an image forming apparatus of the second invention of the present application having the above-mentioned characteristics, the flat plate discharge electrode (5) is provided.
Since it is a semiconductive electrode having a volume resistivity of 10 6 to 10 13 Ω · cm, the discharge gap length (distance between the flat plate discharge electrode (5) and the charge acceptor (1) is ), It is possible to obtain a uniform discharge in a predetermined range.

In the image forming apparatus of the third invention of the present application having the above characteristics, the endless recording sheet conveying member (21).
Are conveyed along a predetermined route by the conveying means. A recording sheet (S) is supplied to the recording sheet conveying member (21) by a recording sheet supply device (26). Also,
The electrostatic attraction force is applied to the recording sheet conveying member (21) by the attraction static electricity applying member (27). Therefore, the recording sheet (S) supplied to the recording sheet conveying member (21) by the recording sheet supply device (26) is attracted and conveyed by the electrostatic attraction force.

On the recording sheet (S) conveyed by the recording sheet conveying member (21), toner images are sequentially transferred by a plurality of toner image forming transfer devices (Y, M, C, K). The plurality of toner image forming transfer devices (Y, M,
The recording sheet (S) to which the respective toner images have been transferred by C, K) is peeled from the recording sheet conveying member (21) by the recording sheet peeling member (28). The toner image on the recording sheet (S) separated by the recording sheet separating member (28) is fixed by the fixing device (34).

The static electricity of the recording sheet conveying member (21) from which the recording sheet (S) has been peeled off by the recording sheet peeling member is removed by a static eliminator (29) similar to the static eliminator of the first invention. A recording sheet conveying member (2
By removing the electrostatic charge of 1), a high quality image can be stably output for a long period of time without causing a recording sheet (S) adsorption failure, a toner transfer failure to a sheet, a sheet conveyance body cleaning failure, and the like. be able to.

[0021]

EXAMPLES Examples of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following examples. [Embodiment 1] FIG. 1 is an explanatory diagram of an embodiment (Embodiment 1 of the present invention) of a charge eliminating device for an image forming apparatus of the present invention. In FIG. 1, a recording sheet conveying member (that is, a charge receptor) 1 for electrostatically adsorbing and conveying a recording sheet (not shown) is brought into contact with a grounded metal roll 2 by a conveying means (not shown) in the direction of arrow X1. Be transported. The discharge electrode member 3 arranged at a position facing the recording sheet conveying member 1 at a predetermined distance is an insulating substrate 4 made of glass or the like.
The insulating substrate 4 is provided with a thin film discharge electrode of a high electric resistance, that is, a flat plate discharge electrode 5 having a thickness of 1 μm or less and a predetermined volume specific resistance (volume resistivity) formed by vapor deposition on the surface of the insulating substrate 4. A connection electrode 6 and an insulating film 7 that covers the surface of the connection electrode 6 are provided at one end of the flat discharge electrode 5.

FIG. 2 is a graph showing the uniform discharge region with respect to the distance between the recording sheet conveying member 1 and the flat plate discharge electrode 5, that is, the discharge gap length, and the volume specific resistance of the flat plate discharge electrode 5. The volume resistivity of the flat plate discharge electrode 5 is set in a range of 10 6 to 10 13 Ω · cm, and the discharge gap length is set to be within the uniform discharge region of FIG. .. In FIG. 1, the connection electrode 6
Is connected to a high voltage AC power supply 8. High voltage AC power supply 8
Is the recording sheet conveying member 1 and the flat discharge electrode 5
An alternating current having a peak-to-peak voltage that is at least twice the voltage at which discharge is started is applied to the flat plate discharge electrode.

Corona discharge is generated between the recording sheet conveying member 1 and the flat plate discharge electrode 5 by the application of the alternating current. Since the flat plate-shaped discharge electrode 5 has a large resistance, the discharge is stable and no spark discharge occurs. Further, by using a high electric resistance for the flat plate discharge electrode 5, it is possible to prevent an excessive current from flowing to any part of the void, and it is possible to discharge the recording sheet conveying member 1 uniformly. Is. Due to this uniform discharge, the electrostatic charge of the recording sheet conveying member 1 is almost removed, and the charging potential approaches zero.

[Experimental Example] Next, an experimental example in which the discharge performance of the discharge electrode member 3 having the flat discharge electrode 5 of the first embodiment and the conventional static elimination corotron are compared will be described. FIG. 3 is an explanatory view of the device used in the experiment. In FIG. 3, 11 is a material for the recording sheet conveying member such as PET, and the material 11 for the recording sheet conveying member is wound around the grounded metal drum 12. Around the metal drum 12, the material 11 for the recording sheet conveying member is provided.
A charging corotron 13 for charging the battery, a surface potential sensor 14 for detecting potential before static elimination, a discharge electrode member 3 or a conventional corotron 15 for static elimination, and a surface potential sensor 16 for detecting potential after static elimination are arranged. .. By adjusting the voltage applied to the discharge wire of the charging corotron 13 of FIG. 3, the surface potential of the material 11 of the recording sheet conveying member at the time of entering the static eliminator (the discharge electrode member 3 or the conventional static elimination corotron 15) can be adjusted. It can be controlled arbitrarily.

Using the experimental apparatus having the structure as shown in FIG. 3, the discharge electrode member 3 and the conventional corotron 15 for eliminating static electricity were exchanged and arranged, and the static eliminating performance was compared. FIG. 4 shows a comparison of their static elimination performance. Peak voltage 10K
When the conventional static elimination corotron 15 to which a voltage of V is applied is used, the penetration potential into the static elimination corotron 15 is -2.
The electric potential after static elimination was about −400 V at 000 V, while the discharge electrode member 3 of Example 1 was about 200 μm.
Supported so as to face each other through the gap of
When an AC voltage of KV was applied and the same test was conducted, the potential after static elimination was only about -50V. Therefore, it was demonstrated that the present invention can obtain higher static elimination performance at low voltage.

Further, FIG. 5 shows the material 1 of the recording sheet conveying member.
1 and the discharge electrode member 3 have different gap lengths, the effect of the peak-to-peak voltage on the static elimination performance was investigated, and FIG. 6 shows the relation between the gap length and the discharge start voltage.
Is the applied voltage, and Vg is the void voltage (that is, the voltage between the surfaces of the members 3 and 11 forming the void). From the values of Va in FIGS. 5 and 6, the discharge electrode member 3 of Example 1 was obtained.
In order to obtain a sufficient charge removal capability, it is found that it is necessary to apply an AC voltage having a peak-to-peak voltage that is at least twice the discharge start voltage to the flat plate discharge electrode 5 of the discharge electrode member 3. It was

[Embodiment 2] FIG. 7 is an explanatory view of an embodiment of the image forming apparatus of the present invention (Embodiment 2 of the present invention). Hereinafter, an image forming apparatus using the static eliminator of the present invention will be described in detail with reference to the accompanying drawings. The overall configuration of the embodiment of the image forming apparatus shown in FIG. 7 is substantially the same as that of the conventional image forming apparatus shown in FIG. Therefore, in the description of the embodiment of the image forming apparatus shown in FIG. 7, the components corresponding to the components of the conventional image forming apparatus shown in FIG. 8 except the first 0 of the reference numerals used in FIG. The code which added 20 to the code is attached. In FIG. 7, the image forming apparatus U
Is provided with an endless recording sheet conveying member (that is, a charge receptor) 21 and a conveying unit H that conveys the recording sheet conveying member 21 along a predetermined path. Carrier H
Is composed of a drive roller 22 that holds the recording sheet conveying member 21 in a predetermined shape and supports the recording sheet conveying member 21 and a plurality of sheet supporting rollers 23 to 25. One sheet support roller 24 of the plurality of sheet support rollers 23 to 25 is configured as a tension roller that keeps the tension of the recording sheet conveying member 21 constant.

Around the recording sheet conveying member 21, along the conveying direction, a recording sheet supply device 26, a static electricity applying member 27 for attraction, a yellow toner image forming transfer device Y, a magenta toner image forming transfer device M, Cyan toner image forming transfer device C, black toner image forming transfer device K, recording sheet peeling member 28, charge eliminating device 29, and cleaner 30
Are arranged. Each of the toner image forming transfer devices Y,
M, C and K are toner image forming devices Y1, M1 and
C1, K1 and toner image transfer device (transfer corotron) Y
It is composed of 2, M2, C2 and K2. The toner image forming apparatus Y1 is composed of an image carrier Y1a on which a yellow toner image is formed, and an image forming member such as a charger, an exposure device, a developing device, and a cleaner disposed around the image carrier Y1a. Similarly, the toner image forming devices M1, C1 and K1 are provided with image carrier M for forming magenta, cyan and black toner images, respectively.
1a, C1a, K1a and image forming members such as a charging device, an exposing device, a developing device, and a cleaner disposed around them. In addition, the image forming apparatus U includes a plurality of supply trays 31, 32 in which recording sheets S having different sizes are stored.
33, a fixing device 34, and a discharge tray 35.

In FIG. 7, the static eliminator 29 of the image forming apparatus U includes the metal roll 2 shown in FIG. 1 and the insulating substrate 4.
And a discharge electrode member 3 composed of a flat plate discharge electrode 5 of a high electric resistance having a predetermined volume resistivity of 1 μm or less formed by vapor deposition on the surface thereof, and a high voltage AC power source 8
It consists of and. When the charge removal of the recording sheet carrying member 21 is performed by the charge removing device 29 prior to the next copying cycle, the recording sheet carrying member 21 is removed to approximately 0V. As a result, it is possible to stably output a high-quality color image for a long period of time without causing a suction failure of a sheet, a transfer failure of a toner onto a sheet, a cleaning failure of a sheet conveying body, or the like.

[Modifications] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-mentioned embodiments, and is within the scope of the gist of the present invention described in the claims. Thus, it is possible to make various small design changes.

For example, in each of the above-described embodiments, the target potential after static elimination can be set to a predetermined potential other than 0V. In that case, an AC voltage having an AC waveform displaced from the reference line to the plus side or the minus side may be applied to the flat plate discharge electrode.

[0032]

According to the above-described charge eliminating device for an image forming apparatus of the present invention, when the charge static electricity of the charge receptor used in the image forming apparatus is removed, the charge potential of the charge receptor is set to a target potential (for example, It can be close to 0V). Also,
The static eliminator of the present invention can bring the charge potential of the charge acceptor close to a target potential (for example, approximately 0 V) without performing high-voltage discharge that generates a large amount of ozone. Therefore, according to the image forming apparatus of the present invention equipped with the static eliminator, there is a suction failure of the sheet or a transfer failure of the toner onto the sheet.
It is possible to stably output a high-quality color image that does not cause cleaning failure of the sheet conveying body for a long period of time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment (Embodiment 1 of the present invention) of a static eliminator for an image forming apparatus according to the present invention.

FIG. 2 is a graph showing a uniform discharge area with respect to the distance between the recording sheet conveying member 1 and the flat plate discharge electrode 5, that is, the discharge gap length, and the volume resistivity of the flat plate discharge electrode 5 of the same embodiment. ..

FIG. 3 is an explanatory diagram of an apparatus used in an experimental example for comparing the static elimination performance between the discharge electrode member 3 having the flat discharge electrode 5 of the first embodiment and a conventional static elimination corotron.

FIG. 4 is a diagram showing a comparison of experimental results of static elimination performance of a conventional static eliminator Corotron and the discharge electrode member 3 of the first embodiment.

FIG. 5 is a diagram in which the effect of the peak-to-peak voltage on the charge removal performance when the gap length between the material 11 of the recording sheet conveying member and the discharge electrode member 3 is different is examined.

FIG. 6 is a diagram showing a relationship between a void length and a discharge starting voltage.

FIG. 7 is an explanatory diagram of an embodiment (second embodiment of the present invention) of the image forming apparatus of the present invention.

FIG. 8 is an explanatory diagram of a conventional image forming apparatus.

[Explanation of symbols]

Y, M, C, K ... Toner image forming transfer device, S ... Recording sheet, U ... Image forming device, 1 ... Charge acceptor, 5 ... Flat plate discharge electrode, 8 ... AC power source for static elimination, 21 ... Recording sheet conveyance Members, 26 ... Recording sheet supply device, 27 ... Adsorption static electricity imparting member, 28 ... Recording sheet peeling member, 29 ... Eliminating device,
34 ... a fixing device,

Claims (3)

[Claims] 1. A static eliminator for an image forming apparatus for removing static electricity of a charge receptor used in an image forming apparatus, comprising: a predetermined volume facing the charge receptor and separated by a predetermined gap length. A semi-conductive flat plate discharge electrode having a resistivity, and static elimination for applying to the flat plate discharge electrode an alternating current having a peak-to-peak voltage that is at least twice the discharge start voltage between the flat plate discharge electrode and the charge receptor. An alternating current power supply, and a moving means for relatively moving the charge acceptor and the flat plate discharge electrode while keeping the gap between the charge acceptor and the flat plate discharge electrode in a state where the alternating current is applied to the flat plate discharge electrode, The static eliminator for an image forming apparatus, wherein the void length and the volume resistivity of the flat plate discharge electrode are set to values within a range in which uniform discharge is performed between the charge acceptor and the flat plate discharge electrode. 2. The volume resistivity of the flat discharge electrode is 10
The charge eliminating device for an image forming apparatus according to claim 1, wherein the charge eliminating device is set in a range of 6 to 10 13 Ω · cm. 3. An endless recording sheet conveying member that is conveyed along a predetermined path by a conveying unit, a recording sheet feeding device that feeds a recording sheet to the recording sheet feeding member, and a feeding unit that feeds the recording sheet by the recording sheet feeding device. A static electricity applying member for attracting static electricity for electrostatically adsorbing the formed recording sheet to the recording sheet conveying member, and an image carrier on which a toner image to be transferred to the recording sheet conveyed by the recording sheet conveying member is formed. Body, and a plurality of toner image forming transfer devices having a toner image transfer static electricity generating member for transferring the toner image on the image carrier to the recording sheet conveyed by the recording sheet conveying member; A recording sheet peeling member for peeling the recording sheet on which each toner image is transferred by the transfer device from the recording sheet conveying member; A fixing device for fixing the toner image on the recording sheet which has been peeled off by over preparative peeling member, a charge removing apparatus for removing static electricity of the recording sheet transport member the recording sheet has been peeled off by the recording sheet peeling member,
In the image forming apparatus, the static eliminator is a semi-conductive flat plate discharge electrode having a volume resistivity of 10 6 to 10 13 Ω · cm arranged facing the recording sheet conveying member. An image forming apparatus comprising: a flat-plate discharge electrode; and an AC power source for static elimination that applies an alternating current having a peak-to-peak voltage that is at least twice the discharge start voltage between the flat-plate discharge electrode and the recording sheet conveying member to the flat-plate discharge electrode. ..