JPH08112938A - Cleaning method and device in image forming apparatus - Google Patents

Abstract

PURPOSE: To simply remove and clean the toner accumulated on the surface of an electrode array. CONSTITUTION: A film like electrode array 1 is arranged between a rear electrode element 2 with which the rear surface of an image recording medium 3 comes into contact and a toner carrying roller 16 so that a row of a large number of aperture parts 12 is arranged in parallel to the rotary axial line of the toner carrying roller 16 and a press means 40 is arranged on the feed upstream side of the rear electrode element 2 of the feed route of the image recording medium 3 to press the surface or rear edge part of the image recording medium 3 to the surface of the electrode array 1 and toner 18 is transferred to the image recording medium 3 to clean the surface of the electrode array 1. A toner recovery means consisting of a shaking dusting element and a recovery box is arranged to the feed route between the rear electrode element 2 and a fixing device 5 and the toner once transferred to the image recording medium 3 before fixed is recovered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which can be used in a copying machine, a facsimile, a printer and the like, and which forms an image by causing charged toner to fly by an electric field in an electrode array. , More specifically,
The present invention relates to a cleaning method for removing or collecting toner adhering to an electrode array and an apparatus therefor.

[0002]

2. Description of the Related Art Heretofore, as one type of image forming apparatus, the present applicant has previously proposed that, in JP-A-6-155798, a toner charged by an electrode array having a plurality of openings arranged in a line. Of the electrically conductive toner carrying roller to form an image on an image recording medium located on the opposite side of the electrode array with respect to the conductive toner carrying roller. The sheet is arranged so as to face the peripheral surface of the toner carrying roller, and on one side of the sheet that faces the image recording medium, control electrodes are arranged separately for each opening and pulled out from the opening. In order to cause the generated toner to fly toward the front surface of the image recording medium by electrostatic force, the back electrode body is arranged so as to contact the back surface side of the image recording medium, and the back electrode body is charged with a predetermined polarity. Configured to apply a. Further, it has been proposed that the toner attached to the surface of the image recording medium as a pixel fixes the image by a fixing device provided on the downstream side of the conveyance.

[0003]

However, in the above-mentioned conventional structure, not all the toner from the toner carrying roller passes through the opening and fly to the surface of the image recording medium during image formation, and one toner The part remains attached to the surface side of the electrode array and near the opening. Then, when the amount of adhered toner increases, the opening is clogged, the control of the toner flow becomes incomplete or impossible, and in some cases, the toner flies toward the image recording medium regardless of the application of the control voltage. The image fog phenomenon occurs.

Further, when a large amount of toner accumulates on the surface of the electrode array facing the image recording medium, the accumulated toner comes into contact with the surface of the image recording medium as the image recording medium moves, and There was a problem of soiling the surface. As a means for solving this problem, a cleaning device for removing the toner adhering to the surface of the electrode array may be arranged between the surface of the electrode array and the back electrode body. The gap between the back electrode body and the
Since the density of the parts to be arranged is high, there is also a problem that a cleaning device having a complicated structure cannot be arranged.

The present invention has been made to solve these problems, and provides a cleaning method for an image forming apparatus and a cleaning apparatus therefor, which makes it possible to easily remove and collect the toner adhering to the surface of the electrode array. The purpose is to do.

[0006]

In order to achieve the above object, a cleaning method in an image forming apparatus according to a first aspect of the present invention is an electrode array having a plurality of openings and a control electrode for each opening. A toner supply means for supplying toner to the openings of the electrode array, a back electrode body and an image recording medium arranged on the side opposite to the toner supply means with respect to the electrode array, and each control electrode of the electrode array. An image forming apparatus comprising a control electrode driving unit for selectively flying the toner from the toner supply unit onto the image recording medium through an opening by independently controlling the surface of the image recording medium. Alternatively, the edge portion is pressed against or brought into contact with the surface of the electrode array to remove the toner adhering to the vicinity of the opening.

The invention described in claim 2 is the cleaning method in the image forming apparatus according to claim 1, wherein the surface or the edge portion of the image recording medium is pressed or brought into contact with the surface of the electrode array. After that, the image recording medium is fixed to remove the toner. The cleaning device in the image forming apparatus according to claim 3, wherein an electrode array having a plurality of openings and a control electrode for each opening, and a toner supply unit that supplies toner to the openings of the electrode array. The toner is opened from the toner supply unit by independently controlling the back electrode body and the image recording medium arranged on the side opposite to the toner supply unit with respect to the electrode array, and each control electrode of the electrode array. An image forming apparatus comprising control electrode driving means for selectively flying on the image recording medium through a portion, a pressing means for pressing the surface or edge portion of the image recording medium against the surface of the electrode array is provided. On the other hand, a toner collecting means for collecting the toner adhering to the surface of the image recording medium is provided downstream of the electrode array in the conveying direction of the image recording medium. Those were.

[0008]

Next, an embodiment of the present invention will be described. FIG. 1 shows an outline of an image forming apparatus of the present invention, in which a metal flat plate-shaped rear electrode body 2 facing a surface of an electrode array 1 as a toner flow control means is a frame (not shown).
The back electrode body 2 is supported by a pressing means 24, which will be described in detail later, and is arranged at a distance of about 0.5 mm to 1 mm from the surface of the electrode array 1 to record an image on printing paper or the like. It is configured so that the medium 3 can be selectively held in a state of being conveyed and a state of pressing or contacting the surface or the edge portion of the image recording medium 3 with the surface of the electrode array 1.

The image recording medium 3 inserted in the gap between the electrode array 1 and the back electrode body 2 is constructed so that it can be conveyed in the direction of arrow A by a paper feeding device 4 consisting of a roller pair. A fixing device 5 including a heating roller 6 and a pressing roller 7 for fixing an image is arranged on the downstream side of the image recording medium 3 in the conveying direction. Further, the electrode array 1 is attached by applying an appropriate tension to the opening hole of the toner case 9 of the toner supply device 8.

As shown in FIGS. 3 and 4, the pressing means 24 includes a biasing member such as a leaf spring 25 for pressing the back side of the back electrode body 2 toward the surface of the electrode array 1, and the toner case 9. It is composed of position change restricting means such as a set of four eccentric cams 26 arranged on the upstream and downstream sides of the image recording medium 3 on both the left and right sides to support the front surface side of the back electrode body 2, and is not shown. When the eccentric cam 26 is rotated by the drive motor, the surface of the back electrode body 2 approaches the surface of the electrode array 1 in the solid line state of FIG. 3 to cause the surface of the image recording medium 3 or normally a non-image. An edge of the image recording medium which is a forming portion, for example, a leading edge portion or a trailing edge portion in the transport direction is pressed or slidably contacted in the vicinity of the opening 12 in the electrode array 1, and is indicated by a chain double-dashed line in FIG. Back, as shown in the state If retraction electrode body 2 from the electrode array 2, so that a gap is the approximately 0.5 mm to 1 mm, a configuration that can change the gap between the electrode array 1.

Next, the respective components will be described in detail. A toner supply device 8 as a toner supply means includes a toner case 9 also serving as a housing, a toner 18 housed in the toner case 9, and a supply roller. 15, an electrically conductive toner carrying roller 16 made of a metal cylinder such as copper or aluminum, and an agitator 17 for supplying the toner 18 in the toner reservoir 14 to the supply roller 15 while stirring.
And a regulation blade 19 for rubbing the toner 18 on the peripheral surface of the toner carrying roller 16 with a constant layer thickness. Toner carrying roller 1 having a rotating shaft in a direction orthogonal to the direction in which the image recording medium 3 is conveyed.
6, the supply roller 15 and the agitator 17 have substantially the same length, and are rotated in the arrow direction of FIG. 1 by a rotation drive device (not shown).

A part of the outer peripheral surface of the toner carrying roller 16 is
It is arranged so as to face the back surface of the insulating sheet 11 so as to come into contact with the vicinity of the opening 12 row of the electrode array 1 described later. The base end of a regulation blade 19 for regulating the thickness of the toner layer, which is in pressure contact with the peripheral surface on the upstream side of the rotation of the toner carrying roller 16, is fixed to the toner case 9, and the toner supplied from the agitator 17 via the supply roller 15 is supplied. The wide blade 18 of the regulation blade 19 slidably contacts the outer peripheral surface of the toner carrying roller 16 to regulate the layer thickness of the toner 18 to a predetermined uniform thickness and to charge the toner 18.

The electrode array 1, as shown in FIG.
A plurality of openings 12 having a diameter of about 40 μm to 100 μm are formed in a row in a direction orthogonal to the moving direction of the image recording medium 3 on an insulating sheet 11 made of polyimide as an electrically insulating base material having a thickness of 5 μm. And the control electrode 1 divided for each of the openings 12 on the side facing the image recording medium 3.
3 is formed.

If the insulating sheet 11 is made too thin,
A polyimide resin having a thickness of 25 μm is suitable because it becomes difficult to form the control electrode 13 and handle the electrode array 1 itself. As shown in FIG. 2, for each opening 12 such as a round hole formed by penetrating the insulating sheet 11, an annular electrode portion is provided on the upper side of the insulating sheet 11 along the circumferential edge of each opening 12. A control electrode 13 composed of 13a and a lead portion 13b for connecting each electrode portion 13a to the control voltage applying circuit 21 is formed of a metal such as copper or gold having a thickness of about 1 μm.

Further, as can be understood with reference to FIG.
In the electrode array 1, the sheet 11 is bent with respect to the toner carrying roller 16 about the row of the openings 12 at the same angle on the upstream side and the downstream side in the moving direction of the image recording medium 3.
The row-shaped openings 12 are evenly pressed against the outer peripheral surface of the toner carrying roller 16 and stretched so that the contact area with the outer peripheral surface of the toner carrying roller 16 is increased.

A DC power source 20 is connected between the back electrode body 2 and the toner carrying roller 16, and the back electrode body 2
Is applied with a high voltage of about +1 kV, a control voltage application circuit 21 is connected between the toner carrying roller 16 and the control electrode 13, and based on the image forming signal,
A voltage of 0 V or +50 V is applied to the control electrode 13.

The agitator 17, the toner supply roller 15, and the regulation blade 19 are grounded at 0V. Further, on the downstream side of the conveyance of the image recording medium 3, between the back electrode body 2 and the fixing device 5, the toner 18 once transferred to the surface of the image recording medium 3 is removed and collected (cleaned). The toner collecting means 27 is arranged. The first embodiment of the toner collecting means 27 is, as shown in FIG. 1, a collecting box 2 having an opening facing the surface of the image recording medium 3.
8, a collecting roller 29 that rotates in the direction of the arrow by a drive motor (not shown), a collecting blade 30 that contacts the peripheral surface of the collecting roller 29, and a constant distance from the peripheral surface of the collecting roller 29 with the image recording medium 3 interposed therebetween. And a recovery electrode 31 arranged so as to hold. Like the back electrode body 2, the recovery electrode 31 is configured to be able to adjust the perspective position with respect to the peripheral surface of the recovery roller 29 by an eccentric cam (not shown).

The recovery roller 29 is in the form of a brush roller in which a nylon brush is planted on a stainless steel shaft, and thereby scrapes (sweeps off) the toner 18 adhering to the surface of the image recording medium 3. The collecting blade 30 is brought into contact with the tip of the brush of the collecting roller 29, and the toner 18 adhering to the brush of the collecting roller 29 is swept off into the collecting box 28. The collection roller 29 and the collection electrode 30 are connected to collection power sources 32 and 33 for applying a voltage of a predetermined polarity, respectively.

The toner 18 is an electrically insulating toner having an electrically insulating property, and is supplied to the surface of the toner carrying roller 16 by the supply roller 15. Conductive toner carrying roller 1
Including the surface 6 and the toner 18 attached thereto, the potential becomes the same as a whole. Next, the recording operation (printing operation) of the image forming apparatus thus configured will be described.

First, the toner carrying roller 16 and the toner supplying roller 15 and the agitator 17 having substantially the same length as the toner carrying roller 16 are respectively rotated in the arrow directions shown in FIG. The insulating toner 18 sent from the roller 15 is rubbed against the surface of the toner carrying roller 16. Next, the toner layer thickness regulating blade 19 reduces the layer thickness of the toner 18 to a predetermined value, and the negatively charged toner 18 is carried on the surface of the toner carrying roller 16. The toner 18 conveyed toward the electrode array 1 by the rotation of the toner carrying roller 16 is rubbed against the insulating sheet 11 of the electrode array 1 and supplied below the opening 12.

On the other hand, in response to a paper feed command, the image recording medium 3
Is transported into the gap between the back electrode body 2 and the electrode array 1 via the paper feeding device 4 shown in FIG. +1 for back electrode body 2
Since the voltage of kV is applied, the back surface of the image recording medium 3 which is in contact with the back electrode body 2 at the location is positively charged by electrostatic force. Here, if there is an image, the control voltage application circuit 21 is driven based on the image signal, and a voltage of +50 V is applied to the control electrode 13 corresponding to the image portion. As a result, in the vicinity of the opening portion 12 corresponding to the image portion, due to the potential difference between the control electrode 13 and the conductive toner carrying roller 16, an electric force line from the annular control electrode portion 13a toward the toner carrying roller 16 is formed. To be done. The strength of the line of electric force at this time is proportional to the potential difference and inversely proportional to the distance between the control electrode 13 and the surface of the toner carrying roller 16.

Then, the negatively charged toner 18
Is subjected to an electrostatic force in the direction of higher potential by the line of electric force from the control electrode 13 toward the toner carrying roller 16, and is drawn out so as to pass through the opening 12. The toner 18 thus extracted is further subjected to the voltage (+1 kV) applied to the back electrode body 2 so that the image recording medium 3
The electric field formed between the electrode array 1 and the electrode array 1 causes the toner 18 to fly toward the image recording medium 3, and the toner 18 is deposited on the surface of the image recording medium 3 to form a visible pixel.

For the non-image portion, the control electrode 1
A voltage of 0 V is applied to 3. As a result, since no electric field is formed between the toner carrying roller 16 and the control electrode 13, the toner 18 on the toner carrying roller 16 is not subjected to electrostatic force, and these toners 18 do not pass through the opening 12. Absent. Further, the opening 1 is formed on the surface of the image recording medium 3.
While one row of toner 18 is formed by the two rows, the image recording medium 3 is conveyed by one pixel in the direction perpendicular to the row of the openings 12 (direction of arrow A in FIG. 1). By repeating such an operation, a predetermined image is formed by the toner 18 on the surface of the image recording medium 3. After that, the toner image is heated and fixed on the image recording medium 3 at the position of the fixing device 5.

Next, the surface of the electrode array 1, especially the opening 1
A method for cleaning the toner 18 deposited in the vicinity of 2 will be described. In the first method, one image recording medium 3 is executed every time when it passes over the surface of the electrode array 2, and image formation is executed in a predetermined area on the surface of the image recording medium 3 as described above. After that, when the rear edge portion of the image recording medium 3 in the transport direction (edge portion orthogonal to the transport direction) passes through the row of openings 12 on the surface of the electrode array 2, the eccentric cam 26 in the pressing means 24 is moved. By rotating it, the gap between the back electrode body 2 and the electrode array 2 is made minute so that the rear edge portion of the image recording medium 3 comes into light contact with the vicinity of the row of the openings 12 on the surface of the electrode array 2, or The gap with the image recording medium 3 is controlled to be a minimum. At this time, at the same time, a negative voltage is applied to the control electrode 13 and a positive voltage larger than normal (+1 kV) is applied to the back electrode 2.

As a result, the toner 18 adhering and depositing in the vicinity of the opening 12 flies and adheres to the trailing edge portion of the image recording medium 3, so that the electrode array 1 can be cleaned. After that, when the trailing edge of the image recording medium 3 is passed through the fixing device 5, the adhered toner 18 is fixed on the trailing edge of the image recording medium 3 as a black horizontal streak-like portion and the like. The image forming portion of the recording medium 3 is not soiled.

The second cleaning method is to switch to the cleaning operation and pass one or several unnecessary image recording media 3 between the back electrode body 2 and the electrode array 1. At this time, the eccentric cam 26 in the pressing means 24 is rotated in the same manner as in the first method,
The gap between the back electrode body 2 and the electrode array 2 is made small so that the entire surface of the image recording medium 3 or a part of the surface lightly contacts the vicinity of the row of the openings 12 on the surface of the electrode array 2, or image recording is performed. The gap with the medium 3 is controlled to be a minimum. At the same time, a negative voltage is applied to the control electrode 13,
Further, a positive voltage larger than normal (+1 kV) is applied to the back electrode 2. As a result, the toner 18 that has adhered and accumulated in the vicinity of the opening 12 flies and adheres to the entire surface of the image recording medium 3 or a part of the surface, and thus the electrode array 1 can be cleaned. Thereafter, when the image recording medium 3 is passed through the fixing device 5, the adhered toner 18 is fixed on the surface of the image recording medium 3, so that the image recording medium 3 may be discarded.

The third cleaning method is a method in which the toner is collected by slightly modifying the first method of the preceding group. That is, after image formation is performed on a predetermined area of the surface of one image recording medium 3 as described above, the trailing edge portion of the image recording medium 3 in the transport direction or the rear portion of the surface on which normal image formation is not performed is Openings 12 on the surface of the electrode array 2
When passing through the row, the eccentric cam 26 of the pressing means 24 is rotated to make the gap between the back electrode body 2 and the electrode array 2 small, and the rear edge portion or the rear surface of the image recording medium 3 is the electrode. It is controlled so as to lightly contact the vicinity of the row of the openings 12 on the surface of the array 2 or to minimize the gap with the image recording medium 3. At the same time, a negative voltage is applied to the control electrode 13 and a normal voltage (+1 kV) is applied to the back electrode 2.
Apply a larger positive voltage.

As a result, the toner 18 that is adhered and accumulated in the vicinity of the opening 12 and that is negatively charged flies to and adheres to the rear edge portion and the rear surface of the image recording medium 3. The array 1 can be cleaned. After that, when the rear edge portion or the rear surface of the image recording medium 3 reaches the location of the toner collecting means 27 of FIG. 1,
The collecting roller 29 is rotated by a gap adjusting means (not shown) while the rear edge portion and the rear surface of the image recording medium 3 are lightly brought into contact with the brush tip of the collecting roller 29 via the collecting electrode 31. At this time, at the same time, a positive voltage is applied to the recovery roller 29 and a negative voltage is applied to the recovery electrode 31. As a result, the toner 18 flying and adhering to the rear edge portion and the rear surface of the image recording medium 3 and being negatively charged is easily swept off by the collecting roller 29.
It can be collected in the collection box 28. According to this method, since the toner 18 is no longer attached to the rear edge portion and the rear surface of the image recording medium 3 passing through the fixing device 5, the image recording medium 3 having only a clean image forming portion. Is obtained. In this method, the area of the surface of the image recording medium 3 that is not used for image formation may be the central portion or the tip portion of the surface of the image recording medium 3.

Instead of the brush, the collecting roller 29 may be a roller made of silicone rubber having a strong adhesive property. Further, the collecting roller may be omitted, and a collecting blade made of urethane resin or the like may be brought into direct contact with the surface of the image recording medium 3. In the embodiment shown in FIG. 5, the image recording medium 3 that is conveyed between the back electrode body 2 and the electrode array 1 is on the upstream side of the back electrode body 2 in the conveyance direction, and the back surface of the image recording medium 3 is the front surface of the electrode array 1. Pressing means 40 for pressing toward
To provide. In the illustrated embodiment, the pressing means 40 in the form of a rotary lever
Is rotated in the direction of the arrow in FIG. 5 by an actuator (not shown), the intermediate portion or the rear end portion of the surface of the image recording medium 3 is pressed or brought into contact with the vicinity of the 12 rows of openings on the surface of the electrode array 1, and the electrode The toner 18 attached to the surface of the array 1 can be attached to the image recording medium 3 for cleaning. The operation of the pressing means 40 may be executed during the image forming operation, or the unnecessary image recording medium 3
May be carried during the cleaning operation.

Further, as shown in FIG. 5, the back electrode body 2
Between the fixing device 5 and the fixing device 5, as a toner collecting means, a collecting box 4 having a receiving opening on the surface side of the image recording medium 3.
On the other hand, while No. 1 is arranged, the drum body 42 is arranged on the back side with the image recording medium 3 sandwiched therebetween, and the toner 18 once adhered to the surface of the image recording medium 3 as in each of the above-described embodiments is arranged on the drum body 42. It may be configured such that it is knocked down in the collection box 41 by swinging drive with a minute amplitude. In this case, an ultrasonic wave generation actuator may be connected to the swatter body 42 to apply vibration of minute amplitude.

When the insulating toner 18 is used in the image forming apparatus constructed as described above, the conductive toner carrying roller 16 and the control electrode 1 in the electrode array 1 are used.
The electrical insulation between 3 and 3 is maintained. In the non-image operation, -10 V is applied to the control electrode 13 for the non-image portion.
Alternatively, a negative voltage may be applied. In this case, an electric field opposite to the electric field with respect to the image forming portion is formed between the toner carrying roller 16 and the control electrode 13, and the flying of the toner 18 on the toner carrying roller 16 is further suppressed. It is possible to form an image with less fogging.

According to the above-mentioned process, the control electric field in the electrode array 1 is formed between the control electrode 13 and the surface of the toner carrying roller 16 as one electrode facing the opening 12. The electric field for control can be directly applied to the toner 18 conveyed by the toner carrying roller 16 to the vicinity of the opening 12, and the toner control efficiency is excellent.

Since the toner carrying roller 16 which is one of the electrodes and the electrode array 1 having the control electrode 13 are located very close to each other with the toner 18 being conveyed therebetween, the applied voltage for control is lowered. However, since the electric field strength can be increased and the flight force of the toner 18 can be increased,
As the control voltage application circuit 21 for driving the control electrode 13, a low voltage one can be used, which reduces the manufacturing cost of the image forming apparatus.

Electrically insulating sheet 11 in the electrode array 1
When the toner is carried on the outer peripheral surface of the toner carrying roller 16 as one electrode, there is no electrical short circuit even if the toner 18 is not carried on the toner carrying roller 16. It goes without saying that the back electrode body 2 in the present invention may be formed in a roller shape.

[0035]

As described above, claim 1
According to another aspect of the invention, there is provided a cleaning method for an image forming apparatus, comprising: an electrode array having a plurality of openings and control electrodes for the openings; a toner supply unit that supplies toner to the openings of the electrode array; The back electrode body and the image recording medium arranged on the side opposite to the toner supply means with respect to the electrode array and the control electrodes of the electrode array are independently controlled, so that the toner is opened from the toner supply means by an opening portion. In an image forming apparatus comprising a control electrode driving unit for selectively flying on the image recording medium via the opening, the surface or the edge portion of the image recording medium is pressed against or brought into contact with the surface of the electrode array to form an opening. The toner adhering to the vicinity of the portion is removed.

Therefore, according to the present invention, only the extremely simple operation of pressing or contacting the surface or the edge portion of the image recording medium being conveyed with the surface of the electrode array,
The toner adhering to the surface of the electrode array can be transferred to the image recording medium side, and as a result, the cleaning of removing the toner adhering to the surface of the electrode array can be easily performed.

According to a second aspect of the present invention, there is provided a cleaning method for an image forming apparatus according to the first aspect, wherein the surface of the image recording medium or the edge portion is pressed against or brought into contact with the surface of the electrode array. After that, the image recording medium is fixed to remove the toner. Therefore, in addition to the operation and effect of the invention described in claim 1, since the toner once transferred to the surface or the edge portion of the image recording medium can be fixed by fixing, the toner can be fixed. There is an effect that it will not be relocated to the place of and will not be polluted.

According to a third aspect of the present invention, there is provided a cleaning device including an electrode array having a plurality of openings and a control electrode for each opening, and a toner supply means for supplying toner to the openings of the electrode array. The toner is supplied from the toner supply unit by independently controlling the back electrode body and the image recording medium arranged on the side opposite to the toner supply unit with respect to the electrode array, and each control electrode of the electrode array. In an image forming apparatus comprising a control electrode driving means for selectively flying on the image recording medium through an opening, a pressing means for pressing the surface or edge portion of the image recording medium against the surface of the electrode array. While provided, on the downstream side of the electrode array in the transport direction of the image recording medium,
A toner collecting unit for collecting the toner attached to the surface of the image recording medium is provided.

According to the present invention, the pressing means presses the surface or the edge portion of the moving image recording medium facing the surface of the electrode array against the surface of the electrode array to temporarily transfer the toner to the image recording medium side. It can be transferred to clean the surface of the electrode array. This pressing means does not need to be provided between the back electrode and the electrode array, and has the effect that the structure can be made extremely simple.

Further, since the toner transferred to the surface or the edge portion of the image recording medium can be collected by the toner collecting means provided on the downstream side of the electrode array in the conveying direction of the image recording medium, the toner is transferred to the image recording medium. An effect is obtained in that the toner is fixed as it is adhered, and unnecessary stain of the toner does not occur on the image recording medium.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of an image forming apparatus according to a first embodiment.

FIG. 2 is a partially cutaway enlarged perspective view of an electrode array.

FIG. 3 is a partially cutaway side view of the first embodiment of the pressing means.

FIG. 4 is a sectional view taken along the line IV-IV of FIG.

FIG. 5 is a schematic side sectional view of an image forming apparatus according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 electrode array 2 back electrode body 3 image recording medium 4 sheet feeding device 5 fixing device 9 toner case 11 insulating sheet 12 opening 13 control electrode 16 toner carrying roller 20 DC power supply 21 control voltage applying circuit 24, 40 pressing means 25 leaf spring 26 eccentric cam 27 toner recovery means 28, 41 recovery box 29 recovery roller 31 recovery electrode 42 slap body

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03G 21/00 310 326

Claims (3)

[Claims] 1. An electrode array having a plurality of openings and control electrodes for the openings, toner supply means for supplying toner to the openings of the electrode array, and the toner supply for the electrode array. By independently controlling the back electrode body and the image recording medium arranged on the side opposite to the means, and each control electrode of the electrode array, the toner is supplied from the toner supplying means to the image recording medium through the opening. In an image forming apparatus including control electrode driving means for selectively flying the surface of the image recording medium, the surface or the edge portion of the image recording medium is pressed or brought into contact with the surface of the electrode array to remove the toner adhering to the vicinity of the opening. A cleaning method for an image forming apparatus characterized by: 2. After pressing or contacting the surface or edge portion of the image recording medium with the surface of the electrode array,
The cleaning method for an image forming apparatus according to claim 1, wherein the image recording medium is fixed to remove the toner. 3. An electrode array having a plurality of openings and control electrodes for the respective openings, toner supply means for supplying toner to the openings of the electrode array, and toner supply for the electrode array. By independently controlling the back electrode body and the image recording medium arranged on the side opposite to the means, and each control electrode of the electrode array, the toner is supplied from the toner supplying means to the image recording medium through the opening. In an image forming apparatus comprising control electrode driving means for selectively flying the image recording medium, a pressing means for pressing the surface or the edge portion of the image recording medium against the surface of the electrode array is provided, while the image recording medium is more than the electrode array. In the image forming apparatus, a toner collecting unit for collecting the toner adhering to the surface of the image recording medium is provided on the downstream side in the conveying direction of the image forming apparatus. Burning device.