JPH08142388A - Image forming apparatus - Google Patents

Abstract

PURPOSE: To automatically clean the opening of an aperture electrode. CONSTITUTION: An aperture electrode 10 made of a polyimide resin film having a plurality of openings is arranged between a back surface electrode roller 29 in contact with the rear surface of a recording sheet and a toner conveying roller 22. At the time of energizing a power source, replacing a process cartridge or when the maintenance cover 2a of a body frame 2 is closed, first and second takeup spools 31, 33 fixedly wound with both the ends of the electrode 10 are rotated to clean the opening of the electrode 10 by rotatably driving the brush rollers 41, 42 of a cleaning mechanism 40.

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 for controlling a toner passing through a plurality of openings formed in a flexible film-shaped aperture electrode body to form an image, and particularly to the plurality of openings. Related to cleaning processing.

[0002]

2. Description of the Related Art Conventionally, the applicant of the present invention has disclosed in Japanese Patent Laid-Open No. 6-799
As described in Japanese Patent Application Laid-Open No. 07-2007, an aperture electrode having a large number of minute apertures (apertures) arranged in a row in the width direction of a recording medium and having an electrode array made up of control electrodes provided in each of these many apertures. A toner supply roller that has a body and has a toner conveyance roller that conveys toner to a large number of openings of this aperture electrode body, and a toner regulation blade that presses and contacts the toner conveyance roller to regulate the amount of toner conveyed by the toner conveyance roller. A mechanism is provided, and a back electrode for generating an electric field is provided on the side opposite to the toner supply mechanism with respect to the aperture electrode body, and the drive voltage supplied to the electrode array is individually controlled while recording along the back electrode. By transporting the medium, the toner transported by the toner transport roller passes through the opening, and the electrostatic attraction force of the back electrode causes
It jumps out toward the back electrode and is attached to the recording medium,
After that, an image forming apparatus was proposed in which a toner image is formed by performing a fixing process.

[0003]

[Patent Document 1] Japanese Patent Application Laid-Open No. 6-799
In the image forming apparatus described in Japanese Patent Application Laid-Open No. 07-2007, since each of the plurality of openings formed in the aperture electrode body comes into pressure contact with the toner carrying roller, the surface of the toner carrying roller driven to carry is firmly attached. Each opening comes into contact with the toner group adhering to the toner to loosen the toner group so that the toner group can move. At the time of image formation, the loosened toner passes through the opening. By the way, during the image formation, all the toner supplied to the opening does not pass through the opening, and the toner not used for the image formation easily adheres to the vicinity of the opening in a pressed state.

That is, when the amount of toner adhering to the vicinity of the opening increases, the unnecessary toner also adheres to or accumulates in the opening, and the size of the opening is reduced. The amount of toner that passes through
The image density becomes low, or the toner deposited in the opening is subjected to a large electrostatic force by the back electrode and adheres to the recording medium even when the image is not formed, and the recording medium becomes dirty. There is a problem that a large amount of toner adhering to the vicinity of the portion causes a jot between adjacent openings to damage the electronic component.

Particularly, when the image forming apparatus is powered on for the first time to form an image, the toner adhered inside the opening or in the vicinity thereof in a pressed state contains moisture in the air, Since the solidified state is comparatively strong, there is a problem that the image quality of the recorded image is degraded until the solidified state is loosened when the image is formed immediately after the power is turned on.

In addition, when a used process cartridge which is detachably mounted is replaced with a new one, the maintenance cover is opened and closed by the vibration when the new process cartridge is mounted or at the time of maintenance. Due to the vibration, the toner contained in the process cartridge is inadvertently attached to the opening, and excess toner is attached to the recording medium when the image is formed immediately after the replacement of the process cartridge or immediately after the end of maintenance. However, similarly, there is a problem that the image quality of the recorded image is deteriorated.

Therefore, the inventor of the present application provides a cleaning mechanism having a cleaning member for cleaning unnecessary toner adhering to the opening of the aperture electrode body and its vicinity, and immediately after turning on the power or after replacing the process cartridge, Alternatively, it is conceived that the cleaning member is inserted between the back electrode and the aperture electrode body immediately after the end of maintenance to remove unnecessary toner adhering to the opening and its vicinity. However, since the toner is moved by an electrostatic force between the back electrode and the aperture electrode body, a narrow gap of about 1 mm is set, so that a complicated cleaning mechanism cannot be provided. There is.

An object of the present invention is to move an aperture electrode body in the form of a thin film to a predetermined cleaning position to remove unnecessary toner attached to a plurality of openings formed in the aperture electrode body and the vicinity thereof. An object of the present invention is to provide an image forming apparatus that can be surely cleaned by a simple mechanism.

[0009]

According to another aspect of the present invention, there is provided an image forming apparatus, wherein a plurality of openings are formed in a row in a horizontal direction orthogonal to a conveying direction of a recording medium, and control electrodes are respectively provided in the plurality of openings. An aperture electrode body having an electrode array consisting of
A toner supply mechanism having a toner transport roller for supplying toner to the opening of the aperture electrode body, a back electrode provided in the opening on the opposite side of the aperture electrode body from the toner supply mechanism, and an electrode array. And a toner control unit that controls the voltage supplied to each control electrode individually to control the toner passing through each opening, and to the recording medium on the side opposite to the toner supply mechanism with respect to the aperture electrode body, In an image forming apparatus adapted to record the toner that has passed through the openings, the aperture electrode body is provided with an image forming position where the plurality of openings are located between the toner carrying roller and the back electrode, and an image thereof. The electrode body driving means for moving and driving the cleaning position moved from the formation position to one side in the extending direction of the aperture electrode body by a predetermined distance and the cleaning position moved to the cleaning position. Cleaning means for cleaning the plurality of openings of the aperture electrode body, and cleaning control means for controlling the electrode body driving means so as to switch the aperture electrode body to the cleaning position when the image forming apparatus is activated and activating the cleaning means. It is equipped with.

Here, the image forming apparatus according to a second aspect is the image forming apparatus according to the first aspect, further comprising cover detecting means for detecting opening / closing of a cover for closing an opening formed in the main body frame of the image forming apparatus, The cleaning control means receives the output of the cover detection means, and is configured to operate when the cover is closed. According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, a cartridge detecting unit for detecting attachment / detachment of the process cartridge included in the toner supply mechanism is provided, and the cleaning control unit receives an output of the cartridge detecting unit and processes the process. It is configured to operate when the cartridge is installed.

An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects of the invention, wherein the cleaning means is configured to rotate the brush roller for cleaning. . According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the cleaning unit ejects pressurized air,
It is configured to clean the plurality of openings and the vicinity thereof.

[0012]

In the image forming apparatus according to the first aspect of the present invention, when the image forming apparatus is started up, the cleaning control means first controls the electrode body driving means. Is moved and driven from the image forming position located between the toner transport roller and the back electrode to a cleaning position which is moved a predetermined distance to one side in the extending direction of the aperture electrode body. Further, since the cleaning means is operated by the cleaning control means, the plurality of openings of the aperture electrode body moved to the cleaning position are cleaned by this cleaning means.

Then, after the aperture electrode body is switched to the original image forming position and moved back by the electrode body driving means, toner is supplied to the opening of the cleaned aperture electrode body by the toner supply mechanism, For the electrode array consisting of control electrodes provided in each of the multiple openings,
When the driving voltage to be supplied is individually controlled by the toner control means, the toner on the surface of the toner transport roller passes through the corresponding opening and is transported by the electrostatic force due to the electric field generated at the back electrode. A toner image is attached to the medium and a toner image is formed on the recording medium.

As described above, when the power is turned on, the aperture electrode body is moved and driven to the cleaning position which is moved from the image forming position to one side in the extending direction by a predetermined distance, and the plurality of aperture electrode bodies which are moved to the cleaning position are driven. Since the opening is cleaned, only a large amount of toner that passes through the plurality of openings adheres to the recording medium after the aperture electrode body is moved back to the original image forming position and sufficient image density can be obtained. In addition, since there is no density unevenness and unnecessary toner does not adhere, it is possible to form a clean image without paper stains. Furthermore, there is no short circuit between adjacent openings, and there is no damage to electronic components.

According to another aspect of the image forming apparatus of the present invention, the cover detecting means detects the opening / closing of the cover for closing the opening formed in the main body frame of the image forming apparatus, and the cleaning control means is the cover detecting means. It receives output and operates when the cover is closed.Therefore, during maintenance, due to vibration when the maintenance cover is opened or closed, the toner contained in the process cartridge will be discharged to the opening of the aperture electrode body. Even if carelessly adhered, the cleaning is surely performed, and therefore, the same operation as that of the first aspect is achieved.

According to another aspect of the image forming apparatus of the present invention, the cartridge detection means detects the attachment / detachment of the process cartridge included in the toner supply mechanism, and the cleaning control means receives the output of the cartridge detection means and mounts the process cartridge. When the used process cartridge is replaced with a new one, the toner stored inside the process cartridge will not be able to get into the aperture electrode body opening due to the vibration when the new process cartridge is installed. Even if it is easily attached, it is surely cleaned, so that the same operation as that of the first aspect is achieved.

In the image forming apparatus according to the present invention, the cleaning means rotationally drives and cleans the brush roller, so that unnecessary toner firmly adhered not only to the opening and the inside thereof but also to the vicinity of the opening. Can be cleaned reliably and in a short time.

In the image forming apparatus of the fifth aspect, the cleaning means injects pressurized air to clean the plurality of openings and the vicinity thereof, so that the aperture electrode body and the control electrode are not damaged. Unnecessary toner that adheres to the opening of the aperture electrode body and the vicinity thereof can be reliably and cleanly cleaned in a short time.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the movement of the toner supplied from the toner supply mechanism is controlled by an aperture electrode body to apply the present invention to an image forming apparatus for forming a toner image on a recording sheet. As shown in FIG. 1, the image forming apparatus 1 includes an aperture electrode body 10 inside a main body frame 2.
A toner supply mechanism 20, a transport mechanism for transporting the recording paper P, a back electrode roller 29, an electrode body drive mechanism 30 for moving the aperture of the aperture electrode body 10 to a cleaning position, and a plurality of these apertures. The cleaning mechanism 40 for cleaning and a fixing mechanism are basically provided.

Here, the transport mechanism includes the guide plates 3 to 6 for supporting the transported recording paper P and the paper feed roller 7.
And the transport rollers 8 and 9 and are rotationally driven by a paper transport motor 63 (see FIG. 4). Further, the fixing mechanism is composed of a fixing heating roller 27 having a halogen lamp built therein and a pressing roller 28 which presses the fixing heating roller 27 via the recording paper P, and each is driven to rotate by a paper conveying motor 63. Further, on the lower side of the main body frame 2, there is provided a paper feed cassette CS containing a large number of recording papers P,
Further, on the upper side of the main body frame 2, a paper discharge table DT that stores the recording paper P on which an image has been formed and discharged is placed. That is, the recording paper P fed from the paper feed cassette CS by the rotation of the paper feed roller 7 is guided by these guide plates 3 to 6 and is moved upward in the carrying direction F by these carrying rollers 8 and 9. Is transported and transported between the back electrode roller 29 and the aperture electrode body 10,
After the fixing process by the fixing mechanism, the sheet is stored in the sheet discharge table DT.

First, the toner supply mechanism 20 will be described. At a substantially interrupted position in the height direction of the main body frame 2, an electrically insulating toner T having an electrically insulating property is accommodated and a toner transport for transporting the toner T is carried out. A roller 22, a toner supply roller 23 that supplies the toner T to the toner transport roller 22, and a toner supply plate 24 that supplies the toner T to the toner supply roller 23 are provided inside as shown in the drawing. The process cartridge 21 is detachably attached from the front side by opening and closing the cover 2b of the main body frame 2. Here, these toner conveying rollers 2
2. The toner supply roller 23 and the toner replenishing plate 24 are rotationally driven in predetermined rotational directions as shown by arrows by a toner carrying motor 62 (see FIG. 4) via a drive mechanism (not shown).

The toner carrying roller 22 is formed by mounting a nickel cylindrical sleeve 22b on the outer peripheral portion of a sponge roller main body 22a.
b is grounded. Then, when the toner T is supplied from the toner supply roller 23 to the toner transport roller 22,
The toner T is rubbed by the rollers 22 and 23 and charged to the negative electrode. However, an insulating coating layer made of an insulating material may be formed on the surface of the toner conveying roller 22.

Inside the process cartridge 21, a base end portion of a thin plate-shaped elastic toner regulating blade 25 is further attached, and a curved portion of the tip end portion thereof contacts the toner conveying roller 22 in a pressing state. Therefore, the amount of the toner T supplied by the toner supply roller 23 and attached to the surface of the toner transport roller 22 and its charge amount are regulated to a predetermined amount by the toner regulation blade 25.

A back electrode roller 29 is disposed immediately to the left of the process cartridge 21 so as to face the toner carrying roller 22, and is rotatably supported by the main body frame 2. As shown in FIGS. 1 to 3, the aperture electrode body 10 having flexibility contacts the left end portion of the process cartridge 21 and is disposed so as to cover the left end portion thereof.

The aperture electrode body 10 is formed on a flexible base substrate having a predetermined length in the vertical direction, which is made of a polyimide resin film having a thickness of about 25 μm and having an insulating property, and is placed at a position higher than the middle position in the vertical direction. Horizontal direction on the upper side (corresponding to the horizontal direction orthogonal to the transport direction F)
In addition, circular openings (apertures) 11 having a diameter of about 60 to 65 μm are formed in a row at intervals of about 127 μm, for example, about 1700 in the case of the print width of A4 paper, The plurality of openings 11 are in pressure contact with the left end of the toner transport roller 22.

Further, an annular control electrode 12 made of a metal foil is attached to the outer peripheral surface of each of the large number of openings 11, and a thin conducting wire 1 extending from each control electrode 12 is provided.
3 are attached to the base substrate, respectively. And
As shown in FIG. 4, each of these many conductors 13 has
The drive voltage of +30 V or −30 V according to the image signal is individually supplied by the drive circuit 71.

Next, the electrode body driving mechanism 30 for moving the aperture electrode body 10 by switching the position between the image forming position and the cleaning position will be described with reference to FIGS. As shown in FIG. 3, the aperture electrode body 10 is a flexible strip having a predetermined width and a predetermined length in the vertical direction, and its upper end is
It is fixed to the first winding spool 31 pivotally mounted on the body frame 2 and wound by a predetermined amount. On the other hand, the lower end portion of the aperture electrode body 10 is fixed to the second winding spool 33 connected to the drive shaft of the electrode body moving motor 65. Then, the first take-up spool 31 is urged in the clockwise direction by the urging force of the mainspring 32,
The aperture electrode body 10 is always wound up.

That is, as shown in FIG. 1, the aperture electrode body 10 has a plurality of openings 11 in which the toner transport roller 2 is provided.
2 and the image forming position located between the back electrode roller 29 and the forward rotation drive of the electrode body moving motor 65, as shown in FIG. 2, against the biasing force of the mainspring 32.
The lower end portion of the aperture electrode body 10 is wound up by the second take-up spool 33, and the plurality of openings 11 are on the lower side which is one side in the extending direction of the aperture electrode body 10 from the image forming position, that is, It is moved and driven over the cleaning position moved by a predetermined distance in the cleaning movement direction D shown in FIG. On the other hand, when the electrode body moving motor 65 is driven to rotate in the reverse direction, the aperture electrode body 10 is paid out from the second take-up spool 33 and is taken up by the first take-up spool 31 on which the urging force of the main spring 32 acts. To be That is, a predetermined tension is always applied to the aperture electrode body 10 regardless of whether the aperture electrode body 10 moves to the image establishing position or the cleaning position.

Here, at portions other than the plurality of openings 11 of the aperture electrode body 10, two minute first slits are provided at positions slightly shifted to the left and right with respect to the extending direction of the aperture electrode body 10. The second slit is formed respectively, and when the first slit is detected by the first detection sensor 34, the aperture electrode body 10 is moved to the image forming position, and the second detection sensor 35 detects that When the second slit is detected, the aperture electrode body 10 has moved to the cleaning position. The first and second detection sensors 34 and 35 are reflection type sensors each having a light projector and a light receiver.

Next, the cleaning mechanism 40 for cleaning the opening 11 of the aperture electrode body 10 that has moved to the cleaning position will be described with reference to FIG.
Immediately below the process cartridge 21, brush rollers 41 and 42 having a width substantially the same as the width of the aperture electrode body 10 are provided at positions corresponding to the front and rear sides of the opening 11 of the aperture electrode body 10, respectively. In contact with the opening 11, the main body frame 2 is rotatably and rotatably supported by the main body frame 2 and is rotationally driven by a brush drive motor 64 (see FIG. 4).

The brush rollers 41 and 42 are formed by implanting a flexible nylon brush, and can be cleaned without damaging the aperture electrode body 10. Then, so as to surround each brush roller 41, 42,
Toner recovery boxes 43 and 44 for recovering the unnecessary toner T removed by the cleaning process are provided respectively.

Next, the control system of the image forming apparatus 1 is constructed as shown in the book diagram of FIG. Control device C
The input / output interface 54 of D includes the first detection sensor 34, the second detection sensor 35, and the main body frame 2 when removing unnecessary recording paper P that has become defective in conveyance during paper conveyance or image formation. A cover switch (see FIG. 1) 60 that detects opening and closing of the maintenance cover 2a that closes the opening of the process cartridge, and a cartridge switch (see FIG. 2) 61 that detects attachment / detachment of the process cartridge 21;
A drive circuit 66 for the toner carrying motor 62, a drive circuit 67 for the paper carrying motor 63, a drive circuit 68 for the brush drive motor 64, and a drive circuit 69 for the electrode body moving motor 65. , And a communication interface (communication I / F) 53 for receiving image data transmitted from the image transmission device 80 including a computer or the like.

Further, from the input / output interface 54, in order to attract the toner T charged on the negative electrode to the back electrode roller 29 with a large electrostatic force, the power circuit 72 is provided.
A supply command signal for supplying a high voltage of about +1 KV to the back electrode roller 29 is output from the back electrode roller 29, and the drive circuit 71 supplies the control electrode 12 corresponding to the image signal to the power circuit 7.
A supply command signal for selectively supplying two types of drive voltages of + 30V and -30V supplied from 0 is output. Further, the cylindrical sleeve 23b of the toner carrying roller 22 is always grounded (see FIG. 5).

The control device CD includes a CPU 50 and this CP.
It is composed of an input / output interface 54 connected to the U50 via a control bus 55 including a data bus, a ROM 51 and a RAM 52. In the ROM 51, a control program for image forming processing control for driving the drive circuit 71 and each of the motors 62 to 63 based on the image data transmitted from the image transmission device 80, when the power is turned on, the cover switch 60 and the cartridge. A control program for cleaning control for cleaning the opening of the aperture electrode body 10 when the switch 61 operates is stored. Further, the RAM 52 is provided with an image storage memory for storing the received image data, various memories and buffers for temporarily storing the calculation result calculated by the CPU 50.

Next, the control device CD of the image forming apparatus 1
Thus, the operation of the cleaning process for cleaning the opening 11 of the aperture electrode body 10 via the cleaning mechanism 40 will be described. When the power is turned on and the image forming apparatus 1 is started, first, the electrode body moving motor 6 is
5 is driven to rotate forward. As a result, the lower end portion of the aperture electrode body 10 is wound by the second take-up spool 33, and the aperture electrode body 10 moves in the lower cleaning movement direction D from the image forming position. Then, when the second detection sensor 35 detects the second slit formed in the aperture electrode body 10, the aperture electrode body 10 is moved to the cleaning position. That is, at this time, the one-row-shaped opening 11 of the aperture electrode body 10 is formed by the pair of brush rollers 4.
It is located at a position facing 1, 42.

Next, since the brush drive motor 64 is driven for a predetermined time (for example, about 30 seconds), both the brush rollers 41 and 42 are rotationally driven, and the inside of the opening 11 and the vicinity of the opening 11 are driven. The unnecessary toner T adhering to both the front and rear surfaces of the portion is reliably peeled off and cleanly cleaned.
By this cleaning process, the removed unnecessary toner T is collected in the toner collection boxes 43 and 44, respectively.

When the cleaning process is completed, the drive of the brush drive motor 64 is stopped, and the electrode body moving motor 65 is driven to rotate in the reverse direction. As a result, as described above, the aperture electrode body 10 is unwound from the second take-up spool 33 and taken up by the first take-up spool 31 on which the biasing force of the mainspring 32 acts, and the aperture electrode body 10 is cleaned. It is moved in the direction opposite to the moving direction D. Then, when the first detection sensor 34 detects the first slit formed in the aperture electrode body 10, the aperture electrode body 10 is moved and returned to the original image forming position.

Next, the operation of forming the toner image by adhering the toner T to the recording paper P based on the received image data will be described. The toner T is adhered to the toner conveying roller 22 by rubbing the toner supply roller 23, and the toner T adhered to the toner conveying roller 22 is further pressed by the toner regulating blade 25 so that the conveying amount is regulated and the conveying amount is regulated. The removed toner T adheres to the toner conveying roller 22 and the opening 11 of the aperture electrode body 10
Then, it is continuously conveyed.

When the image data is transmitted from the external image transmitting device 80, as described above, the sheet feeding roller 7 and the conveying rollers 8 and 9 are first driven to feed the sheet from the sheet feeding cassette CS. The recording paper P that has been printed is the back electrode roller
9 is conveyed to a predetermined recordable position between the aperture electrode body 9 and the aperture electrode body 10, and then a drive signal is output to the drive circuit 71. As a result, as shown in FIG. 5, when the drive circuit 71 outputs +30 V to the control electrode 12 based on the drive signal, the control electrode 12 causes the toner conveying roller 22 to move.
An electric field directed toward the positive direction is generated, and the electric field causes the toner T charged on the negative electrode on the surface of the toner carrying roller 22 to receive an electrostatic force in the direction of the higher potential and open from the surface of the toner carrying roller 22. It passes through the portion 11 and is attracted to the control electrode 12.

Further, a high voltage (about +1 KV) applied to the back electrode roller 29 causes an electrostatic force due to an electric field generated between the back electrode roller 29 and the control electrode 12,
The toner T that has passed through the opening 11 is transferred to the back electrode roller 2
9, that is, the recording paper P is attracted and jumps out and adheres to the surface thereof. At this time, the toner T is collectively adhered in layers on the adhered surface of the recording paper P. But,
When a drive voltage of −30 V is applied to the control electrode 12, the toner carrying roller 22 causes the control electrode 1 to be reversed, contrary to the above.
Due to the electric field toward 2, the toner T on the surface of the toner transport roller 22 does not pass through the opening 11. After that, the toner T adhering to the recording paper P is subjected to a fixing process by the fixing heating roller 27 on the downstream side in the transport direction, and is discharged to the paper discharge table DT.

Here, when the process cartridge 21 is removed and a new process cartridge 21 is mounted, the cleaning process is executed as described above based on the mounting signal from the cartridge switch 61. Similarly, the cleaning mechanism 40 reliably and cleanly cleans the opening 11 of the aperture electrode body 10 and the vicinity thereof. Further, when the sheet is conveyed or an image is formed, the cover 2a for maintenance of the main body frame 2 is opened to remove the unnecessary recording sheet P which has become defective in conveyance, and when the cover 2a is closed, the cover switch 60 is opened. The cleaning control is executed as described above on the basis of the closing signal from the above, and similarly to the above, the cleaning mechanism 40 reliably and cleanly cleans the opening 11 of the aperture electrode body 10 and the vicinity thereof. It

As described above, when the power is turned on, the process cartridge 21 is replaced, or the maintenance cover 2a of the main body frame 2 is closed, the aperture electrode body 10 is opened.
However, the plurality of openings 11 of the aperture electrode body 10 moved to the cleaning position are cleaned by being driven to a cleaning position which is moved by a predetermined distance in the cleaning movement direction D which is one side in the extending direction from the image forming position. Therefore, the unnecessary toner T adhering to the inside of each opening 11 or the vicinity thereof is reliably removed.

Then, after the aperture electrode body 10 is moved back to the original image forming position, only a large amount of toner T passing through the plurality of openings 11 adheres to the recording paper P, and a sufficient image density is obtained. In addition, since there is no density unevenness and unnecessary toner T does not adhere, it is possible to form a clean image without paper stains. Furthermore, there is no short circuit between adjacent openings, and there is no damage to electronic components. In addition, since the pair of brush rollers 41 and 42 are rotationally driven for cleaning, unnecessary toner T firmly attached not only to the opening 11 and the inside thereof but also to the vicinity of the opening 11 can be surely and for a short time. You can clean it with.

By the way, as shown in FIG. 6, instead of the brush rollers 41 and 42, a cleaning mechanism 90 may be constructed so that the opening 11 is cleaned with pressurized air. That is, a cleaning pipe 91 having a length similar to the width of the aperture electrode body 10A is arranged in the left-right direction so as to correspond to the opening 11A of the aperture electrode body 10A that has moved to the cleaning position. The cleaning pipe 91 has a diameter of about 5 to 10 mm, and the cleaning pipe 91 has an opening 11
Opposite A, a slit having a slit width of about 30 μm is formed over the entire length, and both left and right ends thereof are closed.

Then, this cleaning pipe 91
Is connected to a compressor 93 via a pipe 92 at an arbitrary portion, and a drive motor 94 is connected to the compressor 93. As a result, when the electrode electrode moving motor 65A is driven to move the aperture electrode body 10A to the cleaning position and the drive motor 94 is rotationally driven, the pressurized air generated by the compressor 93 is used for cleaning via the pipe 92. The pressurized air sent to the pipe 91 and jetted from the slit of the cleaning pipe 91 blows off all of the unnecessary toner T adhering to the opening 11A and the vicinity thereof, and cleans it cleanly.

In this way, the pressurized air is jetted to clean the plurality of openings 11 and the vicinity thereof, so that the openings 11 of the aperture electrode body 10 are not damaged, without damaging the aperture electrode body 10 or the control electrode 12. It is possible to clean the unnecessary toner T adhering to the vicinity thereof and cleanly surely in a short time.

It should be noted that, in place of the back electrode roller 29, a back electrode plate having a plate shape is used, and various other techniques are available within the scope of the technical idea of the present invention, based on existing techniques and techniques obvious to those skilled in the art. May be changed. The recording paper P
It is needless to say that the present invention can be applied to various image forming apparatuses configured to convey the toner T in the horizontal direction and to control the adhesion of the toner T to the recording paper P by the aperture electrode body 10.

[0048]

According to the image forming apparatus of the first aspect, the aperture electrode body having the opening and the electrode array, the toner supply mechanism having the toner conveying roller, the back electrode, and the toner control means are further provided. An electrode body drive means, a cleaning means, and a cleaning control means are provided, and when the power is turned on, the aperture electrode body is moved and driven to a cleaning position which is moved from the image forming position to one side in the extending direction by a predetermined distance to perform cleaning. Since the plurality of openings of the aperture electrode body that has moved to the position are cleaned, each opening 1
After the unnecessary toner T adhering to the inside of 1 and its vicinity is reliably removed and the aperture electrode body is moved and returned to the original image forming position, only a large amount of toner passing through the plurality of openings is the recording medium. Adheres to and obtains sufficient image density,
Since there is no density unevenness and unnecessary toner does not adhere, it is possible to form a clean image without paper stains. Furthermore, there is no short circuit between adjacent openings, and there is no damage to electronic components.

According to the image forming apparatus of the second aspect, the cover detecting means for detecting the opening and closing of the cover for closing the opening formed in the main body frame of the image forming apparatus is provided, and the cleaning control means is the cover detecting means. When the cover is closed for maintenance, the toner stored inside the process cartridge will not be released from the opening of the aperture electrode body due to the vibration when the cover for maintenance is opened or closed. Even if carelessly adhered to, the cleaning is surely performed, so that the same effect as in claim 1 can be obtained.

According to the image forming apparatus of the third aspect, the cartridge detecting means for detecting the attachment / detachment of the process cartridge included in the toner supply mechanism is provided, and the cleaning control means receives the output of the cartridge detecting means and detects the process cartridge. Since it operates when it is installed, when a used process cartridge is replaced with a new one, the toner stored inside the process cartridge will be vibrated by the vibration when the new process cartridge is installed. Even if carelessly adhered to, the cleaning is surely performed, so that the same effect as in claim 1 can be obtained.

According to the image forming apparatus of the fourth aspect, the cleaning means rotationally drives and cleans the brush roller, so that it is unnecessary to firmly adhere not only to the opening and the inside thereof but also to the vicinity of the opening. It is possible to clean the toner reliably and in a short time.

According to the image forming apparatus of the fifth aspect, the cleaning means injects pressurized air to clean the plurality of openings and the vicinity thereof, so that the aperture electrode body and the control electrode are not damaged. The unnecessary toner attached to the opening of the aperture electrode body and its vicinity can be cleaned surely and quickly in a short time.

[Brief description of drawings]

FIG. 1 is a schematic side view illustrating an internal mechanism of an image forming apparatus.

FIG. 2 is an enlarged partial side view of an essential part of FIG.

FIG. 3 is an enlarged perspective view of an aperture electrode body.

FIG. 4 is a block diagram of a control system of the image forming apparatus.

FIG. 5 is a vertical cross-sectional side view of a main part of FIG. 1, illustrating the adhesion of toner to recording paper.

FIG. 6 is a view corresponding to FIG. 2 in which a cleaning mechanism for injecting pressurized air is provided according to the modification.

[Explanation of symbols]

 1 Image Forming Apparatus 2 Main Body Frame 2a Maintenance Cover 10 Aperture Electrode Body 11 Opening 12 Control Electrode 20 Toner Supply Mechanism 22 Toner Conveying Roller 23 Toner Supply Roller 29 Back Electrode Roller 30 Electrode Drive Mechanism 31 First Take-up Spool 33 Third 2 Take-up spool 40 Cleaning mechanism 41 Brush roller 42 Brush roller 71 Drive circuit 90 Cleaning mechanism 91 Cleaning pipe 93 Compressor CD controller P Recording paper T Toner

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

Claims (5)

[Claims] 1. An aperture electrode body having an aperture array formed of a plurality of apertures formed in a row in a horizontal direction orthogonal to the transport direction of a recording medium and an electrode array provided in each of the apertures, and an aperture thereof. A toner supply mechanism having a toner carrying roller for supplying toner to the opening of the electrode body, a back electrode provided in the opening on the opposite side of the aperture electrode body from the toner supply mechanism, and the electrode array. A toner control unit that individually controls the voltage supplied to each of the control electrodes to control the toner passing through each opening.
An image forming apparatus configured to record the toner passing through an opening onto a recording medium on the side opposite to the toner supply mechanism with respect to the aperture electrode, for recording the aperture electrode. An electrode body which is driven between an image forming position located between the toner transport roller and the back electrode and a cleaning position which is moved from the image forming position to one side in the extending direction of the aperture electrode body by a predetermined distance. Drive means, cleaning means for cleaning the plurality of openings of the aperture electrode body that has moved to the cleaning position, and control of the electrode body drive means for switching the aperture electrode body to the cleaning position when the image forming apparatus is started up. An image forming apparatus comprising: a cleaning control unit that operates the cleaning unit. 2. A cover detection means for detecting opening / closing of a cover for closing an opening formed in a main body frame of the image forming apparatus is provided, and the cleaning control means receives an output of the cover detection means and receives the output of the cover detection means. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to operate when the is closed. 3. A cartridge detection unit for detecting attachment / detachment of a process cartridge included in the toner supply mechanism is provided, and the cleaning control unit receives an output of the cartridge detection unit and operates when the process cartridge is attached. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured as described above. 4. The image forming apparatus according to claim 1, wherein the cleaning unit is configured to rotationally drive and clean a brush roller. 5. The cleaning unit is configured to inject pressurized air to clean the plurality of openings and their vicinity, according to any one of claims 1 to 3. The image forming apparatus according to item.