JPH05313441A - Cleaning device, cleaning system and image forming device - Google Patents

Abstract

PURPOSE:To prevent a photosensitive drum and a transfer drum from being damaged by toner sticking to a non-image forming area on the photosensitive drum. CONSTITUTION:A 1st cleaning device 6A is arranged between the transfer drum 29 and an electrostatic charging device 21 and a 2nd cleaning device 6B is arranged between a developing roller 22a and the transfer drum 29 along the periphery of the photosensitive drum 9. As to the 1st cleaning device 6A, a 1st blade 6A is allowed to abut on an image forming area on the photosensitive drum 9 so as to remove residual toner in this area. Meanwhile, the 2nd cleaning device 6B is provided with a 2nd blade 61 abutting on the non-image forming area on the drum 9 so as to remove the toner in the non-image forming area on the drum 9 immediately after developing. Thus, the entire surface of the drum 9 is cleaned every time the drum 9 rotates once, and failure that the toner remaining on the drum 9 is transferred and stuck to the drum 29 is not caused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device, a cleaning system and an image forming apparatus for removing toner adhering to an image bearing member. Here, the image forming apparatus includes a copying machine, a printer, a word processor, a facsimile machine, and the like.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus such as a copying machine or a laser beam printer, a toner image formed on a photosensitive drum as an image carrier is transferred to a transfer material such as paper to form an image. At this time, the toner remaining on the photosensitive drum without being transferred to the transfer material, so-called residual toner, is removed by a cleaning device.

The cleaning device is equipped with a cleaning blade that comes into contact with the surface of the photosensitive drum to remove residual toner. The residual toner on the surface of the photosensitive drum is scraped into the cleaning device by the cleaning blade, and then conveyed in a predetermined direction by a toner conveying member such as a screw. When the screw is rotated in the pipe member that guides the movement of the toner, the spiral blade around the rotation axis of the screw rotates, and the blade comes into sliding contact with the toner to impart a component force in the traveling direction to the toner. To do. The transported toner is collected in, for example, a collection container separate from the cleaning container or a storage chamber integrated with the cleaning container.

This waste toner is discarded from the collection container at the time of inspection or maintenance, or is removed together with the cleaning device while being stored in the storage chamber at the time of replacement due to the life of the cleaning device.

The above-mentioned screws and pipe members are often made of metal.

Such a cleaning device is generally
It is arranged between the transfer unit and the latent image forming unit around the photosensitive drum. A latent image forming unit, a developing unit, a transfer unit, and the like are sequentially arranged around the photosensitive drum along the rotation direction thereof, and the cleaning device is provided on the downstream side of the transfer unit.
And it is arranged on the upstream side of the latent image forming means. The cleaning device removes unnecessary residual toner remaining on the surface of the photosensitive drum after transfer to clean the surface of the photosensitive drum and prepares for the next image formation starting from latent image formation.

In forming an image, first, the latent image forming means is
After uniformly charging the surface of the photosensitive drum by the charging device,
This surface is exposed by an exposure device to form a latent image.
The developing means that stores toner (developer) in the developing container is
It has a developing roller, and toner in the developing container is adhered to the latent image on the photosensitive drum via the developing roller to form a toner image. This toner image is transferred to the transfer drum or transfer material by the next transfer means. At this time,
The residual toner remaining on the photosensitive drum without being transferred to the transfer drum or the transfer material is removed by the cleaning blade of the cleaning device and collected in the cleaning container. The surface of the photosensitive drum has an image forming area (portion used for image formation) at the center in the axial direction and annular non-image forming areas (portion not used for image formation) on both left and right sides of the image forming area. Then, the cleaning blade formed in a rectangular shape by the elastic member has a left and right effective width set to be slightly larger than the image forming area, and abuts on the surface of the photosensitive drum with an appropriate abutment pressure, thereby The residual toner can be reliably scraped off.

On the photosensitive drum from which the residual toner in the image forming area has been removed, a latent image is formed again by the latent image forming means, and thereafter, image formation is sequentially performed in the same manner as described above.

[0009]

However, according to the above-mentioned conventional example, the toner adheres to the screw to reduce the toner conveying force, or the photosensitive surface of the photosensitive drum (image carrier) is damaged. There was fear. That is, the toner is
Since it adheres to the image carrier at the time of development, it is likely to be charged with positive or negative charges, and is charged to a specific polarity. For this reason, when the screw is grounded, the screw is induced by the charging of the toner and is charged with a polarity opposite to that of the toner. Therefore, the toner electrostatically adheres to the periphery of the screw, which makes it difficult for the toner to move. On the other hand, when the screw is not grounded, the screw is charged up by frictional charging due to the rubbing with the toner.
When the screw is charged up and reaches several thousand volts, the screw discharges to the image carrier, and at this time, the charged surface of the image carrier is damaged such as a pinhole. Even when the image carrier is not discharged, a discharge is generated in the nearby grounding member, and the spark discharge at this time causes malfunction or destruction of the electric circuit, or if toner is present in the discharge path, the toner aggregates. There was a risk that. In order to prevent such charge-up and discharge, it is common to ground metal parts such as screws unless it is necessary not to ground them. Depending on the arrangement position, it may be difficult to ground, or the number of assembly steps may be large. Also,
The screw has the same drawbacks as described above not only when it is made of metal but also when it is made of a resinous member.

Further, since the cleaning device is designed to remove the residual toner in the image forming area,
Unwanted toner adhering to the non-image forming area cannot be sufficiently removed. To develop the latent image formed on the photosensitive drum, toner is attached in the developing device. At this time, unnecessary toner is scattered even in the non-image forming area other than the image forming area where the electrostatic latent image is formed. Is attached. Although the amount of scattered toner generated by one image formation is extremely small, the toner in the image forming area is transferred to the transfer material or the like, but this toner is not transferred to the transfer material and is transferred. There is a risk of gradually accumulating on the drum and growing in a fixed state, damaging the photosensitive drum and the transfer drum.

Therefore, it is an object of the present invention to provide a cleaning device, a cleaning system, and an image forming apparatus which are capable of smoothly removing the toner on the image carrier to further improve the image quality. is there.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a cleaning device is a cleaning device for removing toner on an image carrier.
A cleaning member for removing the toner on the image carrier, a toner transport member for transporting the toner removed by the cleaning member, and a grounded electric conductor are provided, and the electric conductor is provided from the toner transport member. It is characterized in that the distance to the electric conductor is smaller than the distance from the toner conveying member to the image carrier.

In the cleaning device for removing the toner on the image bearing member, a cleaning member for removing the toner on the image bearing member, a toner transport member for transporting the toner removed by the cleaning member, and the toner transporting member. A plurality of guide members for guiding the movement of the toner conveyed by the members, and a connecting member formed of a conductive member and connecting the plurality of guide members are provided.

In this case, it is preferable that the guide member has a pipe shape.

Next, the cleaning system is a cleaning system for removing the toner on the image carrier around which the latent image forming means, the developing means and the transfer means are arranged.
A first cleaning device and a second cleaning device are provided at different positions along the moving direction of the image carrier, and the first cleaning device is provided between the transfer means and the latent image forming means. The second cleaning device is disposed between the developing unit and the transfer unit and has a first cleaner that removes toner in an image forming area on the image carrier. It has a 2nd cleaner which removes the toner of the upper non-image formation area.

In this case, the second cleaner removes the toner in the non-image forming areas located at both outer ends of the image forming area on the image carrier where the toner image is formed. A second cleaning member is provided, and the second cleaning member is an elastic cleaning blade that comes into contact with a non-image forming area of the image carrier to remove toner, and the second cleaning member. It is preferable that the apparatus has a configuration in which the toner removed by the second cleaner is stored in a storage unit integrated with the second cleaner.

Further, the second cleaner conveys the toner removed from the image bearing member along the axial center side of the image bearing member, and a container for receiving the toner from the toner feeding member. A chamber, and an electric conductor that is arranged between the toner conveying member and the image carrier and is grounded, and a lid member that covers the storage chamber. The member may be composed of the grounded electric conductor. In addition, the first cleaning device includes a toner transport device that transports the toner removed by the first cleaner, and a recovery container that is separate from the first cleaner and that receives the toner from the toner transport device. It is preferable to provide the above because it is not necessary to remove the connecting portion with the recovery container when the second cleaner is removed, but the discharge port by the screw may be introduced into the same container.

Next, the image forming apparatus is an image forming apparatus for forming an image on a recording medium, an image carrier, image forming means for forming an image on the image carrier, and a toner image on the image carrier. Transfer means for transferring the image, and claim 1 to claim 3.
And the cleaning device according to any one of 1.

Further, in an image forming apparatus for forming an image on a recording medium, an image carrier, an image forming unit for forming an image on the image carrier, and a transfer unit for transferring a toner image on the image carrier. The cleaning system according to any one of claims 4 to 10 may be provided.

[0020]

According to the above construction, the grounded electric conductor is arranged, and the arrangement position is set such that the distance from the toner carrying member to the electric conductor is smaller than the distance from the toner carrying member to the image carrier. By arranging, even if the toner carrying member is charged by the carrying of toner, electric discharge is performed to the electric conductor in the vicinity thereof, so that electric discharge to the image carrier and other metal members is eliminated,
Damage to the image carrier and electric circuit is eliminated. Further, the adhesion of toner to the toner conveying member is reduced, and the conveying property is not impaired. Since the electric conductor is discharged while the charge-up is low as the electric conductor is brought closer to the toner conveying member, malfunction of the electric circuit due to discharge noise can be prevented.

Further, the second cleaner is provided between the developing means and the transfer means, and is provided with the second cleaner for removing toner in the non-image forming area of the image carrier after development.
The toner adhering to the non-image forming area is removed immediately after development and is not transferred to the transfer drum.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

First, a four-color full-color copying machine will be described as an example of the image forming apparatus to which the cleaning device and the cleaning system according to the present invention are applied.

FIG. 1 is a vertical sectional view showing the outline of this copying machine. The copying machine M includes an image reading unit 1, a latent image forming unit 2, a developing unit 3, a transfer unit 5, a cleaning unit 6, a feeding / conveying unit 7, and a photosensitive drum 9 as an image carrier.

The image reading means 1 is arranged on the upper part of the copying machine M, and the platen glass 10 on which the document D is placed is arranged on the upper surface thereof. The document D is placed with its image surface facing downward, and is pressed against the platen glass 10 by the document pressure plate 11. Below the platen glass 10, an illumination lamp 12 that illuminates the image surface of the document D and a plurality of mirrors 13, 13 ... That change the path of light reflected from the document surface are arranged in the front-back direction of the platen glass 10 (in FIG. It is arranged so as to be movable in the left-right direction. The light reflected from the mirrors 13, 13 ... Is imaged on the image sensor 16 by the lens 15, converted into an electric signal here, and then input to the laser scanner 19 via the image processing unit 17.

The latent image forming means 2 is a laser scanner 19 provided with a polygon mirror (not shown), and a laser scanner 19
Mirrors 20 and 20 that guide the laser light from the photosensitive drum 9
And an charging device 21 including a corona discharger.

The developing means 3 is disposed below the latent image forming means 2 and includes developing devices 22, 23, 25 and 26 which store four color toners, that is, magenta, cyan, yellow and black color toners, respectively. I have it. These developing devices 22, 23, 25, and 26 are movably arranged in the direction of arrow K1, and a developing device (developing device 22 for magenta in the figure) provided for development is exposed by a cam member 27. It is pushed up toward the drum 9.

The transfer drum 29, which is a main constituent member of the transfer means 5, is in contact with the photosensitive drum 9 obliquely from above.
The transfer drum 29 has a resin film formed in a cylindrical shape, and around the periphery thereof, the attraction roller 30, the attraction charger 31, the transfer charger 32, and the internal removal unit are arranged in this order along the rotation direction (direction of arrow R2). Electric appliance 33, external static eliminator 35, push-up roller 3
6, and the separation claw 37 is arranged.

The cleaning means 6 has two first cleaning devices 6A and second cleaning devices 6B which are arranged at positions substantially symmetrical with respect to the cylindrical photosensitive drum 9.
A cleaning system (detailed later) is built as a whole. The first cleaning device 6A has a transfer unit 5 when the rotation direction of the photosensitive drum 9 (direction of arrow R1) is taken as a reference.
2 which is a downstream side of and which constitutes the latent image forming means 2.
1 is arranged on the upstream side, while the cleaning device 6B
Is arranged on the downstream side of the developing means 3 and on the upstream side of the transfer means 5. The first cleaning device 6A and the second cleaning device 6B each include a cleaning member (described in detail later) that comes into contact with the surface of the photosensitive drum 9 to scrape off the toner on the photosensitive drum 9.

The feeding / conveying means 7 includes a sheet feeding cassette 39 for accommodating the transfer material P to be image-formed, a sheet feeding roller 40 for feeding the transfer material P from the sheet feeding cassette 39, a conveying roller 41 on the downstream side thereof. It is constituted by a registration roller 42, a conveyor belt 45 wound around rollers 43, 43 at positions half way around the transfer drum 29, a discharge roller 47 downstream of the fixing device 46, a discharge tray 49, and the like.

Next, an outline of the operation of the copying machine M having the above-mentioned structure will be described. The photosensitive drum 9 is rotated in the arrow R1 direction, and the transfer drum 29 is rotated in the arrow R2 direction. The surface of the photosensitive drum 9 is uniformly charged by the charging device 21, and then exposed by the latent image forming means 2. This exposure is performed by irradiating the charged photosensitive drum 9 with laser light generated by the laser scanner 19 according to the image information of the document D read by the image reading means 1. The electrostatic latent image formed on the photosensitive drum 9 by the exposure of the laser light is developed by the developing means 3. For example, in FIG. 1, magenta toner accommodated in the magenta developing unit 22 is attached to the electrostatic latent image on the photosensitive drum 9 via a developing roller or the like. At this time, normally, the developing roller and the photosensitive drum 9
An alternating electric field is formed between them and the toner having a charge to fly so that the toner finally adheres to the electrostatic latent image. Next, the cleaning device 6B downstream of the developing means 3 removes unnecessary toner adhering to the non-image forming area on the photosensitive drum 9. The toner image thus formed is
The image is transferred onto the transfer material P by the transfer means 5. Transfer material P
From the paper feed cassette 39 via the paper feed roller 40, the conveyance roller 41, the registration roller 42, etc.
Supply to 9. Transfer material P supplied to transfer drum 29
Is adsorbed and carried on the surface of the transfer drum 29 by the adsorption charger 31 or the like. Then, the toner image on the photosensitive drum 9 is transferred onto the transfer material P by the transfer charger 32. The rotation of the transfer drum 29 is further continued, and the cyan, yellow, and black developing units 23 on the transfer material P,
The toner images formed on the photosensitive drum 9 are sequentially transferred by 25 and 27. The transfer material P having completed the transfer of the four color toner images is separated from the transfer drum 29 by the static eliminators 33 and 35, the separation claw 37, and the like, and is conveyed to the fixing device 46 by the conveying belt 45. Here, the toner image is heated under pressure and fixed onto the transfer material P. After that, the transfer material P is discharged onto the discharge tray 49 by the discharge rollers 47, and the four-color full-color image formation (copy) is completed.

On the other hand, on the photosensitive drum 9 having no toner image after being transferred to the transfer material P, the residual toner in the image forming area is removed by the first cleaning device 6A on the downstream side. This removal can be done with cyan, magenta, yellow,
This is performed after each black toner image is transferred. The photosensitive drum 9 whose surface has been cleaned by the first cleaning device 6A is subjected to the next image forming process starting from the charging by the charging device 21.

Next, the first cleaning device 6A and the second cleaning device 6B which form the cleaning system.
Will be explained in detail. When the arrangement positions of the first cleaning device 6A and the second cleaning device 6B with respect to the photosensitive drum 9 are confirmed again with reference to FIG. 2, the first cleaning device 6A shows that the transfer drum 29 (transfer means 5) and the charging device 21 (latent image). The second cleaning device 6B is arranged between the forming device 2) and the developing device 22 (developing device 3, but in FIG. 2, the developing roller 22a of the developing device 22 is represented. ) And transfer drum 29
It is located between and. That is, with the charging device 21 as the starting point, the charging device 21, the developing roller 22a, and the second cleaning device 6 are sequentially arranged along the rotation direction R1 of the photosensitive drum 9.
B, the transfer drum 29, and the first cleaning device 6A are arranged. Therefore, the second cleaning device 6B removes the surface of the photosensitive drum 9 after development, and the first cleaning device 6A removes the surface of the photosensitive drum 9 after transfer.

FIG. 3 shows a cross section of the first cleaner 6A ₁ which constitutes a part of the first cleaning device 6A.
The cleaning device 6A includes the first cleaner 6A ₁ in addition to the first cleaner 6A ₁ arranged to face the photosensitive drum 9.
A toner collecting container, which will be described later, which is separate from A _1, and a toner conveying device which connects this collecting container and the first cleaner 6A ₁ are included. However, since the second cleaning device 6B, which will be described in detail later, does not have a separate collection container or the like, the first cleaning device 6B and the first cleaner 6B have the same contents. The first cleaner 6A ₁ is
The cleaning container 50 is provided along the axial direction (left-right direction) of the photosensitive drum 9.
At 0, an opening serving as a toner recovery port is formed. The lateral width of the opening is set to be approximately the same as the lateral length of the photosensitive drum 9, and a cleaning blade (cleaning member) 53 is held in the opening by a support member 51 and a pressing member 52. The cleaning blade 53 is formed in a rectangular shape by an elastic member such as urethane rubber, and its left and right width is substantially equal to the left and right width of the opening. The cleaning blade 53 employs a so-called doctor system in which the front end portion 53a of the cleaning blade 53 is brought into contact with the surface of the photosensitive drum 9 which moves in the arrow R1 direction from below to above with the tip portion 53a thereof facing downward. Below the opening, a rake sheet holding plate 56 having a film-shaped rake sheet 55 attached to the tip is attached to the cleaning container 50.
It is attached by screws 57. Like the cleaning blade 53, the scooping sheet 55 and the scooping sheet holding plate 56 are arranged at the full width of the opening. The rake sheet holding plate 56 is made of metal and is electrically connected to the metal portion of the copying machine main body via the screw 57. In this way, the rake sheet holding plate 5
Reference numeral 6 constitutes a grounded electric conductor. A screw 59 as a toner conveying member is disposed in the lower portion inside the cleaning container 50 with its shaft portion 59a oriented in the left-right direction. The screw 59 has a spiral blade portion 59b around a shaft portion 59a, is made of, for example, resin or metal as a whole, and is rotatably supported in a so-called "floating" state that is not grounded. The above-mentioned rake sheet holding plate 56 is arranged substantially in the middle of this screw 59 and the above-mentioned photosensitive drum 9. Regarding the disposition position of the rake sheet holding plate 56, the screw 5
The distance L ₁ between the scooping sheet holding plate 56 and the scooping sheet holding plate 56 is smaller than the distance L ₂ between the screw 59 and the photosensitive drum 9 described above. That is, the rake sheet holding plate 56 is arranged closer to the screw 59 than the photosensitive drum 9. Screw 59
The toner is moved along the shaft 59a by rotating the blade 59b through the shaft 59a.

Next, with reference to FIGS. 7, 8 and 9, a structure for collecting the removed toner in a collecting container separate from the first cleaner 6A ₁ will be described. However, FIG. 7 illustrates a structure slightly different from that of the first cleaner 6A ₁ shown in FIG. The cleaning container 50 is provided with a rotating member 54 rotatable in the direction of arrow R3 for moving the toner removed from the photosensitive drum 9 toward the screw 59. The cleaning container 50 includes a cleaning blade 53 as shown in FIG.
A side seal 53a formed of a sponge such as urethane foam is provided between and to prevent the toner from leaking from the left and right ends of the cleaning blade 53. Also,
A toner discharge pipe portion 50a is integrally projectingly provided at one end portion of the cleaning container 50 in the horizontal direction. The toner discharge pipe portion 50a is provided with a screw 73a on the main body of the copying machine M.
Is supported by the toner receiving portion 73 fixed by
The toner that has dropped from the toner outlet 50b below the toner discharge pipe portion 50a is once received by the toner receiving portion 73. A pipe 76 as a guide member is connected to the toner receiving portion 73, and a waste toner outlet 77 is connected to the tip of the pipe 76. Pipe 76
Is formed of, for example, a metal, and the waste toner outlet 77 is formed of a conductive resin. The waste toner outlet 77 is fixed to the main body of the copying machine with a screw 79, and is grounded together with the pipe 76. Inside the toner receiving portion 73, the pipe 76, and the waste toner outlet 77, the second screw 75 as a toner conveying member is provided.
Are arranged. The second screw 75 is formed in a spring shape, and the toner receiving portion 73 side is rotatably supported by a cantilever, while the waste toner outlet 77 side is a free end. The second screw 75 is in contact with the waste toner outlet 77 at the portion Q in FIG. 8 and is thus held at the ground potential. Therefore, the charge due to the triboelectrification generated in the second screw 75 and the pipe 76 by the toner being conveyed by the second screw 75 which is rotationally driven by a motor (not shown) does not unnecessarily accumulate.
When the pipe 76 is made of resin, the amount of charge accumulated in the pipe 76 is small, and therefore even if the potential becomes high, no electric discharge will occur between the pipe 76 and a nearby ground member.

Below the waste toner outlet 77, a waste toner collecting container 80 is installed. As shown in FIG. 9, a transmission type waste toner sensor including a waste toner detection LED S ₁ and a waste toner detection phototransistor S ₂ is installed above the collection container 80, and the amount of waste toner is regulated. When the amount exceeds the amount, for example, after the completion of copying, a waste toner recovery display is displayed on the operation unit of the copying machine M.

Next, referring to FIG. 2, FIG. 4 and FIG.
The cleaning device (second cleaner) 6B will be described in detail. The second cleaner 6B has a container-shaped second blade housing 60, and plate-shaped second cleaning blades (second cleaning members) 61, 61 made of an elastic body are provided near the left and right ends of the second blade housing 60. Is installed. Each second cleaning blade 61 is fixed to the second blade housing 60 by a screw 62 and a pressing member 63, and its tip end is brought into contact with the non-image forming area on the surface of the photosensitive drum 9 with an appropriate pressure. A lid member 65 is arranged to be openable and closable between the second blade housing 60 and the second cleaning blades 61, 61 on the center side of the second blade housing 60, and a toner storage chamber 66 is formed between the lid member 65 and the second blade housing 60. is doing. This storage room 66
A screw 67 that conveys toner to the penetrating storage chamber 66 and is disposed over the entire length of the second blade housing 60. Near the left and right ends of the screw 67, blade portions 67 having lead angles opposite to each other are provided.
While a and 67b are provided, a storage chamber 66 is provided at the center.
A straight portion 67c having no blade is provided so that a large amount of toner can be stored therein. The entire screw 67 is rotatably supported by the second blade housing 60, and a drive gear 67d is fixed to one end of the screw 67. The gear 67d meshes with a gear (not shown) that is coaxial with the photosensitive drum 9, so that
The second cleaning blades 61, 61 are driven to rotate.
However, the toner removed from the left and right non-image forming areas of the photosensitive drum 9 is conveyed by the screw 67 toward the central storage chamber 66. Second blade housing 6
A support plate 70 formed of a metal plate is attached to the 0 through a screw 69, and the support plate 70 includes the left and right bent portions 70.
It is fixed to the main body of the copying machine in a grounded state via a and 70b. Between the support plate 70 and the lid member 65, a leaf spring 71 is fixed by a screw 72 so as to contact them. Therefore, the lid member 65 is grounded via the leaf spring 71 and the support plate 70.

Next, referring to FIG. 6, a cleaning blade (hereinafter referred to as "first blade") 53 and a second cleaning blade (hereinafter referred to as "second blade").
The cleaning share of the photosensitive drum 9 by 61 and 61 will be described. However, in FIG. 6, A4 size paper (height 297 mm, width 210 mm) is passed horizontally (length 29 mm).
7 mm is oriented in the left-right lateral direction), and the numbers in parentheses in the figure are the dimensions of each member and the like in mm. The photosensitive drum 9 has an image forming region (image forming region) 9a on the center side along its axial direction.
And non-image forming regions (regions on which no image is formed) 9b, 9b formed in an annular shape on the left and right sides thereof. In the figure, the effective development width 295 mm indicates the width of the image forming area 9a. The left-right width W ₁ of the first blade 53 of the first cleaning device 6A is set to be slightly larger than the left-right width of the image forming area 9a.
Can be effectively removed if the toner is on the image forming area 9a. On the other hand, the second blades 61, 61 of the second cleaning device 6B have a lateral width of W ₂
Is set so that it partially overlaps with the first blade 53 (shown by OL in the drawing), and is arranged up to a position that coincides with both left and right ends of the photosensitive drum 9. Therefore, the second blades 61, 61 can effectively remove the toner on the non-image forming areas 9b, 9b, which the first blade 53 cannot remove.

Next, the cleaning system, that is, the first
The operation of the cleaning device 6A and the second cleaning device 6B will be described.

As shown in FIG. 2, the photosensitive drum 9 is rotated in the direction of arrow R1, the entire surface of the photosensitive drum 9 is uniformly charged by the charging device 21, and then the image forming area 9a is exposed (L in the figure). Form an electrostatic latent image. Next, developing device 2
Toner is attached to the electrostatic latent image by the second developing roller 22a. At this time, an alternating electric field is formed between the developing roller 22a and the photosensitive drum 9 so that the toner flies between them. Therefore, a part of the toner is attached to the non-image forming areas 9b and 9b in addition to the electrostatic latent image on the image forming area 9a. The toner in the non-image forming areas 9b and 9b is the second
Removed by cleaner 6B. As shown in FIG. 6, the second blades 61, 61 of the second cleaner 6B are provided in the non-image forming areas 9b, 9b at the left and right ends of the photosensitive drum 9, respectively.
Is pressed, and the toner in the non-image forming areas 9b, 9b is scraped off by the second blades 61, 61 into the second blade housing 60 in FIG. The scraped toner is conveyed in the direction of the arrow by the blade portions 67a and 67b of the screw 67 rotated through the gear 67d and is collected in the storage chamber 66. The screw 67 is charged up by this toner conveyance, but the screw 67
Since the lid member 65 disposed in the vicinity of is not grounded properly to have a high potential, the toner can be smoothly transported, and other electric circuits such as the photosensitive drum 9 are also provided. It doesn't damage. The waste toner collected in the storage chamber 66 is, for example, 1 copy.
The second blade 61 by the serviceman, which is performed every time,
Discard when replacing 61. The amount of this waste toner for each copy is very small, and the storage chamber 66 can normally collect about 20,000 waste toners.

In the photosensitive drum 9 from which the toner in the non-image forming areas 9b and 9b is thus removed by the second cleaner 6B, the toner on the image forming area 9a is transferred by the transfer charger 32 to the transfer drum 29. Is transferred onto the transfer material P carried by the. At this time, a part of the toner remains on the photosensitive drum 9 without being transferred to the transfer material P. The first cleaning device 6A removes the residual toner.

The first blade 53 of the first cleaning device 6A is in contact with the entire width of the image forming area 9a of the photosensitive drum 9, and the residual toner is cleaned by the cleaning container 50.
Scrape it inside. This first blade 53 and the above-mentioned second blade
As described with reference to FIG. 6, the width dimensions W ₁ and W ₂ and the installation position of the second blades 61 and 61 of the cleaner 6B are set so as to partially overlap each other, and therefore the blades 53 , 61, 61, the toner can be effectively removed from the entire surface of the photosensitive drum 9 including the image forming area 9a and the non-image forming areas 9b, 9b.

The first blade 53 is the cleaning container 50.
As shown in FIG. 8, the toner scraped inside is conveyed in the direction of the arrow by the rotation of the screw 59, and from the toner outlet 50b of the toner discharge pipe portion 50a to the toner receiving portion 7.
It falls to 3. The toner that has fallen is conveyed in the pipe 76 by the rotation of the second screw 75 and falls from the waste toner outlet 77 into the collection container 80. When the amount of the waste toner in the collecting container 80 exceeds the specified amount while copying, the LED S ₁ and the photo interrupter S ₂ in FIG. 9 detect this and perform a waste toner collecting display. Discard from the collection container 80.

The screw 5 is fed by the above-mentioned toner conveyance.
9 charges up, but as shown in FIG.
The rake sheet holding plate 56 disposed between the screw 59 and the photosensitive drum 9 is composed of a grounded electric conductor, and the distance L ₁ between the screw 59 and the holding plate 56 is L _1.
However, since it is set to be smaller than the distance L ₂ between the screw 59 and the photosensitive drum 9, the screw 59 discharges between the holding plate 56 and the photosensitive drum 9 before the potential becomes high. There is no risk of causing harmful discharge. Further, the toner can be smoothly conveyed by the screw 59.

As in the case of the screw 59 described above, the toner is conveyed by the second screw 75, so that the second screw 75 is charged up. However, since the second screw 75 is grounded by contacting the waste toner outlet 77 at the Q portion, it does not charge up to a high potential. Therefore, no electric discharge is caused between the metal member and another metal member, and the toner can be conveyed without any trouble.

As described above, the second cleaner 6B is provided immediately after the developing device 22 (developing means 3) where the scattered toner is most likely to adhere to the photosensitive drum 9, and the non-image forming area 9 is provided.
By removing the unnecessary toner of b and 9b, it is possible to effectively prevent the photosensitive drum 9 and the transfer drum 29 from being damaged,
In addition, toner tends to be charged up due to toner transport,
By disposing the rake sheet holding plate 56 and the lid member 65 which are ground conductors in the vicinity of the screw 59 of the first cleaning device 6A and in the vicinity of the screw 67 of the second cleaner 6B, respectively, these screws 59 and 67 are It is possible to prevent electric discharge from being generated between the photosensitive drum 9 and other metal members and to smoothly convey the toner.

FIG. 10 shows another embodiment of the first cleaning device. In the previous embodiment, the screw 59
Is not grounded, but is grounded via the high resistance body 81 in this embodiment. As the high resistance body 81, for example, 1
A resistance of about 0 MΩ and a varistor of about 1000 V can be used. As a result, the screw 59 can have a potential different from that of the ground, and the same effect as that of the previous embodiment can be obtained.

The first cleaning device 6C shown in FIGS. 11 and 12 uses a fur brush instead of the first cleaning device 6A which uses the first blade 53 as a cleaning member. This is an example.

The residual toner T ₀ on the photosensitive drum 9 is collected by the fur brush 83 held by the metal fur brush shaft 82.
The toner T _{1 that} has been scraped off by is further knocked off the surface of the fur brush 83 by the baffle plate 85 and drops. In addition, the toner T ₂ which is scattered and floated
Are conveyed in a predetermined direction by the fan 86. The dropped toner T ₁ is sent in a predetermined direction by a screw 59 and is stored in a waste toner collecting container (not shown in the figure). FIG. 12 shows a cross section taken along the line AA of FIG. The fur brush shaft 82 is rotatably supported at both left and right ends by resin bearings 87, 87 and floats from the ground. The fur brush shaft 82 is driven by the coupling pin 89 fixed to the eccentric boss 95 of the motor 90.
And the pin groove 82a of the fur brush shaft 82 are joined together. The pin groove 82a is tapered in that if the coupling pin 89 is slightly inclined, a repulsive force is generated due to the grooving motion, and the coupling pin 89 and the pin groove 82a are gradually separated from each other. This is because it is likely to occur and to prevent this.

Both sides of the screw 59 are held by resin bearings 91 and float above the ground. For driving, the arm 92 is swung by the resinous eccentric boss 95, and the one-way clutch 93 intermittently rotates the screw 59. It is preferable that the toner-conveying screw 59 rotates intermittently with a change in speed rather than a constant rotation because the toner is less likely to crosslink around the screw 59.

The cleaner back side plate 96 is fixed to the cleaning container 50 by the screw 97 while the motor 90 is fixed. Further, a positioning pin 99 for fixing the cleaning container 50 at a predetermined position is fixed to the cleaner back side plate 96, and the positioning pin 99 is inserted into the back side plate 102 of the copying machine main body to ground the back side plate 102. ing. The cleaner front side plate 100 is fixed to the cleaning container 50 by a screw 101 and is fixed to the main body front side plate 103 by a screw 105 to fix the cleaning container 50 to the main body of the copying machine. Here, the cleaner front side plate 100 is , Grounded.
Reference numeral 106 denotes a drum centering plate that is removed when the photosensitive drum 9 is replaced.

Here, the cleaner front side plate 100 and the cleaner rear side plate 96, which are at the potential of the fur brush shaft 82 and the ground, more than the distance L ₃ between the fur brush shaft 82 and the photosensitive drum 9.
Since the distance L ₄ between and is sufficiently short, the discharge is not performed and the photosensitive drum 9 is not damaged during the distance L ₄ . The same applies to screw 59 because L ₅ is sufficiently closer than L ₆ .

FIG. 13 shows an embodiment in which a pipe as a guide member of the first cleaning device 6A is connected.
The screw shaft 75a at one end of the second screw 75 is rotatably supported by the bearing 107, and the gear 1
It is rotationally driven by 09. The screw 75 is formed of a spring metal whose one end is fixed to the screw shaft 75a. The pipes 76A and 76B are integrally connected by a connecting member 111 formed of a conductive resin. Here, the connecting member 111 is fixed to the main body of the copying machine by a screw 112 in a grounded state, and its inlet side, that is, the pipe 7
The 6A side is thicker than the inner diameter of the pipe 76A, and the outlet side, that is, the pipe 76B side is thinner than the inner diameter of the pipe 76B. This is to prevent the rotation of the screw 75 from being alienated at the step of the connecting portion when the screw 75 rotates. In addition, the screw 75 has a bent portion at the connecting member 11.
Since it is in contact with 1, it is in a grounded state. When the pipes 76A and 76B are made of metal, they are grounded by the connecting member 111. In the figure, 110 is a resin seal that closes the end of the pipe 76A.

14, 15 and 16 show another embodiment of the pipe as the guide member. The pipe 76C is formed by bending a metal such as an aluminum alloy, and the bearing 107 that holds the screw 75 may be a conductive resin or metal bearing to ensure contact. The metal pipe 76C is fixed by a holder 113, and is screwed to the main body lateral side plate 115 with a screw 112.
The toner conveying member is not limited to the cantilevered second screw 75, but a bendable metal, such as a chain or beads, is arranged along the toner conveying direction.
You may make it convey toner by moving this.

FIG. 17 shows another embodiment of the second cleaner. This second cleaner 6D is different from the second cleaner 6B shown in FIG.
In addition to the blades 61, 61 and the screw 67, a toner storage chamber 68 covered by the lid members 65a, 65b,
It has two 68. Each of the storage chambers 68 is arranged immediately inside the blades 67a and 67b at the left and right ends of the screw 67, and the lid members 65a and 65b are grounded by the ground members 71a and 71b, respectively. Therefore,
The second cleaner 6D uses the screw 67 to store the toner removed from the non-image forming areas 9b and 9b of the photosensitive drum 9 by the second blades 61 and 61 by the screw 67.
And is stored in these storage chambers 68, 68. That is, the second cleaner 6D stores the removed toner in the second cleaning unit U. Therefore, in the second cleaner 6D, the toner conveying distance by the screw 67 is shorter than that in the second cleaner 6B in FIG. The amount of toner removed from the non-image forming areas 9b and 9b is very small, and the storage chambers 68 and 68 normally have 20,000 copies (A
4 size) of removed toner can be stored. The toner stored in the storage chambers 68, 68 is discarded, for example, by a service person every about 10,000 copy counters of the apparatus main body. The second blades 61, 61 are replaced or the blades contacting the photosensitive drum 9 are discarded. This can be done when the edge of is replaced.

[0056]

As described above, according to the present invention,
A second cleaner is provided immediately after the developing unit and before the transfer unit where scattered toner is most likely to adhere to the image carrier (eg, photosensitive drum) to remove unnecessary toner adhering to the non-image forming area. Thus, for example, it is possible to effectively prevent the photosensitive drum and the transfer drum from being damaged by the adhered toner. According to yet another aspect of the present invention, grounding is performed near the toner carrying member (for example, screw) of the first cleaning device and the toner carrying member (for example, screw) of the second cleaner, which are apt to be charged up by carrying toner. By disposing the conductor, it is possible to prevent these toner transport members from causing harmful discharge between the toner transport member and other metal members such as the image carrier, and to realize smooth transport of the toner. .. By preventing this discharge, it is possible to effectively prevent the image carrier and other electric circuits from being damaged.

[Brief description of drawings]

FIG. 1 is a sectional view showing an outline of an image forming apparatus.

FIG. 2 is a cross-sectional view showing the arrangement of a cleaning device.

FIG. 3 is a sectional view showing the configuration of a first cleaner.

FIG. 4 is a perspective view showing a configuration of a second cleaner.

FIG. 5 is a vertical sectional view of a second cleaner.

FIG. 6 is a schematic diagram showing a cleaning region of a first blade and a second blade.

FIG. 7 is a cross-sectional view showing the configuration of a first cleaner.

FIG. 8 is a cross-sectional view showing a guide member and a second screw of the first cleaning device.

FIG. 9 is a schematic diagram showing the overall configuration of a first cleaning device.

FIG. 10 is a cross-sectional view of another first cleaner.

FIG. 11 is a cross-sectional view of another first cleaner.

12 is a cross-sectional view taken along the line AA in FIG.

FIG. 13 is a cross-sectional view showing a plurality of pipes (guide members) and a connecting member that connects them.

FIG. 14 is another pipe and screw (toner conveying member)
FIG.

FIG. 15 is a perspective view showing the same pipe.

FIG. 16 is a sectional view showing a section of the pipe and a screw.

FIG. 17 is a perspective view showing another embodiment of the second cleaner.

[Explanation of symbols]

2 latent image forming means 3 developing means 5 transfer means 6 cleaning system 6A first cleaning device (first blade) 6A ₁ first cleaner 6B second cleaning device (second cleaner, second blade) 9 image carrier (photosensitive drum) ) 9a image forming area 9b non-image forming area 53 cleaning member (cleaning blade) 56 electric conductor (rake sheet holding plate) 59, 67 toner conveying member (screw) 61 second cleaning member (second cleaning blade) 65 electric conductor ( Lid member) 66 Storage chamber 76 Guide member (pipe) 80 Recovery container 111 Connecting member M Image forming apparatus (copying machine)

Claims (13)

[Claims] 1. A cleaning device for removing toner on an image carrier, a cleaning member for removing toner on the image carrier, a toner carrying member for carrying the toner removed by the cleaning member, and a grounding member. An electric conductor, and the electric conductor is arranged at a position where a distance from the toner conveying member to the electric conductor is smaller than a distance from the toner conveying member to the image carrier. A characteristic cleaning device. 2. A cleaning device for removing toner on an image carrier, a cleaning member for removing toner on the image carrier, a toner carrier member for carrying toner removed by the cleaning member, and the toner carrier. A cleaning device, comprising: a plurality of guide members that guide the movement of the toner conveyed by the members; and a connecting member that is formed of a conductive member and that connects the plurality of guide members. 3. The cleaning device according to claim 2, wherein the guide member is formed in a pipe shape. 4. A cleaning system for removing toner on an image carrier around which a latent image forming unit, a developing unit and a transfer unit are arranged, the cleaning system being arranged at different positions along the moving direction of the image carrier. A first cleaning device and a second cleaning device, wherein the first cleaning device is arranged between the transfer means and the latent image forming means, and removes toner in an image forming area on the image carrier. The second cleaning device is disposed between the developing unit and the transfer unit and removes the toner in the non-image forming area on the image carrier. A cleaning system characterized by that. 5. The second cleaner removes toner from a non-image forming area located at both outer ends of the image forming area on the image bearing member where a toner image is formed. The cleaning system according to claim 4, further comprising two cleaning members. 6. The cleaning system according to claim 5, wherein the second cleaning member is an elastic cleaning blade that comes into contact with a non-image forming area of the image carrier to remove toner. 7. The second cleaning device comprises:
The cleaning system according to any one of claims 4 to 6, wherein the toner removed by the cleaner is housed in a housing unit integrated with the second cleaner. 8. The second cleaner includes a toner carrying member for carrying the toner removed from the image carrier along an axial center of the image carrier, and a housing for receiving the toner from the toner carrying member. The cleaning system according to claim 7, further comprising: a chamber. 9. The cleaning system according to claim 8, wherein the second cleaner includes an electric conductor that is arranged between the toner conveying member and the image carrier and is grounded. .. 10. The cleaning system according to claim 9, wherein the second cleaner has a lid member that covers the storage chamber, and the lid member is configured by the grounded electric conductor. .. 11. The first cleaning device conveys toner removed by the first cleaner, and a recovery device separate from the first cleaner that receives toner from the toner conveying device. A cleaning system according to claim 4, further comprising: a container. 12. An image forming apparatus for forming an image on a recording medium, an image carrier, an image forming unit for forming an image on the image carrier, and a transfer unit for transferring a toner image on the image carrier. An image forming apparatus comprising: the cleaning device according to any one of claims 1 to 3. 13. An image forming apparatus for forming an image on a recording medium, an image carrier, an image forming unit for forming an image on the image carrier, and a transfer unit for transferring a toner image on the image carrier. An image forming apparatus comprising: the cleaning system according to any one of claims 4 to 10.