JP6598012B2 - Cleaning device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to a cleaning device that cleans untransferred toner adhered to the surface of an image carrier such as a photosensitive drum, a photosensitive belt, an intermediate transfer belt, and an intermediate transfer drum, a process cartridge including the cleaning device, a copying machine, The present invention relates to an image forming apparatus using an electrophotographic system such as a printer, a facsimile, or a multifunction machine thereof.

  Conventionally, in an image forming apparatus using an electrophotographic method such as a copying machine or a printer, a cleaning blade is brought into contact with an image carrier such as a photosensitive drum, a photosensitive belt, an intermediate transfer belt, or an intermediate transfer drum, thereby A technique for removing untransferred toner remaining on a carrier with a cleaning blade is known (see, for example, Patent Documents 1 to 3).

Specifically, the cleaning blade is in contact with the surface of the image carrier at a predetermined angle and pressure on the downstream side in the running direction of the image carrier with respect to the transfer unit. Then, the untransferred toner remaining (attached) on the image carrier by the cleaning blade is removed together with other attached matters (toner additive, paper powder, etc.), and the cleaning device in which the cleaning blade is installed. Deposits such as untransferred toner are collected inside.
In these cleaning apparatuses, paper dust is caught in the edge portion (contact portion) of the cleaning blade that contacts the image carrier, and the paper powder slips through the edge portion together with the toner, resulting in poor cleaning. There is a known problem that an abnormal image is generated.

On the other hand, in Patent Documents 1 and 2, in order to prevent paper dust from entering the edge portion of the cleaning blade, a brush-like or sheet-like shape is used so as to contact the image carrier at a position upstream of the cleaning blade. A technique for installing a paper dust removing member is disclosed.
Further, in Patent Document 3, a predetermined voltage is applied so as to face the image carrier at a position upstream of the cleaning blade in order to prevent paper dust from entering the edge of the cleaning blade. A technique for installing a paper dust removing member that electrostatically adsorbs powder is disclosed.

The techniques of Patent Documents 1 and 2 described above also remove untransferred toner as well as paper dust by a brush-like or sheet-like paper dust removing member installed so as to contact the image carrier at a position upstream of the cleaning blade. It has been done. For this reason, there is a problem that a lump of paper dust and toner is formed at the contact portion between the paper dust removing member and the image carrier and scratches the surface of the image carrier, and the untransferred toner input to the cleaning blade There is a possibility that the amount of the cleaning blade may be reduced and a cleaning blade may be swung or abnormal noise may be generated.
Further, since the technique of Patent Document 3 described above applies a relatively large voltage to the paper dust removing member installed so as to face the image carrier at a position upstream of the cleaning blade, Discharge occurs between the image carrier and the deterioration of the image carrier, or the friction coefficient of the image carrier increases to cause the cleaning blade to bend. There was a possibility.

  The present invention has been made to solve the above-described problems, and has a relatively simple configuration without accelerating the deterioration of the image carrier or causing the cleaning blade to bend or cause abnormal noise. Cleaning device and process cartridge in which paper dust biting into the edge portion of the cleaning blade that contacts the image carrier slips through the edge portion together with the toner and an abnormal image such as defective cleaning is suppressed. And providing an image forming apparatus.

According to a first aspect of the present invention, there is provided a cleaning device that contacts an image carrier that travels in a predetermined direction and cleans untransferred toner adhering to the surface of the image carrier, and the cleaning blade. The image carrier is disposed at a position upstream of the image carrier in the running direction so as to face the image carrier with a predetermined gap, and the position of the gap is set to a predetermined value with the untransferred toner. A paper dust regulating member formed so as to pass paper dust of less than a predetermined size and not to pass paper dust of a predetermined value or more, and a traveling direction of the image carrier with respect to the cleaning blade It is disposed so as to come into contact with the image carrier at a downstream position, and has a size less than the predetermined value that has passed through the position of the cleaning blade. Comprising a paper dust cleaning member for cleaning the powder, wherein the paper powder cleaning member, so as to extend over the end portion of the sheet passing area of the maximum size passable, but placed is divided in the width direction .

  According to the present invention, the edge of the cleaning blade in contact with the image carrier is engaged with a relatively simple structure without accelerating the deterioration of the image carrier or causing the cleaning blade to bend or cause abnormal noise. It is possible to provide a cleaning device, a process cartridge, and an image forming apparatus in which a problem that abnormal paper such as defective cleaning occurs due to slipped paper dust passing through the edge portion together with toner is suppressed.

1 is an overall configuration diagram illustrating an image forming apparatus according to Embodiment 1 of the present invention. It is a block diagram which shows an image creation part. FIG. 5 is an enlarged schematic view showing a state where the tip of the cleaning blade comes into contact with the photosensitive drum and the tip of the paper dust regulating blade faces. It is the schematic which shows a photoconductor drum, a cleaning blade, and a paper dust control blade in the width direction. FIG. 10 is a schematic diagram showing a main part of a cleaning device as a first modification. FIG. 10 is a schematic diagram showing a main part of a cleaning device as a second modification. It is a block diagram which shows the image creation part in Embodiment 2 of this invention. 8 is an enlarged schematic view showing a state in which the tip of the cleaning blade and the paper dust cleaning member are in contact with the photosensitive drum and the tip of the paper dust regulating blade is opposed to the photosensitive drum in the image forming unit of FIG. It is the schematic which shows a cleaning blade and a paper dust cleaning member in the width direction.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
The first embodiment of the present invention will be described in detail with reference to FIGS.
First, the overall configuration and operation of the image forming apparatus will be described with reference to FIG.
The image forming apparatus 1 according to the first embodiment is a tandem color image forming apparatus in which a plurality of process cartridges 10Y, 10M, 10C, and 10BK are arranged in parallel so as to face an intermediate transfer belt 17 as an intermediate transfer member. is there.

  In FIG. 1, 1 is a color copier as an image forming apparatus, 3 is a document conveying unit that conveys a document to a document reading unit 4, 4 is a document reading unit that reads image information of a document, and 6 is based on input image information. A writing unit (exposure unit) that emits laser light, 7 is a paper feeding unit that stores a recording medium P such as transfer paper, and 10Y, 10M, 10C, and 10BK are products corresponding to each color (yellow, magenta, cyan, and black). A process cartridge as an image portion, 17 is an intermediate transfer belt (image carrier) on which toner images of a plurality of colors are transferred in an overlapping manner, and 18 transfers a toner image formed on the intermediate transfer belt 17 to a recording medium P 2 The next transfer roller 20 is a fixing unit for fixing an unfixed image on the recording medium P, and 28 is for supplying toner of each color to the developing devices of the process cartridges 10Y, 10M, 10C, and 10BK. Toner container, 30 denotes a waste toner container, the waste toner is collected.

Here, each of the process cartridges 10Y, 10M, 10C, and 10BK (image forming unit) includes a photosensitive drum 11 as an image carrier, a charging unit 12, a developing unit 13 (developing device), and a cleaning device 15 (cleaning unit). ) Are integrated (see FIG. 2). And each process cartridge 10Y, 10M, 10C, 10BK is replaced | exchanged for a new thing when the lifetime is reached.
A toner image of each color (yellow, magenta, cyan, black) is formed on the photosensitive drum 11 (image carrier) in each of the process cartridges 10Y, 10M, 10C, and 10BK.

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the document is transported from the document table by the transport rollers of the document transport unit 3 and placed on the contact glass of the document reading unit 4. Then, the document reading unit 4 optically reads the image information of the document placed on the contact glass.
Specifically, the document reading unit 4 scans an image of a document on the contact glass while irradiating light emitted from an illumination lamp. Then, the light reflected from the original is imaged on the color sensor via the mirror group and the lens. The color image information of the original is read for each color separation light of RGB (red, green, blue) by the color sensor, and then converted into an electrical image signal. Further, an image processing unit (not shown) performs color conversion processing, color correction processing, spatial frequency correction processing, and the like on the basis of RGB color separation image signals, so that yellow, magenta, cyan, and black are processed. Get color image information.

  Then, image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 6. Then, laser light (exposure light) based on the image information of each color is emitted from the writing unit 6 toward the photosensitive drums 11 of the corresponding process cartridges 10Y, 10M, 10C, and 10BK, respectively.

On the other hand, the photosensitive drums 11 serving as the four image carriers rotate in the clockwise direction (predetermined direction) in FIG. Referring to FIG. 2, first, the surface of the photosensitive drum 11 is uniformly charged at a position facing the charging unit 12 (charging roller) (a charging process). Thus, a charged potential is formed on the photosensitive drum 11 as an image carrier. Thereafter, the surface of the charged photosensitive drum 11 reaches the irradiation position of each laser beam.
In the writing unit 6, laser light corresponding to the image signal is emitted from the light source corresponding to each color. Although not shown, the laser light is incident on the polygon mirror and reflected, and then passes through a plurality of lenses. The laser light after passing through the plurality of lenses passes through different optical paths for each of the yellow, magenta, cyan, and black color components (this is an exposure process).

  Laser light corresponding to the yellow component is irradiated onto the surface of the photosensitive drum 11 of the first process cartridge 10Y from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotational axis direction (main scanning direction) of the photosensitive drum 11 by a polygon mirror (not shown) that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11 after being charged by the charging unit 12a.

  Similarly, the cyan component laser light is applied to the surface of the photosensitive drum 11 of the second process cartridge 10 </ b> C from the left side of the sheet, thereby forming an electrostatic latent image of the cyan component. The laser beam corresponding to the magenta component is irradiated onto the surface of the photosensitive drum 11 of the third process cartridge 10M from the left side of the paper, and an electrostatic latent image corresponding to the magenta component is formed. The black component laser light is applied to the surface of the photosensitive drum 11 of the process cartridge 10BK (black image forming unit), which is fourth from the left side of the drawing (the most downstream side with respect to the traveling direction of the intermediate transfer belt 17). Thus, an electrostatic latent image of the black component is formed.

Thereafter, the surface of the photosensitive drum 11 on which the electrostatic latent image of each color is formed reaches a position facing the developing unit 13 (see FIG. 2). Then, each color toner is supplied from each developing unit 13 onto the photosensitive drum 11, and the latent image on the photosensitive drum 11 is developed (this is a developing step).
Thereafter, the surface of the photosensitive drum 11 after the development process reaches a position facing the intermediate transfer belt 17 (intermediate transfer body). Here, the primary transfer roller 14 is installed at each facing position so as to contact the inner peripheral surface of the intermediate transfer belt 17. Then, at the position of the primary transfer roller 14, the toner images of the respective colors formed on the photosensitive drum 11 are sequentially transferred onto the intermediate transfer belt 17 (first transfer process).

Then, the surface of the photosensitive drum 11 after the first transfer process reaches a position facing the cleaning device 15 (see FIG. 2). Then, the cleaning device 15 collects deposits (cleaning target) such as untransferred toner remaining on the photosensitive drum 11 (image carrier) (this is a cleaning process).
Thereafter, the surface of the photoconductive drum 11 passes through the position of a static elimination unit (not shown), and a series of image forming processes on the photoconductive drum 11 is completed.

On the other hand, the surface of the intermediate transfer belt 17 on which the images of the respective colors on the photosensitive drum 11 are transferred in an overlapping manner travels in the direction of the arrow in the drawing and reaches the position of the secondary transfer roller 18. Then, the full color image on the intermediate transfer belt 17 is secondarily transferred onto the recording medium P at the position of the secondary transfer roller 18 (second transfer step).
Thereafter, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning device 9 (cleaning device). Then, the untransferred toner on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning device 9 (cleaning device), and a series of transfer processes on the intermediate transfer belt 17 is completed.

Here, the recording medium P at the position of the secondary transfer roller 18 is conveyed from the paper supply unit 7 via the conveyance guide, the registration roller 19 and the like.
Specifically, the transfer paper P fed by the paper feed roller 8 from the paper feed unit 7 that stores the recording medium P is guided to the registration roller 19 after passing through the conveyance guide. The recording medium P that has reached the registration roller 19 is conveyed toward the position of the secondary transfer roller 18 in synchronization with the toner image on the intermediate transfer belt 17.

Thereafter, the recording medium P on which the full-color image is transferred is guided to the fixing unit 20. In the fixing unit 20, the color image is fixed on the recording medium P at the nip between the fixing roller and the pressure roller.
The recording medium P after the fixing step is discharged as an output image outside the apparatus main body 1 by the paper discharge roller 29 and then stacked on the paper discharge unit 5 to complete a series of image forming processes.

Next, the image forming unit of the image forming apparatus will be described in detail with reference to FIG.
FIG. 2 is a configuration diagram showing the black process cartridge 10BK. The other three process cartridges 10Y, 10M, and 10C are configured substantially the same as the black process cartridge 10BK except that the color of the toner used in the image forming process is different. Are omitted.

  As shown in FIG. 2, the process cartridge 10BK contains a photosensitive drum 11 as an image carrier, a charging unit 12 for charging the photosensitive drum 11, and an electrostatic latent image formed on the photosensitive drum 11. A developing unit 13 for developing and a cleaning device 15 for cleaning (removing) deposits such as untransferred toner on the photosensitive drum 11 are integrally stored in a case.

Here, the photosensitive drum 11 as an image bearing member is a negatively charged organic photosensitive member, and a photosensitive layer or the like is provided on a drum-shaped conductive support. Although not shown, the photosensitive drum 11 is formed by sequentially laminating an undercoat layer as an insulating layer, a charge generation layer as a photosensitive layer, and a charge transport layer on a conductive support as a base layer. A protective layer can be further laminated as a surface layer of the photosensitive drum 11.
The charging unit 12 is a charging roller formed by covering an outer periphery of a conductive metal core with an intermediate resistance elastic layer. Then, a predetermined voltage is applied to the charging unit 12 (charging roller) from a power supply unit (not shown), thereby uniformly charging the surface of the opposing photoconductive drum 11.

The developing unit 13 (developing device) mainly includes a developing roller 13a facing the photoconductive drum 11, a first transporting screw 13b1 facing the developing roller 13a, and a first transporting screw 13b1 facing the first transporting screw 13b1 via a partition member. It is comprised by the 2 conveyance screw 13b2 and the doctor blade 13c facing the developing roller 13a. The developing roller 13a includes a magnet that is fixed inside and forms a magnetic pole on the peripheral surface of the roller, and a sleeve that rotates around the magnet. A plurality of magnetic poles are formed on the developing roller 13a (sleeve) by the magnet, and the developer is carried on the developing roller 13a.
In the developing unit 13, a two-component developer composed of a carrier and a toner is accommodated. In the first exemplary embodiment, the toner has a small particle size (about 5 μm) for improving the image quality, and is substantially spherical, and has a low melting point in order to reduce the amount of heat consumed by the fixing unit 20. Something is used. Further, as the additive contained in the toner, those having a particle size of several tens to several hundreds of nm are often used.

  Referring to FIG. 2, cleaning device 15 (cleaning unit) conveys cleaning blade 15 a in contact with photosensitive drum 11, and untransferred toner collected in cleaning device 15 as recycled toner toward developing unit 13. A conveying coil 15b (recycle conveying unit 25), a paper dust regulating blade 16 as a paper dust regulating member, a paper dust collecting unit 26, and the like are installed.

The cleaning blade 15a is a substantially plate-like member made of a rubber material such as urethane rubber, and is in contact with the surface of the photosensitive drum 11 at a predetermined angle and a predetermined pressure. As a result, deposits such as untransferred toner remaining on the surface of the photosensitive drum 11 are mechanically scraped off by the cleaning blade 15a and collected in the untransferred toner collecting section 15c. Then, the untransferred toner collected in the untransferred toner collecting unit 15c is conveyed to the developing unit 13 via the recycle conveying unit 25 (conveying coil 15b is provided) and developed as recycled toner. The developer in the section 13 is mixed.
In the first embodiment, the cleaning blade 15a is configured to come into contact with the photoconductor drum 11 in the counter direction (the direction opposite to the rotation direction of the photoconductor drum 11). The photosensitive drum 11 may be configured to come into contact with a trading direction (a direction along the rotational direction of the photosensitive drum 11).
Here, the cleaning device 15 according to the first exemplary embodiment includes a paper dust regulating blade 16 (paper dust regulating member) that regulates large paper dust attached to the photosensitive drum 11 from passing therethrough, and a paper dust regulating blade 16. A paper dust collecting unit 26 for removing and collecting large paper dust regulated by the above is provided, which will be described in detail later.

Further, referring to FIG. 1, the intermediate transfer belt cleaning device 9 as a cleaning device also has a cleaning blade in contact with the intermediate transfer belt 17 (intermediate transfer member), and the untransferred collected in the intermediate transfer belt cleaning device 9. A conveying coil (conveying tube) that conveys an adhering substance such as toner toward a waste toner collecting container (not shown) as waste toner is installed. Then, the untransferred toner and the like collected in the intermediate transfer belt cleaning device 9 is conveyed to a waste toner collection container via a conveyance tube (a conveyance coil is provided), and is used as waste toner. It is collected inside the collection container.
In addition to the non-transferred toner, the adhering matter (cleaning target) adhering (remaining) on the photosensitive drum 11 and the intermediate transfer belt 17 includes paper powder generated from the recording medium P (paper), and the charging unit 12 ( There are discharge products generated on the photosensitive drum 11 during discharge by the charging roller), additives added to the toner, and the like. In the present application, these are collectively referred to as “untransferred toner” as appropriate.

The image forming process described above will be described in more detail with reference to FIG.
The developing roller 13a rotates in the arrow direction (counterclockwise direction) in FIG. The developer in the developing unit 13 is replenished from the toner container 28 by a toner replenishing unit (not shown) by the rotation of the first transport screw 13b1 and the second transport screw 13b2 that are disposed so as to interpose a partition member therebetween. The toner (and the recycled toner replenished via the recycle transport unit 25) circulates in the longitudinal direction while being agitated and mixed (the direction perpendicular to the paper surface in FIG. 2).

  The toner that is frictionally charged and adsorbed on the carrier is carried on the developing roller 13a together with the carrier. The developer carried on the developing roller 13a then reaches the position of the doctor blade 13c. The developer on the developing roller 13a is adjusted to an appropriate amount at the position of the doctor blade 13c and then reaches a position facing the photosensitive drum 11 (development region).

  Thereafter, in the developing region, the toner in the developer adheres to the electrostatic latent image formed on the surface of the photosensitive drum 11. Specifically, the latent image potential (exposure potential) of the image portion irradiated with the laser beam L and the electric field formed by the potential difference (development potential) between the development bias applied to the developing roller 13a cause the toner to become a latent image. (Toner image is formed).

  Thereafter, most of the toner adhering to the photosensitive drum 11 in the developing process is transferred onto the intermediate transfer belt 17. The untransferred toner (adhered matter) remaining on the photosensitive drum 11 is collected in the cleaning device 15 by the cleaning blade 15a.

  Here, although not shown in the figure, a toner replenishing unit provided in the apparatus main body 1 has a bottle-shaped toner container 28 configured to be replaceable, and holds and rotates the toner container 28, and a new one in the developing unit 13. And a toner hopper for replenishing toner. Also, a new toner (any one of yellow, magenta, cyan, and black) is accommodated in the toner container 28. In addition, a spiral protrusion is formed on the inner peripheral surface of the toner container 28 (toner bottle).

  The new toner in the toner container 28 is appropriately supplied from the toner supply port into the developing unit 13 as the toner in the developing unit 13 (existing toner) is consumed. Although illustration is omitted, consumption of toner in the developing unit 13 is indirectly caused by a reflection type photo sensor facing the photosensitive drum 11 and a magnetic sensor installed below the second conveying screw 13b2 of the developing unit 13. Or detected directly.

Hereinafter, the configuration and operation of the cleaning device 15 (process cartridge) characteristic of the first embodiment will be described in detail.
As described above with reference to FIGS. 1 and 2, the cleaning device 15 has a cleaning blade 15a for cleaning untransferred toner attached to the surface of the photosensitive drum 11 as an image carrier in a predetermined direction (see FIG. 1). 2 is arranged in the counter direction with respect to the photosensitive drum 11 that runs (rotates) in the clockwise direction.

2 to 4, the cleaning device 15 (process cartridge 10BK) according to the first embodiment has an upstream side in the rotational direction of the photosensitive drum 11 (image carrier) with respect to the cleaning blade 15a. A predetermined gap G with respect to the photosensitive drum 11 at a position (upstream in the running direction) and downstream of the primary transfer roller 14 (primary transfer nip) in the rotation direction of the photosensitive drum 11. A paper dust regulating blade 16 as a paper dust regulating member is disposed so as to face each other.
This paper dust regulating blade 16 (paper dust regulating member) is a substantially plate-like member made of a rubber material, a resin material, a metal material or the like, and the position of the gap G satisfies the untransferred toner T and a predetermined value. The paper powder S1 (small paper powder) having a small size is allowed to pass therethrough, and the paper powder S0 (large paper powder) having a size larger than a predetermined value is not allowed to pass through. Specifically, the gap G between the paper dust regulating blade 16 and the photosensitive drum 11 is preferably set within a range of 0.05 to 0.5 mm, and is set to 0.1 mm in the first embodiment. Yes. In order to prevent discharge at the position of the gap G, no electric charge is applied to the paper dust regulating blade 16.

  Thus, paper dust generated from the recording medium P adheres to the surface of the photosensitive drum 11 via the intermediate transfer belt 17 at the position of the primary transfer roller 14 (primary transfer nip). The paper powder includes a paper powder S0 having a large particle size and a small paper powder S1. Referring to FIG. 3, paper powder S1 having a small particle size (paper powder having a size less than a predetermined value) is calcium carbonate as a filler, and the particle size is substantially equal to the toner particle size. About 5 μm. On the other hand, paper powder S0 having a large particle size (a paper powder having a size equal to or larger than a predetermined value) is a mixture of calcium carbonate that can be made into a small paper powder and cellulose that is a paper fiber. Thus, cellulose is the core and the particle size exceeds 0.5 mm.

In Embodiment 1, since the gap G between the paper dust regulating blade 16 and the photosensitive drum 11 is set to the above-described value, the large paper dust S0 is blocked by the paper dust regulating blade 16, The transfer toner T and the small paper dust S1 pass through the position of the paper dust regulating blade 16 and reach the position of the cleaning blade 15a.
Here, most of the small paper dust S1 that has reached the position of the cleaning blade 15a is scraped off from the surface of the photosensitive drum 11 by the cleaning blade 15a together with the untransferred toner T, and the inside of the untransferred toner collecting portion 15c. However, a very small amount of toner is deposited on the edge portion (the contact portion between the cleaning blade 15a and the photosensitive drum 11) together with a small amount of untransferred toner T. When the small paper dust S1 deposited on the edge of the cleaning blade 15a gradually increases and exceeds a certain amount, the small paper dust S1 deposited on the edge passes through the edge together with the untransferred toner T. It causes abnormal images such as poor cleaning. However, such an abnormal image caused by the accumulation of small paper dust S1 on the edge of the cleaning blade 15a does not occur at the initial stage of the product, and the timing before and after the cleaning blade 15a (cleaning device 15) reaches the end of its life. For this reason, there are many cases where the problem hardly arises due to replacement maintenance of the cleaning device 15 (process cartridge).

  On the other hand, when the large paper dust S0 reaches the position of the cleaning blade 15a and the paper dust S0 is not scraped off by the cleaning blade 15a and bites into the edge portion, the paper dust S0 immediately becomes untransferred toner. It passes through the edge portion together with T, and causes an abnormal image such as poor cleaning. The abnormal image generated when the large paper dust S0 reaches the edge of the cleaning blade 15a suddenly occurs even at the initial stage of the product regardless of the life of the cleaning blade 15a (cleaning device 15). It can be.

  For this reason, in the first embodiment, the paper dust regulating blade 16 prevents the large paper dust S0, which causes an abnormal image that occurs regardless of the initial time, from reaching the position of the cleaning blade 15a. A small paper dust S1 that hardly causes an abnormal image in the range of the life of the process cartridge) is configured to reach the position of the cleaning blade 15a together with the untransferred toner T. As a result, the occurrence of an abnormal image due to paper dust is suppressed, and the trouble that the cleaning blade 15a is curled or abnormal noise is generated by reducing the amount of untransferred toner input to the cleaning blade 15a is also suppressed. become. In the first embodiment, a special voltage is not applied to the paper dust regulating blade 16, and no discharge is generated between the paper dust regulating blade 16 and the photosensitive drum 11. It is also possible to suppress a problem that the deterioration of the photosensitive drum 11 is accelerated.

Here, referring to FIG. 2, the cleaning device 15 according to the first embodiment includes a large paper dust S0 (paper having a size equal to or larger than a predetermined value) regulated by a paper dust regulating blade 16 (paper dust regulating member). A paper dust collection unit 26 is provided to collect the powder and remove it. Specifically, the large paper dust S0 blocked by the paper dust regulating blade 16 is then slid along the inclined surface of the paper dust regulating blade 16 and collected inside the paper dust collecting unit 26. .
The paper powder collecting unit 26 is isolated from the non-transferred toner collecting unit 15c so that large paper powder S0 (paper powder having a size equal to or larger than a predetermined value) is not mixed in the untransferred toner collecting unit 15c. Is formed. Thereby, the large paper dust S0 is not mixed with the untransferred toner used as the recycled toner in the developing unit 13, and the occurrence of an abnormal image caused by the large paper dust S0 can be reliably reduced.

Further, in the first embodiment, the photosensitive drum 11 (image carrier) is counterclockwise in FIG. 2 at a predetermined timing when the non-image is formed (the reverse direction to the normal rotation direction). For a predetermined time.
Specifically, in the first embodiment, a drive motor 41 (see FIG. 2) that rotationally drives the photosensitive drum 11 is a forward / reverse rotation type motor, and is a normal image forming process (image forming operation). ) (When normal), the photosensitive drum 11 is rotated in the forward direction (clockwise in FIG. 2), and in the reverse rotation mode, the photosensitive drum 11 is rotated in the reverse direction (counterclockwise in FIG. 2). It is controlled by the control unit 40 so as to be rotationally driven in the direction. Note that this “reverse rotation mode (cleaning mode)” is a state in which the untransferred toner adhered to the edge portion of the cleaning blade 15a, adhered matter such as small paper dust S1 (originally scraped off by the cleaning blade 15a and within the cleaning device 15). And the large paper dust S0 blocked by the paper dust regulating blade 16 is prevented from getting caught in the gap G, and the removal / recovery to the paper dust collecting unit 26 is promoted. In the first embodiment, every time the number of prints counted by the counter 43 reaches 50, it is executed at the end of the job, which is the time of non-image formation.
When the large paper dust S0 blocked by the paper dust regulating blade 16 is caught in the gap G, the rotation of the photosensitive drum 11 causes the large paper dust S0 to be crushed and small paper dust S1 (calcium carbonate). And paper fibers (cellulose) are not separated from each other. Therefore, a problem that large paper powder S0 aggregates at the position of the gap G and damages the surface of the photosensitive drum 11 does not occur immediately. In the first embodiment, the reverse rotation mode is intermittently performed at an appropriate timing to remove the large paper dust S0 staying at the position of the gap G. Therefore, the surface of the photosensitive drum 11 is caused by the large paper dust S0. Can be prevented beforehand.

Referring to FIG. 4, in the first embodiment, paper dust regulating blade 16 (paper dust regulating member) is in the width direction (the vertical direction in FIG. 2 and the left-right direction in FIG. 4). .) Is formed so as to extend in the width direction so as to include the range M in the width direction of the cleaning blade 15a. That is, the width N of the paper dust regulating blade 16 is longer than the length M of the cleaning blade 15a in the width direction (M <N), and the latter range is included in the former range. .
With such a configuration, the paper dust regulating blade 16 reliably blocks the large paper dust S0 and reliably prevents the large paper dust S0 from passing through the position of the paper dust regulating blade 16 and being input to the cleaning blade 15a. can do.

In the first embodiment, as shown in FIGS. 5A and 5B (corresponding to FIG. 4), the paper dust regulating blade 16 has a size of the gap G in the width direction. In addition to being formed to be constant, both end portions in the width direction may be formed so as to be inclined toward the downstream side along the running direction of the photosensitive drum 11 in the arrow direction with respect to the center portion in the width direction.
Specifically, in the paper dust regulating blade 16 shown in FIG. 5A, the opposite surface facing the photosensitive drum 11 has the widthwise center portion located on the upstream side and the widthwise both ends located on the downstream side. Thus, it is formed in a substantially V shape. Further, the paper dust regulating blade 16 shown in FIG. 5B has an opposing surface facing the photosensitive drum 11 such that the center in the width direction is located on the upstream side and the both ends in the width direction are located on the downstream side. It is formed in a substantially bow shape.
With this configuration, the paper dust S0 that is not collected by the paper dust collecting unit 26 and is retained at the position of the gap G of the paper dust regulating blade 16 is retained by the rotation of the photosensitive drum 11. Since it moves in the direction of the white arrow toward both ends in the width direction along the inclination of the blade 16 and eventually moves out of the image area, the surface of the photosensitive drum 11 is damaged by the paper dust S0 and abnormal. It is possible to prevent a problem that an image is generated.

In particular, when the “reverse rotation mode” for reversely rotating the photosensitive drum 11 is performed for each predetermined number of printed sheets as described above, the paper dust regulating blade 16 is rotated as shown in FIG. The paper dust S0 biting into the edge portion behaves in the order of arrows K1 to K4 in the figure, and the biting paper dust S0 is driven away to the end in the width direction while being removed from the edge portion. become. In other words, the paper dust S0 that has been caught in the edge portion moves from the edge portion as indicated by the arrow K1 along the rotation of the photosensitive drum 11 in the direction of the broken arrow in the reverse rotation mode, and in the subsequent normal time, the photosensitive material in the direction of the arrow. As the body drum 11 rotates, it reaches the edge as indicated by the arrow K2, and further moves toward the end in the width direction along the inclination of the blade as indicated by the arrow K3. When the reverse rotation mode is executed again, the paper dust S0 moves again from the edge portion as indicated by the arrow K4, and the same operation is repeated thereafter, and finally the paper dust S0 deviates from the image area. It will be moved to the position.
In this way, the problem that the surface of the photosensitive drum 11 is damaged by the paper dust S0 and an abnormal image is generated can be prevented more reliably.

Further, as shown in FIG. 6A (corresponding to FIG. 4), in the first embodiment, the paper dust regulating blades 16A and 16B (paper dust regulating members) are disposed at both ends in the width direction. It is also possible to divide each two and arrange them. That is, the first paper dust regulating blade 16A is installed on one end side in the width direction so that a desired gap G is formed between the photosensitive drum 11 and the second paper dust regulation blade on the other end side in the width direction. The blade 16B can be installed such that a desired gap G is formed between the blade 16B and the photosensitive drum 11. At this time, the two paper dust regulating blades 16A and 16B are in the width direction range including the width direction both ends of the cleaning blade 15a, and extend in the range from the width direction both ends of the image area to the non-image area. It is preferable to be formed to exist.
In such a configuration, the large paper dust S0 is not removed and collected by the paper dust regulating blades 16A and 16B in the central portion in the width direction, but the central portion in the width direction is printed compared to both end portions in the width direction in the first place. In the region where the ratio (image area ratio) is high and the printing ratio is high at the position of the primary transfer nip on the photosensitive drum 11, the large paper dust S0 is difficult to adhere, so this configuration is used. However, it is possible to obtain substantially the same effect as that of the first embodiment described above. In particular, when the two paper dust regulating blades 16A and 16B are installed by dividing in the width direction as described above, the photosensitive drum is compared with the case where one paper dust regulating blade extending in the width direction is installed. 11 can be set uniformly and accurately in the width direction, so that the function of blocking only the large paper powder S0 and allowing the untransferred toner T and the small paper powder S1 to pass through can be reliably achieved in the width direction. become.

Further, when the two paper dust regulating blades 16A and 16B are installed in this manner, as shown in FIG. 6B (a diagram corresponding to FIG. 4), the two paper dust regulating blades 16A and 16B are provided. Are formed such that the size of the gap G described above is constant over the width direction, and the end in the width direction is directed downstream in the running direction of the photosensitive drum 11 with respect to the center portion in the width direction. It can also be formed so as to be inclined.
By configuring in this way, the paper dust S0 staying in the gap G of the paper dust regulating blade 16 without being collected by the paper dust collecting portion 26 is retained as in the case of FIG. 5 described above. The rotation of the photosensitive drum 11 moves toward both ends in the width direction along the inclination of the paper dust regulating blades 16A and 16B and eventually moves out of the image area. It is possible to prevent a problem that the surface is damaged by the paper dust S0 and an abnormal image is generated. Further, by appropriately performing the “reverse rotation mode” in which the photosensitive drum 11 is reversely rotated at the time of non-image formation, the effect is more reliably exhibited.

As described above, in the first embodiment, the photosensitive drum 11 is positioned on the upstream side in the rotational direction (upstream in the running direction) of the photosensitive drum 11 (image carrier) with respect to the cleaning blade 15a. A paper dust regulating blade 16 (paper dust regulating member) is disposed so as to face each other with a predetermined gap G, and the position of the gap G is set to the untransferred toner T and paper having a size less than a predetermined value. The powder S1 (small paper powder) is allowed to pass through, and the paper powder S0 (large paper powder) having a size greater than or equal to a predetermined value is not allowed to pass through.
Thus, the edge of the cleaning blade 15a that contacts the photosensitive drum 11 can be formed with a relatively simple structure without accelerating the deterioration of the photosensitive drum 11 or causing the cleaning blade 15a to bend or cause abnormal noise. It is possible to reliably reduce the problem that the paper dust S0 that has been caught slips through the edge portion together with the toner T and an abnormal image such as a cleaning failure occurs.

Embodiment 2. FIG.
A second embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 7 is a configuration diagram illustrating the image forming unit in the second embodiment, and corresponds to FIG. 2 in the first embodiment. FIG. 8 is an enlarged schematic view showing a state in which the tip of the cleaning blade 15a and the paper dust cleaning member 24 are in contact with the photosensitive drum 11 and the tip of the paper dust regulating blade 16 is opposed. FIG. 4 is a diagram corresponding to FIG. 3 in the first embodiment. Further, FIG. 9 is a schematic view showing the cleaning blade 15a and the paper dust cleaning member 24 in the width direction.
The cleaning device 15 in the second embodiment is different from that in the first embodiment in that a paper dust cleaning member 24 is installed at a position downstream of the cleaning blade 15a.

As shown in FIG. 7, the process cartridge 10BK according to the second embodiment is also composed of a photosensitive drum 11, a charging unit 12, a developing unit 13, a cleaning device 15, and the like, as in the first embodiment. ing.
As shown in FIGS. 7 and 8, the cleaning device 15 according to the second embodiment also has a photosensitive drum 11 (image carrier) with respect to the cleaning blade 15a as in the first embodiment. In the rotational direction upstream (traveling direction upstream) of the photosensitive drum 11 with respect to the primary transfer roller 14 (primary transfer nip) in the rotational direction downstream of the photosensitive drum 11. A paper dust regulating blade 16 (paper dust regulating member) for removing large paper dust S0 is disposed so as to face each other with a predetermined gap G therebetween.

  Here, referring to FIGS. 7 to 9, the cleaning device 15 according to the second embodiment includes a downstream side in the rotational direction of the photosensitive drum 11 (image carrier) with respect to the cleaning blade 15a (a downstream side in the traveling direction). ) (The position downstream of the edge of the cleaning blade 15a), and the paper dust cleaning member 24 is disposed at a position upstream of the charging unit 12 in the rotation direction of the photosensitive drum 11. Has been. Referring to FIG. 8, the paper dust cleaning member 24 is for cleaning paper dust S1 (small paper dust) having a size less than a predetermined value that has passed through the position of the cleaning blade 15a.

Specifically, the paper dust cleaning member 24 is a substantially rectangular fabric sheet having a thickness of about several mm to 10 mm, and is on the surface of the cleaning blade 15a (the surface on the side facing the photosensitive drum 11). It is attached via double-sided tape. The paper dust cleaning member 24 is sandwiched between the cleaning blade 15 a and the photosensitive drum 11 and is installed in a state of being compressed to some extent, and is in sliding contact with the photosensitive drum 11.
By providing the paper dust cleaning member 24 in this way, as described in the first embodiment, the paper dust cleaning member 24 captures small paper dust S1 that has passed through the edge of the cleaning blade 15a over time. Therefore, an abnormal image (a black streak image) such as a cleaning failure due to the small paper dust S1 is less likely to occur.

Here, as shown in FIG. 9, in the second embodiment, the paper dust cleaning member 24 is not installed over the entire width direction, but is divided into both ends in the width direction and installed in two. Has been. Each of the two paper dust cleaning members 24 has a sheet passing area X (in the second embodiment, the maximum size that can be passed and a range corresponding to the A4 vertical size sheet passing area that is frequently used). It is installed so as to straddle the end of
In this way, the small paper dust S1 is likely to be generated at the end portion in the width direction of the recording medium P (the end portion of the paper passing area X) similarly to the large paper dust S0, and the corresponding cleaning blade 15a. This is because small paper dust S1 accumulates at the position and easily slips through. In the second embodiment, since the paper dust cleaning member 24 is installed only at the positions of both ends of the minimum width direction, the paper dust cleaning is performed as compared with the case where the paper dust cleaning member is installed over the entire width direction. The sliding resistance generated between the member 24 and the photosensitive drum 11 can be reduced.

In addition, as shown in FIG. 9, in the second embodiment, the paper dust cleaning member 24 (textile cloth sheet) has a texture that is centered in the width direction along the rotation direction of the photosensitive drum 11 indicated by a white arrow. It is formed so as to be inclined from the portion side to the width direction end portion side. Specifically, the paper dust cleaning member 24 installed on the left side in FIG. 9 is formed so that the texture is inclined from the upper right to the lower left. On the other hand, the paper dust cleaning member 24 installed on the right side in FIG. 9 is formed so that the texture is inclined from the upper left to the lower right. In the second embodiment, the inclination angle of the texture of the paper dust cleaning member 24 (fiber cloth sheet) is set to be about 45 degrees with respect to the rotation direction of the photosensitive drum 11 indicated by the white arrow. Yes.
With such a configuration, the small paper dust S1 collected by the paper dust cleaning member 24 is slidably contacted with the photosensitive drum 11 rotating in the direction of the white arrow, as shown by the broken arrow in FIG. The sheet gradually moves toward the outside of the sheet passing region X along the texture of the cleaning member 24. Therefore, the small paper dust S1 that has passed through the edge of the cleaning blade 15a stays in the range corresponding to the paper passing area X on the photosensitive drum 11, and defects that cause abnormal images such as defective cleaning are reliably reduced. Will be.
Further, by appropriately performing the “reverse rotation mode” in which the photosensitive drum 11 is reversely rotated at the time of non-image formation, the effect is more surely exhibited as in the mechanism described with reference to FIG. Will be.

Also, as shown in FIG. 9, in the second embodiment, the paper dust cleaning member 24 is not disposed so as to be close to the endmost portion of the width direction range M of the cleaning blade 15a, but is cleaned. The blade 15a is disposed at a position sufficiently away from the endmost portion in the width direction range M toward the center. This position is the width direction from the sealing material 27 (side seal) that seals the width direction end of the opening of the housing of the cleaning device 15 (the portion where the cleaning blade 15a is exposed to the photosensitive drum 11). The position is sufficiently distant from the center side.
With such a configuration, as described above, the small paper powder S1 driven toward the end in the width direction by the texture of the paper powder cleaning member 24 (fiber cloth sheet) adheres to the seal material 27 and accumulates. As a result, the accumulated paper dust S1 falls all at once, and the malfunction that causes the abnormal image is reduced.

As described above, also in the second embodiment, as in the first embodiment, the position on the upstream side in the rotation direction (upstream in the running direction) of the photosensitive drum 11 (image carrier) with respect to the cleaning blade 15a. In addition, a paper dust regulating blade 16 (paper dust regulating member) is disposed so as to face the photosensitive drum 11 with a predetermined gap G, and the position of the gap G is set to the untransferred toner T, The paper powder S1 (small paper powder) having a size less than the predetermined value is allowed to pass through, and the paper powder S0 (large paper powder) having a size greater than the predetermined value is not allowed to pass.
Thus, the edge of the cleaning blade 15a that contacts the photosensitive drum 11 can be formed with a relatively simple structure without accelerating the deterioration of the photosensitive drum 11 or causing the cleaning blade 15a to bend or cause abnormal noise. It is possible to reliably reduce the problem that the paper dust S0 that has been caught slips through the edge portion together with the toner T and an abnormal image such as a cleaning failure occurs.

In each of the above-described embodiments, the process cartridges 10Y, 10M, 10C, and 10BK are configured by integrating the units in the image forming unit (the photosensitive drum 11, the charging unit 12, the developing unit 13, and the cleaning device 15). Thus, the image forming unit is made compact and the maintenance workability is improved. On the other hand, the cleaning device 15 can be configured so as to be detachable (replaceable) from the apparatus main body 1 without being a component of the process cartridge. In such a case, the same effects as those of the above embodiments can be obtained.
In each of the above embodiments, the present invention is applied to the image forming apparatus in which the developing unit 13 of the two-component developing system using the two-component developer is mounted. However, the one-component developing system using the one-component developer is used. Naturally, the present invention can also be applied to an image forming apparatus having the developing unit 13 mounted thereon.
In each of the above embodiments, the untransferred toner collected in the cleaning device 15 is transported to the developing unit 13 as recycled toner. However, the untransferred toner collected in the intermediate transfer belt cleaning device 9 is conveyed. Similarly to the transfer toner, the untransferred toner collected in the cleaning device 15 can be transported as waste toner toward the waste toner collection container.
The “process cartridge” refers to a charging unit that charges the image carrier, a developing unit (developing device) that develops a latent image formed on the image carrier, and a cleaning device (cleaning device) that cleans the image carrier. At least one of the cleaning units) and the image carrier are defined as a unit that is integrated and detachably installed on the main body of the image forming apparatus.

In each of the above embodiments, the present invention is applied to the cleaning device 15 that cleans untransferred toner (object to be cleaned) on the photosensitive drum 11 as an image carrier. On the other hand, a cleaning device for cleaning untransferred toner on a photosensitive belt as an image carrier, and an intermediate transfer belt as an image carrier (intermediate transfer member) (for example, the intermediate transfer belt in each of the above embodiments) 17) on the intermediate transfer drum serving as an image carrier (intermediate transfer member) or a cleaning device for cleaning untransferred toner (for example, the intermediate transfer belt cleaning device 9 in each of the above embodiments). Naturally, the present invention can also be applied to a cleaning device that cleans untransferred toner.
In the above embodiments, the present invention is applied to the cleaning device 15 installed in the color image forming apparatus 1. However, the present invention is naturally applied to a cleaning device installed in the monochrome image forming apparatus. Can be applied.
In such cases, the same effects as those of the above embodiments can be obtained.

  It should be noted that the present invention is not limited to the above-described embodiments, and within the scope of the technical idea of the present invention, the embodiments can be modified as appropriate in addition to those suggested in the embodiments. Is clear. In addition, the number, position, shape, and the like of the constituent members are not limited to the above embodiments, and can be set to a number, position, shape, and the like that are suitable for carrying out the present invention.

1 image forming apparatus (image forming apparatus main body),
9 Intermediate transfer belt cleaning device (cleaning device),
10Y, 10M, 10C, 10BK process cartridge (imaging part),
11 Photosensitive drum (image carrier),
15 Cleaning device (cleaning part),
15a Cleaning blade (blade member),
15c Untransferred toner collecting section,
16, 16A, 16B Paper dust regulating blade (paper dust regulating member),
24 Paper dust cleaning member,
25 Recycled toner transport unit,
26 Paper powder recovery department,
T Untransferred toner (toner),
SO large paper dust (mixture of paper fiber and calcium carbonate),
S1 Small paper dust (calcium carbonate).

JP 2007-310229 A JP 2008-89770 A JP-A-6-118842

Claims (13)

A cleaning blade that contacts an image carrier that travels in a predetermined direction and cleans untransferred toner adhered to the surface of the image carrier;
The cleaning blade is disposed at a position upstream of the image carrier in the running direction of the image carrier so as to face the image carrier with a predetermined gap, and the position of the gap is defined as untransferred toner. A paper dust regulating member formed so as to pass paper dust having a size less than a predetermined value and not to pass paper dust having a size greater than or equal to the predetermined value;
A size that is disposed so as to contact the image carrier at a position downstream of the image carrier in the running direction with respect to the cleaning blade, and is less than the predetermined value that has passed through the position of the cleaning blade. A paper dust cleaning member for cleaning the paper dust of
With
The cleaning device, wherein the paper dust cleaning member is divided and installed in the width direction so as to straddle an end of a maximum size paper passing region capable of passing paper . A paper dust collecting unit that removes and collects paper dust of a size greater than or equal to the predetermined value regulated by the paper dust regulating member;
The paper dust collecting unit includes a non-transferred toner collecting unit for collecting untransferred toner collected by the cleaning blade so that paper powder having a size equal to or larger than the predetermined value is not mixed in the untransferred toner collecting unit. The cleaning device according to claim 1, wherein the cleaning device is isolated from the cleaning device.   The paper dust regulating member is formed to extend in the width direction so that a range in the width direction includes a range in the width direction of the cleaning blade. The cleaning device described.   The paper dust regulating member is formed so that the size of the gap is constant over the width direction, and both ends in the width direction are downstream in the running direction of the image carrier with respect to the center portion in the width direction. The cleaning device according to claim 3, wherein the cleaning device is formed to be inclined toward the surface.   The cleaning device according to claim 1, wherein the paper dust regulating member is divided into two at both ends in the width direction.   Each of the two paper dust regulating members is formed such that the size of the gap is constant over the width direction, and the end in the width direction is in the running direction of the image carrier with respect to the center in the width direction. The cleaning apparatus according to claim 5, wherein the cleaning apparatus is formed so as to incline toward the downstream side along the line.   The cleaning apparatus according to claim 1, wherein the image carrier travels in a direction opposite to the predetermined direction for a predetermined time during non-image formation at a predetermined timing. The predetermined gap is in a range of 0.01 to 0.5 mm,
The cleaning apparatus according to claim 1, wherein no voltage is applied to the paper dust regulating member. The said paper dust cleaning member consists of a woven fabric sheet, and the texture was formed so that it might incline from the width direction center part side to the width direction edge part side, The one of Claims 1-8 characterized by the above-mentioned. A cleaning device according to claim 1. 10. The paper dust cleaning member is provided on each surface of the cleaning blade on the side facing the image carrier and at both ends in the width direction, respectively. 10. Cleaning device. A sealing material that seals the widthwise end of the portion of the cleaning device housing that is exposed to the image carrier on the side of the image carrier is installed.
The cleaning device according to any one of claims 1 to 10, wherein the paper dust cleaning member is installed at a position away from the sealing material toward the center in the width direction. A process cartridge that is detachably attached to the image forming apparatus main body,
12. A process cartridge in which the cleaning device according to claim 1 and the image carrier are integrated. An image forming apparatus comprising the cleaning device according to claim 1 and the image carrier.

Images