JPH1074028A - Cleaning device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a deterioration in the quality of a recorded image caused by a fact that an additive of toner is stuck to the surface of an image carrier such as a photoreceptor, so as to form a filming layer of the additive and this filming layer becomes an obstacle. SOLUTION: A fur brush 25 is pressed on the photoreceptor 10, together with a cleaning blade 20, a recovering roller 30 comes into contact with the fur brush 25 and a solid lubricant 35 is pressed on the recovering roller 30. As this recovering roller 30, one whose surface roughness, that is, 10-point average surface height Rz is 3μm<=20μm is used. At the time of executing a cleaning, the solid lubricant 35 is shaved/powdered by a specific amount every time the recovering roller 30 is rotated, by its rotation and then, the powdered lubricant is stuck on the roller 30. This powdered lubricant stuck on the roller 30 is stuck on the fur brush 25 and further, on the surface of the photoreceptor 10 by the fur brush 25, to form a thin film of the lubricant on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can be applied to an image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine thereof. More specifically, the present invention relates to a cleaning device that transfers a toner image formed on an image carrier to a sheet in such an image forming apparatus, and then removes residual toner on the image carrier to clean the image carrier.

[0002]

2. Description of the Related Art Conventionally, for example, there is an image forming apparatus as shown in FIG. In the cleaning device A, the cleaning blade 1 is pressed against the surface of the photosensitive member a as the image carrier, and the fur brush 2 is pressed rotatably, and the collection roller 3 is rotatably brought into contact with the fur brush 2. The scraper 4 is pressed against the collecting roller 3, and a toner discharge coil 5 is provided below the scraper 4.

After the toner image formed on the photosensitive member a is transferred onto the sheet P at the position of the transfer device b, when the surface of the photosensitive member a is cleaned, the residual toner on the photosensitive member a is removed by the fur brush 2 In addition to scraping with the cleaning blade 1, a bias voltage is applied to the collection roller 3, the toner adhered to the fur brush 2 is electrostatically attracted to the surface of the collection roller 3 and collected, and further adhered to the collection roller 3. The scraped toner is scraped off by the scraper 4, and the toner discharging coil 5 is rotated to be conveyed to the outside and discharged appropriately.

[0004]

Meanwhile, in the image forming apparatus, recently, the particle size of the toner has been reduced in order to further improve the image quality, and in order to secure the fluidity of the small particle size toner, the toner is used as a toner. In many cases, a base material mixed with various additives is used.

However, when an image is formed on the photoreceptor a using a toner containing such an additive, the additive adheres to the surface over time, so that an additive filming layer is easily formed. The additive filming layer cannot be completely removed by the cleaning brush 1 or the fur brush 2. Therefore, conventionally, at the time of recording, the additive filming layer hinders the exposure of the photoreceptor a, thereby causing a problem that the quality of a recorded image on paper is reduced.

[0006]

Therefore, the invention according to claim 1 is, for example, as in the embodiment shown in FIG.
The residual toner on the image carrier such as the photoconductor 10 after the image transfer is scraped off by the cleaning blade 20 and the fur brush 25 pressed against the image carrier, and the collection roller 30 is brought into contact with the fur brush 25. Then, a bias voltage is applied to the collection roller 30 while rotating the collection roller 30 to electrostatically attract the toner adhered to the fur brush 25 to the collection roller 30 while adhering to the collection roller 30. In the cleaning device 16 of the image forming apparatus in which the toner is scraped off by the scraper 40 pressed against the collection roller 30 to perform cleaning, the surface roughness of the collection roller 30 is determined by a ten-point average surface roughness Rz.
The solid lubricant 35 is pressed against the surface of the collection roller 30.

At the time of cleaning, the collection roller 30
The solid lubricant 35 is shaved and powdered by a fixed amount with the rotation of
The powder lubricant adheres to the collection roller 30, the powder lubricant adhered to the collection roller 30 adheres to the fur brush 25, and further adheres to the surface of the image carrier by the fur brush 25.

According to a second aspect of the present invention, there is provided a cleaning device for an image forming apparatus according to the first aspect, for example, as shown in FIG.
5 at a position downstream of the pressing position x of the scraper 40 in the rotation direction of the collecting roller 30 and at an upstream side of the contact position y of the fur brush 25,
Characterized by being pressed against.

When the collection roller 30 is rotated, immediately after the toner is finely scraped off by the scraper 40 at the pressing position x, the solid lubricant 35 is always scraped off in the clean area to adhere the powder lubricant, The powder lubricant is reliably adhered to the fur brush 25 at the contact position y.

According to a third aspect of the present invention, in the cleaning device 16 of the image forming apparatus according to the first or second aspect, for example, as in the embodiment shown in FIG. First and second conductive layers 61 in which a large number of rounded irregularities are continuously formed on the outer periphery of the first conductive layer 61
-It is characterized by comprising a conductive layer such as 62.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a laser copying machine provided with the cleaning device of the invention according to claim 1,
It is a schematic block diagram showing the principal part. In the drawing, reference numeral 10 denotes a drum-shaped photoconductor serving as an image carrier. Around a photoreceptor 10, a charging device 11 provided on the photoreceptor 10 causes
0 in the rotation direction (clockwise in the figure) in order.
Transfer device 13, paper separation device 14, post-transfer charging device 1
5. A cleaning device 16 and a static elimination device 17 are provided. Further, a sheet conveying device 18 is provided on the left side of the sheet separating device 14 in the drawing, and a fixing device 19 is further provided on the left side thereof.

When making a copy, the original to be read is set on a contact glass (not shown) and a start switch (not shown) is pressed. Then, at the same time as reading the image on the original, the photoconductor 10 is rotated, and the sheet P is conveyed to the lower side of the photoconductor 10 at a timing by the registration roller pair 22. Then, photoconductor 1
With the rotation of 0, the surface is first uniformly charged by the charging device 11. Next, a laser writing device (not shown) irradiates a laser beam L to perform writing according to the read content, thereby forming an electrostatic latent image on the photoconductor 10. Then, when the toner passes through the position of the developing device 12, the toner adheres and the latent image is visualized. Then, the visible image is transferred to the photoconductor 1
The image is transferred onto the sheet P conveyed below 0 by the transfer device 13, and the image on the read document is recorded on the sheet. The paper P after image recording is separated from the photoreceptor 10 by the paper separating device 14 and transported to the fixing device 19 by the paper transporting device 18 where heat and pressure are applied to fix the recorded image on the paper, The paper is discharged onto the paper discharge tray 23.

On the other hand, the photoreceptor 10 after image transfer has its surface polarity and charge amount controlled to a predetermined state by a post-transfer charging device 15 and then the surface is cleaned by a cleaning device 16.
To clean. Further, the surface of the photoconductor 10 is neutralized by the neutralization device 17 to be electrostatically initialized to prepare for the next use.

Now, the cleaning device 16 described above
Specifically, the outer case 24 is formed in a box shape that is long in the axial direction of the photoconductor 10, and a horizontally long opening 24a is provided on the right side in FIG. Then, a horizontally long sheet-shaped entrance seal member 26 is attached to the outer case 24 at the lower edge of the opening, and the entrance seal member 26 seals between the lower edge of the opening and the photoconductor 10. On the other hand, the outer case 24 at the upper edge of the opening
, A base end of a horizontally long cleaning blade 20 is attached, and the front end thereof is pressed against the surface of the photoconductor 10 through the opening 24a. In addition, the cleaning blade 20
Below, the fur brush 20 is provided inside the outer case 24.

The fur brush 25 is formed by arranging a large number of conductive fiber bristles radially on the outer circumference of a tube shaft 25a made of, for example, aluminum to form a brush portion. And pipe shaft 2
Both ends of 5a are attached to both side plates of the outer case 24 and supported rotatably in the clockwise direction in the figure, and are arranged at positions where the photoreceptor 10 is partially cut into the outer periphery of the brush.

The fur brush 25 has a photoconductor 10 on it.
And the recovery roller 30 contacts the opposite side. Collection row
The la 30 is made of, for example, stainless steel and has a roughened surface, and is rotatably provided in a clockwise direction in FIG. Then, a bias applying device 33 is connected to the collection roller 30.

Thus, a solid lubricant 35 is placed on the surface of the recovery roller 30 directly above, and the tip of a scraper 40 whose base end is attached to the outer case 24 is pressed against the left side in the figure. . The scraper 40 is made of, for example, a nylon-based sheet member that is long in the axial direction of the collection roller 30.

As the solid lubricant 35, for example, a material obtained by solidifying zinc stearate into a horizontally long rectangular material is used.
A weight member 50 is placed on the solid lubricant 35 via a holding member 45, and is held between left and right guide plates 34 provided in the outer case 24 so as to be movable in the vertical direction in the figure. .

The holding member 45 is formed in a horizontally long box shape having a U-shaped cross section using a sheet metal, and a square rod-shaped weight member 50 is put in the box, and a solid lubricant 35 is adhered to the bottom surface with a double-sided adhesive tape. It becomes. The solid lubricant 30 is pressed against the collection roller 30 by applying a predetermined load from above together with the weight member 50 and the holding member 45.

In the outer case 24, a toner discharge coil 55 for discharging the collected toner from the outer case 24 to the outside is provided directly below the collecting roller 30 so as to be rotatable clockwise in FIG.

In the cleaning device 16 having the above-described structure, the cleaning roller 30 rotates together with the toner discharge coil 55 and the fur brush 25 during cleaning, and the bias voltage is applied to the collecting roller 30 from the bias applying device 33. Is applied.

Then, the residual toner adhering to the photoreceptor 10 is mechanically rubbed with a fur brush 25,
The toner passing through the fur brush 25 is scraped off onto the fur brush 25 by the cleaning blade 20.

Further, since the fur brush 25 comes into contact with the collecting roller 30 to which the bias voltage is applied and retains a bias voltage at a somewhat lower pressure, the residual toner on the photoreceptor 10 is mechanically removed as described above. And at the same time, electrostatically attract and collect with a bias voltage. The toner thus adhered to the fur brush 25 is electrostatically attracted to the surface of the collection roller 30 by the bias voltage applied to the collection roller 30 and collected.

Further, the collected toner adhered to the collection roller 30 is scraped off by the scraper 40. Then, the toner is conveyed by the rotation of the toner discharge coil 55 and is appropriately discharged to the outside of the outer case 24.

On the other hand, at the time of this cleaning, the cleaning device 16 rotates the collection roller 30 to rotate the solid lubricant 35.
And the powder lubricant is attached to the surface of the collection roller 30. Then, most of the powder lubricant attached to the collection roller 30 is attached to the fur brush 25 except for a part. Thus, most of the powder lubricant adhered to the fur brush 25 is transferred to the surface of the photoconductor 11 except for a part thereof. Then, the lubricant adhering to the photoreceptor 10 is carried by the rotation thereof and a part thereof is cleaned by the cleaning blade 20.
And scrape it off onto the fur brush 25, and leave the rest
0 to form a lubricant thin film. Then, the thin film of the lubricant makes the surface of the photoreceptor 10 slippery, making it difficult for the additive contained in the toner to adhere on the surface, and preventing the filming layer of the additive from being formed on the photoreceptor 10. .

Also, since the powder lubricant is kept attached to the brush portion of the fur brush 25 as well, it is difficult for the brush portion to have an additive, and filming with the additive is prevented. Further, in order to keep the powder lubricant adhered to the surface of the collection roller 30 as well, similarly,
The surface of the recovery roller 30 is prevented from being filmed by the additive transferred from the photoconductor 10 via the fur brush 25.

In the cleaning device 16, the solid lubricant 30 is put on the collection roller 30 together with the weight member 50 and the holding member 45, and a predetermined load is constantly applied to the collection roller 30. A certain amount of the lubricant 35 is scraped off. Then, over time, the guide members 34
The solid lubricant 35 is supplied to the surface of the photoreceptor 10 as a powder lubricant until the solid lubricant 35 almost disappears.

When the solid lubricant 35 is almost consumed, it is replaced with a new one as appropriate. In that case,
For example, an opening / closing door may be provided above the weight member 50 of the outer case 24 so that the solid lubricant 35 can be easily replaced.

The amount of shaving of the solid lubricant 35 described above often corresponds not only to the load on the collection roller 30 but also to the surface roughness of the solid lubricant 35. That is, if the collection roller 30 has a relatively small surface roughness, for example, a ten-point average surface roughness Rz of 3
When an experiment was performed using a material having a size of less than μm, fine irregularities on the surface were covered with the lubricant attached to the collection roller 30, and therefore, the solid lubricant 35 could be effectively shaved by the irregularities on the surface. No, the amount of shaving decreases. As a result, the supply amount of the lubricant to the photoconductor 10 decreases as the number of copies increases over time, and when the number of copies reaches a certain value, the lubricant amount falls below the lower limit of the appropriate amount range.

On the other hand, if the collection roller 30 has a relatively large surface roughness, for example, a surface roughness Rz of 20 μm.
If the solid lubricant 35 is used, when the solid lubricant 35 is shaved, excessive shaving occurs, and the lubricant supply amount easily exceeds the upper limit of the appropriate amount range. In addition, if the surface is so rough, the scraper 40 will be severely worn, and its life will be significantly shortened. Further, the solid lubricant 35 may be chipped, generate abnormal noise or vibration.

Therefore, in the cleaning device 16 according to the first aspect, the recovery roller 30 having a ten-point average surface roughness Rz of not less than 3 μm and not more than 20 μm is used as the collection roller 30.

According to the second aspect of the present invention, in the cleaning device 16 according to the first aspect, for example, as shown in the embodiment shown in FIG.
To the scraper 40 in the rotation direction of the collection roller 30.
At a position downstream of the pressing position x and at a position upstream of the contact position y of the fur brush 25.

Therefore, in the cleaning device 16,
At such a relative position, the solid lubricant is pressed against the recovery roller 30 against the scraper 40 and the fur brush 25. Therefore, when the recovery roller 30 rotates, immediately after the scraper 40 cleanly scrapes off the toner at the pressing position x. While the solid lubricant 35 is always scraped off in the clean area and the powder lubricant is adhered, immediately thereafter, the powder lubricant is securely adhered to the fur brush 25 at the contact position y.

Even when the collecting roller 30 has a ten-point average surface roughness Rz of not less than 3 μm and not more than 20 μm, the powdered lubricant is filled in the fine concave portions on the surface of the collecting roller 30. This may cause clogging, which may cause the erosion ability of the collection roller 30 to decrease with time.

According to a third aspect of the present invention, for example, in the above-described illustrated embodiment, in the cleaning device 16 according to the first or second aspect, the collection roller 30 is provided on the outer periphery of the core metal with a round surface. It is characterized by being provided with a conductive layer in which a number of irregularities attached are continuously formed.

For example, as shown in FIG.
Is configured. That is, a metal core 60 made of stainless steel or the like is used.
A conductive adhesive is applied to the outer periphery of the first conductive layer 61 to form a first conductive layer 61. On the first conductive layer 61, a large number of metal particles 63 having substantially the same particle size are bonded substantially uniformly. A second conductive layer 62 is formed by applying a conductive adhesive to
It is covered with a conductive layer 62. Then, on the surface of the second conductive layer 62, a large number of irregularities rounded by the metal particles 63 are continuously formed, and the surface roughness of the collection roller 30 is determined by the irregularities described above. Rz 3μm or more and 20μ
m or less. Note that, for example, an epoxy resin containing carbon is used as the conductive adhesive.

At the time of cleaning, the collection roller 30
When the is rotated, the surface thereof is formed with a number of rounded irregularities, so that even if the powder lubricant enters the recess, for example, the powder lubricant receives extreme pressure concentration due to the curved shape of the recess. Therefore, clogging hardly occurs in the concave portion. The slight elasticity of the conductive layers 61 and 62 made of resin also has the effect of preventing clogging of the powder lubricant.

In the above-described embodiment, an example in which the photosensitive member 10 is used as the image carrier has been described. However, the image carrier is not limited to such a photoconductor. For example, an intermediate transfer belt, that is, each color image on the photoconductor is individually transferred to form a color image, and then the color image is formed on paper at once. A transfer belt or the like may be used.

[0039]

According to the first aspect of the present invention, during cleaning, the solid lubricant is scraped off by the rotation of the collecting roller, and the powder lubricant adhering to the collecting roller is removed by the rotation of the fur brush. A thin film of lubricant is formed on the surface of the image carrier, and the thin film of the lubricant makes the surface of the image carrier slippery, so that the toner additive adheres to the surface of the image carrier and is filmed. As a result, it is possible to prevent the additive filming layer from hindering the exposure of the photoreceptor and the like, thereby reducing the quality of the recorded image on the paper as in the related art. .

In addition, since the recovery roller is of an appropriate size having a ten-point average surface roughness Rz of not less than 3 μm and not more than 20 μm, the amount of lubricant shaved by the recovery roller is always kept constant. As a result, an appropriate amount of lubricant can always be supplied to the surface of the image carrier. In addition, the contact surface of the solid lubricant is prevented from being melted due to a sudden increase in frictional heat between the collection roller and the solid lubricant, or the solid lubricant is chipped due to excessive surface roughness, and abnormal noise or noise is generated. Vibration can also be prevented.

According to the second aspect of the present invention, the solid lubricant is always scraped off in the clean area immediately after the scraper cleanly removes the toner during the rotation of the collection roller. Surface roughness (Rz = 3μ)
m to 20 μm), the solid lubricant is scraped off by a predetermined amount, and the powder lubricant can be attached. Immediately thereafter, the powder lubricant can be reliably adhered from the collection roller to the fur brush by bringing the collection roller into contact with the fur brush.

According to the third aspect of the present invention, when the collecting roller is rotated, its surface is formed to have a predetermined surface roughness (Rz = 3 μm to 20 μm) with a number of rounded irregularities. When the roller rotates, even if the powder lubricant enters the fine concave portions on the surface, the powder lubricant does not receive extreme pressure concentration due to the curved surface shape of the concave portions, and the powder lubricant is clogged in the concave portions. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a main part of a laser copying machine including a cleaning device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a collecting roller provided in the cleaning device according to the embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a main part of an image forming apparatus including a conventional cleaning device.

[Explanation of symbols]

 Reference Signs List 10 photoconductor (image carrier) 16 cleaning device 20 cleaning blade 25 fur brush 30 collection roller 35 solid lubricant 40 scraper 60 core metal 61 first conductive layer (conductive layer) 62 second conductive layer (conductive layer) Rz surface roughness X Contact position of scraper y Contact position of fur brush

Claims (3)

[Claims] A cleaning brush pressed against the image carrier and a fur brush to scrape residual toner remaining on the image carrier after the image transfer, and contacting a recovery roller with the fur brush; A scraper that applies a bias voltage to the collection roller while rotating the toner to electrostatically attract the toner attached to the fur brush to the collection roller, and presses the toner attached to the collection roller against the collection roller. In the cleaning device of the image forming apparatus, the surface roughness of the collection roller is set to be not less than 3 μm and not more than 20 μm in ten-point average surface roughness Rz, and a solid lubricant is pressed against the surface of the collection roller. A cleaning device for an image forming apparatus. 2. The method according to claim 1, wherein the solid lubricant is pressed against the collecting roller at a position downstream of a pressing position of the scraper in a rotating direction of the collecting roller and at an upstream of a contact position of the fur brush. 2. The cleaning device for an image forming apparatus according to claim 1. 3. The image forming apparatus according to claim 1, wherein the collecting roller is configured by providing a conductive layer having a plurality of rounded irregularities continuously formed on the outer surface of a cored bar. Equipment cleaning device.