JP2002108114A - Electrophotographic apparatus and its cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the turning over of a cleaning blade particularly in both ends of a cleaning device. SOLUTION: The cleaning device 29 for electrophotographic apparatus which cleans a transfer belt (rotating body to be cleaned) 25 rotating while contacting a photoreceptor is provided with the cleaning blade 30 which removes a developer adhering to the peripheral surface of the transfer belt by being pressed on the transfer belt, and a developer holding member 35 pressed on the transfer belt at the upper position of both ends 30a longer than the developer adhesion area E on the transfer belt of the cleaning blade. The developer holding member is formed of a brush member or a foaming member. For example, the brush member is supported by a cleaning case through a mounting bracket. When there is a large amount of developer adhering to the transfer belt accompanying the rotation of the transfer belt, the developer is wiped off by the developer holding member 35, and when few, the wiped-off developer is adhered to the transfer belt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to an electrophotographic apparatus, such as a printer, a copying machine, and a facsimile, which uses a laser to record on paper by an electrophotographic method. More specifically, the present invention relates to a cleaning device in which the cleaning blade is pressed against a rotating body to be cleaned which rotates while being in contact with a photosensitive member in the electrophotographic apparatus, thereby removing a developer attached to a peripheral surface of the rotating body to be cleaned.

[0002]

2. Description of the Related Art Conventionally, among rotating bodies to be cleaned which are cleaned by a cleaning device of this kind, there is a transfer belt indicated by a reference numeral 1 in FIG. The transfer belt 1 rotates while being in contact with the drum-shaped photoreceptor 2, and applies a predetermined bias voltage to a bias roller 3 to apply a developer to the photoreceptor 2 and visualize the image. This is a belt for transferring to the paper P.

In this cleaning device, a cleaning blade 4 is pressed against the roller winding portion 1a of the transfer belt 1, and the cleaning blade 4 removes the developer adhering to the peripheral surface of the transfer belt 1.

In order to more reliably clean the transfer belt 1, the length L of the cleaning blade 4 is
The width of the developer adhering area E of the transfer belt 1 corresponding to the effective development area D on the photoconductor 2 was made longer, and the developer adhering to the transfer belt 1 at both ends 1b corresponding to the longer portion was also removed. .

[0005]

However, in this type of cleaning device, it is necessary to press the cleaning blade 4 against the transfer belt 1 with a predetermined pressing force in order to obtain sufficient cleaning performance.

However, if the developer does not adhere to the transfer belt 1, the frictional force with the cleaning blade 4 in contact therewith increases. In particular, the developer often does not adhere to the transfer belt 1 at both end portions 1b where the cleaning blade 4 is longer than the developer attaching region E, and if the developer does not adhere for a long time,
The frictional force with both ends 4a of the cleaning blade 4 in contact therewith becomes particularly large. Therefore, in the related art, as shown in FIG. 5, for example, there has been a problem that the cleaning blade 4 is turned up due to the frictional force, particularly at both ends 4a.

SUMMARY OF THE INVENTION An object of the present invention is to prevent the cleaning device from turning up, particularly at both ends, in the above-described cleaning apparatus.

[0008]

According to the present invention, there is provided a rotating member to be cleaned such as a transfer belt which rotates while being in contact with a photosensitive member as shown in the following example. A cleaning device 29 of an electrophotographic apparatus for cleaning the cleaning member, the cleaning blade 30 being pressed against the rotating body to be cleaned to remove the developer adhering to the peripheral surface thereof; At a position upstream of both ends 30a longer than the region E, the developer is pressed against the rotating body to be cleaned, and when the amount of the developer adhering to the rotating body to be cleaned is large due to the rotation of the rotating body to be cleaned, the developer is removed. A developer holding member that wipes off the developer and, when the amount is small, attaches the wiped developer to a rotating body to be cleaned. 5-35, made comprise, characterized in that.

According to a second aspect of the present invention, there is provided a cleaning device 29 for an electrophotographic apparatus according to the first aspect, as shown in the following example.
5 is formed by a brush member.

According to a third aspect of the present invention, in the cleaning device 29 of the second aspect, the brush member is supported by a cleaning case 29a via a mounting bracket 36, as shown in the following example. It is characterized by that.

According to a fourth aspect of the present invention, there is provided a cleaning device 29 for an electrophotographic apparatus according to the first aspect of the present invention, as shown in the following example.
5 is formed of a foamed member.

According to a fifth aspect of the present invention, there is provided a cleaning apparatus for an electrophotographic apparatus according to any one of the first to fourth aspects, wherein the photosensitive member is a rotating member to be cleaned. A transfer belt 25 is provided at a transfer position a where the upper image is transferred to the paper P and transports the paper P after image transfer to a fixing device.

An electrophotographic apparatus according to a sixth aspect is provided with the cleaning device 29 according to any one of the first to fifth aspects, for example, as shown in the following illustration example.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a color laser copying machine provided with a cleaning device according to the present invention, and shows a schematic configuration thereof.

Although not shown, the color laser copying machine includes a color scanner at the top of the copying machine main body.
Inside, a drum-shaped photoreceptor 10 shown substantially at the center in FIG. 3 is provided. Although not shown, the color scanner reads an image of a document set on a document setting table for each of two colors, for example, black and red color separation lights, and converts the image into an electric digital image signal.

Around the photoreceptor 10, a transfer device 11, a separation claw 12, a photoreceptor cleaning device 13, a static eliminator 14, a first charging device 15, and a first developing device are arranged in this order from the lower side in the rotation direction indicated by the arrow. Device 16, second charging device 17, second optical writing device 18, second developing device 19, pre-transfer neutralization device 20
Is provided. Further, a first optical writing device 21 is provided above the first charging device 15. The developing container 16a of the first developing device 16 accommodates the developer including the black toner and the carrier, while the developing container 19a of the second developing device 19 stores the developer.
In the illustrated embodiment, a color developer including a red toner and a carrier is accommodated therein.

Now, for example, when it is desired to make a copy of a color original of two colors of red and black, although not shown, the user first operates the operation panel to select the two-color mode. Then, the color original is set on the above-mentioned original set table, and the copy is started by appropriately selecting the paper size and the like. The color scanner described above reads a red / black color image on a color original for each color image and converts it into an electrical digital image signal. On the other hand, a sheet in a sheet cassette (not shown) is sent in the direction of arrow A in FIG. 3, and the sheet P is conveyed to a transfer position a between the photoreceptor 10 and the transfer device 11 at a timing by a registration roller 23.

On the other hand, the photosensitive member 10 is driven to rotate clockwise as indicated by an arrow, and at this time, the first charging device 1 is moved to the first charging position b.
5, the surface is uniformly charged, and in accordance with a black image signal based on reading, the surface is irradiated with laser light by the first optical writing device 21 to form an electrostatic latent image corresponding to a black image component. Then, when passing through the position of the first developing device 16, a black developer is adhered by the developing sleeves 16b and 16b, and the electrostatic latent image is visualized in black.

Next, the photosensitive member 10 advances to the second charging position c, where the surface thereof is charged again by the second charging device 17, and in accordance with a red image signal based on reading, a second optical writing device is applied to the surface. At 18, a laser beam is irradiated to form an electrostatic latent image corresponding to the red image component. And the second
When the developer passes through the position of the developing device 19, a red developer is attached by the developing roller 19b, and the electrostatic latent image is visualized in red.

Thereafter, the surface of the photoreceptor 10 is neutralized by the pre-transfer neutralizer 20. Then, at the transfer position a, the transfer device 11 transfers the two color images of red and black to the paper P. Then, the paper P to which the color image has been transferred is directly conveyed by the transfer device 11 to a fixing device (not shown) on the left side as shown by an arrow B in FIG. 3, and the color image is fixed by the fixing device. After the image is fixed, the paper P is discharged to the outside by a discharge roller (not shown).

On the other hand, after the transfer of the color image, the residual developer remaining on the surface of the photoconductor 10 is removed by the cleaning brush 13a and the cleaning blade 13b of the photoconductor cleaning device 13. Then, the surface of the photoconductor 10 is neutralized by the neutralization device 14. When the sheet P after the image transfer adheres to the surface of the photoconductor 10, the sheet P is separated by the separation claw 12.

Now, with the above-described color laser copying machine,
When a monochrome copy of a document is to be made, the operation panel section is appropriately operated to select the monochrome mode. Then, as described above, the original is set and copying is started. Then, read the image of the original with the above color scanner,
It is converted to an electrical digital image signal. On the other hand, the sheet P is transported to the transfer position a.

Next, as described above, the surface of the photoreceptor 10 is uniformly charged by the first charging device 15 at the first charging position b, and the first optical writing is performed on the surface in accordance with the black image signal based on the reading. The apparatus 21 forms an electrostatic latent image corresponding to the black image component. Then, a black developer is attached by the first developing device 16, and the electrostatic latent image is visualized in black.

In this case, since the monochrome mode is selected, the second charging device 17, the second optical writing device 18, and the second developing device 19 do not operate. Therefore, the photoconductor 10 is
After passing through the position of the first developing device 16, the surface thereof is discharged by the pre-transfer discharging device 20. Then, the process proceeds to the transfer position a, where the transfer device 11 transfers the monochrome image to the paper P. Then, the monochrome image is fixed by the fixing device, and the sheet P is discharged to the outside.

On the other hand, after the transfer of the monochrome image, the surface of the photoreceptor 10 is cleaned by the photoreceptor cleaning device 13 and the charge is removed by the charge removing device 14. The paper P attached to the surface of the photoconductor 10 is separated by the separation claw 12.

In the color laser copying machine of the embodiment described above, for example, it is possible to make a copy of a red-colored original. In that case, the operation panel section is appropriately operated to select the mono color mode. Then, in the same manner as described above, the manuscript is set and the mono-color copy is started. Then
The above-described color scanner reads an image of a document and converts it into an electric digital image signal. On the other hand, paper P
To the transfer position a.

In this case, since the monocolor mode is selected, the first charging device 15, the first optical writing device 21, and the first developing device 16 do not operate. Therefore, the photoconductor 10
Is charged uniformly by the second charging device 17 when passing through the second charging position c, and forms an electrostatic latent image on the surface thereof with the second optical writing device 18 in accordance with a red image signal based on reading. . Then, the second developer 18 adheres a red developer to visualize the electrostatic latent image into red.

Thereafter, the surface of the photoreceptor 10 is neutralized by the pre-transfer static eliminator 20, and the transfer device 11 transfers the monocolor image to the paper P. Then, the monocolor image is fixed by the fixing device, and the sheet P is discharged to the outside.

On the other hand, after the transfer of the monocolor image, the surface of the photoconductor 10 is cleaned by the photoconductor cleaning device 13, and
The charge is removed by the charge removing device 14. The paper P attached to the surface of the photoconductor 10 is separated by the separation claw 12.

Incidentally, the transfer device 11 described above is
As shown in (1), an endless transfer belt (rotating member to be cleaned) 25 is stretched between a driving roller 26 and a driven roller 27, and is provided in contact with the photoconductor 10 at a transfer position a.
Then, the driving force transmitted from a driving motor (not shown) is appropriately controlled so that the transfer belt 25 can be driven to rotate at the same speed as the photoconductor 10. On the other hand, the transfer belt 25 is provided with a bias roller 28 in contact with the back surface near the transfer position a.

In the transfer device 11, the transfer belt 25 is rotated in the direction of arrow B in FIG. 3 at the time of image transfer, and a predetermined bias voltage is applied to the bias roller 28 to transfer the above-described color image and the like to the paper. Transfer to P. And
The paper P after the image transfer is directly conveyed to the fixing device by the transfer belt 25.

Now, in the above-described color laser copying machine,
The cleaning device 29 according to the first aspect of the present invention is provided on the drive roller 26 side of the transfer device 11. The cleaning device 29 includes a cleaning blade 30 made of rubber, for example, for cleaning the transfer belt 25. Then, the cleaning blade 30 is supported by a blade holder (not shown), and the tip is protruded from the blade holder and pressed against the roller winding portion 25 a of the transfer belt 25. Further, a developer transfer coil 31 is provided at the bottom of the cleaning case 29a.

When the transfer belt 25 is cleaned, the developer adhered onto the transfer belt 25 is scraped off by the cleaning blade 30, and the scraped waste developer is removed by the developer transfer coil 31. Conveyed to waste developer tank.

Incidentally, the cleaning device 29 described above is used.
Is a cleaning blade 3 as shown in FIG.
The length L is formed to be longer than the width of the developer attachment area E of the transfer belt 25 corresponding to the effective development area on the photoconductor 10. Then, the developer holding members 35 are pressed against the transfer belt 25 at the upstream positions of the both end portions 30a corresponding to portions longer than the developer attachment region E.
The developer holding members 35 are formed of, for example, brush members made of nylon, polyester, or the like, and the brush members are attached to the mounting bracket 36 as shown in FIG. The mounting bracket 36 is attached to and supported by the cleaning case 29a. Note that a foam member such as foamed polyurethane may be used as the developer holding members 35.

In the cleaning device 29, when the transfer belt 25 is cleaned, if the amount of the developer adhering to both ends 25b of the transfer belt 25 is large due to the rotation of the transfer belt 25, the transfer device 25 is moved to the developer holding member. Wipe off with 35.35. On the other hand, when the amount of the developer adhered to both end portions 25b is small, the wiped developer is adhered to the transfer belt 25 by the developer holding members 35. And
Since the length is longer than the developer adhering area E, the frictional force on the transfer belt 25 is reduced by eliminating the case where there is no developer especially at both end portions 25b where the developer is less likely to adhere.

In the illustrated embodiment described above, the case where the transfer belt 25 is cleaned by the cleaning device 29 has been described. However, the present invention is not limited thereto. The present invention can be applied to a case where a roller or the like is cleaned.

[0037]

Therefore, according to the first aspect of the present invention, when the amount of the developer adhering to the rotating member to be cleaned is large in the developer holding member with the rotation of the rotating member to be cleaned, the developing is performed. Since the developer is wiped off, and when the amount is small, the wiped developer adheres to the rotating body to be cleaned, so that there is no case where there is no developer at both ends of the rotating body to be cleaned, thereby reducing the frictional force against the rotating body to be cleaned. Thus, it is possible to prevent the cleaning blade from being turned up, particularly at both ends. As a result, it is possible to prevent the image quality from deteriorating due to defective cleaning and to prevent the paper from being stained.

According to the second aspect of the present invention, since the developer holding member is formed by the brush member, the developer holding member formed of the brush member effectively wipes and adheres the developer to the rotary member to be cleaned. Can be done.

According to the third aspect of the present invention, since the brush member is supported by the cleaning case via the mounting bracket, the brush member serving as the developer holding member can be easily supported.

According to the fourth aspect of the present invention, since the developer holding member is formed of a foamed member, the developer holding member made of the foamed member effectively wipes and adheres the developer to the rotary member to be cleaned. Can be done.

According to the fifth aspect of the present invention, since the transfer belt is used as the rotating member to be cleaned, it is possible to prevent the cleaning blade from being turned up at both ends of the transfer belt and to lower the image quality due to defective cleaning. And paper stains can be prevented.

According to the invention of claim 6, according to claim 1,
Since the cleaning device according to any one of the above items 5 is provided, it is possible to provide an electrophotographic apparatus including the cleaning device having the above-described effects.

[Brief description of the drawings]

FIG. 1 is a partial schematic perspective view of a cleaning device according to the present invention.

FIG. 2 is an explanatory diagram showing a state in which a developer holding member of the cleaning device is supported by a mounting bracket and pressed against a transfer belt.

FIG. 3 shows a color laser copying machine provided with the cleaning device, and is a schematic configuration diagram around a photoconductor.

FIG. 4 is a schematic explanatory view illustrating a relationship between the length of a cleaning blade and the length of a developer adhering area of a transfer belt in a conventional cleaning device.

FIG. 5 is a state explanatory view for explaining a state in which a conventional cleaning blade is turned up.

[Explanation of symbols]

 Reference Signs List 10 photoconductor 25 transfer belt (rotating member to be cleaned) 29 cleaning device 29a cleaning case 30 cleaning blade 30a both ends of cleaning blade 35 developer holding member 36 mounting bracket E developer adhesion area L length of cleaning blade P paper a transfer position

Continued on the front page F term (reference) 2H200 FA09 FA11 GA03 GA23 GA34 GA44 GA47 GB12 GB13 GB22 HA02 HA12 HA28 HB03 HB12 HB13 HB22 JA03 JB06 JB40 JB42 LA12 LB02 LB09 LB12 LB13 LB35 MA04 MA08 MA20

Claims (6)

[Claims] 1. A cleaning device for an electrophotographic apparatus for cleaning a rotating body to be cleaned which rotates while being in contact with a photosensitive member, wherein the cleaning blade presses the rotating body to be cleaned to remove a developer adhered to a peripheral surface thereof. The cleaning blade is pressed against the cleaning rotator at positions upstream of both ends of the cleaning rotator that are longer than the developer adhering area of the cleaning rotator, and the cleaning blade rotates with the rotation of the cleaning rotator. A developer holding member that wipes off the developer when the amount of the developer attached to the body is large, and adheres the wiped developer to the cleaning rotary member when the amount is small, Cleaning device. 2. The cleaning device for an electrophotographic apparatus according to claim 1, wherein said developer holding member is formed by a brush member. 3. The cleaning device for an electrophotographic apparatus according to claim 2, wherein said brush member is supported by a cleaning case via a mounting bracket. 4. The cleaning device for an electrophotographic apparatus according to claim 1, wherein said developer holding member is formed of a foamed member. 5. A transfer belt which is provided at a transfer position where an image on the photoconductor is transferred to a sheet and transports the sheet after image transfer to a fixing device, as the rotator to be cleaned. 5. The cleaning device for an electrophotographic apparatus according to any one of items 4 to 4. 6. An electrophotographic apparatus comprising the cleaning device according to claim 1. Description: