JP3527601B2 - Belt conveyor for image forming equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be applied to an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine thereof. More specifically, the present invention relates to a belt conveyance device for stretching an endless belt between a driving roller and a driven roller and driving the driving roller to convey the belt in such an image forming apparatus.

[0002]

2. Description of the Related Art Heretofore, some belt conveyors of this type use a rubber roller as a driving roller in order to reliably transmit a driving force to the belt. However, the driving roller made of rubber has a problem that the friction coefficient of the surface thereof is lowered under the environmental conditions of high temperature and high humidity.

Therefore, as a driving roller, there is one using a resin-coated roller in which the outer periphery of a core metal is coated with a resin material to form a rough surface.

[0004]

However, conventionally, even when such a resin-coated roller is used as the driving roller, foreign matter such as paper dust, dust, and floating toner is present between the surface of the roller and the back surface of the belt. When it enters, there is a problem that the belt slips during belt conveyance and the driving force of the driving roller cannot be reliably transmitted to the belt.

[0005]

Therefore, according to the invention described in claim 1, a driving roller such as driving rollers 40 and 45 and driven rollers 41 and 46 are provided, for example, as shown in the following embodiments. In the belt conveying device of the image forming apparatus, an endless belt such as the photoconductor belt 12 or the intermediate transfer belt 44 is stretched between at least one driven roller, and the belt is driven by driving the driving roller. It is characterized in that at least one of the driven rollers has a cleaning function for removing foreign matters attached to the back surface of the belt.

Then, when the belt is conveyed, the foreign matter adhering to the back surface of the belt is removed by the driven roller having the cleaning function.

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiment, in the belt conveying device of the image forming apparatus according to the first aspect, at least one of the driven rollers has a surface thereof. The feature is that it is made to have flocking and a cleaning function.

Then, when the belt is conveyed, foreign matter adhering to the back surface of the belt is removed by a driven roller having flocked surface.

The invention described in claim 3 is, for example, as shown in the following illustrated embodiment, in the belt conveying device of the image forming apparatus according to claim 1 or 2, for example, the photosensitive belt 12 or the intermediate transfer belt 44. As described above, the belt forms an image on the surface thereof.

According to a fourth aspect of the present invention, for example, as shown in the following embodiment, in the belt conveying device of the image forming apparatus according to the first or second aspect, the belt conveys the sheet. It is characterized by

According to a fifth aspect of the present invention, for example, as shown in the following embodiments, in the belt conveying device of the image forming apparatus according to the first or second aspect, the belt transmits the driving force. , Is characterized.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a schematic configuration of a color laser printer provided with a belt conveying device according to an embodiment of the present invention.

Reference numeral 10 in the figure denotes a printer body. Inside the printer main body 10, there is provided a photosensitive belt transporting device, which is one example of the present invention, indicated by reference numeral 11 in FIG. The photoconductor belt transport device 11 includes an endless photoconductor belt 12 that is stretched between a drive roller 40, a first driven roller 41, and a second driven roller 42 having a small diameter.

Around the photoconductor belt transporting device 11, a multicolor developing device 14 and a black color developing device 14 are arranged in that order from the charging device 13 provided thereunder in the transporting direction of the photoconductor belt 12 (direction of arrow A in the figure). Developing device 15, intermediate transfer belt conveying device 16 which is another example of the present invention, photoconductor cleaning device 1
7, a static eliminator 18 is provided. A laser writing device 19 is provided below the multicolor developing device 14.

The multicolor developing device 14 includes three developing devices, which accommodate toners of respective colors of blue, red, and yellow, around the central axis 14b in the cylindrical case 14a, and the supporting frame 1
Attach to 4c to support. Then, the supporting frame 14c is rotated about the central axis 14b so that the developing sleeve position of each developing device can sequentially face the photoconductor belt 12. The black developing device 15 has a cam 1 which is always provided behind it.
While biasing the spring toward 5a, the cam 15a thereof is rotated to allow the developing sleeve 15b to come into contact with and separate from the photosensitive belt 12.

The intermediate transfer belt conveying device 16 comprises an endless intermediate transfer belt 44 stretched between a driving roller 45 and a driven roller 46, and a part of the intermediate transfer belt 44 is in contact with the photosensitive belt 12. A belt transfer charger 23 is provided inside the contact position. Further, the intermediate transfer belt transport device 16 is provided with the belt cleaning device 20 and the transfer device 21 on both right and left sides of the drive roller 45 separately from the intermediate transfer belt 44.

Further, in the printer body 10, a fixing device 22 is provided on the upper side of the black developing device 15, and electrical equipment is provided on the left side.
A control device 24 is provided, and an exhaust fan 25 is provided above the control device 24. Further, a paper feed cassette 26 accommodating the paper P is provided on the bottom side.

Thus, in the illustrated printer, at the time of image recording, the photosensitive belt 12 is conveyed in the A direction in FIG. 2, the intermediate transfer belt 44 is conveyed in the B direction, and the paper P in the paper feed cassette 26 is conveyed. The paper feed roller 29 is rotated and fed out. Further, the sheet P is conveyed by the conveying roller pair 30 to the conveying path 3
The sheet is conveyed through 1 and abuts against the registration roller pair 32 to stop.

On the other hand, as the photosensitive belt 12 is conveyed, its surface is first uniformly charged by the charging device 13. Then, based on the writing information of the first color, the laser writing device 1
The laser beam L is irradiated at 9 to form an electrostatic latent image of the first color on the photosensitive belt 12.

Then, for example, the developing device for the first color of the multi-color developing device 14 is made to face the photoconductor belt 12, the toner for the first color is adhered to develop the electrostatic latent image, and the visible image is formed. Is temporarily transferred onto the intermediate transfer belt 44 by the belt transfer charger 23. After the image transfer, the photoconductor belt 12
The toner of the first color remaining on the upper surface is scraped off and cleaned by the blade 17a of the photoconductor cleaning device 17, and is collected in the waste toner collecting container 17b provided below the photoconductor cleaning device 17.

Thereafter, when forming the second and third color images, laser writing is similarly performed to form respective electrostatic latent images based on the respective writing information, and the multicolor developing device 14 is formed. The second and third color developing devices are moved to developing positions to develop the electrostatic latent images, the visible images are transferred onto the intermediate transfer belts 44, and after the image transfer, the photosensitive belt 12 is transferred.
The top is cleaned to collect the waste toner in the waste toner collection container 17
Collect in b.

Similarly, when forming a black image, laser writing is performed based on the writing information to form an electrostatic latent image, and the developing sleeve 15b of the black developing device 15 is formed.
Is contacted with the photoconductor belt 12 to develop an electrostatic latent image, the visible image is transferred onto the intermediate transfer belt 44, and after the image transfer, the photoconductor belt 12 is cleaned to collect waste toner into a waste toner collecting container. Collect in 17b. In this way, a transfer image of a single color or a plurality of colors is formed on the intermediate transfer belt 44.

After that, the transfer roller 21 of the transfer device 21
a and the blade 20a of the belt cleaning device 20 are brought into contact with the intermediate transfer belt 44, while the transfer image on the intermediate transfer belt 44 is transferred to the intermediate transfer belt 44 and the transfer roller 2 by the registration roller pair 32 at a timing.
Transport between 1a. Then, a transfer image of a single color or a plurality of colors is transferred onto the paper P. After the color image is transferred, the paper P is conveyed to the fixing device 22, where heat and pressure are applied to fix the image, and after the fixing, the paper discharge roller pair 33.
Then, the sheet is discharged onto the discharged sheet stack section 34.

On the other hand, after the image transfer, the toner remaining on the intermediate transfer belt 44 is scraped off and cleaned by the blade 20a of the belt cleaning device 20. The scraped toner is conveyed in the axial direction by the auger 20b, further conveyed to a waste toner collecting container 17b through a conveying path (not shown), and collected there.

By the way, in the illustrated printer described above, the photoconductor belt carrying device 11 and the intermediate transfer belt carrying device 16 are connected to the charging device 13, the photoconductor cleaning device 17, and the photoconductor cleaning device 17.
The belt cleaning device 20 and the transfer device 21 are integrated together, and they are assembled into a frame 35 as shown in FIG.
And the process cartridge C is supported.

In the photoconductor belt conveying device 11 according to the present invention, as the photoconductor belt 12, for example, an endless belt made of nickel electroforming having high releasability is used.

Further, in the photoconductor belt conveying device 11, as the driving roller 40, for example, the outer periphery of a pipe-shaped cored bar is coated with urethane resin, and the surface thereof has a surface roughness R.
A resin-coated roller formed on a rough surface with z of about 3 μm to 50 μm is used. As a coating material,
A mixture of urethane resin and EP rubber in a proportion of 20 to 50 wt % may be used.

Further, as the first driven roller 41, for example, a flocking roller for cleaning is used in which an adhesive is applied to the outer periphery of a pipe-shaped cored bar, and a large number of bristles are raised on the adhesive layer to flock. The length of the bristles is preferably about 0.5-3 mm.

On the other hand, in the intermediate transfer belt conveying device 16 according to the present invention, as the intermediate transfer belt 44, for example, an endless belt made of a resin material having a high releasability is used. Then, similarly to the photoconductor belt conveying device 11, both ends of the roller shafts of the rollers 45 and 46 are rotatably supported by the frame 35, and the driven roller 46 is urged by an urging spring (not shown) to form an intermediate transfer belt. 44 is stretched between rollers 45 and 46.

Further, the intermediate transfer belt conveying device 16
As the drive roller 45, for example, a resin coat roller similar to the drive roller 40 described above is used. Further, as the driven roller 46, for example, the first driven roller 4 described above is used.
As in the case of 1, a flocking roller for cleaning with flocked surfaces is used.

Then, at the time of image recording, the driving force from a driving source (not shown) is transmitted to the driving roller 40 of the photosensitive belt conveying device 11 to rotate the driving roller 40 , and the photosensitive belt 12 is moved to the first and second positions. Second driven roller 41/42
While being driven to rotate, it is conveyed in the direction A in FIG. Further, the same driving force is transmitted to the drive roller 45 of the intermediate transfer belt transport device 16 to rotate and drive the drive roller 45 , and the intermediate transfer belt 44 is transported in the B direction while the driven roller 46 is driven to rotate.

In the illustrated embodiment, when the belt is conveyed,
If foreign matter such as paper powder, dust, and floating toner adheres to the back surface of the photoreceptor belt 12, the foreign matter on the back surface passes from the position of the first driven roller 41 to the back surface of the belt having releasability. 1 Transferred to the flocked portion of the driven roller 41 and removed from the back surface of the belt.

If foreign matter is attached to the back surface of the intermediate transfer belt 44, when the foreign matter on the back surface passes through the position of the driven roller 46, it is transferred to the flocked portion on the outer periphery of the intermediate transfer belt 44 and the back surface of the intermediate transfer belt 44. Removed from.

In the above-described embodiment, the back surface of the belt is cleaned by adhering foreign matter to the flocked portion on the outer periphery of the driven roller. The back surface of the belt can be cleaned by attaching foreign matter.

In the above-described embodiment, one of the driven rollers has the belt cleaning function.
One or more driven rollers may have such a cleaning function.

According to the second aspect of the invention, for example, as shown in the above-described embodiment, the first driven roller 41 of the photosensitive belt conveyor 11 and the driven roller 46 of the intermediate transfer belt conveyor 16 are used. In addition, at least one of the driven rollers has a cleaning function by applying flocking to the surface thereof.

According to the third aspect of the invention, the belt forms an image on its surface like the photoconductor belt 12 and the intermediate transfer belt 44, as shown in the above-described embodiment. There is a feature.

Further, the invention according to claim 4 is characterized in that the belt conveys the paper, such as a paper conveying belt for conveying the paper after the image transfer onto the fixing device. To do.

In the invention described in claim 5, the belt transmits the driving force, such as a drive transmission belt for transmitting the driving force of the motor to the rotating body such as the photoconductor, the conveying roller, and the developing sleeve. It is characterized by

[0040]

Therefore, according to the first and second aspects of the present invention, even if foreign matter such as paper powder, dust, and floating toner adheres to the back surface of the belt when the belt is conveyed, the foreign matter has a cleaning function. Since the belt is removed by the driven roller, it is possible to prevent the belt from slipping due to foreign matter attached to the back surface of the belt, and to reliably transmit the driving force of the driving roller to the belt.

According to the third aspect of the present invention, since the belt forms an image on the surface thereof, an image shift or the like occurs due to the slip of the belt at the time of image formation, and the image quality is improved. It is possible to prevent the deterioration. In addition, lumps of foreign matter that enter between the front surface of the drive roller and the back surface of the belt may cause, for example, a convex portion on the surface of the photoconductor belt or the intermediate transfer belt, which may cause abnormal images or the like and deteriorate image quality. It can also be prevented.

According to the fourth aspect of the invention, since the belt conveys the paper, the paper can always be smoothly conveyed at a constant speed and the deterioration of the image quality can be prevented.

According to the invention described in claim 5, since the belt transmits the driving force, the driving force of the driving roller is surely transmitted to the belt to prevent the deterioration of the image quality. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram of a process cartridge of a color laser printer including a belt conveying device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of the entire color laser printer.

[Explanation of symbols]

12 photoconductor belt 40/45 drive roller 41.46 Driven roller 44 Intermediate transfer belt

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 5/00 G03G 21/00 350

Claims (5)

(57) [Claims] 1. A belt conveying device of an image forming apparatus, wherein an endless belt is stretched between a driving roller and at least one driven roller, and the belt is driven by the driving roller to convey the belt. Finally, a belt conveying device of the image forming apparatus, which has a cleaning function of removing foreign matters attached to the back surface of the belt. 2. The belt conveying device for an image forming apparatus according to claim 1, wherein at least one of the driven rollers is provided with a flock on its surface to have a cleaning function. 3. The belt conveying device of the image forming apparatus according to claim 1, wherein the belt forms an image on the surface thereof. 4. The belt conveying device of the image forming apparatus according to claim 1, wherein the belt conveys a sheet. 5. The belt conveying device for an image forming apparatus according to claim 1, wherein the belt is for transmitting a driving force.