JP3484285B2 - Cleaning device for transfer conveyor belt - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for a transfer / transport belt used in an image forming apparatus such as a copying machine or a fax machine.

[0002]

2. Description of the Related Art A transfer conveyance belt in an image forming apparatus conveys electrostatically adsorbed transfer paper to a discharge section after transfer at a transfer section. Contamination of the transfer conveyance belt causes image quality of the image forming apparatus. It has a great impact on and it is important to remove it. Then, a problem when molding the transfer belt is how to coat the elastic belt having elongation with a material having a low friction coefficient, that is, a hard material. A material having a low coefficient of friction has a lower coefficient of friction as it is harder and exhibits its original properties. However, when the material is coated on an elastic belt, the tension of the belt becomes high and the belt cannot stretch. If you try to forcibly stretch the belt in this state, cracks will form in the coating layer on the belt surface, toner will enter into the cracks, and you will not be able to scrape it with a cleaning plate or brush, and cleaning failure on the transfer belt surface will occur. There is a problem.

On the other hand, if a relatively soft material is used as a material having a low coefficient of friction so that it can follow an elastic low belt, the tension of the belt will not be so high and cracks will be suppressed, but the friction of the belt surface will be reduced. There is a problem in that the coefficient becomes high and the releasability of the toner becomes poor, resulting in poor cleaning of the transfer belt. As described above, there are many problems in cleaning the transfer belt, and it is difficult to completely maintain the cleaning property over time.

Another problem is the problem of cleaning failure due to paper dust. Since the transfer belt comes into contact with the paper, if the paper dust attached to the belt bites into the cleaning blade edge, the ability to scrape off the toner at the blade edge decreases, and cleaning failure tends to occur. In particular, a large amount of paper dust is generated in the part where the paper is rubbed against the paper feed roller (generally the central part of the paper is large), and cleaning defects are particularly large in the belt area (generally the central part of the belt) corresponding to that part of the paper. .

Heretofore, the following measures have heretofore been implemented as countermeasures for defective paper dust cleaning. That is, FIG.
As shown in FIG. 3, a seal member 3 is provided on the upstream side of the cleaning blade 2 so as to face the drive roller 1 of the transfer unit. The seal member 3 has a brushed brush shape and is generally made of a material such as conductive acrylic fiber or insulating polyester fiber, and is provided in contact with the transfer / transport belt 4. As a result, the paper dust on the belt is removed to some extent, and the seal member 3 also functions as a seal for preventing the toner scraped off by the cleaning blade 2 from scattering and contaminating the periphery of the unit. However, since 100% of the paper dust cannot be removed by the seal member 3, the paper dust that has passed through the seal member 3 stays at the edge of the cleaning blade 2. To remove the paper dust,
At the time of stopping the transfer belt unit at the end of one job of the copying machine, the drive motor is rotated in the reverse direction to rotate the transfer conveyance belt 4 in the reverse direction to remove the paper dust that has bitten into the edge of the cleaning blade 2. In the figure, 11 is a photosensitive drum, 12 is a driven roller, 13 is a registration roller, and 14 is a bias roller.

[0006]

However, in the above-mentioned conventional cleaning device, the paper dust can be removed,
On the other hand, since the brush of the seal member 3 also moves in the opposite direction when the belt rotates in the reverse direction, the toner staying in the seal member diffuses due to the movement and adheres onto the transfer / conveying belt 4. In this case, if the cleaning performance is deteriorated as a whole, the portion to which the toner is attached cannot be completely removed by the cleaning blade 2, resulting in poor cleaning, which causes stain on the back side of the first sheet of the next copy, which causes a problem. Becomes Therefore, it is an object of the present invention to provide a cleaning device for a transfer / conveying belt, which makes it possible to prevent defective cleaning of paper dust and prevention of dirt on the back side of the first sheet.

[0007]

According to a first aspect of the present invention, there is provided a cleaning device for a transfer / conveying belt, which conveys electrostatically adsorbed transfer paper to a discharge part after transferring at a transfer part. In a cleaning device, a toner seal having a brush-like seal portion in contact with an area in the belt width direction corresponding to the position of a paper feed roller and a film-like seal portion in contact with an area other than the area, upstream of the cleaning blade. A member is provided.

[0008] 請 Motomeko cleaning device of the transfer conveyor belt according to 2, downstream of the cleaning blade, at least in contact with the area of the corresponding belt width direction to the position of the paper feed roller, another Kleene and the cleaning blade < The present invention is characterized in that a cutting blade is provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 2 and 3 relate to an embodiment of the cleaning device of the present invention, and FIG. 2 is a side view thereof.
FIG. 3 is a perspective view. Reference numeral 5 in the drawing denotes a toner seal member, which is fixed to the frame 10 on the housing side in the vicinity of the drive roller 1. The toner seal member 5 has a brush-like seal portion 6 and a film-like seal portion 7 at a tip end portion thereof facing the transfer / transport belt 4. As shown in FIG. 3, the brush-like seal portion 6 is located at the center of the toner seal member 5 in the width direction, and this corresponds to the area of the transfer paper that comes into contact with a paper feed roller (not shown). The brush-like seal portion 6 is the frame 1
0 is attached to the inclined surface, and the leading end of the transfer conveyor belt 4
To remove the paper dust adhering to the belt. As the material of the brush-shaped seal portion 6, conductive acrylic fiber or insulating polyester fiber can be used.

The film-shaped seal portion 7 is provided below the exit guide 15 so as to come into contact with other portions of the transfer / conveyance belt 4 excluding the area of the brush-shaped seal portion 6, and the tip portion thereof is relative to the transfer / conveyance belt 4. Lightly touching vertically.
As the material of the film-like sheet portion 7, it is preferable to use a polyurethane film having a thickness of about 0.1 to 0.2 mm,
Other materials such as a film sheet of PET or PVdF may be used. The thickness should have elasticity to some extent according to the material.

Here, the film-like seal portion 7 has a function of preventing toner scattering in the cleaning portion, but the paper dust removing performance is low. On the other hand, the brush-like seal portion 6 has a high paper dust removing performance. As a result, the brush-shaped seal portion 6 removes the paper dust at the central portion of the belt where the paper dust is often attached by the paper feed roller. Further, paper dust accumulated on the edge of the cleaning blade is removed by the transfer / conveying belt reverse rotation mechanism at the end of the job, but toner adhesion to the transfer / conveying belt 4 caused by this reverse rotation is prevented by the film-shaped seal portion 7.
Only the central portion of the transfer / transport belt 4 is provided, and toner adhesion does not occur in the area of the transfer / transport belt 4 corresponding to the film seal portion 7. This is because the amount of toner staying in the film seal portion 7 is small. As a result, the dirt on the back side of the first sheet of the transfer paper is conspicuous only at a limited portion (the position of the paper feed roller) in the center of the transfer paper, and the degree of the back dirt is extremely small.

FIG. 4 is a side view showing a second embodiment of the present invention. In the present embodiment, in addition to the previous embodiment, at least a width equal to or larger than the width of the brush-shaped seal portion 6 is provided at a position corresponding to the brush-shaped seal portion 6 (a region of the transfer conveyance belt in contact with the sheet feeding roller). The blade 8 is provided. The blade 8 is provided in the trailing system downstream of the cleaning blade 2 provided in the counter system. Although the trailing method is slightly inferior in cleaning performance to the counter method, the purpose of the cleaning here is to remove the toner adhesion to the transfer / conveying belt 4 caused by the reverse rotation at the end of the job generated by the brush-like seal portion 6 by the cleaning blade 2. The amount of input toner is not so large because the portion that could not be cleaned is cleaned. Therefore, a sufficient cleaning effect can be obtained even with the trailing method.

[0013]

As described above, the cleaning device for the transfer / conveying belt according to the first aspect of the present invention has a structure in which the brush-like seal portion is used for cleaning a portion where a large amount of paper dust is generated, and the film-like seal portion is used for cleaning the other portion. Therefore, it is possible to prevent defective cleaning of the paper dust, suppress toner adhesion that occurs when the transfer / conveyance belt rotates in the reverse direction, and reduce stains on the back side of the first transfer sheet.

In addition to the effect of the first aspect, the cleaning device for the transfer and transport belt according to the second aspect further has the cleaning blade, so that the cleaning effect of the transfer and transport belt can be further enhanced.

[Brief description of drawings]

FIG. 1 is a schematic side view showing the overall configuration of a transfer / transport belt.

FIG. 2 is a side view of the cleaning device according to the first embodiment of the present invention.

FIG. 3 is a perspective view of FIG. 2.

FIG. 4 is a side view of a cleaning device according to another embodiment of the present invention.

[Explanation of symbols]

1 drive roller 2 cleaning blade 3 seal members 4 Transfer conveyor belt 5 Toner seal member 6 Brush-shaped seal part 7 Film seal part 8 blades 10 frames

Front page continued (72) Inventor Kazue Miyamoto 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) Reference JP-A-7-168454 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/16 G03G 21/10

Claims (2)

(57) [Claims] 1. A cleaning device for a transfer / conveying belt, which conveys electrostatically adsorbed transfer paper to a discharge part after transfer at a transfer part, in a belt width direction corresponding to a position of a paper feed roller upstream of a cleaning blade. And a toner seal member having a film-shaped seal portion contacting with a region other than the brush-shaped seal portion. 2. A cleaning blade different from the cleaning blade, which is in contact with at least a region in the belt width direction corresponding to the position of the paper feed roller, is provided downstream of the cleaning blade. The cleaning device for the transfer / transport belt according to claim 1.