JP3542246B2 - Cleaning device for transfer conveyor belt - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transfer and transport belt cleaning device used in an image forming apparatus such as a copying machine and a facsimile.
[0002]
[Prior art]
The transfer conveyance belt in the image forming apparatus is to transfer the electrostatically attracted transfer paper to the paper discharge section after the transfer in the transfer section, and the contamination of the transfer conveyance belt has a great effect on the image quality of the image forming apparatus. It is important to remove this. What is problematic in forming the transfer / conveying belt is how to coat a material having a low coefficient of friction, that is, a hard material, on the stretchable elastic belt. A material having a low coefficient of friction has a lower coefficient of friction as it is harder and exhibits its original properties. However, if the material is coated on an elastic belt, the tension of the belt is increased and the belt cannot be extended. If you try to forcibly stretch the belt in this state, a crack will occur in the coating layer on the belt surface, toner will enter the crack, and it will not be able to be scraped off with a cleaning blade or brush, resulting in poor cleaning of the transfer / transport belt surface. There is a problem of doing.
[0003]
Conversely, if the elastic belt can be followed by using a relatively soft material with a low coefficient of friction, the belt tension will not be so high and cracks will be suppressed, but the friction coefficient of the belt surface will be high. As a result, there is a problem that the releasability of the toner is not good and cleaning failure of the transfer conveyance belt is caused. As described above, there are many problems in cleaning the transfer conveyance belt, and it is difficult to completely maintain the cleaning property over time.
[0004]
Another problem is the problem of poor cleaning due to paper dust. Since the transfer conveyance belt comes into contact with the paper, if paper dust adhering to the belt digs into the cleaning blade edge, the toner scraping ability of the blade edge is reduced, and cleaning failure is likely to occur. In particular, a large amount of paper dust is generated in a portion where the paper is rubbed by the paper feed roller (generally, the central portion of the paper is large), and cleaning failure particularly in a belt region (generally, the central portion of the belt) corresponding to that portion of the paper increases. .
[0005]
Here, the following measures have conventionally been taken as measures against the paper powder cleaning failure. That is, as shown in FIG. 1, the cleaning unit 2 is located on the upstream side of the cleaning blade 2 opposite to the drive roller 1 of the transfer unit, specifically, a fixing and discharging unit (not shown) from the transfer unit (left side in FIG. 1). A seal member 3 is provided on the downstream side of the transfer section and on the upstream side of the cleaning blade 2 along the transport direction (indicated by an arrow in FIG. 1). The seal member 3 is in the form of a brush that has been planted, and is generally made of a material of conductive acrylic fiber or insulating polyester fiber. The seal member 3 is provided in contact with the transfer conveyance belt 4. As a result, the paper dust on the transfer / transport belt 4 is removed to some extent, and the seal member 3 also exerts a seal function for preventing the toner scraped off by the cleaning blade 2 from scattering and soiling the periphery of the unit. However, since the paper dust cannot be removed by the 100% sealing member 3, the paper dust passing through the sealing member 3 stays at the edge of the cleaning blade 2. As the paper dust removal, when the transfer / conveyance belt unit is stopped at the end of one job of the copying machine, the drive motor is reversed to reverse the transfer / conveyance belt 4, and the paper dust that has entered the edge of the cleaning blade 2 is removed. Have done that. In FIG. 1, reference numeral 5 denotes a toner collecting coil, 6 denotes a lower case, 7 denotes a bias roller, 8 denotes a photosensitive drum, 9 denotes a pre-transfer neutralizing lamp, 10 denotes a registration roller, and 11 denotes a driven roller.
[0006]
[Problems to be solved by the invention]
In the above-described conventional apparatus, as shown in FIG. 1, a seal member 3 is provided on the upstream side of the cleaning blade 2 so as to face the drive roller 1. However, since the seal member 3 is fixed to the lower case 6, Although the paper dust removing effect is high in the early stage of the operation of the apparatus, there is a problem that the paper dust gradually accumulates in the seal member 3 and the removing effect decreases with time.
[0007]
Furthermore, in recent years, there is a problem due to an increase in the use of recycled paper called recycled paper. In other words, the recycled paper is more fragile than the genuine pulp paper and easily generates a large amount of paper powder from the cut surface. As a result, when such recycled paper is used in a large amount, the fixed sealing member 3 is not used. The durability of paper dust removal is increasingly reduced.
[0008]
Therefore, the present invention provides a transfer / transport belt cleaning device that can constantly refresh the portion that comes into contact with the transfer / transport belt, can remove paper dust stably with time, and can therefore respond to the use of recycled paper in recent years. The purpose is to do.
[0009]
[Means for Solving the Problems]
According to a first aspect of the present invention, in order to achieve the above object, the transfer sheet cleaning device of the present invention transfers a transfer sheet at a transfer section, then electrostatically adsorbs the transfer sheet as it is, and fixes the transfer sheet to a transfer section. A sponge roller is rotated downstream of the transfer unit and upstream of the cleaning blade along a conveyance direction from the transfer section to the fixing and discharging section of the transfer conveyance belt. The sponge roller is interlocked with the transfer conveyance belt when the transfer conveyance belt is reversely driven to remove paper dust from the edge of the cleaning blade. It is characterized by making it.
[0010]
According to a second aspect of the present invention, the rotational drive system of the sponge roller is gear-connected to the rotational drive system of the transfer / transport belt via a one-way clutch.
[0011]
According to a third aspect of the present invention, the sponge roller is detachably supported by a case supporting the transfer conveyance belt.
[0012]
According to a fourth aspect of the present invention, in place of the sponge roller, a brush roller formed by implanting a brush material in a loop shape is used.
[0013]
Embodiments and Examples of the Invention
Hereinafter, embodiments and examples of the present invention will be described with reference to the drawings. In the following, portions common to the conventional example will be denoted by the same reference numerals, and redundant description will be omitted.
[0014]
FIG. 2 is a side sectional view showing an enlarged main part of an embodiment of the transfer / transport belt cleaning device according to the present invention. In this embodiment, the sponge roller 20 is rotatably supported at a position facing the drive roller 1 with the transfer / conveyance belt 4 interposed therebetween. The width of the sponge roller 20 in the depth direction of the drawing in the drawing is the maximum width of the transfer paper that passes though not shown. For example, if the transfer paper having the maximum width is A3 length, it may be about 300 mm. Further, the sponge roller 20 is brought into contact with the surface of the transfer / transport belt 4 so as to cut into the surface by a predetermined dimension t (for example, about 1.5 mm).
[0015]
A stop claw 21 is provided coaxially with the axis of the sponge roller 20 so as to engage with the stopper 22, and the stopper 22 is caught on the stop claw 21 when the transfer / conveyance belt 4 rotates forward (counterclockwise in the figure). Then, the sponge roller 20 slides on the surface of the transfer conveyance belt 4 in a stationary state. As a result, the sponge roller 20 removes toner, paper dust, dust and the like adhering to the surface of the transfer / conveying belt 4. Further, the sponge roller 20 is provided with a mylar 23 so as to clean the surface of the sponge roller 20 so as to further extend the removal effect.
[0016]
After one job such as copying is completed, the transfer conveyance belt 4 is rotated in reverse (clockwise in the figure) to remove paper dust and the like from the tip of the cleaning blade 2 as described above. Since the rotation prevention by the stopper 22 does not work, the sponge roller 20 rotates along with the transfer conveyance belt 4, and the contact surface between the sponge roller 20 and the transfer conveyance belt 4 changes. By repeating this operation, the foreign matter on the transfer / conveying belt 4 can be uniformly attached to the sponge roller 20, and the effect of removing the foreign matter over time can be reduced as compared with the conventional fixed seal member. Can be maintained.
[0017]
In addition, the number of teeth of the stop claw 21 is as follows, assuming that the rotation angle of the sponge roller 20 is θ and the number of teeth of the stop claw 21 is Z.
(Equation 1)
θ> (360 / Z) × a
Set so that However, the coefficient a is 1 or more, and it is better to increase the number of teeth of the stop claw 21 so that a is actually about 2. As an example, the stop claw 21 is made of a resin molded product and has 16 teeth, and the rotation angle θ of the sponge roller 20 is about 50 degrees. The stopper 22 is made of a leaf spring made of stainless steel.
[0018]
In the first embodiment, the sponge roller 20 is brought into contact with the transfer / conveyance belt 4 to rotate the transfer / conveyance belt 4 during the reverse rotation operation. Slippage is likely to occur between the sponge rollers 20 and the rotation of the sponge roller 20 is likely to have a large variation. Therefore, in order to reduce such variations, in the apparatus according to the second embodiment of the present invention shown in FIG. 2, a gear 24 with a one-way clutch is provided coaxially with the axis of the sponge roller 20. The sponge roller 20 is reliably rotated by being connected to a gear 25 which is coaxial with the shaft. In this embodiment, when the transfer / conveyance belt 4 rotates forward (ie, during copying or the like), the one-way clutch incorporated in the gear 24 idles, and the sponge roller 20 is stopped by the stop claws 21 to stop. While the surface of the transfer conveyor belt 4 is being rotated, the rotational driving force of the transfer conveyor belt 4 is transmitted via the gears 26 and 24 when the transfer conveyor belt 4 is rotated in the reverse direction, and the sponge roller 20 is reliably rotated in accordance with the rotation of the transfer conveyor belt 4. To rotate.
[0019]
As shown in FIG. 3, the sponge roller 20 of the present embodiment can be easily removed from the lower case 6 by removing the snap ring 26 and the gear 24 with the one-way clutch. It is convenient for maintenance such as cleaning and replacement.
[0020]
Note that, instead of the sponge roller 20, a flocked brush roller 30 shown in FIG. 4 can be used. The flocked brush roller 30 is obtained by flocking the brush material 32 in a loop on the base 31, paper dust is caught on the loop-shaped portion of the brush material 32, and furthermore, the effect of removing the paper dust on the surface of the transfer conveyance belt 4 is improved. Can be expected.
[0021]
【The invention's effect】
As described above, in the transfer conveying belt cleaning device of the first aspect, a rotatable sponge roller is used, and the surface that contacts the surface of the transfer conveying belt is always rotated during the reverse rotation driving operation of the transfer conveying belt. Since the paper is refreshed, the paper dust can be removed with stability over time, and there is an effect that the paper can be used even when using paper which generates a lot of foreign substances such as paper dust, such as recycled paper.
[0022]
In the transfer / transport belt cleaning device of the second aspect, the rotational drive system of the sponge roller and the rotational drive system of the transfer / transport belt are connected by a gear via a one-way clutch. There is an effect that the sponge roller can be surely rotated without being affected by the deformation of the sponge, the slip at the time of sliding contact, and the like.
[0023]
The sponge roller is detachably supported by the case supporting the transfer / transport belt, so that the sponge roller is detachably supported on the transfer / transport belt. There is an effect that the maintenance of can be easily performed.
[0024]
In the transfer / transport belt cleaning device according to the fourth aspect, a brush roller formed by flocking a brush material in a loop shape is used in place of the sponge roller. There is an effect that the powder removing effect can be further improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a conventional transfer and transport belt cleaning device.
FIG. 2 is a side cross-sectional view showing an enlarged main part of one embodiment of a transfer / conveying belt cleaning device according to the present invention.
FIG. 3 is an enlarged perspective view showing a main part of a second embodiment of the transfer / conveying belt cleaning device according to the present invention;
FIGS. 4A and 4B are an enlarged perspective view and a cross-sectional view, respectively, showing a main part of a brush roller that can be used in the cleaning device of the transfer conveyance belt according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Driving roller of transfer unit 2 Cleaning blade 4 Transfer conveyance belt 5 Toner recovery coil 6 Lower case 8 Photoreceptor drum 9 Pre-transfer static elimination lamp 10 Registration roller 11 Follower roller 20 Sponge roller 21 Stop claw 22 Stopper 23 Mylar 24 Gear with one-way clutch 25 gear 26 snap ring 30 flocking brush roller 32 brush material

Claims (4)

In the cleaning device of the transfer conveyance belt, which transfers the transfer paper to the transfer unit and then electrostatically attracts and fixes the transfer paper to the discharge unit, the transfer of the transfer conveyance belt from the transfer unit to the fixing and discharge unit is performed. A sponge roller is disposed rotatably and slidably in contact with the surface of the transfer conveyance belt on the downstream side of the transfer section and on the upstream side of the cleaning blade along the direction, and paper dust is removed from the edge of the cleaning blade. A cleaning device for the transfer conveyance belt, wherein the sponge roller is interlocked with the transfer conveyance belt during a reverse driving operation of the transfer conveyance belt. 2. The transfer and transport belt cleaning device according to claim 1, wherein the rotational drive system of the sponge roller is gear-connected to the rotational drive system of the transfer and transport belt via a one-way clutch. 3. The transfer and transport belt cleaning device according to claim 1, wherein the sponge roller is detachably supported by a case that supports the transfer and transport belt. 4. The transfer / conveying belt cleaning device according to claim 1, wherein a brush roller formed by flocking a brush material in a loop shape is used instead of the sponge roller.

Images