JPH10186931A - Cleaning device for fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sufficient cleaning capacity in a color image forming device and to prevent the occurrence of an offset phenomenon by abutting a cleaning web in a position nearer to the downstream in the rotational direction of a fixing rotary body than a cleaning roller. SOLUTION: The cleaning roller 16 is abutted with the fixing rotary body 12a and is rotatably arranged. The cleaning web 17 is abutted with the fixing rotary body 12a and the cleaning roller 16 and is movably arranged. Then, the cleaning roller 16 and the cleaning web 17 come into contact with the fixing rotary body 12a. The cleaning web 17 is abutted in the position nearer to the downstream side in the rotational direction of the fixing rotary body 12a than the cleaning roller 16, so that cleaning is attained by the cleaning web 17 after cleaning by the cleaning roller 16. Thus, the sufficient cleaning capacity is obtained and even if a large quantity of meltable toner and paper powder are stuck to the fixing rotary body 12a, the meltable toner and paper powder can be removed.

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 cleaning a fixing device in an electrophotographic image forming apparatus such as a copying machine and a printer.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for a fixing device, which is suitable for removing molten toner, paper powder, and the like from a pair of fixing rotating members arranged in pressure contact with each other.

[0002]

2. Description of the Related Art In recent years, as an electrophotographic image forming apparatus of this type, for example, a photoreceptor drum which is rotatably disposed and sequentially forms a single-color toner image of each color, and a photoreceptor drum facing the photoreceptor drum A transfer corotron that transfers a toner image to a transfer material such as paper at a transfer position between the photoconductor drum and a transfer material such as paper so that the transfer material passes through the transfer position. A transfer drum rotatably disposed, and a heating roller and a pressure roller pressed against each other so as to sandwich the transfer path downstream of the transfer position in a transfer path of the transfer material. And a fixing device that heats and presses the transfer material onto which the toner image has been transferred at the position, sequentially transfers a plurality of single-color toner images onto the transfer material carried on the transfer drum, and transfers the transfer material along the transport path. Transport There is a full-color image is formed on the transfer material in the.

In the image forming apparatus having such a configuration, when a toner image is fixed on a transfer material, the transfer material is sandwiched between a pair of fixing rollers (a heating roller and a pressure roller). As a result, a part of the melted toner and paper powder adhere to the surface of the fixing roller. As a result, the surface of the roller to which the toner has adhered stains the image surface of the next transfer material, or the surface of the roller to which the toner has adhered re-adheres to the other roller, and then the back surface of the next transfer material becomes dirty. Would be lost.

Therefore, in a color image forming apparatus having such a configuration, a cleaning device for a fixing device is used in order to remove molten toner, paper powder, and the like from the surfaces of these fixing rollers.

A cleaning device for cleaning such a fixing roller is disclosed, for example, in Japanese Patent Application Laid-Open No. 61-1986.
As disclosed in JP-A-221773, there is a printer having a cleaning roller rotatably disposed in contact with a fixing roller. In the cleaning device, at the pressure contact position between the fixing roller and the cleaning roller, the molten toner or paper powder attached to the surface of the fixing roller can be transferred to the surface of the cleaning roller, thereby cleaning the fixing roller. be able to.

Further, as disclosed in Japanese Utility Model Laid-Open Publication No. Sho 61-176573, there is a printer having a web provided so as to be in sliding contact with a fixing roller. In this cleaning device, at the contact position between the fixing roller and the web, the molten toner or paper powder adhered to the surface of the fixing roller can be transferred to the web, thereby cleaning the fixing roller. .

[0007]

However, according to the study by the inventors, in each of these cleaning apparatuses, one cleaning member is brought into contact with a fixing roller, and
Since the cleaning member attempts to remove all of the molten toner and paper dust at once, it has been found that the cleaning ability is not sufficient and the fixing roller cannot be sufficiently cleaned. Specifically, for example, when four single-color toner images are superimposed on a transfer material, the toner of each color overlaps, so that the thickness is about four times that of a conventional toner image for a black-and-white image. Is formed. When the transfer material on which the toner image having such a thickness is formed is sandwiched between a heating roller and a pressure roller and heated and pressed,
In some cases, only the portion near the surface of the toner layer is heated and melted. At this time, a relatively large amount of the melted toner adheres to the heating roller, and the cleaning member must remove all of the toner at once. Could not. As a result, the heating roller comes into contact with the next transfer material on its dirty surface, and contaminates the transfer material with the molten toner.

Accordingly, an object of the present invention is to provide a cleaning device for a fixing device which has a sufficient cleaning ability even in a color image forming apparatus and can prevent the occurrence of an offset phenomenon in the color image forming apparatus. It is in.

[0009]

That is, the present invention relates to a cleaning roller which is rotatably disposed in contact with a fixing rotating member of a fixing device, and a cleaning roller which is in contact with the fixing rotating member and the cleaning roller. A cleaning web movably disposed, the cleaning web being in contact with the cleaning roller downstream of the cleaning roller in the rotation direction of the fixing rotator.

In the present invention, the fixing rotator of the fixing device may be any as long as it can contact the transfer material and fix the toner image formed on the transfer material.
There are a heating roller, a pressure roller, a fixing belt, and the like.

The cleaning roller may be a roller which is rotatably disposed in contact with the fixing rotary member. For example, a roller formed by forming a metal material such as stainless steel into a pipe shape or a column shape is used. be able to. When the cleaning roller is used as a cleaning roller, it is less bent in its length direction (that is, in the direction of the rotation axis of the roller), and can be uniformly pressed in the axial direction. It is preferred.

The cleaning web only needs to be movably disposed in contact with the fixing rotating body and the cleaning roller. For example, the cleaning web is wound around a delivery roller and the leading edge is fixed to a winding roller. There is a long web of nonwoven fabric. Further, the moving direction of the web is preferably to move in the opposite direction to the fixing rotator at the contact position with the fixing rotator, and in the moving direction, the web is located ahead of the cleaning roller. It is better to be disposed so as to be in contact with the fixing rotating body.

In the cleaning device for a fixing device according to the present invention, the cleaning roller and the cleaning web are brought into contact with the fixing rotating body, and the cleaning by the cleaning web is performed after the cleaning by the cleaning roller. Since the cleaning web is abutted downstream of the cleaning roller in the rotation direction of the fixing rotator, the cleaning web has a sufficient cleaning ability, and a relatively large amount of molten toner and paper powder adhere to the fixing rotator. They can be cleaned even if they are.

The reason why such a cleaning roller and the cleaning web are provided with sufficient cleaning ability is that the cleaning roller is effective for cleaning the melted toner while the cleaning web is a paper powder. This is because the use of the web without wetting it with the molten toner is more effective in removing paper dust and the like.

In the present invention, in order to enable the molten toner to move efficiently and reliably from the fixing rotator to the cleaning roller and from the cleaning roller to the cleaning web, the releasability of these members is required. (Such as surface energy). Specifically, it is preferable that the cleaning roller is formed of a material having a lower releasability than the fixing rotator and a higher releasability than the cleaning web. Rubber is widely used as a surface material of the fixing rotating body, and a cloth woven with fibers such as nylon is used as a cleaning web. In such a combination, a metal such as stainless steel is used. May be used to form a cleaning roller.

Further, in the cleaning device for a fixing device of the present invention, after use, the surface of the fixing rotating body that is in contact with the toner image on the transfer material is cleaned with a cleaning roller, and the cleaning portion of the cleaning roller is cleaned. It is preferable to stop after the trailing edge has passed the contact position between the cleaning roller and the cleaning web. Further, when the linear velocity of the cleaning web is set to be lower than the linear velocity of the cleaning roller, the recovery part of the cleaning web that contacts the cleaning part of the cleaning roller is further positioned at the contact position between the cleaning roller and the cleaning web. It is good to stop after passing. Thus, the toner can be stopped in a state where the melted toner does not contact the cleaning roller, so that the toner does not adhere to the surface of the cleaning roller. Incidentally, if the toner adheres to the surface of the cleaning roller, the toner is melted again at the time of the next image formation, and the toner adheres to the fixing rotator to stain the transfer material.

In addition, as shown in FIG. 8, the cleaning roller is configured to be retractable by a driving force of an electromagnetic solenoid or the like, and the surface of the fixing rotating body that contacts the toner image on the transfer material is cleaned by the cleaning roller. Even if the cleaning roller is cleaned and the rear edge of the cleaning portion of the cleaning roller comes into contact with the cleaning web, the cleaning roller and the cleaning web are separated from each other, thereby preventing the toner from sticking to the surface of the cleaning roller. can do.

The cleaning portion of the cleaning roller refers to a surface portion of the cleaning roller that cleans a surface portion of the fixing rotating body that is in contact with the toner image on the transfer material when the toner image is fixed on the transfer material. The collection portion of the cleaning web refers to a surface portion of the cleaning web in contact with the cleaning portion of the cleaning roller.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a schematic configuration diagram of an image forming apparatus to which the present invention is applied. In the figure, reference numeral 1 denotes a rotatable photosensitive drum;
Is a charging corotron that charges the photosensitive drum 1 to a uniform potential; 3 is a laser exposure device that exposes the charged photosensitive drum 1 in accordance with image information; 4 is yellow, magenta, cyan, and black 4 A rotary developing device for holding a color toner and supplying a toner of a predetermined color with one toner supply unit facing the photoreceptor drum 1 after exposure is provided at a transfer position between the photoreceptor drum 1 and 5. A transfer corotron 6 for transferring a toner image to the supplied paper P, and a cleaning member 6 for removing residual toner and the like from the photosensitive drum 1 after the transfer, and a charging corotron 2 while the photosensitive drum 1 is rotated. A laser exposure unit 3 forms an electrostatic latent image on the photosensitive drum 1 in accordance with image information, and a rotary developing unit 4 develops the electrostatic latent image with a toner of a predetermined color to form a monochromatic toner image. Formed and then transferred By transferring the single-color toner image on the supplied sheet P to the transfer position Rotoron 5, and forms an unfixed toner image on the paper sheet P.

On the other hand, in FIG. 1, reference numeral 7 denotes a transfer drum rotatably disposed so that the paper P can pass through the transfer position, 8 denotes two paper trays capable of storing a large number of papers P, and 9 denotes a paper tray. Suction charging means for adsorbing the sheet P to the transfer drum 7, a pair of registration rollers 10 for supplying the sheet P discharged from the sheet tray 8 to the transfer drum 7 at a predetermined timing, and 11 for separating the sheet P from the transfer drum 7 A peeling corotron 12 is a fixing means for fixing the unfixed toner image to the paper P by sandwiching the paper P on which the unfixed toner image is formed between the heating roller 12a and the pressure roller 12b, and 13 is a paper P after the peeling. A paper guide for supplying
A discharge tray 14 for storing a sheet P on which an image is formed;
Reference numeral 15 denotes a discharge roller pair for discharging the sheet P after fixing to the discharge tray 14. Then, the sheet P discharged from the sheet tray 8 is carried out from the pair of registration rollers 10 and is attracted to a predetermined position of the transfer drum 7 by being charged by the attraction / charging means 9, and is discharged by the peeling corotron 11 to remove the sheet guide. 13 and is carried out in the direction along
The toner image is fixed, and the toner image is further discharged to the discharge tray 14 by the discharge roller pair 15. Further, on the transport path, an image is formed by transferring the toner image at the transfer position and fixing the toner image at the fixing position.

In the image forming apparatus thus configured, for example, the transfer drum 7 on which the paper P is
On the other hand, the toner image of each color is sequentially formed on the photosensitive drum 1 while being rotated, so that the single-color toner images of four colors are transferred onto the paper P in an overlapping manner, and the multicolor toner image is formed on the paper P. Can be formed. Thereafter, the paper P on which the multicolor toner image is formed is heated by the heating roller 12a and the pressure roller 12a.
By heating and pressurizing with b, a full-color image can be formed. The toner on the paper P is melted by being heated and pressurized, and then absorbed by the paper P and cooled to be fixed on the paper P.

Therefore, as shown in FIG. 2, in the present embodiment, the molten toner and paper powder adhered to the heating roller 12a are removed, and the heating and pressing can be performed in a clean state at all times. The cleaning device for a fixing device of the present invention was used.

In FIG. 1, reference numeral 16 denotes a cleaning roller which is formed in a cylindrical shape and is rotatably disposed in pressure contact with the heating roller 12a. Reference numeral 17 denotes an elongated web.
Reference numeral 8 denotes a delivery roller around which the web 17 is wound and rotatably disposed. Reference numeral 19 denotes a tip with a fixed leading edge of the web 17 and rotatably disposed upstream of the delivery roller 18 in the rotation direction of the heating roller 12a. The taken-up roller 20 is located downstream of the cleaning roller 16 in the rotation direction of the heating roller 12a, and the web 17 is moved to the pressing roller 12a and the cleaning roller 16a.
The cleaning roller 16 is rotatably disposed at a position where the cleaning roller 16 is pressed against the heating roller 12.
By rotating the web 17 by the take-up roller 19 while rotating the web 17 in the opposite direction, the dirt is cleaned from the surface of the heating roller 12a, and the dirt attached to the surface of the cleaning roller 16 is collected by the web 17. ing.
Note that rubber is used as a surface material of the heating roller 12a, while a cloth woven by mixing nylon fibers or polyester fibers is used as the cleaning web 17, so that the cleaning roller 16 is made of stainless steel (SU).
S306).

Therefore, in the image forming apparatus of the present embodiment,
Even when the toner on the paper P is transferred and adhered to the surface of the heating roller 12a at the fixing position (see FIG. 3A), the cleaning roller 16 cleans the toner from the surface of the heating roller 12a (see FIG. 3A). (B), (c)) Further, the cleaning web 17 can collect the toner from the surface of the cleaning roller 16 ((d) in FIG.
(E), (f)), the heating roller 12a and the pressure roller 1
In addition to 2b, the surface of the cleaning roller 17 can be maintained in a clean state.

In this embodiment, since the cleaning web 17 moves at a lower linear velocity than the cleaning roller 16, the rear edge of the collection portion of the cleaning web 17 is separated by the cleaning roller 16 and the cleaning web 17. After being separated from the abutment position, these 16 and 17 are stopped (see FIG. 3 (f)). Therefore, the toner does not cool down when the toner remains or adheres to the surface of the cleaning roller 16.

When a full-color image was formed on the sheet P by using the image forming apparatus having the above-described structure, the toner was peeled off in the first half of the image in the sheet conveying direction, and image quality defects such as a change in hue occurred. However, the offset phenomenon did not occur in the image in the second half of the paper transport direction. Further, even if an image defect such as a hue change due to toner separation occurs in the previously formed image, the heating roller 12a and the pressure roller 12
b, or the toner did not adhere to the surface of the cleaning roller 16, and the image and the paper P were not stained when the image was formed later.

In this embodiment, the heating roller 12a
Both the cleaning roller 16 and the cleaning web 17 are used to clean the toner. However, since the cleaning web 17 is used to collect the toner from the cleaning roller 16, it is necessary to remove the molten toner from the cleaning roller 16. It is not necessary to provide this member exclusively, and the configuration can be simplified, downsized, and cost reduced.

Embodiment 2 In this embodiment, as shown in FIG. 4, the cleaning roller 16, the heating roller 12a and the cleaning web 17
The cleaning roller 16 can be linearly retracted by a driving force of an electromagnetic solenoid (not shown) so that the cleaning roller 16
The configuration and operation are the same as those of the first embodiment, except that when the part B is moved to the separation position between the cleaning roller 16 and the cleaning web 17, the cleaning roller 16 is separated and then stopped.

The same effect as that of the first embodiment can be confirmed in the image forming apparatus thus configured.

The way of moving the cleaning roller 16 is not limited to the linear movement in the present embodiment, but may be, for example, as shown in FIG. 5, a direction along the peripheral surface of the heating roller 12a. May be moved in an arc shape.

[0032]

As described above, in the cleaning device for a fixing device according to the present invention, the cleaning roller and the cleaning web are brought into contact with the fixing rotary member, and the rotation of the fixing rotary member is more advanced than the cleaning roller. The cleaning web can be abutted on the downstream side in the direction to clean even a relatively large amount of molten toner and paper powder even if they adhere to the fixing rotating body. It has a good cleaning ability and can prevent the occurrence of an offset phenomenon in the color image forming apparatus.

In the cleaning device for a fixing device according to the present invention, the cleaning web is brought into contact with the cleaning roller, and the cleaning web is used to remove the molten toner from the cleaning roller. It is not necessary to provide a dedicated member for performing the operation, and there are effects such as simplification of the configuration, miniaturization, and cost reduction.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a fixing unit and a cleaning device in FIG.

FIG. 3 is an operation explanatory view (part 1) of the fixing unit and the cleaning device of FIG. 2;

FIG. 4 is an enlarged view of a cleaning device and a peripheral portion according to the second embodiment.

FIG. 5 is an enlarged view of a cleaning device and a peripheral portion according to a modification of the second embodiment.

[Explanation of symbols]

12a: heating roller, 16: cleaning roller, 1
7: Cleaning web.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Naoto Yoshino 2274 Hongo, Ebina City, Kanagawa Prefecture, within Fuji Xerox Co., Ltd. (72) Inventor Makoto Ochiai 2274 Hongo, Ebina City, Kanagawa Prefecture, within Fuji Xerox Co., Ltd.

Claims (3)

[Claims] A cleaning roller rotatably disposed in contact with the rotatable member for fixing of the fixing device; and a cleaning web rotatably disposed in contact with the rotatable member for fixing and the cleaning roller. Wherein the cleaning web is in contact with the cleaning roller at a position downstream of the cleaning roller in the rotation direction of the fixing rotator. 2. The cleaning device for a fixing device according to claim 1, wherein the surface of the fixing rotator in contact with the toner image on the transfer material is cleaned by a cleaning roller, and further, dirt is collected from the cleaning roller by a cleaning web. In the apparatus, a rear edge of the cleaning portion of the cleaning roller, and
2. The cleaning device for a fixing device according to claim 1, wherein the cleaning roller and the cleaning web are stopped after a rear edge of the recovery portion of the cleaning web passes through a contact position between the cleaning roller and the cleaning web. . 3. The cleaning device for a fixing device according to claim 1, wherein the surface of the fixing rotating body that is in contact with the toner image on the transfer material is cleaned by a cleaning roller, and further, dirt is collected from the cleaning roller by a cleaning web. 2. The apparatus according to claim 1, wherein the cleaning roller is separated from the cleaning web after a rear edge of the cleaning portion of the cleaning roller contacts the cleaning web.
A cleaning device for the fixing device as described in the above.