JPH04301873A - Fixing device - Google Patents

Abstract

PURPOSE:To provide a fixing device having a cleaning device sufficiently displaying a cleaning ability and removing only offset toner without shaving the surface of a roller. CONSTITUTION:In a device having a pair of the rotary bodies of a fixing rotary body and a pressurizing rotary body press-contacted to the fixing rotary body and rotated, a heating means, at least, on one rotary body, and a belt-like cleaning member, at least, coming into contact with the periphery of the fixing rotary body and cleaning it, and fixing an unfixed image in such a manner that a transfer material having the unfixed image passes a press-contact part formed by a pair of the rotary bodies, the cleaning member alternately, has a region 1 whose surface has the vapor deposition of an abrasive grain and a region 2 whose surface does not have it, in the advancing direction of the transfer material, at a prescribed interval, and two kinds of the regions have a quadrature component in the travelling direction, to be extended and formed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device, and more particularly to a fixing device that fixes the unfixed toner image by passing a transfer material having an unfixed toner image between a fixing roller and a pressure roller that are in pressure contact with each other. .

0002

[Prior Art] Conventionally, when a dry powder developer is used as a fixing device in an image forming apparatus such as an electrostatic recording device, an unfixed developed image is placed between a fixing roller and a pressure roller. BACKGROUND ART Heat roller fixing devices are widely used that pass a transferred transfer material and fix it as a permanent image.

FIG. 5 shows a schematic diagram of such a conventional fixing device, which includes a rotatable fixing roller 1, a pressure roller 2 that rotates while being in pressure contact with the fixing roller 1, and the fixing roller 1. It has a configuration including a release agent applicator 3 that can come into contact with and separate from the surface and supplies a release agent, and a cleaning device 4 that cleans toner and paper dust adhering to the surfaces of the fixing roller 1 and pressure roller 2. ing.

The fixing roller 1 has a metal core coated with silicone rubber, fluororubber, etc. to a predetermined thickness. The pressure roller 2 has silicone rubber on the surface of a metal core, and a fluororesin coating is applied to the surface. A heater such as a halogen lamp is provided inside the fixing roller 1 or inside the fixing roller 1 and the pressure roller 2 as heating means. Further, a thermistor 5 is placed in contact with the pressure roller 2, and the temperature of the surface of the roller is adjusted by controlling the voltage applied to the heater via a temperature adjustment circuit.

[0005] The rollers 1 and 2 are the main body of the device (not shown).
It is rotatably supported in the direction of the arrow. The release agent coating device 3 includes a release agent tank 3a containing silicone oil as a release agent, a pumping roller 3b that pumps up the release agent from the release agent tank 3a, and a release agent coating device 3 that applies the release agent to the fixing roller 1. It is composed of a coating roller 3c for controlling the coating amount of the mold release agent, and a blade 3d for controlling the coating amount of the mold release agent. The coating roller 3c is rotatable and has a sponge rubber surface coated with silicone rubber, and is movable toward and away from the fixing roller 1 to apply a release agent. The amount of release agent applied is adjusted by the blade 3d, and a constant amount of release agent is applied from the leading edge to the trailing edge of the transfer material.

In this state, when the transfer material is conveyed to the fixing device, the fixing roller 1 and the pressure roller 2 rotate at a constant speed, and when the transfer material passes between the rollers 1 and 2, both the front and back sides are The unfixed toner carried on the surface is melted and fixed by applying pressure and heating at a substantially constant pressure and temperature. At this time, the toner forming the unfixed image on the transfer material is slightly transferred to the surface of the fixing roller 1 or the pressure roller 2 rotating in pressure contact with the fixing roller 1, that is, offset. Since the toner offset to the fixing roller 1 deteriorates the quality of the image, a cleaning device 4 for cleaning the surfaces of the fixing roller 1 and the pressure roller 2 is provided.

[0007] Conventionally, such a cleaning device has been designed to perform cleaning by bringing a web made of a fibrous material (such as Nomex (trade name)) into contact with the device. In particular, in a heat roller fixing type fixing device, the fixing roller 1 is
When the surface of the fixing roller 1 becomes rough and the releasability decreases, the adhesion between the surface of the fixing roller 1 and the toner increases, and the toner adheres to the surface of the fixing roller 1. Therefore, the web may not be able to completely remove the toner on the fixing roller 1 from the roller. Therefore, a cleaning device is used that uses a fibrous cleaning member on which abrasive particles are entirely deposited on the surface of a web such as Nomex (trade name). When such a cleaning member is used, the abrasive particles deposited on the fibers scrape off the developer offset on the roller surface, further increasing the cleaning ability.

The cleaning device 4 in FIG.
A nickel web 4a is pressed on the side and a Nomex felt 4b is pressed on the pressure roller 2 side. The nickel web 4a is made by plating a heat-resistant nonwoven fabric Nomex (trade name) with nickel by electroless plating, and the surface of the fibers is coated with nickel to a thickness of about several μm. As a result, the toner offset on the surface of the fixing roller 1 is scraped off and cleaned.

[0009]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional cleaning device, in order to improve the cleaning ability,
Because abrasive particles such as nickel were deposited on the entire surface of the web of the fibrous material, when the web came into contact with the roller, it not only scraped off the offset toner, but also scraped the roller surface itself, causing the roller to become damaged. There was a tendency for the durability to decrease.

SUMMARY OF THE INVENTION An object of the present invention is to solve this problem and provide a fixing device equipped with a cleaning device that can remove only the offset toner without scraping the roller surface by fully demonstrating the cleaning ability of the cleaning device. shall be.

[0011]

[Means for Solving the Problems] According to the present invention, the above object includes a pair of rotating bodies, a fixing rotating body and a pressing rotating body that rotates in pressure contact with the fixing rotating body, and at least one of the rotating bodies is heated. a belt-shaped cleaning member that comes into contact with at least the circumferential surface of the fixing rotary body to clean the rotary body; the transfer material having an unfixed image is passed through a pressure contact portion formed by the pair of rotary bodies; In the apparatus for fixing the unfixed image by applying abrasive particles to the surface of the cleaning member, the cleaning member has areas on the surface of which abrasive particles are deposited and areas where the abrasive particles are not deposited, alternating at predetermined intervals in the direction of movement of the transfer material; This is achieved by forming the two types of regions so as to extend with a component perpendicular to the direction of movement.

0012

[Operation] According to the fixing device of the present invention, while a certain number of appropriately set transfer materials are being fixed, the cleaning member is
For example, the area where abrasive particles are not deposited is in sliding contact with the fixing rotating body to clean it, and for the next certain number of sheets, the cleaning member is shifted by a predetermined interval and the area where abrasive particles are deposited is cleaned. I do. Cleaning is performed by repeating this cycle. The number of sheets is determined as appropriate depending on the fixing conditions.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to FIGS. 1 to 4 of the accompanying drawings.

The fixing device of the present invention can be used as is except for the cleaning web as a cleaning member shown in FIG. 5, so the cleaning web, which is a feature of the present invention, will be explained here.

In the first embodiment shown in FIG. 1, a cleaning web 4a made of non-woven fabric or the like is provided with alternating regions (2) plated with abrasive particles such as nickel and unplated regions (2). Both areas are alternately formed with a width of 15 mm in the direction of movement of the transfer material and extend in a direction perpendicular to the direction of movement.

In the fixing device having the cleaning member of this embodiment, for example, in FIG. 5, if the abrasive particle plating area is initially in contact with the fixing roller surface, the roller surface is is vigorously cleaned. When a certain number of sheets have been fixed, the web is wound up by a length corresponding to the width of the area, and then the area where the abrasive particles are not plated comes into contact with the roller. Due to the absence of abrasive particles in this area, cleaning is lighter than in the previous area. In this case, the cleaning ability is inferior to the case where the abrasive particle plated parts are in contact with each other, but there is no effect when the number of sheets is about several hundred. Eventually, after a certain number of sheets have been fixed and the abrasive particle plating section is sent, the roller surface is thoroughly cleaned again.

In this example, nickel was used as the abrasive particles and plated at intervals of 15 mm, and each time 10 sheets were fixed, a 0.5 mm web was wound up to conduct a roller durability test. That is, every time 300 sheets are fixed, the plated area and the non-plated area alternately come into contact with the roller surface, and cleaning is performed.

As a result, compared to the conventional type in which the entire surface was plated, in this example, the cleaning ability remained almost the same, and the life of the roller could be extended by approximately 1.5 times.

Further, in the cleaning web of this embodiment, the number of sheets fixed in each of the plated area and the non-plated area can be changed from those described above.

For example, the feeding of the cleaning web is determined so that the number of fixed sheets is 450 sheets in the plated area and 150 sheets in the non-plated area as shown in FIG. 2, or 600 sheets are fixed in the plated area and 150 sheets in the non-plated area as shown in FIG. 20 in plating area
It was confirmed that even if the number of sheets is reduced to 0, the cleaning ability is better and the life of the roller is improved compared to the conventional one.

Next, FIG. 4 shows a cleaning web as a second embodiment of the present invention. This embodiment differs from the previous embodiment shown in FIG. 1 in that the width of the plated area (2) is 20 mm, and the width of the non-plated area (2) is 10 mm. In this way, by appropriately changing the widths of both areas and setting the number of sheets to be fixed in each area, cleaning can be performed in accordance with the fixing conditions.

[0022]

According to the present invention, in a cleaning device for a fixing device, when cleaning is performed by bringing a band-shaped cleaning member plated with abrasive particles such as nickel onto the roller surface, the abrasive particles are removed from the cleaning member. By plating at regular intervals in a direction perpendicular to the paper traveling direction, compared to the conventional case where the entire surface is plated, the amount of abrasion on the roller surface is reduced and the life of the roller is improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a cleaning member according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of feeding of the cleaning member in FIG. 1;

FIG. 3 is a diagram showing another example of feeding of the cleaning member in FIG. 1;

FIG. 4 is a plan view of a cleaning member according to a second embodiment.

FIG. 5 is a schematic configuration diagram of a conventional fixing device.

[Explanation of symbols]

4a Cleaning member (cleaning web) ■ Abrasive particle deposition area ■ Abrasive particle non-deposition area

Claims (1)

[Claims] 1. A fixing rotor and a pressurizing rotor that rotates in pressure contact with the fixing rotor, and at least one of the rotors is provided with a heating means and is in contact with at least the circumferential surface of the fixing rotor. In the apparatus for fixing an unfixed image by passing a transfer material having an unfixed image through a pressure contact portion formed by the pair of rotating bodies, The cleaning member has regions on its surface where abrasive particles are deposited and regions where abrasive particles are not deposited, alternately at a predetermined interval in the direction of movement of the transfer material, and the two types of regions have a component perpendicular to the direction of movement. A fixing device, characterized in that the fixing device is formed so as to extend with.