JPS58215675A - Heat roll fixation device - Google Patents

Abstract

PURPOSE:To obtain a fixation device which eliminates the need to replace part at every time of maintenance by providing a brushy cleaning roll for cleaning the surface of a fixation roll and a mold release agent impregnated member which contacts the brush to supply a mold release agent. CONSTITUTION:The cleaning roll 5 which rotates by power from a separately provided power source is provided and brushy fiber 5a is implanted in the circumferential surface of this roll 5. Further, the feltlike member 6 impregnated with the mold release agent such as silicone oil is fitted to a supporting member 7 as the receiving dish of the impregnated member 6. Consequently, a maintenance cycle is prolonged and picture quality is prevented from being degraded owing to the movement of toner from transfer paper to the fixation roll.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a thermoplastic toner fixing device used in electronic copying machines and the like, which fixes thermoplastic toner on a support by contact heating it. It is.

For example, in the image forming process using an electronic copying machine, an electrostatic latent image corresponding to the original image is formed on a charge holding body using an insulating photoconductor as a photoconductor by corona charging and light irradiation, and this is transferred to a thermoplastic A visible image is formed by developing with a developer containing colored fine powder as a main component.

The visible image, that is, the toner image on the charge carrier is transferred onto a support such as transfer paper by electrical means such as corona discharge or physical means such as pressing.

The toner image transferred onto the transfer paper by the above method is fixed onto the transfer paper by a conventional heating means, and the image forming process is completed. Here, there is a heat roller fixing device as a fixing device that fixes a toner image on a transfer paper using a heating means.

A heated roller fixing device applies pressure between two rollers, one of which is heated, and performs fixing by inserting and passing a support carrying an unfixed toner image between the rollers.
In this type of fixing device, the fixing roller (hereinafter referred to as the 10th roller) on the side that comes into contact with the toner image on the support is made of a metal with good thermal conductivity, such as brass or aluminum, and has a tubular shape.
The surface is coated with a heat-resistant release material, such as tetrafluoroethylene, and a heat source is provided inside. It is known that the other pressure roller (hereinafter referred to as the 20th roller) is made of elastic rubber, such as silicone rubber.

In such a heat roller fixing device, a support carrying thermoplastic toner is passed between the 20th roller that is in pressure contact with the 10th roller at a set temperature, and the toner is melted and supported by the 10th roller. The toner undergoes a so-called fixing process in which it is fixed on the support, and the toner is fixed on the support by 1.1100%.
It is difficult to maintain a completely clean state on the 0-ra surface.
Some amount of toner residue and dirt on the support will adhere to the surface of the 10th layer. If the surface of the 10th roller gets dirty, the quality of the image after fixing will deteriorate. Toner residues and substrate stains adhering to the 10-layer are removed.

When removing toner residues adhering to the circumferential surface of the 10th roller using the brush-like cleaning roller, the removed toner residues gradually adhere to the cleaning roller. As the cleaning roller becomes dirty, the cleaning effect of the cleaning roller gradually decreases. In order to prevent this, it has become common practice to treat the brush-like fibers of the cleaning roller with a release agent. This treatment improved the durability of the cleaning roller. However, even under such conditions, when the release agent is consumed, the cleaning roller eventually becomes dirty with toner, and it is necessary to replace it at every maintenance.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a heat roller fixing device that does not require parts replacement for each maintenance. This is achieved by a heat roller fixing device characterized in that it is provided with a shaped cleaning roller and a release agent impregnated member that is brought into contact with the brush of the cleaning roller to supply a release agent.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a sectional view showing an outline of a heat roller fixing device according to the present invention. In the figure, reference numeral 1 indicates a cylindrical 10th roller, inside of which a heat source 1a such as an infrared lamp is provided, and rotates clockwise during fixing. Reference numeral 2 denotes a cylindrical 20th roller, which presses against the first TFF roller during fixing and rotates counterclockwise. The transfer paper P, which is conveyed from the right side by the conveyor belt 3 and has the unfixed toner T attached as a toner image, is pressed and pressed by the 10th roller 1 and the 20th roller 2.
It is heated, fixed, and ejected to the left. Separation claws 4a and 4b are used to separate the transfer paper P to prevent it from being wrapped around the 10th roller 1 or the 20th roller 2 and causing poor conveyance.

The present invention newly adds the following structure to the heat roller fixing device described above. Reference numeral 5 denotes a cleaning roller which is separately provided and rotated by power, and 5a denotes brush-like fibers planted on the circumferential surface of the cleaning roller 5. Reference numeral 6 denotes a release agent-impregnated member impregnated with a felt-like mold release agent, and 7 is a holding member corresponding to a receiving tray for the release agent-impregnated member 6.

One of the functions of the release agent used here is to prevent soiling substances such as toner residue removed from the fixing roller from adhering to and accumulating on the cleaning roller, thereby extending the life of the cleaning roller. Another problem is to prevent offset development, that is, toner on the transfer paper from transferring to the fixing roller and deteriorating the image quality.

As the mold release agent used here, for example, silicone oil is suitable, and the felt or sponge-like mold release material-impregnated member 6 is sufficiently impregnated with silicone oil having a high viscosity in the range of 1000 to 50000 CS.

As the brush-like fibers 5a of the cleaning roller 5, heat-resistant polyimide amide fibers or the like are used.
It is in contact with the 0-ra 1 with a biting amount of about one fin, and is also in a similar contact state with the release material impregnated member 6. In such a structure, the cleaning roller 5 has an oil supply control function as an oil supply roller to the 10th roller 1. That is, since the fiber density at the center of the cleaning roller 5 is higher than that at the outer periphery, when the cleaning roller 5 is in a stopped state, the silicone oil impregnated in the release material impregnated member 6 passes through the brush-like fibers 5m by capillary action and reaches the center of the cleaning roller 5. accumulated in the
Wait in a state where no leakage occurs to the outer periphery.

When copying is started, each roller group starts rotating, and the cleaning roller 5 also rotates.

As the cleaning roller 5 rotates, the silicone oil that was in the center of the cleaning roller 5 gradually oozes out to the outer periphery due to centrifugal force and moves to the tenth roller 1. Therefore, excess silicone oil does not transfer to the 10th-ra 1 all at once, and the release material is stably and uniformly applied on the 10th-21st circumferential surface.

According to the present invention, the cleaning roller 5
In addition to the brushing effect of removing the toner adhering to the 10th layer 1, the effect of uniformly applying the release agent onto the circumferential surface of the 10th layer 1 occurs, and the adhesion of toner on the 10th layer 1 is reduced. The amount of toner has decreased significantly, and even when toner adheres to the circumferential surface of the 10th layer, it can be removed very easily. In this way, the durability of the cleaning roller itself has become semi-permanent, and the reliability of the fixing device has also been greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention. 1... 10th-ra 2°°° 2nd I: I-ra 5
... Cleaning roller 5a ... Brush-like fiber 6 ... Release material impregnated member 7 ... Holding member agent
Meimi Kuwahara

Claims (1)

[Claims] A heat roller characterized in that the heat fixing roller is provided with a brush-shaped cleaning roller that cleans the surface of the roller, and a release agent impregnated member that is brought into contact with the brush of the cleaning roller and supplies a release agent. Fusing device.