JPH0438351B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat roller fixing device for an electrophotographic copying machine or the like, that is, a heat roller fixing device that fuses a toner image attached to a recording sheet.

[Prior art]

A heat roller fixing device uses a pair of rollers, at least one of which has an internal heat source, to press and feed a recording sheet with a toner image attached thereon, and uses heat from the heat source to fuse the toner image to the recording sheet. A recording sheet is passed through a heat roller with the surface on which a toner image is attached in contact with a heat roller that has a heat source inside. The surfaces of the pair of rollers have excellent mold releasability to prevent toner from adhering.
It is also common to have a surface layer made of polytetrafluoroethylene or the like, which has excellent heat resistance. However, even if such a surface layer is provided, the surface of the roller is easily soiled by toner adhesion. Therefore, the surface of the heat roller that is in contact with the toner image-attached surface of the recording sheet, which is particularly prone to toner adhesion, is equipped with a rubbing means for removing adhered toner and other stains, and toner adheres to the surface of the heat roller. In order to prevent this, a means for applying an offset prevention liquid such as silicone oil is provided. Providing a rubbing means and an anti-offset liquid application means on the surface of the heat roller,
Although toner stains on the roller are effectively prevented, the provision of a supply device and application device for silicone oil or the like around the roller makes the heat roller portion large and complicated, making the entire heat roller fixing device large.

Therefore, the present inventor first proposed a method in which a rubbing means consisting of a brush roller contacts an anti-offset liquid impregnated member and a heat roller to apply an anti-offset liquid to the surface of the heat roller and also wipe the surface of the heat roller. Invented a fixing device. This invention was filed in the patent application filed in 1983.
No. 710. According to this invention, since the offset prevention liquid-impregnated member does not come into direct contact with the roller, the surroundings of the roller can be simplified and the heat roller fixing device can be easily made compact. However, since the anti-offset liquid impregnated member and the rubbing means are separate, the effect of compactness is not so great. Another problem is that the rubbing means rubs the surface of the offset prevention liquid impregnated member, causing wear and tear.

[Purpose of the invention]

The present invention has been made for the purpose of improving the above-mentioned prior invention, and by incorporating the anti-offset liquid impregnated member into the rubbing means, the area around the roller can be simplified and made compact. The object of the present invention is to provide an improved heat roller fixing device in which the offset prevention liquid impregnated member itself is not worn out.

[Structure of the invention]

That is, in the present invention, a cylindrical body having a large number of small holes in its peripheral wall is sealed at both ends by shaft holding brackets made of an elastic material, and a compressible liquid absorbing member containing an anti-offset liquid is placed inside the cylinder body. is filled, and a one-sided pile fabric from which an anti-offset liquid can leach out is wrapped around the outer periphery of the cylindrical body, with the pile surface facing outward, and a rubbing roller configured to be rotated by a roller shaft held by the bracket is provided. A heat roller fixing device is characterized in that the heat roller is brought into contact with the toner image-attached surface of the recording sheet, and the moving direction at the contact portion is rotated in the opposite direction to the heat roller. Thus, the above objective has been achieved.

〔Example〕

The present invention will be explained below using illustrated examples.

FIG. 1 is a sectional view showing an example of the heat roller fixing device of the present invention, and FIG. 2 is an axial sectional view showing an example of a rubbing roller which also serves as offset prevention liquid application means.

In the figure, 1 is a heat roller with a heat source 1a such as an infrared lamp inside the metal roller core and a surface layer of polytetrafluoroethylene on the outer periphery, and 2 is a heat roller with a silicone rubber layer on the outer periphery of the metal roller core. A pressure roller having a surface layer of polytetrafluoroethylene on top rotates in the direction of the arrow, and the toner image T is attached to the recording sheet P.
The toner image is fused to the recording sheet P by being conveyed under pressure. 3 is a conveyor that sends the recording sheet P to the heat roller fixing device, and 4 and 5 are recording sheets P, respectively.
A separating guide prevents the recording sheet P from being wrapped around the heat roller 1 and the pressure roller 2 and guides the recording sheet P out of the heat roller fixing device. 6 is an anti-offset liquid applying means that contacts the heat roller 1 and rotates in the direction of the arrow. This is a rubbing roller that also serves as a rubbing roller.

The sliding roller 6 shown in the figure is held by passing a roller shaft 8 through the inner diameter of both ends of a metal cylinder 7, which has many holes of about 1 mm in diameter distributed in the peripheral wall, and holds the inside of the metal cylinder 7. A bracket 9 made of a sealing elastic material is fitted, and a compressible material such as felt made of wholly aromatic polyamide fiber containing an anti-offset liquid such as silicone oil is fitted inside the metal cylinder 7 between the brackets 9. Liquid absorbing member 1
0, and around the outer periphery of the metal cylinder 7, a rubbing member 11 made of a single-sided pile fabric made of, for example, fully aromatic polyamide fibers, from which the offset prevention liquid inside the metal cylinder 7 could leak, was wrapped with the pile on the outside. Consists of structure.

Therefore, the rubbing roller 6 rubs the surface of the heat roller 1 with the pile of the sliding member 11 on the surface to remove dirt such as toner adhering to the surface, and also removes dirt such as toner adhering to the surface. The anti-offset liquid contained in the metal cylinder 7 enters the pile of the rubbing member 11 through the hole in the metal cylinder 7 and applies the anti-offset liquid to the surface of the heat roller 1, so that the heat roller 1 is not contaminated by toner or the like. effectively prevent.

The rubbing roller 6 may use a sponge for the liquid absorbing member 10, or may use something like a resin cylinder instead of the metal cylinder 7. Since the bracket 9 is made of an elastic material such as rubber so that it can be compressed and deformed, the metal cylinder 7 becomes eccentric to some extent, so that a squeezing action is exerted on the liquid absorbing member 10 inside. Therefore, most of the offset prevention liquid contained in the liquid absorbing member 10 is effectively utilized.
In addition to improved efficiency, since the rubbing member 11 is made of pile fabric on one side, it is possible to obtain the effect that an appropriate amount of anti-offset liquid can always be stably supplied to one surface of the heat roller without clogging.

Further, the heat roller fixing device of the present invention is not limited to the example shown in FIG. It may be provided with a rubbing roller 6, or it may be provided with a heat source built into the pressure roller 2.

〔Effect of the invention〕

In the heat roller fixing device of the present invention, since the heat roller is provided with a rubbing roller made of a pile cloth on the surface which has an anti-offset liquid impregnated member inside and also serves as means for applying the anti-offset liquid, the heat roller is prevented from becoming dirty. is effectively prevented, the area around the rollers is not complicated, the fixing device can be made more compact, and the anti-offset liquid impregnated member does not suffer wear due to rubbing, and the rubbing member does not become clogged. It has an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the heat roller fixing device of the present invention, and FIG. 2 is an axial sectional view showing an example of a rubbing roller. 1... Heat roller, 1a... Heat source, 2... Pressure roller, 3... Conveyor, 4, 5... Separation guide,
6...Sliding roller, 7...Metal tube, 8...Roller shaft, 9...Bracket, 10...Liquid absorbing member, 11
...Rubbing member.

Claims (1)

[Claims] 1. A cylindrical body having a large number of small holes in its peripheral wall is sealed inside by shaft holding brackets made of an elastic material at both ends, and the inside is filled with a compressible liquid absorbing member containing an anti-offset liquid, A single-sided pile fabric from which an anti-offset liquid can be leached is wrapped around the outer periphery of the cylinder, with the pile surface facing outward, and a rubbing roller rotated by a roller shaft held by the bracket is used to protect the toner image on the recording sheet. 1. A heat roller fixing device, characterized in that the heat roller is brought into contact with the adhesion surface and the moving direction at the contact portion is rotated in a direction opposite to that of the heat roller.