JPH0455879A - Fusing device - Google Patents

Abstract

PURPOSE:To prevent the surface of a fixing roller from being damaged because impurity gathers and adheres to the leading edge of an oil applying member by forming the leading edge of the oil applying member in a triangular shape or a circular arc shape which projects to the upstream side in the rotating direction of a fixing roller. CONSTITUTION:The leading edge of the oil applying member 10 positioned on the uppermost stream side in the rotating direction of the fixing roller 1 is formed in the triangular shape or the circular arc shape which projects to the upstream side in the rotating direction. Toner or the impurity such as paper powder adhering to the surface of the roller 1 is intercepted and gathered at the leading edge of the member 10 and silicone oil dropped on the surface of the roller 1 is also gathered there at the same time. However, the impurity is moved with the silicone oil to the side edge of the member 10 along the leading edge by making the shape of the leading edge inclined. Thus, the surface of the fixing roller 1 is prevented from being damaged by the gathered impurity.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a fixing roller and a pressure roller that are in pressure contact with each other, an oil application member impregnated with offset prevention oil, and a The present invention relates to a fixing device including means for supplying an anti-offset liquid to the surface of the fixing roller upstream of the oil application member.

[Background Art] In image forming apparatuses such as copying machines, facsimiles, and printers, a transfer sheet carrying a toner image is passed between a fixing roller and a pressure roller that are pressed against each other to fix the toner image.

In that case, it is unavoidable that the toner of the toner image is offset to the fixing roller, and in order to prevent this offset, it is not possible to bring an oil application member impregnated with offset prevention oil into contact with the fixing roller using a leaf spring. It is well known.

[Problems to be Solved by the Invention] In the fixing device of the image forming apparatus described above, since the oil application member is in direct contact with the fixing roller, impurities such as offset toner and paper dust from the transfer paper may be absorbed by the rotation of the fixing roller. The oil application portion, which is located upstream in the direction of the fixation, is dammed up by the tip edge of the oil application portion and tends to accumulate there, and the surface of the fixing roller may be damaged due to the accumulated impurities.

The present invention aims to eliminate this inconvenience.

[Means for Solving the Problems] According to the present invention, the tip edge of the oil application portion located furthest upstream in the rotational direction of the fixing roller is triangular and protrudes toward the upstream side in the rotational direction. This is solved by forming a shape or an arc shape.

[Function] Impurities such as toner and paper powder adhering to the surface of the fixing roller are dammed and accumulated at the leading edge of the oil application member located most upstream in the rotational direction of the fixing roller, but at the same time, impurities such as toner and paper dust adhering to the surface of the fixing roller are dammed up and accumulated. Any silicone oil that has been dripped on it will also collect here.

By inclining the shape of the tip edge according to the present invention,
The impurities move along the tip edge toward the side edge of the oil application member along with the silicone oil.

[Embodiment] In FIG. 1, a fixing roller 1 and a pressure roller 2 are arranged so as to be in pressure contact with each other and rotate in the direction of the arrow. 3 is a heater. A transfer paper 5 carrying a toner image 4 is passed between a fixing roller 1 and a pressure roller 2 via a guide plate 6, and after the toner image is fixed there, it is transferred to a tray outside the machine via a pair of discharge rollers 7. is discharged to. 8 is a separating claw, and 9 is an oil application device constructed according to the present invention.

In the oil applicator 9, one end of an oil applicator 10 made of felt material is folded and comes into contact with the fixing roller 1, and the other end is immersed in offset prevention oil 12, such as silicone oil, placed in an oil sump 11. ing. The contact portion of the oil application member 10 with the fixing roller 1 is as follows:
It is pressed against the fixing roller 1 by a leaf spring 13. In this case, the contact portion is pressed more strongly than the release spring 13 at two locations: the first load position 11 px at the tip of the oil application part 10 and the second load position P2 located downstream in the rotational direction of the fixing roller 1. has been done. 14 is a support plate of the leaf spring 13, and 15 is a second cleaning member.

An oil tank 16 is disposed below the oil sump 11, and an oil nozzle 17 is further disposed above the fixing roller 1. The silicone oil 12 in the oil tank 16 is supplied by a pump 18 through a conduit 19 to an oil nozzle 17, and an appropriate amount is dripped from this oil nozzle. The silicone oil from the oil nozzle 17 is applied to the oil application member 10 located most upstream in the rotational direction of the fixing roller.
It falls onto the surface of the fixing roller further upstream from the leading edge of the fixing roller.

In FIG. 2, the leading edge 2 of the oil application member 1o, that is, the leading edge 2 located most upstream in the rotational direction of the fixing roller.
0 has a protruding triangular shape pointing upstream in the rotation direction. Instead of this triangular shape, it is also possible to have a circular arc shape and similarly project the upstream direction.

The impurities dammed up and attached to the tip #2o of the oil application member 10 are released from the oil application member by the silicone oil that drips from the oil nozzle 17 and reaches the tip edge, and then the impurity is formed in an inclined manner according to the present invention. The oil flows along the tip edge toward both side edges of the oil application member.

At this time, the silicone oil permeates into the oil application member 10, thereby ensuring that the oil application member applies the silicone oil to the surface of the fixing roller in a uniform manner.

[Effects of the Invention] According to the present invention, impurities accumulated on the tip edge of the oil application member are always moved to the side, so damage to the surface of the fixing roller due to impurities accumulating and adhering to the tip edge is prevented. The configuration for this is simple.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a fixing device to which the present invention is applied, and FIG. 2 is a perspective view of essential parts of the present invention. 1... Fixing roller 2... Pressure roller 10... Oil application member 11... Oil tank 12... Silicone oil Fig. figure

Claims (1)

[Claims] A fixing roller and a pressure roller that are in pressure contact with each other, an oil coating member impregnated with anti-offset oil, and an anti-offset liquid being supplied to the surface of the fixing roller upstream of the oil coating member when viewed in the rotational direction of the fixing roller. The fixing device is characterized in that the tip edge of the oil application member located furthest upstream in the rotational direction of the fixing roller has a triangular or arcuate shape protruding upstream in the rotational direction. fixing device.