JP3653382B2 - Fixing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device having a fixing roller composed of a pair of rollers.
[0002]
[Prior art]
Conventionally, as this type of fixing device, the one shown in FIG. 5 is well known, and this is a fixing device comprising a fixing roller 1 and a pressure roller 2 for fixing a toner image formed on the transfer paper to the transfer paper. For preventing offset while rotating by being pressed against at least one roller (fixing roller 1 in this example) of the fixing roller by the leaf spring 6 on the machine frame 3 and the fixing roller 1 in contact with the surface of the fixing roller 1 An oil application roller 4 for applying the oil, a cleaning member 5 ′ for cleaning the surface of the oil application roller 4 by being pressed against the machine frame 3 by a leaf spring 8, and a fixing roller 1. Heat source 7.
[0003]
As shown in FIG. 6, the oil application roller 4 is composed of, for example, a foaming sponge or an elastic material such as heat-resistant paper on the outer periphery of the core metal 9, and an oil retaining layer 10 impregnated with oil, and further the outer periphery thereof. A large number of micropores are provided on the surface, and a control layer 11 made of, for example, a porous fluorine tube for controlling the amount of oil oozing is provided. Further, the cleaning member 5 'is as shown in FIG. 7, and is constituted by, for example, a heat-resistant fiber brush or a rubber blade, and the height thereof is uniform.
[0004]
In such a case, an unfixed toner image normally formed on the transfer paper is heated and pressed by the fixing rollers 1 and 2 and fixed on the transfer paper. At this time, a release layer made of fluororesin or the like is provided on the surface of the normal fixing rollers 1 and 2 to prevent foreign matter such as toner and paper dust from adhering. Depending on various conditions such as the temperature of 1 and the type of transfer paper, it is difficult to completely fix the foreign matter on the transfer paper, and some toner and paper powder adhere to the surfaces of the fixing rollers 1 and 2. . In this case, when the release performance of the oil application roller 4 is inferior to that of the fixing roller 1, the foreign matter is removed from the surfaces of the fixing rollers 1 and 2, and the oil application roller 4 is exposed to the surface of the oil application roller 4. The foreign matter is transferred and adhered, and the foreign matter is cleaned by the cleaning member 5 '.
[0005]
[Problems to be solved by the invention]
By the way, if the foreign matter that has been removed from the surfaces of the fixing rollers 1 and 2 as described above and transferred to the oil application roller 4 and remains attached without being completely cleaned by the cleaning member 5 ′ as a result of use over time, this foreign matter is left. As a result, oil seepage from the oil application roller 4 is hindered, and in the state where the surface of the oil application roller 4 immediately after the power is turned on is not sufficiently warmed, these foreign matters do not adhere with sufficient adhesiveness. , Easy to fly. Further, since the toner is easily charged due to its property, when static electricity is generated by sliding between the oil application roller 4 and the cleaning member 5 ', the cleaning member 5' and the toner are electrically repelled and easily scattered. Become. Further, when the cleaning member 5 'is constituted by a brush having a uniform height as shown in FIG. 7, the oil application roller 4 is bitten into the central portion of the brush in order to secure the pressurizing force necessary for cleaning. As shown in FIG. 8, the end 12 is once caught and then rebounds by its own reaction force, so that the foreign matter 13 between the brushes is easily scattered. There is a problem that the foreign matter scattered due to such a phenomenon is re-transferred to the surfaces of the fixing rollers 1 and 2 and transferred onto the transfer paper to appear as black spot stains, thereby generating an abnormal image.
[0006]
Accordingly, the object of the present invention is to solve the problems of the conventional fixing device as described above, and the foreign matter transferred from the fixing roller and adhering to the oil application roller does not scatter from the oil application roller. It is an object of the present invention to provide a fixing device which does not re-transfer to the surface of the roller for transfer, but is transferred to the transfer paper and appears as black spot stains, and does not generate an abnormal image.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a fixing roller comprising a fixing roller and a pressure roller for fixing a toner image formed on the transfer paper onto the transfer paper, and at least one of the fixing rollers. In a fixing device having an oil application roller that contacts the surface of the roller and applies oil for preventing offset while rotating, and a cleaning member that cleans the surface of the oil application roller, the cleaning member is formed of a conductive brush And the tip of the conductive brush approximates the outer shape of the oil application roller, and at least one of the ends along the direction intersecting the longitudinal direction of the oil application roller of the conductive brush, This is characterized in that a minute gap is provided between the surface of the oil application roller and the oil application roller so as not to come into contact therewith.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In each embodiment shown in the drawings, in the conventional example and each other, the same members are denoted by the same reference numerals, description thereof is omitted, and different portions are mainly described.
[0011]
In the first embodiment of the present invention shown in FIG. 1, the cleaning member 5 is made of a conductive material made of metal fiber such as stainless steel or carbon fiber, and grounded by a ground wire 14. In such a case, the unfixed toner image formed on the transfer paper is fixed by the fixing rollers 1 and 2 as in the conventional fixing device, while the foreign matter is removed from the surfaces of the fixing rollers 1 and 2. , Transferred and adhered to the surface of the oil application roller 4, and this foreign material is cleaned by the cleaning member 5.
[0012]
At this time, the sliding between the oil application roller 4 and the cleaning member 5 generates static electricity and charges the toner, and the cleaning member 5 and the toner are electrically repelled and easily scattered. Since the ground wire 14 is grounded, the static electricity generated in the oil application roller 4 is released and the toner is prevented from being charged and scattered. As a result, the toner does not re-transfer to the surface of the fixing roller, and is transferred onto the transfer paper and appears as black spot stains, so that no abnormal image is generated.
[0013]
In the second embodiment of the present invention shown in FIG. 2, the cleaning member 5 is composed of a conductive brush, the tip of the conductive brush is approximated to the outer shape of the oil application roller 4, and the tip of the central portion 16 is It is short and has an arcuate shape that becomes longer gradually toward the ends of the ends 17.
[0014]
In such a case, the unfixed toner image formed on the transfer paper as in the first embodiment is fixed by the fixing rollers 1 and 2 while the foreign matter removed from the surfaces of the fixing rollers 1 and 2. Is transferred and adhered to the surface of the oil application roller 4, and the foreign material is cleaned by the cleaning member 5. At this time, the tip shape of the conductive brush is similar to the outer shape of the oil application roller 4, and the bristles at both ends become longer, the reaction force becomes smaller, and it is difficult to recoil. As described above, it is possible to prevent the foreign matter between the brushes from scattering after the both end portions 17 are once wound. As a result, the toner does not re-transfer to the surface of the fixing roller, and is transferred onto the transfer paper and appears as black spot stains, so that no abnormal image is generated.
[0015]
In the third embodiment of the present invention shown in FIG. 4, the outer shape of the oil application roller 4 and a conductive brush similar to the outer shape of the oil application roller 4 are connected to the surface of the oil application roller 4 and the bristles at both ends 17 'of the conductive brush. As shown in FIG. 4, the tip is not contacted by providing a minute gap of about 0.5 to 1 mm between the two.
[0016]
In such a case, the non-fixed toner image formed on the transfer paper is fixed by the fixing rollers 1 and 2 in the same manner as in the second embodiment, while the foreign matter removed from the surfaces of the fixing rollers 1 and 2. Is transferred and adhered to the surface of the oil application roller 4, and the foreign material is cleaned by the cleaning member 5. At this time, the cleaning is performed by the central portion 16 of the conductive brush. Since the ends of the conductive brush and the oil application roller 4 are not in contact with each other at both ends 17 ', the cleaning is not performed. As a result, in the central portion 16, there is a recoil due to the reaction force of the conductive brush and scattering of the foreign matter occurs. However, the foreign matter is prevented from scattering to the outside by the conductive brushes at both end portions 17 ′. In this embodiment, both end portions 17 'are used, but the present invention is not limited to this, and may be one end portion.
[0017]
【The invention's effect】
The present invention is as described above, and is in contact with a fixing roller comprising a fixing roller and a pressure roller for fixing a toner image formed on the transfer paper to the transfer paper, and a surface of at least one of the fixing rollers. Then, in a fixing device having an oil application roller that applies oil for preventing offset while rotating and a cleaning member that cleans the surface of the oil application roller, the cleaning member is formed of a conductive brush, The brush tip shape approximates the outer shape of the oil application roller, and at least one end of the conductive brush along the direction intersecting the longitudinal direction of the oil application roller, and the surface of the oil application roller minutely because so as not to contact provided gap, cleaning is performed by the central portion of the conductive brush, both end portions in the conductive brush between the And hair, not performed cleaning by the oil applying roller, although this result recoil scattering of foreign matter was due to the reaction force of the conductive brush in the central portion is generated, the foreign matter outside the one end of the conductive brush This has the effect of preventing splashing.
[Brief description of the drawings]
FIG. 1 is a front view of an essential part of a first embodiment of the present invention.
FIG. 2 is a front view of a cleaning member according to a second embodiment of the present invention.
FIG. 3 is an operation explanatory view of the above.
FIG. 4 is an operation explanatory view of a cleaning member according to a third embodiment of the present invention.
FIG. 5 is a front view similar to FIG. 1 of a conventional fixing device of the same type as the present invention.
FIG. 6 is a longitudinal sectional front view of the oil application roller of the above.
FIG. 7 is a front view of the cleaning member.
FIG. 8 is an operation explanatory view of the above.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Pressure roller 3 Machine frame 4 Oil application roller 5 Cleaning member 6 Leaf spring 7 Heat source 8 Leaf spring 9 Core metal 10 Oil retaining layer
11 Control layer 12 Edge
13 Foreign object 14 Ground wire
16 Center part 17, 17 ′ Both ends

Claims (1)

A fixing roller composed of a fixing roller and a pressure roller for fixing the toner image formed on the transfer paper to the transfer paper, and at least one of the rollers of the fixing roller is in contact with the surface of the fixing roller to prevent offset while rotating. In a fixing device having an oil application roller for applying oil and a cleaning member for cleaning the surface of the oil application roller, the cleaning member is constituted by a conductive brush, and the hair tip shape of the conductive brush is defined by the oil application roller. Approximate to the outer shape, and a contact is made by providing a minute gap between the tip of at least one end of the conductive brush along the direction intersecting with the longitudinal direction of the oil application roller and the surface of the oil application roller. A fixing device characterized in that it is not allowed to occur .

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