JP2958833B2 - Release agent supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a releasing agent supply device used for a fixing device of an electrophotographic copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, as a fixing device, as shown in FIG. 3, a fixing roll 50 and a pressure roll 51 are pressed against each other, and an unfixed toner image 52 is placed between the two rolls 50, 51.
The unfixed toner image 5 on the copy paper 53 by heat and pressure
There are those that fix 2. At that time, the fixing roll 50
Since the surface thereof contacts the unfixed toner image 52, the toner may be offset to the fixing roll 50 during fixing. Therefore, a release agent such as silicone oil is applied to the surface of the fixing roll 50 by the release agent supply device 54 to prevent the toner from being offset on the surface of the fixing roll 50.

As shown in FIG. 3, the release agent supply device 54 includes an oil pan 56 containing oil 55, a felt 60 for sucking the oil 55 from the oil pan 56 and applying the oil 55 to a metering roll 57, Ring roll 57
Blade 58 for scraping oil 55 applied to the
And a donor roll 59 for supplying the measured oil 55 to the fixing roll 50.
The metalling roll 57 and the donor roll 59 are rotatably supported, and the metalling roll 57 is in contact with the donor roll 59, and the donor roll 59 is in contact with the fixing roll 50 with a predetermined pressing force. .

Now, when the fixing roll 50 rotates with the copying operation of the copying machine, the donor roll 5 pressing against the fixing roll 50 is pressed.
9, and the metering roll 57 rotates in the direction of the arrow. After the oil 55 in the oil pan 56 is sucked up by the felt 60 and applied to the metering roll 57, the measuring blade 58 is attached to the surface of the metering roll 57.
As a result, an oil film having a predetermined thickness is formed. The oil film formed on the surface of the metalling roll 57 to a predetermined thickness is brought into contact with the donor roll 59 so that the donor roll 59
Is transferred to the fixing roll 50 from the surface of the donor roll 59.

If the amount of the oil supplied to the surface of the fixing roll 50 is too small, the offset of the toner occurs. If the amount is too large, the oil adheres to the copy paper 53 and bleeds the oil. Therefore, the amount of the oil 55 supplied by the release agent supply device 54 needs to be an appropriate amount within a predetermined range. The fixing roll 5
If the amount of the oil 55 supplied to the fixing roller 50 is not uniform in the longitudinal direction of the fixing roller 50, an offset may occur in a part of the fixing roller 50, and therefore, the release agent supplying device 54
Is required to be uniform over the longitudinal direction of the fixing roll 50.

However, this case has the following problems. That is, in the case of the release agent supply device 54, the blade 5 is simply placed on the surface of the metering roll 57.
8, the amount of oil 55 applied to the surface of the metering roll 57 is made constant, so that the supply amount of oil varies due to the edge shape of the blade 58 and the like. There was a point. Especially,
When the metering roll 57 or the blade 58 is replaced, there is a problem that an appropriate amount of applied oil and a uniform amount of oil over the longitudinal direction cannot be obtained.

[0007] In order to solve this problem, the present applicant has already proposed a release agent supply apparatus as disclosed in Japanese Patent Application No. 1-314276.

This release agent supply device includes a plurality of rolls whose surfaces rotate in contact with each other, supplies a release agent to a first roll, and attaches a blade to the surface of the first roll. Regulate the amount of release agent to be supplied in contact with
In a release agent supply device configured to supply a release agent through a roll that contacts the first roll, a leading edge of the blade that contacts the roll is formed into an arc-shaped cross section. Curvature radius R is 0.05 ≦ R ≦ 0.3
mm so as to uniformly supply the release agent to the first roll.

[0009]

However, the above-mentioned prior art has the following problems. That is, in the case of the release agent supply device 54, the blade 58 that regulates the amount of the oil 55 applied to the first roll, the metalling roll 57, is improved, and the first roll, the metalling roll 57, is removed. Although the oil 55 can be uniformly supplied to the roll 57, the surface roughness of the metering roll 57 and the donor roll 59, which is the second roll, is not taken into consideration. There was a problem that the oil 55 could not be applied uniformly. In particular, when the surface roughness of the donor roll 59 as the second roll is close to the mirror surface, coating unevenness occurs in a wide range. Conversely, when the surface roughness of the donor roll 59 is too rough, There is a problem that polishing marks (traces) appear on the image after fixing.

[0010]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art.
The purpose of the release agent is to reliably supply a uniform release amount of the release agent along the axial direction of the roll to the fixing roll of the fixing device, and to obtain a good fixed image. To provide a supply device.

That is, the present invention comprises at least first and second rolls whose surfaces rotate in contact with each other,
In a release agent supply device for supplying a release agent to the first roll and supplying the release agent supplied to the first roll via a second roll, a surface roughness of the first roll is provided. Is set so that the 10-point average roughness Ra satisfies 0.5 ≦ Ra ≦ 5 μm, and the 10-point average roughness Ra is 0.2 ≦ Ra ≦ 3 μm. It is configured to be set so that

The first and second rolls include, for example, two rolls of a metalling roll and a donor roll. However, the present invention is not necessarily limited to this, and three or more rolls may be used. A combination may be used.

The above-mentioned donor roll is disposed, for example, in contact with the surface of the fixing roll. However, the present invention is not limited to this.

[0014]

According to the present invention, various tests are performed to determine what conditions should be satisfied in order for the present inventors to supply the release agent to the fixing roller and the like in a predetermined amount and uniformly. As a result, it was clarified that the above conditions should be satisfied.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

FIG. 1 shows a fixing device to which an embodiment of a release agent supply device according to the present invention is applied. In the figure, reference numeral 1 denotes a fixing device. The fixing device 1 includes a fixing roll 2 and a pressure roll 3 pressed against the fixing roll 2. The fixing roll 2 has a relatively thick coating of an elastic layer 5 made of a heat-resistant synthetic resin or the like on the surface of a metal roll 4. The pressure roll 3 is formed by thinly coating an elastic layer 7 made of a heat-resistant synthetic resin or the like on the surface of a metal roll 6. The fixing roll 2 and the pressure roll 3 are heated to a predetermined temperature by heaters 8 and 9 housed therein, and the copy paper 11 on which the unfixed toner image 10 is formed passes between the two rolls 2 and 3. Thus, the unfixed toner image 10 is fixed on the copy paper 11 by heat and pressure.

In the vicinity of the fixing roll 2, a release agent supply device 12 for applying a release agent such as silicone oil to the surface thereof is provided.

The release agent supply device 12 includes at least first and second rolls whose surfaces rotate in contact with each other, and supplies the release agent to the first roll and the first roll. The blade is brought into contact with the surface of the roll to regulate the amount of the release agent to be supplied, and the release agent is supplied through the second roll contacting the first roll. .

That is, the release agent supply device 12 includes an oil pan 14 containing oil 13 as a release agent.
There is provided a felt 30 for sucking up the oil 13 inside and applying the oil 13 to the metering roll 15. The metering roll 15 is formed by coating a surface of a metal cylinder 15a made of stainless steel or the like with an elastic layer 15b made of silicon rubber or the like. A metering blade 16 for regulating the amount of oil 13 adhering to the surface of the metering roll 15 and measuring the oil 13 to a constant amount is disposed on the surface of the metering roll 15 so as to be pressed against the surface with a predetermined pressing force. Have been.

The measuring blade 16 is disposed over the entire length of the fixing roll 2 in the longitudinal direction.

A donor roll 19 is in contact with the surface of the metering roll 15, and the donor roll 19 is also in contact with the surface of the fixing roller 2. The donor roll 19 is formed by forming an elastic layer 21 made of silicon rubber or the like on the surface of a metal roll 20.

The metering roll 15 and the donor roll 19 are arranged rotatably.

Then, by rotating the fixing roll 2, the donor roll 19 in contact with the surface of the fixing roll 2 and further the metering roll 15 are rotated. Then, the oil 13 in the oil pan 14 is sucked up by the felt 30 and applied to the surface of the metering roll 15. The oil 13 adhering to the surface of the metering roll 15 is measured to a constant amount by the measuring blade 16 to form a film having a predetermined thickness. Excess oil 13 is returned into the oil pan 14. The oil film formed on the surface of the metalling roll 15 is transferred to the surface of the donor roll 19 in contact with the metalling roll 15, and the oil film transferred to the donor roll 19 is fixed in contact with the donor roll 19. It is applied and supplied to the surface of the roll 2.

In such a release agent supply device 12,
The uniformity of the oil 13 supplied to the fixing roll 2 is substantially determined by the surface roughness of the metering roll 15 and the donor roll 19. That is, if the surface roughness of the metering roll 15 and the donor roll 19 is not within a predetermined range, the amount of the oil 13 supplied to the surface of the fixing roll 2 is too large or too small, or becomes uneven.

In order to obtain a stable and uniform oil supply amount, the present inventors have made a trial production of the metalling roll 15 and the donor roll 19 having variously changed surface roughnesses. Was tested. As a result, the present inventors have clarified the surface roughness of the metalling roll 15 and the donor roll 19 that satisfy the application amount and uniformity of the oil on the fixing roll.

Next, the contents of the above test will be described.

The present inventors have proposed the above-mentioned metering roll 15.
In addition, a mold release agent supply device in which the surface roughness of the donor roll 19 was variously changed was prototyped, and the oil supply property was tested.

First, the measuring blade 16 was formed using Viton rubber (trade name, manufactured by DuPont). The elastic layer 1 of the metalling roll 15 and the donor roll 19
5a and 15b were formed of silicon rubber. The hardness of these silicone rubbers is set to 40 degrees.

The elastic layers 15a and 19a of the metalling roll 15 and the donor roll 19 are polished on the surface and the surface roughness is measured along the axial direction and the circumferential direction. With a roughness R of 0.2, 0.
5, 1, 2, 3, 4, 5 μm Ra were variously prepared. These metering roll 15 and donor roll 1
The surface of No. 9 was cleaned with alcohol.

As the oil 13, a mercapto-modified silicone oil having a mercapto group functional group at the terminal was used. The oil pan 14 has a depth of 10 mm and a thickness of 4 m.
m of felt 13 and 50 g of oil 13 was stored.

On the other hand, as a fixing roll 2 for fixing a toner image, a rubber layer 5 made of viton rubber is provided on the outer peripheral surface of an aluminum roll 4 to a thickness of 1.5 mm and a diameter of 50 m.
m was used. In addition, as the pressure roll 3,
A PFA (tetrafluoroethylene perfluoroalkylvinyl copolymer) layer 7 is formed on the outer peripheral surface of the metal roll 6 by 30
What was baked to a thickness of μm was used. Fixing roll 2
Is 200 ° C., and the surface temperature of the pressure roll 3 is
Each was set to 180 ° C. In addition, both rolls 2, 3
Was 80 mm / sec.

The metering roll 15 is pressed against the donor roll 19 with a pressing force of 0.5 kg / cm, and the donor roll 19 is pressed against the fixing roll 2 with a pressing force of 0.5 kg / cm.
/ Cm.

The fixing device 1 and the releasing agent supply device 12 configured as described above are used in a copying machine; Fuji Xerox 6800.
The following experiment was carried out so that L paper (A4 size) manufactured by Fuji Xerox Office Supply Co., Ltd. was fed sideways as copy paper 11.

Experiment 1 The surface roughness of the elastic layers 15a, 15b of the metalling roll 15 and the donor roll 19 was set to 0.2, 0.5, 1,
The prints were taken at 2000 copies each with a change of 2, 3, 4, 5 μm Ra, and the amount of oil supplied to the fixing roll 2 per copy and the uniformity thereof were measured. FIG. 2 shows the result.

As is evident from the results, the surface roughness of the metering roll 15 was determined to be 10 points average roughness Ra of 0.5.
≦ Ra ≦ 5 μm, and the surface roughness of the donor roll 19 is set to be 10 points average roughness Ra of 0.2.
It was found that by setting ≦ Ra ≦ 3 μm, the supply amount of oil can be kept constant within a desirable range of 15 to 40 μg / copy. When the surface of the fixing roll 2 to which the oil 13 was applied was observed, the oil was applied uniformly along the longitudinal direction of the fixing roll 21.

In the above experimental example, the donor roll 1
As an example of No. 9, the case where the silicon rubber layer 21 is provided on the surface of the aluminum cylinder 20 has been described.
0, an elastic body layer 21 is provided around
A layer having a thickness of 10 to 100 μm may be used. In such a case, the cleaning property of the donor roll 19 is improved.

[0037]

The present invention has the above-described structure and operation. It is possible to surely obtain a uniform supply amount of the releasing agent along the axial direction of the fixing roller of the fixing device. A release agent supply device capable of obtaining a fixed image can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a fixing device to which a release agent supply device according to the present invention is applied.

FIG. 2 is a graph showing experimental results.

FIG. 3 is a configuration diagram showing a fixing device to which a conventional release agent supply device is applied.

[Explanation of symbols]

12: release agent supply device, 13: oil, 14: oil pan, 15: metering roll, 16: measuring blade, 1
9 ... donor roll

Claims (1)

(57) [Claims] 1. A method comprising: providing at least first and second rolls whose surfaces rotate in contact with each other, supplying a release agent to the first roll, and supplying a release agent supplied to the first roll; In the release agent supply device that supplies the first roll through a second roll, the surface roughness of the first roll is set such that the 10-point average roughness Ra satisfies 0.5 ≦ Ra ≦ 5 μm. A release agent supply device, wherein the surface roughness of the second roll is set so that the 10-point average roughness Ra satisfies 0.2 ≦ Ra ≦ 3 μm.