JPH04293073A - Fixing device - Google Patents

Abstract

PURPOSE:To save a handling time required for exchanging a cleaning pad by constituting the cleaning pad abutting on a fixing roller of a tank part where oil is stored and a pad part which covers the tank part and which is brought into contact with the fixing roller. CONSTITUTION:The fixing device is obtained by making the cleaning pad 30 press-contact with the upper part of the surface of the fixing roller 21 by a spring 28. Then, the surface of the roller 21 is cleaned and the oil is supplied to the surface of the roller 21 at the same time. Besides, the pad 30 is constituted of the pad part 31 made of felt or the like and the tank part 32. The tank part 32 is arranged with the aperture of a container 33 whose cross section is U-shape faced downward. Then, the pad part 31 is provided so as to enclose the container 33. The large quantity of the silicone oil 34 having high viscosity is stored in the container 33. When the oil 34 in the pad 30 is heated by the heat of the roller 21, it oozes from the pad part 31 and it is supplied to the roller 21. Therefore, the oil is always uniformly supplied for a long time.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention involves sandwiching and conveying a transfer material carrying an unfixed toner image formed by a dry developer using a heated fixing roller and a pressure roller that is pressed against the fixing roller. The present invention relates to a fixing device that fixes an unfixed toner image to a transfer material.

0002

2. Description of the Related Art Fixing devices of the above type are well known and are attached to copiers, printers, facsimile machines, and the like. In this type of fixing device, there is a device that supplies silicone oil to the fixing roller by bringing felt into contact with the fixing roller and dropping silicone oil with a viscosity of 300 cs onto the felt using a pump, and using a two-component developer. Used in image forming devices. This type of fixing device requires a large number of parts, making the fixing device large and increasing the cost. In addition, as a fixing device for image forming apparatuses that use a one-component developer, a cleaning pad type is used, in which a heat-resistant felt with a thickness of 2 to 3 mm is impregnated with silicone oil with a viscosity of 10,000 cs and brought into contact with the fixing roller. is also known. This cleaning pad type fixing device has a simple structure and is inexpensive.

0003

[Problems to be Solved by the Invention] However, in the oil supply method using the heat-resistant felt cleaning pad impregnated with silicone oil, the viscosity of the oil is as low as about 10,000 cs. It is easy for oil to leak out, causing oil to run out at an early stage. This is because the viscosity of silicone oil changes depending on the temperature at which it is used, and for example, oil that is 10,000 cs at room temperature becomes 1/10, ie, 1,000 cs, at 180° C. (fixing roller surface temperature). Therefore, the cleaning pad has a short lifespan and needs to be replaced sooner, and there is a problem in that the silicone oil runs out after 3 to 5,000 prints and the cleaning pad must be replaced.

The present invention solves the above-mentioned conventional problems, and
It is an object of the present invention to provide a fixing device that enables the use of a cleaning pad that holds a large amount of high viscosity silicone oil, can constantly supply uniform oil for a long period of time, and can reduce the effort and cost of replacing the cleaning pad. do.

[0005]

[Means for Solving the Problems] The structure of the present invention that achieves the above object is as follows. (1) A transfer material carrying an unfixed toner image formed by a dry developer is sandwiched and conveyed by a heated fixing roller and a pressure roller that is in pressure contact with the fixing roller, and at this time, the unfixed toner image is transferred to the transfer material. In the fixing device configured to perform fixing, a cleaning pad is provided that is in contact with the surface of the fixing roller, and the cleaning pad includes a tank portion storing oil and a pad portion that covers the tank portion and contacts the surface of the fixing roller. A fixing device comprising:

(2) The fixing device according to (1) above, wherein the oil stored in the tank portion of the cleaning pad is silicone oil with a viscosity of 50,000 to 500,000 cs.

(3) The fixing device according to (1) above, further comprising a member for adjusting the amount of oil supplied at the outlet of the tank portion of the cleaning pad.

[0008]

[Function] According to the configuration (1) above, since the cleaning pad is provided with a tank portion, a large amount of oil can be stored.
The cleaning pad can have a long service life.

According to configuration (2) above, since silicone oil with a viscosity of 50,000 to 500,000 cs is used as the oil, the amount of oil consumed is appropriate and the cleaning pad can be used for a long period of time.

According to the configuration (3) above, since a member for adjusting the amount of oil supplied is provided, the amount of oil seeping out can be adjusted by adjusting the thickness of the adjusting member, which is inexpensive.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a printer using a fixing device of the present invention. In FIG. 1, a printer main body 1 is placed on a box-shaped printer table 2. As shown in FIG. Upper and lower paper feed cassettes 3 are removably loaded into the printer main body 1, and a large quantity paper feed tray 4 is attached to the printer table 2. The paper in paper cassette 3 is transferred to printer main unit 1.
The paper is fed by a paper feed mechanism 5 inside the printer, and the paper is fed to the printer main body 1 through the printer table 2 by a paper feed device 6 inside the bulk paper feed tray 4.

In the case of normal one-sided printing, these fed sheets are hit against the registration rollers 7 to correct the skew, and after being aligned with the rotation of the photoreceptor 8, the sheets are moved by the registration rollers 7. It is conveyed to the lower side of the photoreceptor 8.

The surface of the photoreceptor 8 is charged by corona discharge by the charger 9 while being rotated clockwise, and electrostatic latent is created on the surface of the photoreceptor 8 by being irradiated with laser light from the optical writing unit 10. An image is formed. This latent image is visualized as it passes through the developing unit 11, and is transferred onto the sheet of paper conveyed by the registration rollers 7 as described above. The image is transferred by the separation unit 12. The recording paper onto which this image has been transferred is sent to the fixing device 14 of the present invention via the conveyance path 13 and is fixed thereon. Thereafter, if the paper is to be ejected in a face-up state, the paper advances straight and is collected in the face-up tray 15. Also, if you want to stack in page order with face-down stacking,
The direction of the sheet is changed by the conveyance switching claw 16, the sheet is sent upward, and the sheet is stacked on the face-down tray 18 via the sheet discharge section 17. After the transfer, residual toner is removed from the photoreceptor 8 by a cleaning unit 19, and a static elimination lamp 20 is used to remove residual toner.
After being neutralized by the charger 9, it is charged again by the charger 9.

The fixing device 14, as shown in FIG.
Fixing roller 2 heated by a heater (not shown)
1 and a pressure roller 22 pressed against the fixing roller 21 by a spring 23. When a transfer paper passes between the fixing roller 21 and the pressure roller 22, the toner is melted and fixed onto the transfer paper. 24 and 25 are guide plates for the transfer paper, 26 is a separation claw, and 27 is a fixing cover. And the fixing device 14
A cleaning pad 30 is placed on the upper surface of the fixing roller 21.
is pressed by a spring 28 to clean the surface of the fixing roller 21 and supply oil to the surface of the fixing roller 21.

As shown in FIG. 3, the cleaning pad 30 is composed of a pad portion 31 and a tank portion 32 made of felt or the like. The tank portion 32 is disposed with the opening of a container 33 having a U-shaped cross section facing downward, and the pad portion 31 is provided so as to surround the container 33. container 3
3, silicone oil 34 is stored, and this silicone oil 34 has a viscosity in the range of 50,000 to 500,000 cs.

The fixing device constructed in this way has a long lifespan because a large amount of silicone oil 34 can be stored in the tank portion 32. Moreover, since the silicone oil 34 used has a high viscosity, when the silicone oil 34 in the cleaning pad 30 is heated by the heat of the fixing roller 21, the viscosity decreases and the silicone oil 34 oozes out from the felt pad 31, causing the fixing roller to be heated. can be supplied to When the machine is off, the fixing roller 21 is at room temperature and the silicone oil 34 remains highly viscous, so it does not seep out. Therefore, the viscosity of the silicone oil 34 is reduced only when it is used and is supplied to the fixing roller 21, which is advantageous because there is no wasteful consumption.

The relationship between the viscosity of the silicone oil 34 and the usage time is as shown in the graph of FIG. 5, as shown in the graph of FIG. 5, the higher the viscosity, the longer the life of the oil. Therefore, if the viscosity of the silicone oil 34 is increased, the service life will be extended, but the viscosity is too high and the toner is removed from the transfer paper, resulting in image defects. Therefore, as mentioned above, the viscosity of the silicone oil 34 is 5.
It is best to use it in the range of 500,000 to 500,000.

By the way, the silicone oil 3 in the container 33
The supply amount of No. 4 can be adjusted by adjusting the thickness of the felt of the pad portion 31. However, since the pad portion 31 is formed of felt into a bag shape, if the felt is thick, it becomes difficult to manufacture and increases the cost. FIG. 4 is an explanatory sectional view showing another embodiment of the present invention, and in this embodiment, the tank portion 3
An adjustment felt 35 is disposed on the outlet side of the container 2, that is, on the opening side of the container 33, in order to adjust the supply amount of the silicone oil 34.

With this configuration, the amount of oil seeping out can be adjusted not by the thickness of the felt of the pad portion 31 but by the thickness of the adjustment felt 35. Therefore, the amount of oil seeping out can be adjusted at low cost.

[0020]

According to the above structure, since the cleaning pad of the present invention is provided with a tank portion, a large amount of oil can be stored and the cleaning pad can have a long service life. Moreover, since silicone oil with a viscosity of 50,000 to 500,000 cs is used as the oil, the amount of oil consumed is appropriate and the cleaning pad can be used for a long period of time, reducing the effort and cost of replacing the cleaning pad. If a member for adjusting the amount of oil supplied is provided, the amount of oil seeping out can be adjusted at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a printer using a fixing device of the present invention.

FIG. 2 is an explanatory diagram of a fixing device.

FIG. 3 is an explanatory sectional view showing one embodiment of the present invention.

FIG. 4 is an explanatory sectional view showing another embodiment of the present invention.

FIG. 5 is a graph showing the relationship between usage time and oil consumption for silicone oils with viscosities of 500,000, 100,000, 50,000, and 30,000.

[Explanation of symbols]

14 Fixing device 21 Fixing roller 22 Pressure roller 30 Cleaning pad 31 Pat part 32 Tank part 34 Silicone oil 35 Adjustable felt

Claims (3)

[Claims] Claim 1: A transfer material carrying an unfixed toner image formed by a dry developer is sandwiched and conveyed by a heated fixing roller and a pressure roller that is in pressure contact with the fixing roller, and at this time, the unfixed toner image is transferred. In a fixing device configured to fix onto a material, a cleaning pad is provided in contact with the surface of the fixing roller, and the cleaning pad covers a tank portion storing oil and the tank portion and contacts the surface of the fixing roller. A fixing device comprising a pad portion. 2. The fixing device according to claim 1,
A fixing device characterized in that the oil stored in the tank portion of the cleaning pad is silicone oil with a viscosity of 50,000 to 500,000 cs. 3. The fixing device according to claim 1,
A fixing device characterized in that a member for adjusting the amount of oil supplied is provided at the outlet of the tank portion of the cleaning pad.