JPS5999468A - Heat roll fixing device - Google Patents

Abstract

PURPOSE:To prevent the staining of output data due to deficiency of silicone oil by allowing felt immersed with silicone oil into contact with part of oil-impregnated felt which contacts a heat rool, and supplying oil by capillarity. CONSTITUTION:The oil-impregnated felt 8 is extended in contact with the circumferential surface of the heat roll 5 and moves from a payoff side roll 9 to a take-up side roll 10 slowly during data output to apply silicone oil sticking to the felt 8 over the circumferential surface of the heat roll 5. When the oil in the oil-impregnated felt 8 is consumed, the oil is supplied to the felt 8 by the capillarity of oil supply felt 11 installed on its back surface side to prevent the sticking of a toner image to the oil supply felt 11 and also to clean it up normally.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a hot roll fixing device used for fusing visible toner images formed on paper.

The heat roll fixing device has a halogen lamp built into the roll, and by lighting the heat roll, the surface temperature of the heat roll is raised to a high temperature, and the paper having a visible toner image is pressed against the surface of the heat roll, thereby melting the toner and detecting the toner. Since the toner is to be fixed on the paper, it is necessary to prevent the toner from being transferred to the surface of the hot roll when the toner is melted by pressure. For this reason, a method has been adopted in which the surface of the hot roll is coated with a material that is as smooth as possible and completely heat resistant, and at the same time, silicone oil is applied to the surface of the hot roll.

However, even if silicone oil is applied to the surface of the heat roll, toner will adhere to the surface of the heat roll, albeit in a small amount.
It is necessary to clean the surface of the heat roll after each rotation. Therefore,
The most commonly used method is to bring felt impregnated with silicone oil into contact with a heated roll, apply silicone oil to the heated roll, and clean the surface of the heated roll.

This method does not cause any problems in small copying machines, etc., but in the case of printers used as devices such as computers, silicone oil consumption and toner stains on the heat roll increase, so oil-impregnated felt is used in the form of a roll. The example is such that a new felt section is used and new felt sections are fed to the hot roll over time. On the other hand, Teflon is mostly used as a coating material for the surface of the thermo roll due to the requirements for heat resistance and low abrasion. Since the surface of Teflon used as a coating material becomes soft and hard, the felt that comes into contact with the hot roll must be made of a heat-resistant material that will not damage the hot roll surface.Currently, Teflon, which is the same material as the coating material, is most often used. ing.

In this case, since the material is expensive, the oil-impregnated felt is also very expensive. Therefore, most of the current printers use oil-impregnated felts only when outputting data because it is better to use oil-impregnated felts for as long as possible, which leads to lower running costs of the equipment.
A method is adopted in which the oil-impregnated felt is stopped during the POWER ON standby period. However, even during standby, P
, when 0WER/ON, the heat roll is always kept at a high temperature and rotates while always in contact with the oil-impregnated fer 1:. Therefore, the silicone oil in the felt that is in contact with the hot roll is not consumed, and if you perform the PRINT operation after waiting for a long time, there is a problem that the output data will become dirty due to a lack of silicone oil. Ta.

The present invention solves the above-mentioned problems by bringing another felt moistened with oil into contact with the part of the oil-impregnated felt that comes into contact with the hot roll, so that oil can be supplied to the felt on the hot roll side through the capillary action of the felt. It is characterized by being configured as follows.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a process diagram of an electrophotographic printer using a hot roll fixing method, in which a visible toner image is formed on the surface of a paper 2 fed from a paper supply section 1 in an electrophotographic section 3. The paper is further sandwiched between a pressure roll 4 and a heat roll 5, and the toner is pressed onto the surface of the heat roll 5, and the toner is melted and fixed onto the paper. Thereafter, the paper is pulled out by a delivery roller 6 and stored in a paper stack section 7.

On the other hand, as shown in FIG. 2, an oil-impregnated felt 8 is stretched in contact with the peripheral surface of the heat roll 5.
Both ends are respectively wound around a felt supply side roll 9 and a take-up side roll 10, and when data is output, the felt 8 is fed out from the felt supply side roll 9 toward a take-up 9 side roll 10, and is rolled around the heated roll 50 times. The silicone oil adhering to the felt 8 is applied to the circumferential surface of the hot roll 5 by slowly moving it along the surface to clean dirt on the roll surface.

As shown in FIG. 2, the present invention provides an oil supply felt 1 that supplies silicone oil and oil by capillary action to the back side of an oil-impregnated felt 8 that is in contact with a heat roll 5.
1 is installed, and the oil supply felt 11 is impregnated with the oil stored in the unit 12, and a part of the oil supply felt 11 is impregnated with the oil impregnated felt 8.
It was brought into contact with

In the present invention, when the oil in the oil-impregnated felt 8 is consumed, the oil in the oil supply unit is supplied to the felt 8 by the capillary action of the oil supply felt 11, thereby preventing the toner image from adhering to the heat roll portion. Cleaning is done normally. In particular, in the past, the oil in the oil-impregnated felt 8 was consumed by the heat roll 5 during a long standby after POWGR was turned ON, but according to the present invention,
Even during standby after -ON, oil is supplied from oil supply felt 11 to impregnated felt 8, so after standby P1'?
, there is no problem of dirty output data even when performing INT operations. Oil is manually replenished into the oil supply unit 12 during maintenance, such as once a month.

Further, FIG. 3 shows a second embodiment of the present invention, in which an oil tank 13 is installed as an oil supply unit above the contact area between the oil-impregnated felt 8 and the heat roll 5, and the oil supply felt 11 is installed in the tank 13. A part of the felt 11 is brought into contact with the oil-impregnated felt 8.

Also in this embodiment, when the oil in the oil-impregnated felt 8 is consumed during device operation and when the power is turned on,
The point that the oil in the oil tank 16 is supplied to the oil-impregnated felt 8 through the felt 11 is the same as in the previous embodiment. Oil is supplied to the oil tank 16 using an oil bottle 14.

As explained above, the present invention supplies oil to the felt that is in contact with the hot roll through the capillary action of the felt, thereby ensuring high quality of output data and reducing the running cost of the device. There is an effect that can be done.

[Brief explanation of the drawing]

Fig. 1 is a process diagram of an electrophotographic printer using a heated roll fixing system, Fig. 2 is a sectional view of an oil application unit of the present invention in a heated roll fixing device, and Fig. 5 is a process diagram of an electrophotographic printer using a heated roll fixing device. FIG. 3 is a sectional view of the coating unit of FIG. 5...Heat roll 8...Oil-supplied felt Patent applicant NEC Corporation Representative Patent attorney Naka Kanno

Claims (1)

[Claims] (1) An oil-impregnated felt is placed in contact with the circumferential surface of a heated roll that melts the toner that forms a visible image on the paper and fixes it on the paper. In a heat roll fixing device that applies oil to the circumferential surface of a heat roll by applying moving feed to the felt and also cleans the circumferential surface, an oil supply that supplies oil and oil by capillary action to the vicinity of the oil-impregnated felt. A hot roll fixing device characterized in that an oil supply unit having a felt is installed, and a part of the oil supply felt is brought into contact with the oil-impregnated felt.