JPS5823628B2 - Toner image fixing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a toner image fixing method for electronic copying and the like.

For example, in electrostatic photography, toner images formed on transfer paper through the steps of charging, exposure, development, and transfer, or toner images formed directly on photosensitive paper through the steps of charging, exposure, and development are simply these. It is simply electrostatically attracted to the recording medium and disappears when rubbed.

Therefore, a fixing step is required to fix this onto the recording medium.

There are various methods for fixing an unfixed toner image. There is a heat fixing method in which a toner image is fused to a recording medium using heat, and this method is widely used.

However, this heat fixing method has drawbacks such as poor start-up regarding heat capacity at the start of operation, the need for a large power source, and power consumption.

In order to eliminate these drawbacks, a pressure fixing method using only pressure between rollers was developed, but this also required a strong structure due to the need to apply a huge amount of pressure, and the copy paper became glossy. There are drawbacks.

Therefore, an object of the present invention is to provide a new toner image fixing method that eliminates the above-mentioned drawbacks.

In accordance with this purpose, a recording medium having an unfixed toner image is passed between a pair of fixing rollers, at least one of which vibrates slightly, and which rotate in opposite directions while contacting each other. A toner image fixing method characterized in that the toner image is fixed on the recording medium by impact pressure, and one side generates heat, at least one side vibrates slightly, and the toner image contacts each other and rotates in opposite directions. A recording medium having an unfixed toner image is passed between a pair of fixing rollers, and the toner image is fixed on the recording medium by heat between the rollers and impact pressure caused by the micro vibrations. A toner image fixing method is provided.

The present invention will be described below with reference to the drawings.

FIG. 1 is a schematic structural diagram showing an embodiment of the present invention. A pair of fixing rollers is composed of an upper roller 1 and a lower roller 2 that rotate in opposite directions while lightly touching each other.

The recording medium passes between these rollers, and the toner image on the recording medium is directed toward the upper roller 1 side.

The upper roller 1 is formed by a magnetic vibrator, which is a type of mechanical vibrator, and vibrates by itself.

For example, as shown in FIG. 2, lead zirconate titanate porcelain 3, which is a piezoelectric ceramic material, is formed into a cylindrical shape, and electrodes 4 and 5 are attached to the entire inner and outer peripheries of the cylindrical material, respectively. When connected, the entire device vibrates slightly in the radial direction as shown by the arrow.

Piezoelectric ceramic materials can be fired into any shape and the direction of polarization can be arbitrarily selected, so the direction and magnitude of vibration can also be freely set.

Therefore, the upper roller 1 in FIG.
porcelain) 3 and electrode conductors 4 and 5 fixed to the entire inner and outer circumferential surfaces thereof, which are fixed to a mandrel 8 via an insulating elastic member such as rubber 7. Configure.

The respective electrode conductors 4 and 5 are provided with current collecting brushes 9 and 10 on the end faces of the rollers in order to flow current.
The tips of the brushes are in contact with each other, and each of these brushes is connected to a high frequency oscillator 6.

The lower roller 2 is a rigid metal roller generally used in this type of device, but together with the upper roller 1, the entire circumference thereof may be coated with a tetrafluoroethylene tube to prevent offset.

When a resonance frequency is applied to the PZT magnet 3 by the high frequency oscillator 6, the upper roller 1 vibrates slightly in the radial direction as described above.

Therefore, when the recording medium is fed between the upper roller 1 and the lower roller 2, the unfixed toner image on the recording medium is struck by this slight vibration.

The upper roller 1 and the lower roller 2 are fixed in light contact with each other in the non-operating state, and both are rigid bodies.
This micro-vibration becomes a large impact pressure that is applied to the recording medium, causing toner particles to dig into the recording medium.

The insulating elastic member 7 interposed within the upper roller 1 serves to tolerate this vibration.

This function does not involve interposing an elastic member inside the roller, but instead inserts an elastic member 13 made of rubber or the like between the core metal 11 and the inner periphery of the bearing 12 that supports it, as shown in FIG. This can also be achieved by providing

The vibration frequency of the roller is determined primarily by the material of the toner particles, especially their specific gravity and particle size, but is also influenced by the material of the recording medium.

Now, the feeding speed of the recording medium is 20 cIrL per second, and ■n
In order to obtain 100 vibrations per cycle, 20,000 cycles, that is, a resonant frequency of 20 KHz is required, and the length, thickness, radius, etc. of the roller are determined to obtain this.

In addition to the above-mentioned magnetic resonators, mechanical resonators also include magnetostrictive resonators using metal materials such as ferrite, Ni, Fe-Ni alloy, and AF gold alloy, which can be used instead of the above-mentioned magnetic resonators. You can also use

Also, by changing the shape of the roller and the position of the electrodes, the direction of vibration can be changed, or by dividing the roller into parts and applying larger vibrations to both ends than the center, wrinkles in the recording medium can be avoided. It can also be prevented.

Furthermore, it is also possible to transmit vibrations generated by a separately provided vibration generating means, for example a magnetic vibrator, to a conventional roller to vibrate the roller.

In this case, since the shape of the ceramic vibrator is not limited to a roller, the direction of vibration can be freely selected, and effective vibration can be applied to the roller only in the vertical direction.

Further, it is not limited to the upper roller that is vibrated, but only the lower roller or both may be vibrated.

When making both vibrate, it is necessary to make the resonance frequencies different.

FIG. 4 is a schematic configuration diagram showing an example of another invention related to the above invention, in which the upper roller 21 on the side facing the toner image is
A heating roller with a built-in heater 22, which is commonly used in this type of device, is used.

The lower roller 23, which lightly contacts the upper roller 21 in the non-operating state, is a vibrating roller that vibrates as described above.

In this invention, since the heating roller is used to heat the toner particles and fuse them onto the recording medium, it must be placed on the toner image side.

However, the vibrating roller can be located on either side.

Therefore, the upper roller 21 may be a heating roller or a vibrating roller.

Regarding the vibrating roller, the above-mentioned techniques are applied, but other than that, general techniques such as offset prevention are applied as appropriate.

As described above, according to the present invention, since the pressure applied to the bearing of the fixing roller is small, there is no wear on the roller core part, and overall durability can be improved, and the vibration of the roller allows for good passage of the recording medium. There is no wrapping of the recording material around the roller, and the toner image fixation rate is improved due to the impact pressure of the vibration.

In addition, in the configuration of a combination of a vibrating roller and a heating roller, the fixing speed is faster and the heating temperature is lower than that of conventional ones, and it exhibits excellent effects in terms of fixing characteristics, safety, and economy.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the properties of the piezoelectric ceramic material used in the above embodiment, and FIG. 3 is another embodiment of the above invention. FIG. 4 is a schematic diagram showing an embodiment of another invention related to the above invention. 1... Upper roller, 2... Lower roller, 3...
・Piezoelectric ceramic material, 4, 5... Electrode, 6... High frequency generator, 7... Insulating elastic member, 8... Core metal, 9,
10...Brush for current collection.

Claims (1)

[Scope of Claims] 1. A recording medium having an unfixed toner image is passed between a pair of fixing rollers, at least one of which vibrates slightly and rotates in opposite directions in contact with each other, A toner image fixing method, characterized in that the toner image is fixed on the recording medium by the impact pressure of minute vibrations between the rollers. 2. At least one of the pair of fixing rollers is formed by a mechanical vibrator. 3. The toner image fixing method according to claim 1, wherein the vibration generated by the vibration generating means is transmitted to at least one of a pair of fixing rollers. Toner image fixing method. 4 A recording medium having an unfixed toner image is passed between a pair of fixing rollers, one of which generates heat and at least one of which vibrates slightly, and which rotate in opposite directions while contacting each other. , a toner image fixing device, wherein the toner image is fixed on the recording medium by heat between the rollers and impact pressure caused by the microvibration;