JPH0713449A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce the consumption of power even in fixing through the use of a heater, etc., by irradiating an unfixed developer image with light including ultraviolet rays, in the upstream side in the carrying direction of a recording material than a heating means. CONSTITUTION:An ultraviolet lamp 112 irradiating the surface side having an unfixed toner image of the recording material 102 with the ultraviolet rays is installed in the upstream of a fixing part 103 and in unfixed toner on the recording material 102, the combination of toner molecules as a high polymer material is resolved with the ultraviolet rays emitted from the ultraviolet lamp 112, molecular weight is reduced and a glass transition point temperature (melting temp.) is lowered. Moreover, the fixing part 103 holds/carries the recording material having the unfixed toner image, while heating it, on a nipping part formed between a fixing roller 1 having the heater H as a heat source inside and a pressure roller 2, to fix the unfixed toner image as a permanent image. At this time, a quantity of heat required for fixing toner is decreased so that the power supplied to the heater H is less than that in conventional case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using electrophotography, and more specifically, it lowers the melting point of a toner by reducing the molecular weight of a polymer material toner by irradiating it with ultraviolet rays. The present invention relates to an image forming apparatus in which power consumption of a fixing device is reduced.

[0002]

2. Description of the Related Art Conventionally, in order to make a non-fixed toner image formed on a recording material a permanent image, it is formed between a fixing roller heated by a heater or the like and a pressure roller rotating in pressure contact with the fixing roller. A fixing device that conveys the recording material under pressure at a nipping portion is often used in image forming apparatuses such as a copying machine and a laser beam printer. FIG. 3 shows an example of a conventional image forming apparatus having such a fixing device.

In FIG. 3, H is a heater which is a heat source, and 1 is a fixing roller having a heater H therein.
A pressure roller 2 is pressed against the fixing roller 1 so as to be driven to rotate, and a recording material having an unfixed toner image is formed at a nip portion formed between the pair of rollers 1 and 2. The unfixed toner image is fixed as a permanent image by conveying under pressure while heating.

[0004]

However, in the above-mentioned conventional example, the fixing roller is heated to 150 ° C. by a heater or the like.
It must be heated and maintained at about 200 ° C. Therefore, the power consumption is very large. Therefore, from the viewpoint of energy saving, development of an image forming apparatus with further reduced power consumption is desired.

An object of the present invention is to solve the above problems and to provide an image forming apparatus capable of reducing power consumption even when fixing is performed using a heater or the like.

[0006]

According to the present invention, an object of the present invention is to provide an image forming apparatus for fixing an unfixed developer image on a recording material by using the heat of the heating means, rather than the heating means. This is achieved by providing a means for irradiating the unfixed developer image with light containing ultraviolet rays on the upstream side in the transport direction.

[0007]

According to the present invention, by irradiating the unfixed toner image revealed on the recording material with ultraviolet rays, the molecular bond of the toner, which is a polymer material, is decomposed and the molecular weight is reduced, so that the glass transition of the toner is caused. Since the point temperature (melting temperature) is lowered and then the toner is heated by the heating means to fix the toner, the amount of heat required for the fixing is reduced.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIG. 1 is a diagram showing an image forming apparatus according to a first embodiment of the present invention.

As shown in FIG. 1, the apparatus of this embodiment forms an image on the recording material 102 fed from the feeding section 101 by the process cartridge A, and conveys the recording material 102 to the fixing section 103. The unfixed image is fixed on the recording material 102, and is discharged to the discharge tray 105 outside the apparatus by the discharge roller pair 104.

The exposure of the image forming section is performed by the scanner section 1.
When the image signal is given to the laser diode (not shown) by the image processing unit 06, the laser diode irradiates the polygon mirror 106a with the image light corresponding to the image signal, and the image light reflected by the polygon mirror 106a forms an image. The photosensitive drum 107 inside the process cartridge A is exposed through a lens (not shown) and the reflection mirror 106b.

That is, the photosensitive drum 107 is rotated in the direction of the arrow, and the surface of the photosensitive drum 107 is charged by the charging means 108.
While being uniformly charged, the scanner unit 106 irradiates the image with light.

Then, the toner (developer) 110 stored in the toner container 109 is supplied to the surface of the developer carrying member 111, so that the toner has the same charge polarity as the photosensitive drum 107 so that the toner adheres to the latent image on the photosensitive drum 107. The developer carrying member 111 is applied with a voltage having a polarity and substantially the same potential to develop.

Next, the feeding roller 101b is rotated to separate one sheet of the recording material 102 in the paper feeding cassette 101a, which is fed to the photosensitive drum 107 and is also conveyed in close contact with the photosensitive drum 107 to form the toner image. The recording material 102 is transferred to the recording material 102, the recording material 102 is separated from the photosensitive drum 107, and the fixing unit 10
Transport to 3.

The recording material 10 is provided upstream of the fixing unit 103.
An ultraviolet lamp 112 for irradiating ultraviolet rays is installed on the image surface side of the unfixed toner No. 2 and the unfixed toner on the recording material 102 is bonded by the ultraviolet rays radiated from the ultraviolet lamp 112 to a toner molecule bond which is a polymer material. It decomposes, the molecular weight decreases, and the glass transition temperature (melting temperature) decreases.

Further, the fixing unit 103 is provided with a fixing roller 1 having therein a heater H which is a heat source.
A pressure roller 2 is in pressure contact with the fixing roller 1 and is driven to rotate. Therefore, in the nip portion formed between the pair of rollers 1 and 2, the unfixed toner image is fixed as a permanent image by conveying the recording material having the unfixed toner image while heating and nip. At this time,
As described above, since the amount of heat required to fix the toner is reduced, the electric power supplied to the heater H is smaller than that in the conventional case.

The recording material 102 which has been fixed is discharged to the discharge tray 105 by the discharge roller pair 104, and the image formation is completed.

In the apparatus of this embodiment as described above, the power consumption of the heater H is much smaller than that of the heater of the conventional embodiment, and in view of the power consumption of the added ultraviolet lamp 112, a large amount of electric energy is consumed. Saves

Further, since the heat resistant temperature of the heat resistant resin, the bearing and the heat resistant rubber used in the fixing device can be lowered, the cost of parts can be reduced.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 2 is a sectional view of the copying machine, and 113 is an ultraviolet blocking filter, which irradiates the original 115 with the light of the ultraviolet lamp 112 through the original table glass 114, and irradiates the photosensitive drum 107 with the reflected light.

Thus, the conventional exposure lamp can be eliminated by using the light of the ultraviolet lamp as the exposure lamp of the copying machine without exposing the human body to harmful ultraviolet rays.

[0023]

As described above, according to the present invention,
In an electrophotographic image forming apparatus, by irradiating an unfixed toner image formed on a recording material with ultraviolet rays, the molecular bond of toner, which is a polymer material, is decomposed, the molecular weight is reduced, and the glass transition temperature ( Since the unfixed image is fixed by the fixing device after lowering the melting temperature), the power consumption is much lower than before. Considering the power consumption of the added UV lamp, a significant electric energy saving is achieved. Becomes Further, since the heat resistant temperature of the heat resistant resin, the bearing and the heat resistant rubber used in the fixing device can be lowered, the cost of parts can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional device.

[Explanation of symbols]

102 Recording Material 110 Toner Cured by Irradiation with Ultraviolet Rays (Unfixed Developer) 112 Ultraviolet Lamp (Means for Irradiating Unfixed Developer Image with Light Containing Ultraviolet) H Heater (Heating Means)

Claims (3)

[Claims] 1. An image forming apparatus for fixing an unfixed developer image on a recording material by using heat of a heating means, wherein the unfixed developer image is formed on the upstream side of the heating means in the recording material conveying direction. An image forming apparatus comprising means for irradiating light including ultraviolet rays. 2. The image forming apparatus according to claim 1, wherein the light source of the means for irradiating the light containing ultraviolet rays is the same as the light source for irradiating the original with light. 3. The image forming apparatus according to claim 2, further comprising an ultraviolet blocking filter provided between the light source and the document.