JPH01121883A - Fixing device for forming image - Google Patents

Abstract

PURPOSE:To improve fixing quality by including a pipe-shaped heat removing roller which comes into contact with a press roller and in which cooling fluid passes into the title fixing device, thereby constituting said device. CONSTITUTION:A heating roller 2 which is applied with heat by a heating element 5 melts a toner 7 and fixes an image onto paper 6 while applying the heat and pressure to paper 6 cooperatively with the press roller 3. While the left side of the heating roller 2 is deprived of the heat by the paper 6 at this time, the heat on the right side is transferred through the roller 3 to the surface of the heat removing roller 1. The roller 1 is made into a pipe shape and is mounted with a fan 8 at the left end. The air sucked by this fan 8 deprives the surface of the heat during the passage through the heat removing roller 1. The part of the roller 2 where the paper does not pass is thereby deprived of the heat, by which the uniform surface temp. of the roller 2 is maintained and the fixing quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming fixing device, and more particularly to a heated roller type image forming fixing device that fixes an image drawn with toner onto a sheet of paper.

[Conventional technology]

A conventional image forming fixing device has a heating roller 2 and a pressure roller 3 in contact with the heating roller 2, as shown in FIG. 2(a).The temperature of these rollers is detected by a thermostat 4,
), heat is uniformly applied to the heating roller 2 by a heating element 5 mounted inside the heating roller 2.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional image forming fixing device, when paper that is considerably narrower than the heating roller is continuously passed through, the heat of the corresponding heating roller is taken away by the paper, and the heating roller is heated. The surface temperature distribution of the roller becomes uneven, causing poor fixing performance, and the remaining part of the heating roller does not absorb heat, causing the temperature in this area to become abnormally high, causing thermal deformation of other parts. The downside is that it is dangerous.

[Means for solving problems]

The image forming fixing device of the present invention is configured to include a pipe-shaped heat removal roller that is in contact with the pressure roller and through which cooling gas or liquid flows.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

In the image forming fixing device shown in FIG. 1, a heating roller 2 heated by a heating element 5 applies heat and pressure to a paper 6 together with a pressure roller 3, melting toner 7 and printing an image onto the paper 6. Make it stick.

At this time, heat is removed from the left side of the heating roller 2 by the paper 6.

On the other hand, the heat on the right side is transmitted to the surface of the heat removal roller 1 via the pressure roller 3. The heat removal roller l has a pipe shape, and a fan 8 is attached to the left end. When the air sucked in by the fan 8 passes through the heat removal roller 1, it removes heat from the surface.

〔Effect of the invention〕

By using a heat removal roller, the image forming fixing device of the present invention can remove heat from the areas of the heating roller where the paper does not pass and maintain the surface temperature of the heating roller to a certain degree, which improves the fixing quality. This has the effect of improving thermal stability and preventing thermal deformation of parts attached near the pressure roller.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2(a)
, (b) are a perspective view and a surface temperature distribution diagram of a heating roller showing a conventional example. 1... Heat removal roller, 2... Group/heating roller, 3
... group, pressure roller, 4... thermostat,
5... Heating element, 6... Paper, 7... River/toner, 8... Fan. Agent Patent Attorney Oto Uchihara

Claims (1)

[Claims] 1. A fixing device for image formation, comprising: a pressure roller for image formation; and a pipe-shaped heat removal roller in contact with the pressure roller and through which a cooling fluid passes.