JPS6014279Y2 - Heat fixing device of electrophotographic copying machine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat fixing device for an electrophotographic copying machine.

An electrophotographic copying machine performs fixing by heating and melting the toner attached to the copy paper, and the heating means used for this purpose is to press a heated roller into contact with the copy paper, or use a flash lamp. There is something to use.

FIG. 1 shows a fixing device using a flash lamp, where 1 is a rod-shaped flash lamp and 2 is a reflecting mirror.

When the copy paper 3 to be fixed reaches a predetermined position, the flash lamp 1 emits a flash of light, and the light is transferred to the copy paper 3.
As the upper toner absorbs the toner, the toner generates heat and melts.

This method, like those using heated rollers, uses offset (melted toner adheres to the heated roller and is transferred back to the copy paper).

), but on the other hand, it is inefficient and tends to cause uneven fixing.

That is, since the flash lamp 1 is rod-shaped, if it is brought close to the copy paper 3, the irradiation range will be narrowed. The illuminance is not uniform at the edges.

This is improved to some extent by the reflector 2, but not completely.

Further, light leakage occurs from the end of the reflecting mirror 2, resulting in a loss, and the light returning from the reflecting mirror 2 to the flash lamp 1 is absorbed by it and becomes a loss.

The present invention aims to solve the above-mentioned problems, and FIGS. 2 and 3 show an embodiment thereof.

Reference numeral 4 denotes a reflecting plate, which is shaped like a shallow dish and faces closely to the table 5 of the fixing section.

A transparent conductive film 6 is formed on the inner surface of the reflection plate 4.

Electrodes 7 are attached to both edges of the transparent conductive film 6 and are connected to a power source 8.

The transparent conductive film 6 generates heat due to the current flowing therethrough, and the nuclear heat is radiated to the copy paper 3 on the base 5.

Some of this heat is directed directly toward the copy paper 3, while the other is directed in the opposite direction.The heat directed in the opposite direction is reflected by the reflector plate 4, passes through the transparent conductive film 6, and passes through the copy paper. 3
heading to

As a method for forming the transparent conductive film 6, a vacuum evaporation method, a sputtering method, an ion blating method, etc. can be used, and the material thereof is isodium oxide (Ir120).
3) and tin oxide (Sn02) are suitable.

As described above, in the present invention, a transparent conductive film is formed on the inner surface of the reflective plate, and heat is generated by applying electricity to the film, so that the heat source becomes planar and uneven heating does not occur.

Further, since the heating element is transparent, the heat reflected by the reflective plate can reach the copy paper without being blocked by the heating element.

Since the heat source can be brought close to the copy paper, thermal efficiency can be improved and the apparatus can be downsized.

[Brief explanation of drawings]

FIG. 1 is a front view of a conventional fixing device using a flash lamp, FIG. 2 is a front view of an embodiment of the present invention, and FIG. 3 is a bottom view of the same. 3...Copy paper, 4...Reflector, 6
・Curved/transparent conductive film.

Claims (1)

[Scope of utility model registration request] A heat fixing device for an electrophotographic copying machine, in which a reflective plate having a transparent conductive film on its inner surface is disposed close to and opposite copy paper, and the transparent conductive film is energized to generate heat.