JPS6238489A - Heat fixing device - Google Patents

Abstract

PURPOSE:To attain efficient fixing by forming a heat insulating cover for preventing heat from discharge to the outside, a coat cover for covering the outside of the heat insulating cover and a heat absorbing means formed between both the covers. CONSTITUTION:The heat insulating cover 5 made of a resin covers a heat fixing means to seal the outflow of heat. Since the heat conductivity of the resin is 10X10cal/scmC, the cover 5 insulates heat about 100 times of a metal plate. However when power supply time is extended, heat exerting bad influence upon a photosensitive body or the like is leaked to the outside of the cover 5, air between the covers 5, 6 is sucked by a fan 8 and exhausted to the outside. In addition, a thin heat absorbing member 10 with high heat conductivity is arranged on an opening of a paper inlet/outlet part to efficiently absorb heat trying to flow out from the opening into a developing part. Furthermore, an aluminium plate or a copper plate is formed as a reflecting layer 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heat fixing device for an electronic copying machine.

Conventional Technology Conventionally, a heat fixing device has had the following structure, as shown in, for example, Japanese Unexamined Patent Publication No. 58-31)48. Hereinafter, an example of a heat fixing device will be described with reference to the drawings.

FIG. 6 shows a side sectional view of a conventional heat fixing device. In FIG. 6, reference numeral 19 denotes an opening through which the recording paper passes. 20 is a recording paper path.

The heat fixing means 21 was covered with a case 22, and an intake hood 24 with an air guide plate 23 was provided on the diagonal upper part of the case 22. In order to prevent the radiated heat from raising the temperature of the entire copying machine and adversely affecting the parts surrounding the heat fixing, air was sucked out as shown by the arrow.

Problems to be Solved by the Invention However, in the above configuration, it is necessary to directly suck in the heat of the heat fixing means and the heated air in the vicinity as shown in the figure for the reasons mentioned above. This has resulted in a problem that the thermal efficiency is reduced and a heater with a higher calorific value is required, which is uneconomical.

In view of the above-mentioned problems, the present invention provides a heat fixing machine that secures the necessary heat without raising the temperature of the entire copying machine or adversely affecting surrounding components, and can perform fixing more efficiently. It is something to do.

Means for Solving the Problems In order to solve the above problems, the heat fixing device of the present invention includes a heat insulating cover that covers the heat fixing means to prevent heat from being released to the outside, and a heat insulating cover that covers the outside of the heat insulating cover. The device includes a covering cover, a heat insulating cover, and heat absorbing means within the covering cover.

Further, a reflective layer is provided on the heat insulating cover on the side facing the thermal cutoff means and the heat fixing means at the opening of the recording paper entrance/exit.

Function The present invention will be described with reference to drawings of the surrounding parts that leak into the heat insulating cover and the covering cover so that the heat necessary for fixing the heat fixing unit to the heat insulating cover is not released due to the above-described configuration.

FIG. 1 is a side sectional view of a first embodiment of the present invention, and FIG. 2 is a front sectional view. In Figure 1,
Reference numeral 1 denotes a fixing roller, which has a heat source inside and whose circumferential surface is heated to a temperature that can heat and melt the toner. 2 is a pressure roller provided with a thick layer of material such as silicone rubber on the outer peripheral surface of the pipe. The rollers 1.2 are pressed against each other and rotated. These heating means are covered with a heat insulating cover 5 made of resin, except for an opening 3 on the paper feed side for passing recording paper and an opening 4 on the heating side.

A cover 6 is provided which similarly covers the outside of the heat insulating cover 5 except for the opening 3 on the paper feed side and the opening 4 on the paper discharge side. Further, 7 is a recording paper path, 10 is an aluminum plate provided at the paper entrance/exit opening, and 1) is a reflective layer provided on the cover 5 on the side facing the heat fixing means. In FIG. 2, 8 is a fan that blows air between the cover 5 and the cover 6, and 9 is an air passage hole.

In the heat fixing machine configured as described above, first, the resin heat insulating cover 5 covers the means for heat fixing and seals out the outflow of heat. Here, the thermal conductivity of the resin is 1
0 10 cal/s am C, while steel has 12 10 cal/s cs C, and the resin insulation cover 5 is about 100 times more effective at dissipating heat than sheet metal. However, it takes a long time to turn on the power. If the length is too long, heat that adversely affects the photoreceptor etc. will leak out of the heat insulating cover 5. Therefore, the cover 5
Heat is released to the outside by sucking the air between the cover 6 and the cover 6 using the fan 8 as shown by the arrow in FIG. In addition, as a thermal insulation means, by using a thin endothermic member 10 (for example, an aluminum plate) with good thermal conductivity at the opening of the paper entrance,
It is possible to more efficiently remove the heat that would flow from the opening to the developing section. Furthermore, by providing an aluminum plate or a copper plate as the reflective layer 1), heat radiated from the fixing roller, which has an internal heating source, is prevented from being applied to the heat insulating cover 5 (
By doing so, the heating source can be used effectively. In other words, the temperature inside the copying machine is kept stable without taking away the heat necessary for fixing inside the fixing machine.

The device shown in FIG. 3 uses a surface heating element in place of the fixing roller that has a heating source inside in FIG. It is different from that.

The one shown in Figure 4 is a thermal isolation means for the paper entrance/exit.
This embodiment is different from the embodiments described above in that the cover 6 is provided with an air passage hole 17 for suppressing heat that tends to flow out to the developing section.

The one shown in Fig. 5 is a thermal isolation means for the paper entrance/exit.
This embodiment differs from those of the above-described embodiments by providing the cover 5 or the cover 6 with a mechanical shutter 18 that opens and closes when recording paper is inserted or ejected.

Although air was used as the heat absorbing means in the first embodiment, cooling by liquid or by flowing liquid into a pipe is also effective.

As described above, in this discussion, various fixing devices can be realized by the above combinations, and fixing can be performed effectively in any case.

Effects of the Invention As described above, the present invention provides heat fixing by providing a heat insulating cover, a covering cover covering the outside of the heat insulating cover, heat absorbing means in the heat insulating cover, the covering cover, and a thermal cutoff means in the opening. It retains the heat necessary for fixing the parts and has excellent temperature stability.

Therefore, the powder image can be fixed well on the recording paper. Furthermore, by reducing the amount of heat generated by the heating element, an economical heat fixing device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an embodiment of the heat fixing device of an electronic copying machine of the present invention, FIG. 2 is a front sectional view of the same, and FIG. 3 is a side sectional view of another embodiment of the heating means of the present invention. , FIG. 4, and FIG. 5 are partially detailed side sectional views of an embodiment of another thermal cutoff means for an opening according to the present invention, and FIG. 6 is a side sectional view of an embodiment of a conventional heat fixing device. It is. 5... Heat insulation cover (1), 6... Cover (2), 10... Heat absorbing member, 1)...
・Reflection layer, 17... Air passage hole (2), 18.
...Mechanical shutter. Name of agent, patent attorney Toshio Nakao 1 name 2 - Pressure roller 3 - 1 Feed opening 4 - Paper ejection side opening Fig. 2 7°゛ - Empty! '-''1 hole 16-t
ii Recording paper Figure 4/7--Air hole (2) I9- Opening 20- Recording paper road 21-# Heat fixing means No. 6 Figure 22- Case B--1 Air guide plate 24- Hood

Claims (8)

[Claims] (1) In an electronic copying machine, a device for heat-fixing a powder image formed by toner on a recording paper onto the recording paper, the heat-fixing means and the heat-fixing means being connected to an opening of the recording paper entrance/exit. a heat insulating cover that covers the outside of the heat insulating cover to prevent heat from being released to the outside; a covering cover that covers the outside of the heat insulating cover except for the opening; and heat absorbing means in the heat insulating cover and the covering cover. A heat fixing device featuring: (2) The thermal fixing device according to claim (1), characterized in that a thermal cutoff means is provided in the opening. (3) The heat fixing device according to claim (1), wherein the heat absorbing means sucks or exhausts the inside of the heat insulating cover and the covering cover. (4) As a thermal isolation means for the opening, use a heat absorbing member between the upper heat insulating cover and the covering cover, between the lower heat insulating cover and the covering cover, or both the upper and lower sides with respect to the paper path, or between the above heat insulating cover and the covering. The heat fixing device according to claim 1, wherein the heat fixing device is sealed with a cover member. (5) A patent claim characterized in that, as a thermal isolation means for the opening, an air passage hole is provided on the surface of the opening opposite to the paper path or in the vicinity thereof, thereby forming a ventilation path for suppressing the outflow of internal air. The heat fixing device according to scope (1). (6) As a thermal isolation means for the opening, a mechanical shutter that opens and closes when recording paper is inserted and ejected is provided on the heat insulating cover or the covering cover.
The heat fixing device described in section 1). (7) The heat fixing device according to claim (1), wherein a reflective layer is provided on the heat insulating cover on the side facing the heat fixing means. (8) The heat fixing device according to claim (1), wherein the heat insulating cover and the covering cover partially cover a means for heat fixing.