JPS63281180A - Fixing device - Google Patents

Abstract

PURPOSE:To contrive to improve the thermal efficiency of non-contact heating by providing a reflecting means for reflecting a far infrared radiation radiated from a far infrared radiation substance toward the surface of a recording material, in the periphery of a halogen lamp heater having the far infrared radiation substance on the surface of a glass tube. CONSTITUTION:A halogen lamp heater 1 has an electrode 7 on both ends of a sealed quartz glass tube 5, and in its inside, a tungsten filament 6 for connecting both the electrodes is provided, and on the surface of the quartz glass tube 5, a far infrared radiation substance layer 8 is provided. Also, in the periphery of the halogen lamp heater 1, a reflecting plate 2 for reflecting a far infrared radiation radiated from the far infrared radiation substance layer 8 toward the surface of a recording material 3 is placed. Accordingly, the radiated far infrared radiation reaches effectively the recording material 3 by the reflecting plate 2 and a toner 4 is fixed. In such a way, the thermal efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is utilized in the field of fixing technology for electrophotographic devices, and particularly relates to a fixing device that thermally fixes a recording material having an unfixed toner image by non-contact heating. Regarding.

(Prior Art and Problems) In the fixing of electrophotographic devices, a thermal fixing device that non-contactly heats a recording material with an unfixed toner image is widely known. There are fixing devices, flash fixing devices, etc., but all of them have problems.

First, there is a chamber fixing device, which has a sheathed heater that heats the toner to red heat, heats the recording material with the heat, and fixes the toner by heating it and melting the toner. but,
Not only does the sheathed heater itself have poor thermal efficiency, but much of its radiant heat is radiated to areas other than the recording material, resulting in a large amount of energy loss.

In addition, thermal roller fixing devices that press the recording material against a roller with a built-in heating source have the problem of heat escaping through the roller. The problem is very similar to that of the chamber fixing device described above. Furthermore, flash fixing devices require large capacitors to instantaneously apply high voltage to the flash lamp to cause it to emit light.
This increases the size of the device and makes it difficult to increase the speed due to the charging time of the capacitor.

(Means for Solving the Problems) An object of the present invention is to provide a fixing device that can solve the above-mentioned problems and improve its thermal efficiency in non-contact heating.

To achieve the above object, the present invention provides an apparatus for thermally fixing a recording material having an unfixed toner image by non-contact heating, wherein the heat source for non-contact heating has a far-infrared emitting substance on the surface of the glass tube. Consists of a halogen lamp heater.

It is constructed by disposing a reflecting means around the halogen lamp heater to reflect far infrared rays emitted from the far infrared ray emitting substance toward the surface of the recording material.

(Embodiment) Hereinafter, a device according to an embodiment of the present invention will be described based on the accompanying drawings.

Figure 1 is a sectional view of the device of this embodiment taken in a plane perpendicular to the longitudinal axis of the halogen lamp heater as a heat source;
This figure is a sectional view of the halogen lamp heater of FIG. 1 taken along a plane including the axis.

In FIG. 1, reference numeral 1 denotes a halogen lamp heater, and a reflector plate 2 is disposed above the halogen lamp heater to cover the halogen lamp heater.

As shown in FIG. 2, the halogen lamp heater 2 has electrodes 7 at both ends of a sealed quartz glass tube 5, and a tungsten filament 6 connecting the two electrodes is arranged inside.

A far-infrared emitting material layer 8 is provided on the surface of the quartz glass tube 5.
is provided. Examples of the far-infrared emitting substance include betalite 75%, charcoal lithium 8.4%, limestone 7.0%, zinc white 2.8%, and aluminum hydroxide 6.
．． A substance consisting of, for example, 8% is used.

Here, we will explain the above tungsten filament in comparison with the case where a conventional nichrome wire heater is used.If a nichrome wire is used instead of the tungsten filament shown in Fig. 2, the heat capacity of the halogen lamp heater will be is 8 J/, while for the nichrome wire heater it is 1
9J/, and since nichrome wire heaters need to self-heat up to 600-700°C in order to radiate heat, most of the energy used to reach that temperature after power is supplied is spent on self-heating. It takes a relatively long time to reach a fixable state. On the other hand, with a halogen lamp heater, the heat capacity is small and the heater itself has good startup characteristics, so it takes only a short time for the far-infrared emitting material layer to reach the set temperature of 250 to 350°C.

Next, the characteristics of the far-infrared material 8 on the surface of the halogen lamp heater used in the present invention are such that the emissivity is further increased at wavelengths of 5 l or more, so as to match the absorption wavelength of the toner. Since the peak value of the radiant energy of the halogen lamp heater exists in the vicinity of a wavelength of 1.24 m, the far-infrared material transmits wavelengths in this vicinity.

Next, the reflector 2 is made of a material with high reflectance such as copper or aluminum, and its shape is a parabola so that the reflected far infrared rays reach the recording paper 3 at right angles. The operation of the apparatus of this embodiment is as follows.

First, after power is applied to the halogen lamp heater, the tungsten filament is heated to about 2000°, and the temperature of the quartz glass is increased mainly due to heat conduction. By monitoring the surface temperature of this quartz glass with a temperature sensor (not shown) such as a thermistor, the above surface temperature can be calculated to approximately 50°C to 350°C.
Control settings to a certain degree.

Further, far infrared rays are maintained so as to be efficiently radiated from the far infrared ray emitting material layer 8 shown in FIG. In this case, since the radiation intensity of the far-infrared emitting material changes with the wavelength depending on the temperature as shown in FIG. 3, the wavelength is set so that the efficiency peaks at the temperature corresponding to the above-mentioned set temperature.

The far infrared rays emitted in this way effectively reach the recording material 3 by the reflecting plate 2, and the toner 4 is fixed.

The present invention is basically a radiation fixing method using far infrared rays, but in reality, the air near the fixing device is warmed by heat conduction and near infrared rays radiated from a halogen lamp heater, which also increases the fixing effect. be done.

(Effects of the Invention) As described above, the present invention improves thermal efficiency by using a halogen lamp heater with a far-infrared emitting material layer on the surrounding surface as a heat source in a non-contact heating method, and reflects the emitted far-infrared rays. By using the plate to reflect the light onto the recording material that has an unfixed toner image, it is possible to further improve thermal efficiency, which is particularly effective in low-speed machines such as copying machines, and makes it possible to reduce weight. This brings about effects such as cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an apparatus according to an embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view of a halogen lamp heater used in the apparatus taken along a plane including the axis, and FIG. 3 is a characteristic curve of a far-infrared emitting material provided on the surface of the halogen lamp heater of FIG. l・・・・・・・・・・・・Halogen lamp heater 2・
......Reflection means (reflection plate) 3...
......Recording material 4......Unfixed toner image 8...
・・・・・・Far-infrared emitting material patent applicant
Canon Co., Ltd. Representative Patent Attorney Fuji
Toru Oka Figure 1 Figure 3 Figure 0.10.20512 5102050100 waves
Length (μm)

Claims (2)

[Claims] (1) In an apparatus for thermally fixing a recording material having an unfixed toner image by non-contact heating, the heat source for non-contact heating consists of a halogen lamp heater having a far-infrared emitting substance on the surface of a glass tube, and the halogen lamp described above A fixing device characterized in that a reflecting means for reflecting far infrared rays emitted from the far infrared ray emitting material toward the surface of the recording material is arranged around the heater. (2) The fixing device according to claim (1), wherein the halogen lamp heater is connected to a control means for controlling the surface temperature to a predetermined temperature.