JPH07244439A - Fixing device for electrophotographic device - Google Patents

Abstract

PURPOSE:To provide a fixing device capable of maintaining stable fixing force by making the temperature distribution of the surface of a heating roll uniform, even if the specifications of an electrophotographic device are different. CONSTITUTION:Each of plural heater lamps 6a, 6b, 6c and 6d is independently controlled and even if the specifications of the electrophotographic device are different, the lighting period and time of each heater are controlled to easily set a fixing device in accordance with the specifications.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for an electrophotographic apparatus.

[0002]

2. Description of the Related Art A conventional fixing device for an electrophotographic apparatus is shown in FIGS. In FIG. 3, the toner 2 on the printing paper 1 receives heat from the back surface of the printing paper 1 by the heater plate 3 having the heater wire 4 inside and starts to soften. The toner 2 which has begun to soften has a plurality of heat generating lamps 6a, 6 inside.
It is fixed on the printing paper 1 by being nipped and conveyed by the heating roll 5 having b, 6c and 6d and the pressing roll 8 held by the support 7. At this time, printing paper width,
Even if the printing conditions such as the printing speed are different, the surface temperature of the heating roll 5 is attached to the non-sheet feeding area of the heating roll 5 in order to keep the heating capacity for fixing the toner on the printing paper 1 constant and to make the printing quality uniform. The magnetic chip 9 and the magnetic sensor 10 arranged to face the magnetic chip 9 keep it constant,
The lighting period and the lighting time of the heat generating lamps 6a, 6b, 6c, and 6d are all controlled by the control unit 11 at the same time. Further, the heat generating lamps 6a, 6b, 6c, 6d have different heat generating areas as shown in FIG. 4, and the heat generating area, heat generating amount, etc. of the heat generating lamps are specified in the electrophotographic apparatus while considering the printing speed, the paper used, and the like. It was decided every time.

[0003]

In the above-mentioned conventional fixing device, since the lighting cycle and lighting time of a plurality of heat generating lamps are controlled simultaneously, it is difficult to keep the temperature distribution of the heating roll uniform during printing. Therefore, the specifications of the heating roll, the heat generation area of the heat generation lamp, and the heat generation amount have to be determined for each specification of the electrophotographic apparatus.

An object of the present invention is to provide a fixing device suitable for all electrophotographic devices without changing the specifications of heat generating lamps.

[0005]

In order to achieve the above object, in the fixing device of the electrophotographic apparatus of the present invention, a constitution is adopted which is provided with a control device capable of individually lighting a plurality of heaters.

[0006]

According to the fixing device of the electrophotographic apparatus having the above-described structure, the electrophotographic apparatus having the different printing speed and printing paper to be used is optimal for toner fixing without changing the specifications of the heat lamp. It is possible to stably supply the amount of heat to the printing paper.

[0007]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, the toner 2 on the printing paper 1 is printed on the printing paper 1 by the heater plate 3 having the heater wire 4 inside.
It receives heat from the back side and begins to soften. Toner 2 has started to soften
Is a plurality of heat generating lamps 6a, 6b, 6c, 6d
The printing paper 1 is sandwiched and conveyed by the heating roll 5 having the pressure and the pressing roll 8 held by the support 7.
Fixed on top.

The heating lamps 6a, 6b, 6c and 6d maintain a constant surface temperature of the heating roll 5 by means of a magnetic chip 9 attached to the non-sheet feeding area of the heating roll 5 and a magnetic sensor 10 arranged opposite thereto. In order to maintain uniform printing quality, the control unit 11 controls the heating lamps 6a, 6b, 6
The lighting cycle and lighting time of c and 6d are controlled. By performing a switching operation of the printing conditions such as the width of the printing paper and the printing speed, the lighting period and the lighting time of each of the heat generating lamps 6a, 6b, 6c, 6d are independently controlled by the control unit 11, and as shown in FIG. As shown, a sufficient amount of heat for toner fixing is always stably supplied to the heating roll 5.

[0009]

As described above, according to the present invention, since a control device for individually lighting a plurality of heaters (heating lamps) is provided, even if the specifications of the electrophotographic apparatus are different, the lighting cycle of each heater and By adjusting the lighting time, it is possible to easily set the fixing device according to the specifications.

[Brief description of drawings]

FIG. 1 is a perspective view showing a fixing device according to the present invention.

FIG. 2 is a heating roll surface temperature distribution chart during printing in the fixing device of the present invention.

FIG. 3 is a perspective view showing a conventional fixing device.

FIG. 4 is a schematic diagram showing a lighting region of a heat generating lamp.

FIG. 5 is a heating roll surface temperature distribution chart during printing in a conventional fixing device.

[Explanation of symbols]

1 is printing paper, 5 is heating roll, 6a, 6b, 6c, 6
d is a heat lamp, 9 is a magnetic chip, 10 is a magnetic sensor,
Reference numeral 11 is a control unit.

Front Page Continuation (72) Inventor Masa Sawahata 1060 Takeda, Katsuta-shi, Ibaraki Hitachi Koki Co., Ltd. (72) Inventor Hiroshi Shirada 1060 Takeda, Katsuta-shi, Ibaraki Hitachi Koki Co., Ltd. (72) Inventor Yukio Nakajima 1060 Takeda, Katsuta City, Ibaraki Hitachi Koki Co., Ltd.

Claims (1)

[Claims] 1. A fixing device for an electrophotographic apparatus having a heating roll containing a plurality of heaters, comprising a control device capable of individually turning on the plurality of heaters. Fixing device.