JPH0341831B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixing temperature control device for an electronic copying machine equipped with a fixing device having at least two heat sources.

Conventionally, most electronic copying machines equipped with a heat fixing device have used a single heat source for the fixing device. Therefore, it takes a long time for the fixing device to reach a temperature that allows fixing. In addition, some devices use a heat source with a large heat capacity to shorten the warm-up time, but a heat source with a large heat capacity consumes a large amount of power and is uneconomical, as well as making it difficult to control the temperature once it reaches a fixing temperature. There were flaws.

This invention has been made to eliminate such drawbacks, and by providing a plurality of heat sources for the fixing device, turning on the plurality of heat sources at the same time during warm-up, and controlling a single heat source after warm-up, the fixing device can be maintained at a constant level. It is an object of the present invention to provide a fixing temperature control method for an electronic copying machine in which the temperature can be easily controlled and power can be saved.

An embodiment of the method of this invention will be described in detail below with reference to the drawings. FIG. 1 shows a fixing device A provided in an electronic copying machine main body 1, which includes a plurality of heat sources 2, for example, two heat sources 2,
3 and a pressure roll 5 that presses the paper (not shown) to be fixed onto the fixing roll 4, and the surface temperature of the fixing roll 4 is constantly detected by a temperature detector 6. There is. Further, as shown in FIG. 2, the electronic copying machine main body 1 has a structure in which an internal mechanism 8 including a photoreceptor 7 can be opened upwardly. An operation panel 13 is provided with various operation switches 11 including a power saving switch 10 and a display 12 at an easy-to-operate position.
However, a power switch 14 is provided on the side of the main body 1.

However, when the power switch 14 of the main body 1 is turned on, the plurality of heat sources 2 and 3 provided in the fixing roll 4 are turned on at the same time, and the fixing roll 4 is heated in a short time. When the temperature detector 6 detects that the surface temperature of the fixing roll 4 has reached the fixing temperature _T1 , each of the heat sources 2 and 3 is turned off, and from then on, only one of the heat sources 2 is controlled to blink, and the surface temperature of the fixing roll 4 is The fixing temperature is controlled to a constant fixing temperature _T1 shown in FIG. Furthermore, if a paper jam occurs during copying and the internal mechanism 8 is opened upward, the interlock switch 9 is turned off, which turns off the heat sources 2 and 3, and the internal mechanism 8 is opened again after the paper jam is cleared. 1, the interlock switch 9 is turned on and the heat sources 2 and 3 are turned on at the same time, and the surface temperature of the fixing roll 4 is heated until it reaches T _1. From then on, one of the heat sources 2 is used to maintain a constant temperature T as described above. Controlled by ₁ .

On the other hand, when the power saving switch 10 is turned on during copying standby, the control temperature set value decreases to _T2 , and thereafter the surface temperature of the fixing roll 4 is controlled to this value _T2 , and the power saving switch 10 is turned off during copying. Then,
Both heat sources 2 and 3 are turned on, and the surface temperature of the fixing roll 4 reaches the fixable temperature in a short time, and thereafter the temperature is controlled to this temperature _T1 .

In the above embodiment, the case where two heat sources 2 and 3 are used has been described, but of course there may be two or more heat sources.

As detailed above, this invention heats the fixing roll by turning on multiple heat sources at the same time during warm-up, so the surface temperature of the fixing roll can be raised to the fixing temperature in a short time, reducing the warm-up time. can be achieved. In addition, once the surface temperature of the fixing roll reaches the set temperature, only a single heat source is controlled to maintain the set temperature, making control easier than conventional methods that control a heat source with a large heat capacity. In addition to enabling highly accurate temperature control, if a power saving switch is installed to keep the temperature lower than the set temperature during standby, it is possible to reduce power consumption in the fixing device. By turning on multiple heat sources to heat up to the set temperature, the set temperature can be returned to the set temperature in a short time.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a perspective view of a fixing device, FIG. 2 is a side view of the main body of a copying machine,
FIG. 3 is a front view of the operation panel, and FIG. 4 is a diagram showing the control state. A is a fixing device, 2 and 3 are heat sources, 14 is a power switch, and _T1 is a fixing temperature.

Claims (1)

[Claims] 1. A first lighting step in which all of the plurality of heat sources 2 and 3 provided on the fixing roll 4 of the fixing device A are turned on when the temperature is set to a preset fixing temperature _T1 ; After the first lighting step, a first blinking control step of controlling the single heat source 2 or 3 to blink after detecting the fixing temperature _T1 , and setting the temperature of the fixing roll 4 to a set temperature T lower than the fixing temperature _T1 . ₂ , a second blinking control step in which the single heat source 2 or 3 is blinked, and after this second blinking control step, the fixing roll 4
a second lighting step in which all of the plurality of heat sources 2 and 3 are turned on when the temperature is set to the fixing temperature _T1 .