JPH0326395B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying operation control method for a copying machine that performs fixing using a heat roller, and particularly to a method for controlling the copying operation of a copying machine that performs fixing using a heat roller. The present invention relates to a preferred copying operation control method.

2. Description of the Related Art As a fixing device in a copying machine, a fixing device using a heat roller has been known. For example, as shown in FIG. 1, this fixing device includes a fixing roller 2 having a heater 1 therein, and a pressure roller 3 that is pressed against the fixing roller 2 from the back side. The toner image 4A on the transfer paper 4 is heated and pressed while passing between the rollers 2 and 3, and is fixed on the transfer paper 4.

When a copying machine equipped with such a heat roller continuously copies a plurality of sheets, the temperature T of the fixing roller 2 decreases as shown in FIG. 2, and eventually fixing becomes impossible.

To prevent this, the electric power applied to the heater 1 may be increased, but this increases the power consumption of the entire copying machine and makes it impossible to use a general household power source.

Therefore, conventionally, a temperature detector 5 is provided on the fixing roller 2, and as shown in FIG. 2, when the temperature T of the fixing roller 2 falls below a predetermined lower limit temperature Td,
The copying operation was temporarily stopped, and when the temperature T of the fixing roller 2 became equal to or higher than the upper limit temperature Tu again, the copying operation was restarted.

However, in the conventional method described above, even if there is only one sheet of transfer paper remaining, the copying operation cannot be restarted until the temperature of the fixing roller 2 reaches the upper limit temperature Tu, which unnecessarily lengthens the downtime. It has the disadvantage of wasting power.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying operation control method that can shorten downtime, reduce power consumption, and operate a copying machine efficiently when making continuous copies.

In order to achieve this object, the present invention is characterized in that the copying operation is automatically restarted after the copying operation is stopped when the temperature of the heat roller recovers to a temperature at which the remaining number of sheets can be fixed. .

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a main part configuration diagram of a copying machine for explaining a copying operation control method according to an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 1 indicate the same or corresponding parts. , 6 is an A/D converter, 7 is a CPU (microprocessor), and 8 is a machine control device (MC).
It is.

With the above configuration, when the copying machine is powered on via a main switch (not shown), the mechanical control device 8 operates under the control of the CPU 7, the heater 1 generates heat, and the temperature T of the fixing roller 2 rises. Temperature detector 5 detects the temperature T of fixing roller 2, and A/D converter 6
Enter. The A/D converter 6 converts the detected value into a digital value and inputs it to the CPU 7. Based on this digital value, the CPU 7 monitors the temperature T of the fixing roller 2, and when the temperature T exceeds the upper limit temperature Tu as shown in FIG. 4, it sends a command to the machine control device 8 to permit the copying operation. . Therefore, if a print button (not shown) is pressed at this time, the copying operation is started.

As described above, when a plurality of sheets are continuously copied, the temperature T of the fixing roller 2 gradually decreases with the copying operation. CPU7 monitors the temperature T,
When the temperature eventually falls to the lower limit temperature Td, a command is sent to the machine control device 8 to temporarily stop the copying operation.
At the same time, the CPU 7 calculates the number of remaining sheets and determines the temperature Tα of the fixing roller 2 necessary for fixing the number of sheets.

That is, the heat generation efficiency of the heater 1,
A certain relationship is established that is uniquely determined by the heat storage efficiency of the fixing roller 2, the size of the transfer paper 4, the passing speed, the gap, etc. Therefore, in this embodiment, based on this relationship, the transfer paper for each transfer paper size obtained from a calculation formula or experimental results to determine the roller temperature Tα necessary for fixing that amount from the remaining number of transfer paper sheets P. A comparison table of the number of sheets P and the roller temperature Tα is stored in a predetermined memory in advance, so that when the copying operation enters the hibernation state, the CPU 7
By referring to the memory, it is possible to immediately derive the temperature Tα of the fixing roller 2 required to fix the remaining number of copies.

On the other hand, since the heater 1 continues to generate heat even during the pause period, the temperature T of the fixing roller 2 increases. Eventually, when the temperature T reaches the temperature Tα determined above, the CPU 7 sends a command to the machine control device 8 to automatically restart the copying operation.

In this way, by controlling the start timing of the copying operation after the copying machine has stopped, the rest time and the heating time of the fixing roller 2 are reduced to the time necessary to fix the remaining number of copies, reducing the number of remaining copies. In some cases, waiting time is shortened and power is not wasted. Furthermore, since the copying operation is automatically resumed, the operator can concentrate on other tasks, and office efficiency is greatly improved.

As described above, according to the present invention, downtime is shortened during continuous copying, and unnecessary power consumption is eliminated, making it possible to operate the copying machine efficiently.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a heat roller fixing device, FIG. 2 is a diagram of the relationship between roller temperature and number of transfer sheets and time during continuous copying, and FIG. 3 is a copying machine for explaining an embodiment of the present invention. FIG. 4 is a diagram illustrating the relationship between roller temperature, number of transferred sheets, and time to explain its operation. 1... Heater, 2... Fixing roller, 3... Pressure roller, 4... Transfer paper, 4A... Toner image, 5...
...Temperature detector, 6...A/D converter, 7...
CPU, 8... Machine control device.

Claims (1)

[Claims] 1. In a copying operation control method during continuous copying in a copying machine that performs fixing using a heat roller, when the temperature of the heat roller reaches a lower limit temperature that allows fixing,
While the copying operation is paused, the heat roller temperature required to fix the remaining number of sheets is determined from the relationship between the heat roller temperature and the number of sheets that can be fixed, and when the heat roller temperature recovers to that temperature, the copying operation after the pause is automatically resumed. A copying operation control method characterized in that the copying operation is restarted automatically.