JPH11296023A - Method for controlling operation of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fuming and the burning of parts and to improve the safety by stopping energizing a fixing device and informing a user of the detection of an abnormal operation at the time of turning on a main switch again, in an image forming device in which energizing is cut off when an abnormal operation condition is detected. SOLUTION: When the main switch 1 is turned on, a fixing heater 6 generates heat through an AC control plate 2 and heating temperature is measured by a thermistor 5, and then temperature control is performed. The energizing control of the heater 6 is checked based on the previously set operation condition. When the abnormal operation condition is detected by the check, energizing the image forming device is cut off. When the main switch 1 is turned on again, the heater 6 is not energized because a CPU 3 stores the abnormal operation condition, for example, that abnormal voltage is inputted. Finally, 'code display' showing that the abnormal high voltage is inputted is displayed on the display panel, etc., of an operation part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to abnormality detection of an image forming apparatus having a fixing device, and more particularly to an operation control method of the image forming apparatus in high voltage detection control.

[0002]

2. Description of the Related Art Conventionally, when a high voltage abnormally higher than a normal rated voltage (100 VAC) is supplied (input) to an image forming apparatus such as a copying machine, the image forming apparatus is required to ensure safety. In general, an operation control method for cutting off the power supply to the power supply is performed. First, the operation control method of the conventional image forming apparatus will be briefly described with reference to FIG. 1 showing an embodiment of the present invention. FIG. 1 is a block diagram illustrating an example of a circuit configuration of a fixing device, and includes an AC power supply (A).
An AC control board 2 is connected to a power supply line to which C100V is supplied via a main switch 1, and the AC control board 2 is connected to a DC power board (not shown) for converting an AC voltage to a DC voltage. Have been. The DC power supply plate is connected to a CPU 3 for controlling the entire copying machine.
Keys (switches) for receiving various input operations by the user, an operation unit 4 having a display unit, and various sensors are connected to the CPU 3 as control targets. Also, CP
The input side of U3 is connected to a thermistor 5 as a sensor for detecting the temperature of the surface of the fixing roller, and the output side is connected to a fixing heater 6 via the AC control plate 2. Reference numeral 8 denotes an off trigger for turning off the main switch when a high voltage is input.

[0005] Next, with reference to FIG. 5, the transition of the temperature of the surface of the fixing roller of the fixing device when the power is turned on will be described. Here, the vertical axis represents the temperature detected by the thermistor 5 (° C.), and the horizontal axis represents the elapsed time (t). Then, when the normal rated voltage (AC 100 V) is supplied, the temperature rises in a transition as shown in “diagram A” with the passage of time, and when the temperature reaches a predetermined reload temperature (about 175 ° C.), fixing is performed. At the same time as the power supply to the heater is stopped, a message "COPY OK" is displayed on the operation unit. Actually, the energization / stop of the fixing heater (ON / OFF of the fixing heater) is intermittently repeated along with the temperature transition, so that the fixing heater temperature is maintained in a substantially constant range. On the other hand, for example, when an abnormally high voltage is input to the image forming apparatus, the surface temperature of the fixing heater rises in a transition as shown in “Diagram B”, and when the temperature reaches the upper limit temperature (T2). Then, the power supply to the fixing heater is interrupted and the power supply to the image forming apparatus is stopped.

[0004]

However, as described above, in the prior art, when an abnormally high voltage is input to the image forming apparatus, an operation control method for cutting off the power supply is performed.
For example, when the abnormally high voltage becomes almost twice or more of a predetermined rated voltage (AC100V), there is a possibility that the electric parts and the elements constituting the image forming apparatus are instantaneously heated and smoke or burn out. However, such an accident is not preferable because it has a problem that it appears particularly remarkably in an area where the power supply situation is poor.

Accordingly, an object of the present invention is to solve the above-described problem of the conventional operation control method of an image forming apparatus, and to stop power supply to a fixing device when a main switch is turned on again.
The present invention relates to an operation control method for an image forming apparatus capable of avoiding burnout of electric components and elements constituting the image forming apparatus by notifying detection of an abnormal operation.

[0006]

According to the present invention, in order to achieve the above-mentioned object, after turning on a main switch, the control of energization of a fixing roller of a fixing device is checked based on preset operating conditions. In an operation control method for an image forming apparatus, in which a power supply to the image forming apparatus is cut off when an abnormal operation condition is detected by the check, the invention according to claim 1, wherein when the main switch is turned on again,
The power supply to the fixing device is stopped, and the detection of the abnormal operation is notified.

According to a second aspect of the present invention, in the first aspect of the present invention, when an energizing interval to the fixing device during standby is longer than a preset energizing interval as a condition for detecting an abnormal operation, the input voltage is Is determined to be abnormal.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the notification of the abnormal operation is displayed as a code on the copy number display section of the operation section.

[0009]

1 to 3 show an embodiment of the present invention. A feature of the present invention is that when an abnormally high voltage is input to an image forming apparatus such as a copying machine, the power supply to the fixing device is stopped, and the detection of the abnormal operation can be notified. Hereinafter, the first embodiment of the present invention will be described with reference to the flowchart of FIG.

As shown in the flowchart of FIG. 2, when the main switch 1 is first turned on, the AC control board 2 (FIG.
(See FIG. 1), a voltage is applied to the fixing heater 6 (step 1). This energization causes the fixing heater 6 to generate heat (O
N), and the heat generation temperature is measured by the thermistor 5 (step 2). Then, it is determined whether or not the measured temperature T has reached the preset target temperature T1 (measured temperature T <target temperature T1) (step 3). If the temperature T of the fixing heater 6 has not reached the target temperature T1, the power supply to the fixing heater is continued (step 4). On the other hand, when the measured temperature T has reached the preset target temperature T1, the elapsed time t when the fixing heater 6 reaches the target temperature T1 based on the timing when the main switch 1 is turned on is used as a reference. Is shorter than the standard elapsed time t2 (step 5). As a result of this determination, when the elapsed time t is longer than the standard elapsed time t2, it is determined that a normal temperature transition is being performed, and normal temperature control is continuously performed (step 6).

On the other hand, the elapsed time t and the standard elapsed time t2
When the elapsed time t is shorter than the elapsed time t2 until the elapsed time t reaches the target temperature T1, the input voltage is determined to be abnormal, and the power supply to the fixing heater 6 is stopped (OFF) (step S1). 7). At the same time, the main switch 1 is automatically turned off (step 8). In this example, an energization cutoff function is performed in which the main switch 1 is turned off by a trigger signal generated by the off trigger 8. Then, even when the main switch 1 is turned on again (step 9), since the fact that the abnormal voltage has been input is stored in the CPU 3 in advance, the fixing heater 6 is not energized (step 9). Ten). Finally, a “code display” indicating that the abnormally high voltage has been input is displayed on the display panel or the like of the operation unit 4. The circuit configuration for performing such an operation control can employ the circuit configuration of an existing image forming apparatus as it is.

FIG. 3 shows a flowchart of the second embodiment. Here, an operation control method when an abnormally high voltage is input during standby is shown. That is, when the main switch 1 is first turned on, a voltage is applied to the fixing heater 6 via the AC control plate 2 (step 1). Thereafter, the energization causes the fixing heater 6 to generate heat (ON), and normal temperature control is performed (step 2). In the second embodiment, first, the copying machine is on standby (warm-up).
Is determined (step 3). If not, normal temperature control is continuously performed (step 4). If the apparatus is in the standby state, the power supply interval indicating ON / OFF of the fixing heater is measured (step 5). As a characteristic of this energization interval, as shown in FIG. 4, the input voltage is a normal rated voltage (AC10
0V), the energization interval indicating ON / OFF of the fixing heater changes with the lapse of time (t) at intervals of “C1, C2...”. When the input voltage is abnormally high, the energization interval is changed. The interval changes at intervals of “D1, D2...”. As shown in FIG. 4, the energization intervals “D1, D2...” When an abnormally high voltage is input are larger than the energization intervals “C1, C2.
It has a characteristic that its cycle is long (C1 <D1).

Then, a determination is made to compare the average value "C" with the average value "D" based on the measured value of the power supply interval (step 6). here,
“C” indicates the average value of the energization intervals “C1, C2...”, And “D” indicates the average value of the energization intervals “D1, D2...”. The average value of “C1, C2,...” And the energization interval “D1, D2,. By this determination, when the average value “D” is shorter (or almost equal) than the average value “C”, it is determined that a normal temperature transition is being performed, and normal temperature control is continuously performed. (Step 7).

On the other hand, if the average value "D" is longer than the average value "C", it is determined that the input voltage is abnormal and the fixing heater 6
The energization to is stopped (OFF) (step 8). At the same time, the main switch 1 is automatically turned off (step 9). Hereinafter, even when the main switch 1 is turned on again (step 10), the fixing heater 6 remains OFF (step 11) as in the first embodiment.
"Code display" indicating that the abnormal temperature voltage has been input to the operation unit 4 is displayed (step 12). In this way, even when the main switch is turned on again, the power supply to the fixing device is stopped, and the detection of abnormal operation is easily notified by the "code display", thereby preventing smoke and burnout of the internal parts of the copying machine. Safety can be improved

[0015]

According to the present invention, as described above, after the main switch is turned on, the energization control of the fixing roller of the fixing device is checked based on a preset operation condition, and the abnormal operation condition is detected by this check. In the operation control method of the image forming apparatus, when the main switch is turned on again, the power supply to the fixing device is stopped when the main switch is turned on again. Is notified, the smoke and burnout of the parts can be prevented, and the safety can be improved.

According to a second aspect of the present invention, in the first aspect of the present invention, when an energizing interval to the fixing device during standby is longer than a preset energizing interval as a condition for detecting an abnormal operation, the input voltage becomes abnormal. Therefore, when an abnormally high voltage is input, the current is cut off, so that there is an effect that it is possible to prevent burnout of components and to improve safety.

According to a third aspect of the present invention, in the first or the second aspect of the present invention, the notification of the abnormal operation is displayed as a code on the number-of-copies display section of the operation section, so that the abnormal operation can be easily performed. There is an effect that can be confirmed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a circuit network in a fixing device to which the present invention is applied.

FIG. 2 is a flowchart showing an operation flow of the first embodiment.

FIG. 3 is a flowchart showing an operation flow of the second embodiment.

FIG. 4 is a diagram showing a transition of the energization interval.

FIG. 5 is a diagram showing a temperature transition on the surface of the fixing roller when the main switch is turned on.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main switch 2 AC control board 3 CPU 4 Operation part 5 Thermistor 6 Fixing heater 8 Off trigger

Claims (3)

[Claims] After the main switch is turned on, the control of energization of the fixing roller of the fixing device is checked based on a preset operating condition. When an abnormal operating condition is detected by the check, the energization of the image forming apparatus is cut off. In the operation control method for an image forming apparatus, when the main switch is turned on again, the power supply to the fixing device is stopped, and the detection of an abnormal operation is notified. . 2. The apparatus according to claim 1, wherein, as a condition for detecting an abnormal operation, when the power supply interval to the fixing device during standby is longer than a preset power supply interval, it is determined that the input voltage is abnormal. An operation control method for an image forming apparatus. 3. A notification of abnormal operation is displayed as a code on a copy number display section of an operation section.
An operation control method for an image forming apparatus according to Claim 1.