JPH10301439A - Fixing unit controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance fixation while being suitable for the respective environmental conditions for using an electrophotographic device by controlling to turn on or off heating elements by using a temperature detection means, the set values of a turning-on cycle and a turning-on ratio and a voltage impressing means. SOLUTION: This device is provided with a means setting the turning-on cycles and the turning-on ratios of the respective heating elements 13 and a main control means controlling to turn on or off the elements 13 by using the temperature detection means 14, the set values of the turning-on cycles and the turning-on ratios and the voltage impressing means 12. In this device, the present temperature of the elements 13 is detected as an analog value by the detection means 14 and recognized as a digital value through an A/D converter by a CPU core. Then, it is decided according to the present digital value and the digital value obtained before one cycle which stage of four prescribed stages the present temperature exists in. Besides, a signal for turning on or off the elements 13 is transmitted to the impressing means 12 through an output port according to the combination of the turning-on ratios, etc., read out from a RAM.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a fixing device for fixing a toner image formed on a transfer material in an electrophotographic apparatus.

[0002]

2. Description of the Related Art In a conventional fixing device control apparatus of this type, a plurality of heating elements having different performances are installed inside a fixing roller, and a lighting cycle, which is set in advance according to a paper size detected by self-diagnosis, is set. Using the lighting ratio and the temperature detected by the temperature detecting means for detecting the temperature of the fixing device provided on the surface of the fixing roller, the temperature of the fixing device is controlled to be constant.

[0003] This type of fixing device control device has a set of lighting ratios with respect to the lighting cycle of each heating element for each paper size. In this group, the lighting ratio gradually changes from a smaller one to a larger one, and the fixing device control device lights each heating element according to the lighting ratio indicated by the reference pointer.

Hysteresis is provided for the temperature control target temperature, and the current temperature is “lower than the temperature control target temperature” (hereinafter, referred to as “Low”), and “temperature control target temperature +
Higher than hysteresis ”(hereinafter, referred to as“ High ”),“ in ascending ”, and“ in descending ”are determined. Then, when “High” is attained from another stage and when “High” is continued, the reference pointer is moved to one of the sets of the lighting ratios in which the lighting ratio becomes smaller.

[0005] When it becomes "Low" from other stages,
When “Low” continues, the reference pointer is moved to a portion having a larger lighting ratio among the sets of the lighting ratios. By performing such control, the temperature change of each heating element is made smooth. FIG. 5 shows that the lighting cycle is 500 msec.
FIG. 4 is an explanatory diagram of fixing temperature control when two heating elements (heaters) are provided.

Reference numeral 51 denotes a set of lighting ratios. For identification, DutyNo. It is given a serial number. If the reference pointer is DutyNo. If you are pointing to 15,
The heater 1 is 500 ms for a lighting cycle of 500 ms.
ec, the heater 2 is turned on for 250 msec. A graph 54 in FIG. 5 shows the surface temperature of the fixing roller. Reference numeral 52 indicates in which stage the temperature of each heating element is in each cycle. Each "Hig
"h" is represented by H, "Low" by L, "up" by R, and "down" by F. 53 is DutyNo. Represents
In the first stage in FIG. Is 8 and DutyNo. The state of the transition is shown.

In general, the lighting cycle and the lighting ratio 51 are prepared for each paper size, and are not changed by the same CPU.

[0008]

However, in this type of fixing device control using a lighting cycle and a lighting ratio preset according to the paper size, for example, paper quality, environmental temperature, environmental humidity, etc. are different from normal. When used in rural areas, the fixability was sometimes deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a means for improving the fixing property suitable for each use environment condition of an electrophotographic apparatus. .

[0010]

Therefore, in the present invention, the above object is achieved by providing a fixing device control device according to any one of the following items (1) to (8). .

(1) A plurality of heating elements having different performances, voltage applying means for making each heating element generate a constant amount of heat per unit time, and heating by the heating elements. A temperature detecting unit of the fixing device, a unit for setting a lighting cycle and a lighting ratio of each of the heating elements, and the temperature detecting unit, a setting value of the lighting cycle and the lighting ratio, and a voltage applying unit using the temperature detecting means. A fixing device control device comprising: a main control unit that controls turning on and off.

(2) the lighting cycle of each heating element,
The fixing device control device according to (1), wherein the means for setting the lighting ratio is an external input device operable by a user of the device.

(3) The fixing device control device as described in (2) above, wherein the external input means operable by the user comprises a combination of a button and a liquid crystal panel.

(4) The fixing device control device as described in (2) above, wherein the external input means operable by the user is constituted by a touch panel.

(5) The lighting cycle of each heating element,
The means for setting the lighting ratio is an external input means that can be operated by the user, and the input from the external input means is effective unless a specific dedicated tool used on site by an equipment service person is used at the same time. The fixing device control device according to the above (1), wherein

(6) The fixing device control device as described in (1) above, wherein the heat generating elements having different performances have different power consumptions.

(7) The fixing device control device according to the above (1), wherein the light distributions are different from those of the heating elements having different performances.

(8) The voltage applying means for making the amount of heat generated from the heating element per unit time constant is a means for detecting an input power supply voltage, and a means for detecting an input power supply voltage per unit time according to the detected input voltage. The fixing device control device according to the above item (1), which is a driving device that controls the application time to the heating element.

[0019]

According to the configuration of the present invention as described above, it is possible to make a special specification of the fixing device control device for each electrophotographic apparatus in accordance with the use environment and the transfer material to be used, thereby improving the fixing performance at low cost. Can be planned.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail based on a plurality of examples.

[0021]

(Embodiment 1) An embodiment in which the user resets the lighting cycle and the lighting ratio from outside using an external input means operable by the user of the apparatus will be described. FIG. 1 shows a schematic block diagram of a fixing device control device according to the present embodiment.

Reference numeral 11 denotes main control means (usually a CPU);
Represents a voltage applying means, 13 represents a heating element, 14 represents a temperature detecting means (usually a thermistor), and 15 represents an external input means (usually an operation panel).

FIG. 2 is a block diagram showing the configuration of the main control means (CPU) 21. The main control means comprises a CPU core 21, a ROM 22, a RAM 23, an input port 24, an output port 25 and an A / D converter 26.

When the CPU core 21 is notified by an external input means through the input port 24 to enter the mode for changing the lighting cycle and the lighting ratio, it reads the menu screen data for that purpose from the ROM 22 and outputs the data to the output port 25.
Is displayed on the external input means through. When data of the lighting cycle and the lighting ratio is received from the external input means through the input port 24, the data is stored in the RAM 23.

The current temperature of the heating element 13 shown in FIG. 1 is detected as an analog value by the temperature detecting means 14, and is converted into a digital value through the A / D converter 26.
Recognizes. Based on the current digital value and the digital value one cycle before, it is determined which one of the four levels 52 shown in FIG. A signal for turning on / off the heating element 13 is sent to 12. The voltage applying means 12 receiving the light-on / light-off signal applies a voltage to the heating element 13 according to the signal.

Next, a task (FIG. 3) for accepting a change in operation setting from the external input means and a task (FIG. 4) for performing heater control will be described, and an operation sequence flowchart of each task will be described.

In FIG. 3, the task for accepting a change in the setting of the operation from the external input means accepts a process shift to a mode for changing the lighting cycle and the lighting ratio (step S31). A screen is displayed (step S32), and input is waited for which of the period change, the ratio change, and the termination is to be performed (step S33). When the lighting cycle is changed (step S
1) Save the input lighting cycle (step S3)
4) Return to waiting for input (step S2).

When Changing the Lighting Ratio (Step S
3) Save the lighting ratio input in the same manner (step S)
35) Return to waiting for input. When an end instruction is input (step S4), it is confirmed that the lighting cycle and the lighting ratio have been changed (step S36), and if there has been a change, a flag indicating the change has been set (step S37). ),
The process returns to accepting the transition process to the change mode again (step S5).

On the other hand, the task for controlling the heater determines whether or not a flag indicating that the lighting cycle and the lighting ratio have been changed in FIG. 4 is set (step S4).
1). If the flag is set, the flag is reset (step S42), and the reference table of the lighting cycle and the lighting ratio is changed to the one input by the user (step S42).
43). As the reference table, the table that is currently pointing is used without any change unless otherwise specified. The current state is determined from the current detected temperature and the state one cycle before (step S44).

If "Low" (Step S1)
1) The reference pointer of the lighting ratio is updated in the direction of increasing the ratio (step S45). If it is “High” (step S12), the reference pointer of the lighting ratio is updated in the direction of decreasing the ratio (step S12). S46).
If “up” or “down” (step S1
In 3), the reference pointer is not changed. The lighting ratio of the heater is determined from the reference pointer and the paper size, and a lighting instruction is given as to how much the heater is turned on during the lighting cycle (step S47).

By saving the lighting cycle and lighting ratio input from the external input means in a nonvolatile RAM instead of a mere RAM, it is possible to save the trouble of inputting each time the main body is reset.

(Second Embodiment) In the fixing device control device of the first embodiment, there is a possibility that an inappropriate lighting ratio is set for each paper size, and the fixing property is rather deteriorated. Therefore, a method of preventing a malfunction by making the lighting ratio changeable only within a preset range for each paper size is conceivable.

Step S34 in the flowchart of FIG.
In S35, if the setting value from the user deviates from the allowable range, the input is not accepted, thereby preventing the malfunction.

(Embodiment 3) Next, a fixing device control device according to a fifth embodiment will be described with reference to an embodiment. In view of the danger that the user can change the lighting cycle and the lighting ratio, the fixing device control device of the fifth aspect changes the configuration in order to limit the authority to change the lighting cycle and the lighting ratio to a service person. ing. The lighting cycle and the lighting ratio are changed by using an external input room as in the first embodiment. However, when a service person uses a specific service tool connected to the electrophotographic apparatus main body at the site, the lighting cycle and the lighting ratio are changed. Only the lighting cycle,
The change of the lighting ratio is permitted.

In step S31 of the flowchart of FIG. 3, when accepting the processing shift to the mode for changing the lighting cycle and the lighting ratio, the connection of the service tool is confirmed, and if it is not connected, it is not accepted. I do. Further, as in the second embodiment, the settable range of the set value can be limited.

[0036]

As described above, according to the present invention,
Depending on the use environment of the electrophotographic device and the transfer material used,
The special specification of the fixing device control device becomes possible, and the fixing property can be improved. Since the settings can be individually set for each unit, the cost of the change can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a fixing device control device according to an embodiment.

FIG. 2 is a configuration block diagram of a CPU.

FIG. 3 is an operation sequence flowchart of a setting change receiving task.

FIG. 4 is an operation sequence flowchart of a heater control task.

FIG. 5 is an explanatory diagram of a fixing device temperature control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Main control means 12 Voltage application means 13 Heating element (heater) 14 Temperature detecting means 15 External input means 21 CPU core 22 ROM 23 RAM 24 Input port 25 Output port 26 A / D comparator 51 Lighting ratio table 52 Heating element temperature stage 53 Duty No. 54 Graph of fixing roller surface temperature

Claims (8)

[Claims] 1. A plurality of heating elements having different performances, voltage applying means for causing each heating element to generate a constant amount of heat per unit time, and fixing heated by the heating elements. Temperature detecting means of the device, and means for setting a lighting cycle and a lighting ratio of each of the heating elements;
A fixing device control device, comprising: a main control unit that controls turning on and off of the heating element by using the temperature detecting unit, a set value of a lighting cycle, a lighting ratio, and a voltage applying unit. 2. The fixing device control device according to claim 1, wherein the means for setting the lighting cycle and the lighting ratio of each of the heating elements is an external input means operable by an apparatus user. 3. The fixing device control device according to claim 2, wherein the external input means operable by the user is constituted by a combination of a button and a liquid crystal panel. 4. The fixing device control device according to claim 2, wherein the external input means operable by the user is constituted by a touch panel. 5. A means for setting a lighting cycle and a lighting ratio of each of the heating elements is an external input means operable by the user, and a specific dedicated tool used on site by an equipment service person. 2. The fixing device control device according to claim 1, wherein an input from an external input unit is not validated unless the input device is used at the same time. 6. The fixing device control device according to claim 1, wherein power consumption is different from the heating elements having different performances. 7. The fixing device control device according to claim 1, wherein a light distribution is different from the heating elements having different performances. 8. A voltage applying means for making the amount of heat generated per unit time from the heating element constant, means for detecting an input power supply voltage, and heat generation per unit time according to the detected input voltage. 2. The fixing device control device according to claim 1, further comprising a driving device for controlling the application time to the body.