JPH11184360A - Method for controlling image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the warm-up time by displaying an image forming permission signal based on ambient temperature detected just after turning on a power source and the temperature of a fixing roller detected when a specified time has passed after turning on the power source. SOLUTION: Since the temperature of the fixing roller when the time t2 has passed, reaches lower limit temperature T1 even when the ambient temperature is the lowest temperature within a 1st temperature range R1, it is possible to form the image and image forming permission is displayed. By setting the 1st specified time t1 shorter than the time t2, the temperature of the fixing roller when the time t1 elapses reaches the temperature within a 3rd temperature range R3. If the ambient temperature is within the range R1 at the time of turning on the power source and the temperature of the fixing roller is within the range R3 at the time t1 before the time t2, it is predicted that the temperature of the fixing roller reaches the lower limit temperature T1 at the point of time t2 when the time (t2-t1) elapses from the time t1, so that the image forming permission signal can be displayed on a display unit when the time t2 has passed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a control method for an image forming apparatus such as a copier and a printer, and more particularly to a control method for reducing a warm-up time of the apparatus.

[0002]

2. Description of the Related Art In a conventional image forming apparatus such as an electrophotographic copier, when a fixing roller reaches a predetermined set temperature after the power is turned on and turned on, an image forming permission is displayed on a display section of the apparatus. Is done. This warm-up time is the time from when the apparatus power is turned on to when the fixing temperature is reached. Referring to FIG. 5, steps until the image formation permission is displayed in the conventional image forming apparatus will be described. First, the image forming apparatus is turned on (S1), and the temperature (T ° C.) of the fixing roller is read (S2).
It is determined whether the temperature is equal to or lower than ℃ (S3). If the temperature is 195 ° C. or lower, the next step S
In 5 it is determined whether the temperature of the fixing roller has reached 195 ° C.
If not reached, the heater is turned on (S4), and the process returns to step S2. If reached, it is determined whether the heater has been turned on (S6). If the heater is on, the heater is turned off (S7). If it is off, a ready display is displayed on the display unit (S8). In this way, the user can know that the apparatus is ready for image formation.

In the conventional image forming apparatus as described above, the set temperature (195 ° C. in FIG. 5) of a fixing roller provided for fixing a toner image on a transfer material usually does not cause fixing failure. The setting is made in consideration of all the fixing conditions such as the upper and lower limits of the temperature, the life of the fixing roller, and variations in the power supply voltage, the fixing heater, and the accuracy of the temperature sensor. Therefore, in practice, there is a range in the set temperature at which an image can be formed, and there is a case where the set temperature of the fixing roller at which an image can be formed may be set lower.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control system capable of shortening a warm-up time from when the power of the apparatus is turned on to when an image can be formed in the above-described image forming apparatus. Is to provide a way.

[0005]

In order to achieve the above object, the present invention provides a fixing roller, a pressure roller pressed against the fixing roller, a heater for heating the fixing roller, and a temperature of the fixing roller. Fixing means for fixing a toner image formed on the transfer material, and an environmental temperature detecting means for detecting an environmental temperature in the image forming apparatus or the fixing means, A control unit for displaying an image formation permission signal, the control unit comprising: a display unit configured to display a permission signal for image formation; The display means based on the time elapsed since the power was turned on, based on the temperature of the fixing roller detected by the fixing temperature detecting means before and after the first predetermined time has elapsed since the power was turned on. And displaying the enabling signal of the image formed.

According to the control method of the present invention, the ambient temperature at the time of operation of the apparatus and the temperature of the fixing roller after a first predetermined time elapses before the temperature of the fixing roller reaches the set temperature after the operation of the apparatus. Since the temperature of the fixing roller can be predicted using time as a parameter, the state in which an image can be formed can be known from the elapsed time from when the power is turned on.
Accordingly, it is possible to display the image formation permission signal in a time that is lower than the set temperature (a time shorter than reaching the set temperature). The time is shortened, and the warm-up time of the device can be shortened.

In addition, it is determined whether or not the detected environmental temperature is within a predetermined range, and whether or not the detected fixing roller temperature is within a predetermined range. When the temperature is within each of the predetermined ranges, an image formation permission signal can be displayed on the display means when a second predetermined time has elapsed since the power was turned on. According to this control method, the temperature rise rate of the fixing roller temperature can be obtained if the environmental temperature at the time of operation of the apparatus and the fixing roller temperature at the time when the first predetermined time elapses after the operation are within the respective predetermined ranges. Since the time until the temperature of the fixing roller reaches the temperature at which the image can be formed can be more accurately predicted, the image formation permission signal is displayed at the time (second predetermined time) at which the temperature at which the image can be formed is lower than the set temperature. In this case, accurate display can be achieved.

It is preferable that the first predetermined time is set close to a second predetermined time. The first predetermined time is shorter than the second predetermined time, but is preferably as close as possible to the second predetermined time from the viewpoint of ensuring accuracy. If the first predetermined time and the second predetermined time are too far apart, and if the rate of increase of the fixing roller temperature after the first predetermined time changes, the fixing roller temperature will rise to the set temperature at the time when the second predetermined time has elapsed. This is because the possibility that a lower image forming temperature than the lower limit has not yet been reached is more likely to occur.

When the temperature of the fixing roller has not reached the set temperature when the image formation permission signal is displayed,
The heater may be driven until the set temperature is reached. Thereby, the temperature of the fixing roller can be controlled more accurately.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a control system relating to fixing of an image forming apparatus capable of implementing the control method of the present embodiment. A control unit 1 shown in FIG. 1 is capable of performing the present control method, and includes a fixing temperature detecting unit 2 for detecting a temperature of a fixing roller for fixing a toner image formed on a transfer material, Based on each detection signal from an environmental temperature detecting unit 3 for detecting the temperature in the apparatus or the environmental temperature of the fixing device including the fixing roller, and a time counter 6 capable of measuring an elapsed time after turning on the power, The heater 4 and the display 5 are controlled. The heater 4 heats the fixing roller, and the display 5 displays an image formation permission signal, a standby state signal, and the like. In addition, the detection of the fixing roller temperature and the environmental temperature may be performed at one or more temperature detection points.
Further, it may be limited to a certain range.

The basics of the control method according to the present embodiment will be described with reference to FIG. FIG. 2 shows the relationship between the time elapsed since the power supply of the image forming apparatus was turned on and the temperature of the fixing roller, and the temperature of the fixing roller increases with time. A straight line A in FIG. 2 shows the relationship between the elapsed time and the fixing roller temperature when the environmental temperature is the maximum in the range R1. Straight line B
Shows the relationship between the elapsed time and the fixing roller temperature when the environmental temperature is the minimum within the range R1, and the fixing roller temperature rises at substantially the same rate of temperature rise as the straight line A. In the figure, a temperature T0 is a median set temperature of the fixing roller temperature, and the median T0 is a conventional set temperature. Temperature T1
Is a set temperature lower limit value, and the lower limit value T1 is a temperature at which no image failure occurs even when images are continuously formed. In addition,
The environmental temperature refers to a temperature range in which the inside of the image forming apparatus is determined to be normal temperature.

In FIG. 2, when the power of the image forming apparatus is turned on (time 0 second), the environmental temperature is reduced to a first temperature range R1.
If the temperature is within the range, the fixing roller temperature at the lapse of the second predetermined time t2 reaches the temperature within the second temperature range R2 corresponding to the temperature range (T0 to T1). Since the fixing roller temperature at the time t2 has elapsed has reached the lower limit temperature T1 even if the environmental temperature is the minimum temperature within the first temperature range R1, image formation is possible, and the image formation permission display is displayed. Is done. Here, if the first predetermined time t1 shorter than the time t2 is set, the temperature of the fixing roller after the time t1 reaches the temperature within the third temperature range R3. When the power is turned on, the environmental temperature is within the range of R1 and the time t1 is earlier than the time t2.
If the fixing roller temperature is within the range of R3, it can be predicted that the fixing roller temperature has reached at least the lower limit temperature T1 at the time t2 after the elapse of the time (t2−t1) from the time t1. The display of the image formation permission signal can be displayed on the display 5 in FIG. In this way, it is possible to control the display of the image formation permission using the time as a parameter.

Therefore, if the fixing roller temperature rises as shown by the straight line B in FIG. 2 and also rises after the lapse of time t2 as indicated by the dashed line, it reaches the set temperature T0 after the lapse of time t3. In comparison with, the warm-up time can be reduced by the time difference (t3−t2) between t3 and t2.

Next, the above control method will be described more specifically with reference to FIGS. FIG. 3 is a flowchart for explaining the control method according to the present embodiment. Each step of the control method will be described with reference to FIG.

First, after the power of the image forming apparatus is turned on (S10), the environmental temperature (A) of the image forming apparatus is read by the environmental temperature detecting unit 3 in FIG. It is determined whether the temperature is within the range of 16 ° C. or more and less than 25 ° C. (S12), and if it is within this range, the fixing roller temperature (T) is read by the fixing temperature detector 2 in FIG.
13). If the environmental temperature is out of the range, the control is performed in steps S31 to S37 in the same manner as steps S2 to S8 in FIG. 5, and when the image formation is possible, the ready display is performed (S22).

If it is determined in step 14 that the fixing roller temperature is lower than the set temperature (the set temperature central value T0, which is 195 ° C. in this example), the heater 4 in FIG. It starts (S15). The time elapsed since the power was turned on is read by the time counter 6 in FIG.
In a state where the temperature is lower than 95 ° C., heating is continued until the first predetermined time (87 seconds in this example, which corresponds to t1 in FIG. 2) has elapsed since the power was turned on, and the fixing roller temperature is increased (S1).
7) When the first predetermined time (87 seconds) has elapsed, the fixing roller temperature is read (S18), and this fixing roller temperature is within a predetermined range (p = 185 ° C. or more and q = 190 ° C. in this example).
(Corresponding to R3 in FIG. 2 in the range of less than) (S19). If the fixing roller temperature is within the predetermined temperature range, the elapsed time since the power was turned on is read (S20), and a second predetermined time (in this example, 90 seconds in this example) since the power was turned on in step S21. (Corresponding to t2 in FIG. 2), a ready display is made indicating that the fixing roller temperature has reached a temperature at which image formation is possible (S2).
22). If the fixing temperature roller is out of the predetermined range in step S19, control is performed in steps S31 to S36, and when the fixing roller reaches the set temperature, a ready display is displayed (S37). Further, the fixing roller is heated so as to reach the set temperature central value T0 even after the lapse of the second predetermined period in order to improve the image quality of the toner image formed on the transfer material. After the image formation permission signal is displayed, the fixing roller temperature is controlled so as to maintain the set temperature central value T0.

The above control method will be further described with reference to FIG. FIG. 4 shows the relationship between the time elapsed since the power was turned on and the fixing roller temperature, similarly to FIG. In the drawing, a straight line ba indicated by a wavy line corresponds to the straight line A in FIG. 2, and when the ambient temperature is 25 ° C., the fixing roller temperature rises at a temperature rising rate like a normal straight line ba. Also the straight line b
c corresponds to the straight line B, and when the ambient temperature is 16 ° C., the fixing roller temperature rises at a temperature rising rate like the normal straight line bc. Here, as shown in FIG. 3, the first elapsed time t1 is 8
Set 7 seconds and set the temperature range R to 185 ° C or more and 190 ° C
Set to a value less than.

For example, when the ambient temperature is in the range of 16 ° C. or more and less than 25 ° C. and near 25 ° C., as shown by the straight line bb, the fixing roller temperature falls within the predetermined temperature range R when 87 seconds have elapsed. For example, the ready display is performed assuming that image formation is possible at the elapse of 90 seconds. The rate of temperature rise of the straight line bb is determined by the linear b
Although it is smaller than a and bc, since the fixing roller temperature is within the temperature range R when 87 seconds have elapsed, the control method according to the present embodiment is possible.

Even when the ambient temperature is in the range of 16 ° C. or more and less than 25 ° C., the rate of temperature rise is reduced due to variations in the power supply voltage as shown by the straight line cc, and the fixing roller temperature is 87 ° C. If the temperature does not fall within the predetermined temperature range R at the elapse of the second, the ready display is performed when the set temperature has risen to 195 ° C. in steps S21 to S26 in FIG.
Similarly, even when the environmental temperature is lower than the temperature range, ready display is performed when the set temperature has risen to 195 ° C. in steps S21 to S26 in FIG. 3, as indicated by the straight line dd.
Also, when the fixing roller is heated to some extent, such as when the power supply of the apparatus is turned on again, similarly, the temperature rises to the set temperature of 195 ° C. in steps S21 to S26 in FIG. Display ready at the time.

As described above, according to the control method of the image forming apparatus according to the present embodiment, the temperature of the fixing roller can be predicted using the time as a parameter based on the ambient temperature and the temperature of the fixing roller at the time when the predetermined time t1 has elapsed. Before the roller reaches the set temperature, the image formation permission signal can be displayed on the display, and the warm-up time of the apparatus can be reduced. For this reason, the waiting time until the image can be formed can be shortened, and the usability of the image forming apparatus is improved. When the image formation permission signal is displayed on the display device, for example, a copier can receive a copy.

The predetermined time t1 is preferably before the time for displaying the image formation permission signal and is as close as possible to the time t2 to reach the set temperature as much as possible in order to ensure accuracy. In the case of this example, the time t2 and the time t
Although the time difference from 1 is set to 3 seconds, it is not limited to this. Further, the predetermined time t1, the fixing roller temperature range R3 at the predetermined time t1, the environmental temperature range R1, the predetermined time t2, the set temperature median T0, the set temperature lower limit T1, and the like can be arbitrarily set according to the fixing conditions and the like. Of course.

[0022]

According to the control method of the present invention, it is possible to display the image formation permission signal in such a time that the temperature becomes lower than the set temperature, and the time until the image formation permission signal is displayed. Therefore, the warm-up time from when the power of the apparatus is turned on to when the image forming apparatus is ready for image formation can be shortened.

Further, according to the control method, when the environmental temperature and the fixing roller temperature are within the respective predetermined ranges, an image formation permission signal is displayed on the display means when a second predetermined time has elapsed since the power was turned on. Since the time until the fixing roller temperature reaches the temperature at which the image can be formed can be more accurately predicted, when displaying the image formation permission signal at the second predetermined time at which the temperature at which the image can be formed becomes lower than the set temperature, the accuracy is high. Can be displayed.

According to the control method in which the first predetermined time is set close to the second predetermined time, the temperature of the fixing roller can be controlled more accurately.

Further, according to the control method of driving the heater until the fixing roller temperature does not reach the set temperature when the image forming permission signal is displayed, the fixing roller temperature is controlled more precisely. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a control system related to fixing of an image forming apparatus capable of implementing a control method according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the basics of the control method according to the present embodiment, and is a diagram illustrating a relationship between an elapsed time after power-on of the image forming apparatus and a fixing roller temperature.

FIG. 3 is a flowchart illustrating a control method according to the present embodiment.

FIG. 4 is a diagram illustrating a relationship between an elapsed time after power-on of the image forming apparatus and a fixing roller temperature in the control method described in FIG. 3;

FIG. 5 is a flowchart illustrating a fixing control method in a conventional image forming apparatus.

[Description of Signs] 1 control unit 2 fixing temperature detecting unit 3 environmental temperature detecting unit 4 heater 5 display 6 time counter t1 first predetermined time t2 second predetermined time R1 environmental temperature range R3, R first predetermined time Fixing roller temperature range after t1 T0 Median set temperature (set temperature) T1 Lower limit set temperature

Claims (4)

[Claims] A fixing roller, a pressure roller pressed against the fixing roller, a heater for heating the fixing roller, and fixing temperature detecting means for detecting a temperature of the fixing roller. Image forming apparatus comprising: fixing means for fixing a toner image formed on an image forming apparatus; environmental temperature detecting means for detecting an environmental temperature in the image forming apparatus or the fixing means; and display means for displaying an image forming permission signal. In the method of controlling an apparatus, an environmental temperature detected by the environmental temperature detecting unit immediately after the power of the image forming apparatus is turned on, and a first predetermined time elapses from when the power is turned on before reaching a predetermined set temperature. A permission signal for image formation is displayed on the display means based on an elapsed time from power-on based on the temperature of the fixing roller detected by the fixing temperature detecting means. Your way. Determining whether or not the detected environmental temperature is within a predetermined range; determining whether or not the detected fixing roller temperature is within a predetermined range; 2. The control method according to claim 1, wherein when the temperature is within each of the predetermined ranges, an image formation permission signal is displayed on the display means when a second predetermined time has elapsed since the power was turned on. 3. The control method according to claim 2, wherein the first predetermined time is set close to the second predetermined time. 4. The heater according to claim 1, wherein when the fixing roller temperature does not reach the set temperature when the image formation permission signal is displayed, the heater is driven until the set roller temperature reaches the set temperature. Control method.