JP3451469B2 - Fixing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an image forming apparatus such as a copying machine, a facsimile, a printer and the like.

[0002]

2. Description of the Related Art A fixing device used in an image forming apparatus such as a copying machine, a facsimile or a printer is a fixing device in which a plurality of areas are heated by a plurality of heating means according to the size of the paper and a toner image on the paper is fixed. Means, a plurality of temperature detecting means for respectively detecting temperatures of a plurality of portions of the fixing means corresponding to the plurality of heating means, and the plurality of temperature detecting means based on temperature detection signals of the plurality of temperature detecting means. And a control means for independently controlling the heating means.

Japanese Patent Publication No. 6-73053 discloses that
A fixing roller having a plurality of heating means and a pressure roller are brought into pressure contact with each other, and the recorded transfer paper is passed only between these rollers to fix the toner on the transfer paper by pressure and heating. A plurality of heating means are controlled based on a detection signal of one temperature detecting means for detecting the temperature of the fixing roller, and when the temperature of the fixing roller does not reach a predetermined set temperature, the plurality of heating means are simultaneously driven to fix the fixing roller. A fixing device for maintaining the temperature of the roller at a predetermined set temperature is described.

In Japanese Patent Laid-Open No. 59-111669, the temperature of a fixing device having two or more heaters is detected, and when two or more heaters are energized together, one heater is energized and then detected. Delay by a predetermined time corresponding to the temperature
A method for controlling the energization of the fixing heater, which energizes two heaters, is described.

Japanese Unexamined Patent Publication No. 4-168468 discloses a plurality of electric heating elements and a temperature for detecting the temperature of the electric heating elements in an image forming apparatus in which an electric heating element is used to perform heat fixing using an AC power source. And a control means for selecting a predetermined number of electric heating elements from among the plurality of electric heating elements according to the difference between the temperature detected by the temperature detecting means and the target temperature and energizing them. When a plurality of the electric heating elements are selected and energized, the energization start timing is set so as to be shifted by at least a half cycle of the frequency of the AC power supply or more, and the image forming apparatus is described. ing.

Japanese Unexamined Patent Publication (Kokai) No. 59-33480 discloses a copying machine provided with a drive circuit for detecting a zero cross of an alternating power source voltage and applying the alternating power source voltage to a heater for a heating roll of a fixing device. The heater is composed of a plurality of heaters having different power consumptions, and the drive circuit pre-drives the heaters at a voltage lower than a predetermined voltage in the ascending order of the power consumption of the heater and then drives the heater at the predetermined voltage. A heater driving device for a fixing device for a copying machine is described.

Japanese Unexamined Patent Publication No. 6-236128 discloses an image forming apparatus which forms an image on a recording medium with a developing material such as toner and heat-fixes it to output an image-formed product. A heater control unit that has a heater and selectively drives the plurality of heaters according to the operating state of the apparatus, and shifts the drive start timing of each heater when the heat fixing unit uses the plurality of heaters at the same time. An image forming apparatus is described which has the following.

[0008]

Due to the EU (European Union) market integration since January 1993, uniform safety requirements are applied to products in the EC (Europe) market, and manufacturers are There is an obligation to sell only safe products in the EC market. The safety protection standards for application to the EC market are stipulated in the EC directive, harmonized national standard, and harmonized domestic law for each product.

The CE marking is obligatory for the manufacturer to declare that the product complies with the applicable EC Directives, and through the CE marking, the protection standard applied in the Directive of the product. Has proved its suitability for.

EMC (Electr) in the EC command
The electromagnetic compatibility (electromagnetic compatibility) directive includes EMI (Electronic Compatibility)
magnetic interference (electromagnetic interference) standard and EMS (Electromagnetic)
Susceptibility: electromagnetic wave sensitivity) standards, and IEC standards and EN for measurement methods and regulation values.
It is defined by the standard.

Among the EMC commands, a power supply voltage fluctuation test (around lighting may flicker due to frequently repeated voltage fluctuations, and people may feel uncomfortable. This state is called a flicker state, and the flicker state is measured. The measured values are regulated.) And harmonic current tests (OA equipment that uses an inverter, air conditioners, etc. increase the outflow of harmonic current to the power supply line, which may cause a fire accident or power factor decrease in the power receiving equipment. The harmonic current value is regulated in order to suppress the decrease in the efficiency of power transmission equipment.) Unlike other test items, measures and suppression have not been taken so far, so There is an urgent need to take measures and control.

[0012] In addition, the regulation has been decided not only in EC countries but also in Japan, and there will be no doubt that legal regulations will be imposed in countries all over the world. Furthermore, in recent years, due to the complicated control of electrophotographic processes and the use of high-power heat generators in copying machines, the current fluctuations of the product are larger than in the previous year, and noise, power supply voltage fluctuations, and harmonic currents are generated. There is concern about the influence of malfunction or failure of the device due to entering into another electronic device in the vicinity. Also,
Safety standards and legal regulations against noise are becoming stricter, and countermeasures and controls are also required.

In particular, a fixing device using a heating means having a heating element with a large power consumption consumes a power source voltage fluctuation test due to the operation of the heating means (the surrounding lighting flickers due to frequently repeated voltage fluctuations, which makes people uncomfortable. This condition is called the flicker condition, and the measured value of the flicker condition is regulated.)
It is difficult to achieve the standard value.

In the fixing device described in Japanese Patent Publication No. 6-73053, a plurality of heating means are controlled on the basis of the detection signal of one temperature detecting means for detecting the temperature of the fixing roller. By driving the ICs at the same time, a sudden rush current often occurs, and the voltage fluctuation applied to the power supply is large.

Further, the energization control method for the fixing heater described in the above-mentioned JP-A-59-111669 and JP-A-4-1-1.
Image forming apparatus described in Japanese Patent No. 68468, JP-A-59-3
A heater driving device for a fixing device for a copying machine described in Japanese Patent No. 3480, and an image forming apparatus described in Japanese Patent Application Laid-Open No. 168468/1994 operate at the same time when a plurality of heating units are turned off (not lit) and turned on (lit). Although not allowed, it is difficult to achieve the standard value for the power supply voltage fluctuation test with this alone. SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing device capable of attaining a standard value with sufficient reduction / suppression effects on power supply voltage fluctuations.

[0016]

In order to achieve the above object, the invention according to claim 1 is a fixing means for fixing a toner image on a sheet by being heated by a plurality of heating means, and the fixing means for fixing the toner image. Each of the heating means has a plurality of temperature detecting means for detecting the temperature of a plurality of portions corresponding to the individual heating means, and a timer for lighting the heating means.
A timer for turning off the heating means is provided for each heating means.
And independently controlling the plurality of heating means based on the temperature detection signals of the plurality of temperature detection means, and
Each of said plurality of heating means with activating the timer of the pressurized <br/> heat means for lighting other than heating means when the lighting of the heating means to be lighted when turning on the each of the plurality of heating means said heating means timer for turning off the non-heating means is activated upon turning off of the heating means to be turned off when turning off, said heating means for the lighting to be turned on when lighting the each of the plurality of heating means When the timer is turned on and the heating means is turned on to control the plurality of heating means so as not to be turned on at the same time, and to turn off each of the plurality of heating means. by the heating means off for the timer to be turned off is to turn off the heating means determines that the time is up on the plurality of heating hands Simultaneously are those and control means for controlling so as not from ON to OFF, it is possible to achieve the standard value is sufficient effect of reduction and inhibition obtained with respect to the power supply voltage fluctuations.

According to a second aspect of the present invention, the fixing means for fixing the toner image on the sheet by being heated by the plurality of heating means, and the temperatures of a plurality of portions of the fixing means corresponding to the plurality of heating means are set. Each of the heating means includes a plurality of temperature detecting means for detecting the temperature and a timer for lighting the heating means.
Each has a timer for turning off the heating means.
The heating means has each heating means, controls the plurality of heating means independently based on the temperature detection signals of the plurality of temperature detection means, and turns on each of the plurality of heating means. the pressure of the non-heating means upon turning off of the heating means to be turned off when that said heating means timer for lighting other than heating means causes started when the lighting of the heating means is turned off each of said plurality of heating means to < br /> starts a timer for turning off the heat means, the heating means determines that said heating means timer for lighting to be lighted has timed the time of turning on each of said plurality of heating means by lighting, controls so as not to said plurality of heating means from oFF to oN at the same time, when turning off each of said plurality of heating means prior to be turned off By timer for heating means off is to turn off the heating means determines that the time is up, and controlled not said plurality of heating means at the same time from ON to OFF, each of said plurality of heating means It is provided with a control means for giving a delay time at the timing of turning on from off and the timing of turning on from off, and it is possible to obtain a sufficient reduction / suppression effect with respect to fluctuations in the power supply voltage.

According to a third aspect of the present invention, the fixing means for fixing the toner image on the paper by being heated by the plurality of heating means, and the temperatures of a plurality of portions of the fixing means corresponding to the plurality of heating means are set. Each of the heating means includes a plurality of temperature detecting means for detecting the temperature and a timer for lighting the heating means.
Each has a timer for turning off the heating means.
The heating means has each heating means, controls the plurality of heating means independently based on the temperature detection signals of the plurality of temperature detection means, and turns on each of the plurality of heating means. the pressure of the non-heating means upon turning off of the heating means to be turned off when that said heating means timer for lighting other than heating means causes started when the lighting of the heating means is turned off each of said plurality of heating means to < br /> starts a timer for turning off the heat means, the heating means determines that said heating means timer for lighting to be lighted has timed the time of turning on each of said plurality of heating means by lighting, controls so as not to said plurality of heating means from oFF to oN at the same time, when turning off each of said plurality of heating means prior to be turned off By timer for heating means off is to turn off the heating means determines that the time is up, and controlled not said plurality of heating means at the same time from ON to OFF, each of said plurality of heating means And a control means for delaying the timing for turning on and off by driving with an AC waveform by at least one cycle of the AC waveform, and a sufficient reduction / suppression effect for the power supply voltage fluctuation is obtained. To be

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a fixing roller and a control system of an embodiment of the invention according to claims 1-3. A pressure roller (not shown) is pressed against the fixing roller 1 by a pressure means and is rotationally driven by a driving source, and the pressure roller is the fixing roller 1.
Drive to. The fixing roller 1 and the pressure roller form a fixing unit. The fixing roller 1 has therein heating means 2 and 3 including two heaters. The heater 2 is arranged at the center of the fixing roller 1 and the heater 3 is arranged at the end of the fixing roller 1. The central portion of the fixing roller 1 is an area through which small-sized paper passes, and the central portion and the end portion of the fixing roller 1 are areas through which large-sized paper passes.

One ends of the heaters 2 and 3 are connected to one side of the AC power source 14 via the normally open contact RA1-a of the relay RA1, and the other ends of the heaters 2 and 3 and the other side of the AC power source 14 are connected. Triacs 4 and 5 are respectively connected to the. The triacs 4 and 5 are driven by control drivers 6 and 7, and the control drivers 6 and 7 are on / off controlled by a CPU (microcomputer) 8 as control means. The coil of the relay RA1 is connected between the DC 24V power source and the ground via the transistor 11, and the driver 12 is controlled by the CPU 8 to turn on / off the transistor 11 so that the relay RA1 is turned on.
Turn on / off.

Therefore, when the relay RA1 is in the ON state and the triacs 4 and 5 are turned on, electric power is supplied from the AC power source 14 to the heaters 2 and 3 via the triacs 4 and 5 so that the heaters 2 and 3 are turned on ( Then, the central portion and the end portion of the fixing roller 1 are heated by the heaters 2 and 3, respectively.
The CPU 8 normally controls the drivers 6 and 7 so that only the heater 2 or both the heaters 2 and 3 are turned on depending on the size of the sheet passed between the fixing roller 1 and the pressure roller.
Is controlled to heat only the central portion or the central portion and the end portion of the fixing roller 1 according to the paper size. A sheet carrying a toner image is passed between the fixing roller 1 and the pressure roller,
The fixing roller 1 and the pressure roller fix the toner image on the sheet by heating and pressing.

Temperature detecting elements 9 and 10 formed of thermistors
Are arranged in contact with the outer peripheral surfaces of the central portion and the end portion of the fixing roller 1, and detect the temperatures of the central portion and the end portion of the fixing roller 1 corresponding to the heaters 2 and 3, respectively. The temperature detection signals from the thermistors 9 and 10 are input to the CPU 8. The CPU 8 converts the analog temperature detection signal from the thermistors 9 and 10 into a digital signal to obtain temperature data of the fixing roller 1 by a program.

The CPU 8 controls the triac 4 via the control driver 6 based on the temperature of the central portion of the fixing roller 1 detected by the thermistor 9 to control the turning on / off of the heater 2, and the thermistor 10 detects the temperature. Based on the end temperature of the fixing roller 1, the triac 5 is controlled via the control driver 7 to control the turning on / off of the heater 3.
Therefore, the heater 2 is turned on / off according to the central temperature of the fixing roller 1, and the heater 3 is turned on / off according to the end temperature of the fixing roller 1.

Further, the CPU 8 receives a detection signal from the sub bar switch 13 for detecting whether or not the main body cover of the image forming apparatus such as a copying machine equipped with the fixing device of the present embodiment is opened, and the main body cover is received. When the door is opened, the driver 11 is turned off to turn off the transistor 12 to turn off the relay RA1, and when the main body cover is closed, the driver 11 is turned on to turn on the transistor 12 to turn on the relay RA1. Therefore, the heaters 2 and 3 are not turned on when the main body cover is opened.

Next, the heat generation control of this embodiment will be described. In the present embodiment, when controlling the turning on / off of each of the heaters 2 and 3, the turning on / off of the heater 2 is monitored by monitoring the output state of the heater 3, and the turning on / off of the heater 3 is output from the heater 2. Monitor the status and do it. Heaters 2 and 3
The control contents of are as follows.

If the state of the heater 3 is off when the heater 2 tries to turn on the heater 2, the CPU 8 turns on the heater 2 as it is, and simultaneously with the heater 2, the heater 3 is turned on.
The delay timer for turning on the heater 3 is started so that does not change from the extinguished state to the lit state, and the heater 3 is controlled so as not to go from the extinguished state to the lit state until the delay timer for illuminating the heater 3 expires.

Further, when the heater 8 tries to turn on the heater 2 and the state of the heater 3 is on, the heater 8 turns on.
Check the delay timer for lighting the heater 2 that was started at the time of lighting, and turn on the heater 2 on condition that the delay timer for lighting the heater 2 has timed out, and also start the delay timer for lighting the heater 3. Let

Further, the CPU 8 turns off the heater 2 as it is when the state of the heater 3 is on when the heater 2 is going to be turned off from the on state.
The delay timer for extinguishing the heater 3 is started so that the heater 3 and the heater 3 do not change from the lighting state to the extinction state at the same time, and the heater 3 is changed from the lighting state to the extinction state until the delay timer for extinguishing the heater 3 expires. Control not to become.

If the heater 3 is turned off when the heater 2 is going to be turned off from the lighting state, the CPU 8 checks the delay timer for turning off the heater 2 which is started when the heater 3 is turned off. Then, the heater 2 is turned off under the condition that the delay timer for turning off the heater 2 is up, and the delay timer for turning off the heater 3 is started. The CPU 8 also controls the turning on / off of the heater 3 by turning on / off the heater 2 as described above.
It is performed in the same manner as the turn-off control.

The control of the heaters 2 and 3 will be described with reference to the flow chart. It should be noted that the process of turning off the heaters 2 and 3 when the main body cover is opened in an image forming apparatus such as a copying machine or when an abnormality such as a paper jam occurs is
Since the relay RA1 is turned off by the PU8 and the energization from the AC power supply 14 to the heaters 2 and 3 is cut off, the description with reference to the flowchart will be omitted.

FIG. 2 is a flowchart showing a lighting / extinguishing control flow of the heater 2, and FIG. 3 is a flowchart showing a lighting / extinguishing control flow of the heater 3. Heater 2,
In the control of 3, the heaters 2 and 3 are not controlled from "lighting to extinguishing" and "lighting off to lighting" at the same time.

Basically, the CPU 8 performs a lighting process for lighting the heater 2 if the central temperature of the fixing roller 1 is (target temperature M-3 ° C.) or less based on the temperature detection signal from the thermistor 9. When the central temperature of the fixing roller 1 reaches the target temperature M, the extinguishing process for extinguishing the heater 2 is performed. Therefore, the CPU 8 always keeps the center temperature of the fixing roller 1 at the (target) level when the power is on, except when the main body cover is opened in an image forming apparatus such as a copying machine or when a paper jam occurs. When the temperature becomes equal to or lower than the temperature (M−3 ° C.), the heater 2 is turned on to heat the central portion of the fixing roller 1, and when the central portion temperature of the fixing roller 1 reaches the target temperature M, the heater 2 is turned off.

Further, basically, the CPU 8 determines, based on the temperature detection signal from the thermistor 10, if the end temperature of the fixing roller 1 is (target temperature S-3 ° C.) or less, the heater 3
Is performed, and when the end temperature of the fixing roller 1 reaches the target temperature S, the heater 3 is turned off. Therefore, the CPU 8 keeps the end temperature of the fixing roller 1 at the target temperature S (target temperature S) when the power is on, except when the main body cover of an image forming apparatus such as a copying machine is opened or when a paper jam occurs. -3 ° C) or less, the heater 3 is turned on to heat the end portion of the fixing roller 1,
When the end temperature of the fixing roller 1 reaches the target temperature S, the control of turning off the heater 3 is continued.

In addition to the control contents of the heaters 2 and 3, as means for determining whether to turn on / off the heaters 2 and 3, means for checking a delay timer other than the central temperature and the end temperature of the fixing roller 1 ( It is a feature of the present embodiment that a step (in FIGS. 2 and 3) and a starting means (steps in FIGS. 2 and 3) for starting the delay timer are provided.

In FIG. 2, the route of "A" is the heater 2
Is turned on, and the route of “B” is control to turn off the heater 2. Further, in FIG. 3, the route “A” is the control for turning on the heater 3, and the route “B” is the control for turning off the heater 3. CPU8 is
As shown in FIG. 2, in the route of “A”, it is first checked in step whether or not the heater 2 lighting delay timer has timed out, and the heater 2 is turned off until the heater 2 lighting delay timer has timed up. Control so that it does not turn on. As shown in FIG. 3, the CPU 8 activates the heater 2 lighting delay timer in steps when the heater 3 is lighting. By starting and checking the delay timer for lighting the heater 2 in this way,
The heater 2 cannot be turned on at the same time as the heater 3 is turned on.

Further, the CPU 8 starts the heater 3 lighting delay timer in steps when the heater 2 is turned on as shown in FIG. 2, and the heater 3 lighting delay timer times up in steps as shown in FIG. Whether or not the heater 3 is turned on is checked, and the heater 3 is controlled so as not to be turned on from the extinguished state until the delay timer for turning on the heater 3 is up. By starting and checking the delay timer for turning on the heater 3, the heater 3 cannot be turned on at the same time as the heater 2 is turned on.

Next, as shown in FIG. 2, the CPU 8 checks whether or not the heater 2 turn-off delay timer has timed out in step "B" route, and the heater 2 turn-off delay timer does not time up. In this case, the heater 2 is controlled so as not to be turned off. As shown in FIG. 3, the CPU 8 activates the heater 2 extinguishing delay timer in steps when the heater 3 is extinguished. By starting and checking the delay timer for turning off the heater 2 in this manner, the heater 2 cannot be turned off at the same time that the heater 3 is turned off.

As shown in FIG. 2, the CPU 8 activates the heater 3 extinguishing delay timer in steps when the heater 2 is extinguished, and the heater 3 extinguishing delay timer times up in step as shown in FIG. It is checked whether or not the heater 3 is turned off and the heater 3 is controlled so as not to be turned off from the lighting state until the delay timer for turning off the heater 3 is up. By starting and checking the delay timer for extinguishing the heater 3 in this way, the heater 3 cannot be extinguished at the same time when the heater 2 is extinguished.

By controlling the heaters 2 and 3 as described above, the heaters 2 and 3 are not simultaneously turned on and off. Further, the delay intervals of lighting and extinguishing the heaters 2 and 3 (the interval between the lighting timing of the heater 2 and the lighting timing of the heater 3, the interval between the extinguishing timing of the heater 2 and the extinguishing timing of the heater 3) are for turning on the heater 2. The delay timer, the heater 2 extinguishing delay timer, the heater 3 illuminating delay timer, and the heater 3 extinguishing delay timer can be arbitrarily set by the respective time-up values.

As shown in FIG. 4, the AC current flowing from the AC power supply 14 to the heater 2 flows largely due to the inrush current flowing from the ON state of the heater 2 (ON of the triac 4) to less than one cycle of the AC current. The current value decreases as the AC current is turned on (the triac 4 is turned on) from 1 ON cycle to 2 cycles N cycle of the alternating current. The same applies to the current flowing through the heater 3. Furthermore, when a plurality of heaters 2 and 3 are turned on or off at the same time, the change in current of the heaters 2 and 3 is significant within one cycle from the turning on. Therefore, when the heaters 2 and 3 are turned on,
If the timing of turning off is delayed by one cycle or more of the AC waveform from the AC power supply 14, the change in the inrush current of the current flowing through the heaters 2 and 3 is considerably reduced, and thus the fluctuation of the power supply voltage can be suppressed.

If the heater is turned on or turned off, the heater is turned on and then turned off by delaying from one cycle of the AC waveform from the AC power source 14 to two cycles and two cycles to N cycles (N ≧ 3). As the change in the current flowing through the heater decreases, the effect of suppressing the fluctuation in the power supply voltage increases, but if the timing for turning the heater on and off is delayed too much, such as 10 seconds or 20 seconds, the surface of the fixing roller will be reduced. Since there is a concern that the temperature fluctuation of the heater becomes large and influences the fixing temperature control, the time to delay the timing to turn on the heater and the timing to turn off the heater is several seconds (2-3
Seconds) or less.

Therefore, for example, the time-up values of the heater 2 lighting delay timer, the heater 2 turning off delay timer, the heater 3 turning on delay timer, and the heater 3 turning off delay timer are the same for the heaters 2 and 3, respectively. The timing of driving and turning on with the AC waveform from the power source 14 is delayed by one cycle or more and several seconds (2 to 3 seconds) or less of the AC waveform from the AC power source 14, and the heaters 2, 3
Are set to be delayed by one cycle or more of the AC waveform from the AC power source 14 and several seconds (2 to 3 seconds) or less.

If the frequency of the AC waveform from the AC power supply 14 is 50 Hz, the half cycle of the AC waveform from the AC power supply 14 is 10 msec, and the heater 2 lighting delay timer, the heater 2 turning off delay timer, and the heater 3 are used. The time-up values of the delay timer for lighting and the delay timer for extinguishing the heater 3 are the timings at which the heaters 2 and 3 are turned on by driving the heaters 2 and 3 with the AC waveform from the AC power supply 14, respectively. The turn-off timing is set to 20 msec or more so as to delay 20 msec or more of one cycle of the AC waveform from the AC power supply 14.

Flicker (perceived quantity) of voltage fluctuation (physical quantity)
The flicker value Pst (short-term flicker value: standard value 1.0 or less), Plt (long-term flicker value: standard value) which is a measurement value by a flicker meter which is a measuring device for converting to
0.65 or less), Pst is 1.453 during standby and preheating in the conventional fixing device, and Plt is 1.2 during image formation.
However, in the present embodiment, Pst is 0.634 during standby and preheating, and Plt is 0.56 during image formation.
6, there was an effect of reducing and suppressing about 50% or more with respect to fluctuations in the power supply voltage, and the standard value could be achieved.

Further, as another countermeasure, a transformer, a filter circuit (LCR circuit) and the like are added to increase the number of countermeasure parts, and the space for mounting the countermeasure parts is increased to increase the size and weight of the product and increase the cost. It was possible to achieve the standard value with respect to fluctuations in the power supply voltage without incurring.

As described above, the present embodiment is an embodiment of the invention according to claim 1, and is a fixing roller which is heated by the heaters 2 and 3 as a plurality of heating means to fix the toner image on the sheet. 1 and a pressure roller, thermistors 9 and 10 as a plurality of temperature detecting means for respectively detecting the temperatures of a plurality of portions of the fixing means corresponding to the plurality of heating means 2 and 3. The plurality of heating means 2 and 3 are independently controlled based on the temperature detection signals of the plurality of temperature detection means 9 and 10, and the plurality of heating means 2 and 3 are not turned on at the same time and turned off at the same time. Since the CPU 8 is provided as the control means for controlling so as not to turn from OFF to ON, there is a sufficient reduction and suppression effect of about 50% or more with respect to power supply voltage fluctuation, and the standard value is achieved. It can be. In addition, the increase in the number of countermeasure components due to the addition of a transformer, a filter circuit (LCR circuit), etc., which is considered as another countermeasure, and the increase in the space for mounting the countermeasure components may lead to an increase in product size, weight, and cost. The standard value can be achieved without fluctuations in the power supply voltage.

Further, the present embodiment is an embodiment of the invention according to claim 2, and is a fixing roller 1 for fixing the toner image on the paper which is heated by the heaters 2 and 3 as a plurality of heating means. Fixing means composed of a pressure roller, thermistors 9 and 10 as a plurality of temperature detecting means for respectively detecting temperatures of a plurality of portions corresponding to the plurality of heating means 2 and 3 in the fixing means, and the plurality of thermistors. Timing for turning off each of the plurality of heating means 2 and 3 and controlling each of the plurality of heating means 2 and 3 independently based on the temperature detection signals of the temperature detection means 9 and 10. Since the CPU 8 is provided as the control means for giving the delay time to the timing of turning on the power from the ON state, the delay time is given at the timing of turning on and off the plurality of heating means 2 and 3. Therefore, the plurality of heating means 2 and 3 will not be turned on or off at one time, and the rapid inrush current (the current to the heating means will be sharply increased) from the small current state (a state close to the no-load current in which no current flows in the heating means). Occurs, or conversely, a high current flows (current flowing in the heating means) to a suddenly small current state (state in which no current flows in the heating means, close to a no-load current). ) Does not occur, and there is no significant change in current consumption. This reduces sudden voltage changes, reduces voltage fluctuations applied to the power supply, and changes the voltage fluctuations (physical quantities) into flicker (perceptual quantities). Pst of a certain flicker value,
There is an effect of reducing and suppressing Plt. Also, transformers and filter circuits (LCR circuits) that can be considered as other countermeasures.
It can be implemented without increasing the size and weight of the product and increasing the cost due to an increase in the number of countermeasure parts due to the addition of the above and the like, and an increase in the space for mounting the countermeasure parts.

Further, this embodiment is an embodiment of the invention according to claim 3, and is a fixing roller 1 for fixing the toner image on the paper by being heated by the heaters 2 and 3 as a plurality of heating means. Fixing means composed of a pressure roller, thermistors 9 and 10 as a plurality of temperature detecting means for respectively detecting temperatures of a plurality of portions corresponding to the plurality of heating means 2 and 3 in the fixing means, and the plurality of thermistors. The plurality of heating means 2 and 3 are independently controlled based on the temperature detection signals of the temperature detection means 9 and 10, and each of the plurality of heating means 2 and 3 is driven by an AC waveform to turn on. Since the CPU 8 is provided as a control unit that delays the timing of turning on and the timing of turning off by one cycle or more of the AC waveform, the timing of lighting or extinguishing the plurality of heating units 2 and 3 is determined by the AC waveform (commercial power supply frequency). The case of 50Hz or 60Hz)
By delaying more than one cycle (20 mS in the case of 50 Hz) of more than one lighting means does not turn on or off at once, a drastic change in current consumption disappears and a sudden change in voltage is reduced. The voltage fluctuation applied to the power source is reduced, and there is an effect of reducing and suppressing the flicker value Pst and Plt which are the measurement values by the flicker meter which is a measuring device that converts the voltage fluctuation (physical quantity) into flicker (perceptual quantity).

Particularly, when a plurality of heating means are turned on, a sudden rush current (a current which is 10 to 15 times that at a steady current value) is generated in a half cycle and one cycle of rising, and conversely, a plurality of heating means are turned on. When it becomes unlit, it suddenly changes to a small current (1/10 to 1/20 current from the steady current value).
After one cycle, the current will be almost steady, rapid current changes will be suppressed, and power supply voltage fluctuations will be reduced.
The effect is extremely large. Also, transformers and filter circuits (LCR circuits) that can be considered as other countermeasures.
It can be implemented without increasing the size and weight of the product and increasing the cost due to an increase in the number of countermeasure parts due to the addition of the above and the like, and an increase in the space for mounting the countermeasure parts.

The invention according to each claim is not limited to the above-mentioned embodiments, and the fixing means is heated by, for example, three or more heaters as heating means, so that the fixing means has three or more heating means. The temperature of each part corresponding to
The CPU as the control means independently controls the three heating means based on the temperature detection signals of the plurality of temperature detecting means, and the three or more heating means are detected. It is also possible to control so as not to turn from ON to OFF at the same time and not to turn from OFF to ON at the same time.

[0051]

As described above, according to the first aspect of the invention, the fixing means for fixing the toner image on the sheet by being heated by the plurality of heating means, and the plurality of heating means in the fixing means are provided. A plurality of temperature detecting means for respectively detecting temperatures of a plurality of corresponding parts; and a plurality of heating means independently controlled on the basis of temperature detection signals of the plurality of temperature detecting means; Equipped with a control unit that controls each heating unit so that it does not turn from ON to OFF at the same time and does not turn from OFF to ON at the same time, there is a sufficient reduction and suppression effect on power supply voltage fluctuations, and the standard value is achieved. can do. In addition, the increase in the number of countermeasure components due to the addition of a transformer, a filter circuit (LCR circuit), etc., which is considered as another countermeasure, and the increase in the space for mounting the countermeasure components may lead to an increase in product size, weight, and cost. The standard value can be achieved without fluctuations in the power supply voltage.

According to the second aspect of the invention, the fixing means for fixing the toner image on the paper by being heated by the plurality of heating means, and the plurality of portions of the fixing means corresponding to the plurality of heating means are provided. A plurality of temperature detecting means for respectively detecting the temperature, and the plurality of heating means are independently controlled based on the temperature detection signals of the plurality of temperature detecting means, and each of the plurality of heating means Since the control means for providing a delay time between the timing of turning on the power supply and the timing of turning on the power supply is turned on, there is an effect of sufficiently reducing and suppressing the fluctuation of the power supply voltage. In addition, the increase in the number of countermeasure components due to the addition of a transformer, a filter circuit (LCR circuit), etc., which is considered as another countermeasure, and the increase in the space for mounting the countermeasure components may lead to an increase in product size, weight, and cost. The standard value can be achieved without fluctuations in the power supply voltage.

According to the third aspect of the invention, the fixing means for fixing the toner image on the paper by being heated by the plurality of heating means, and the plurality of portions of the fixing means corresponding to the plurality of heating means are provided. A plurality of temperature detecting means for respectively detecting the temperature, and the plurality of heating means are independently controlled based on the temperature detection signals of the plurality of temperature detecting means, and each of the plurality of heating means Since the control means for delaying the timing for turning on and turning off by driving the AC waveform with one or more cycles of the AC waveform is provided, there is an effect of sufficiently reducing and suppressing fluctuations in the power supply voltage. In addition, the increase in the number of countermeasure components due to the addition of a transformer, a filter circuit (LCR circuit), etc., which is considered as another countermeasure, and the increase in the space for mounting the countermeasure components may lead to an increase in product size, weight, and cost. The standard value can be achieved without fluctuations in the power supply voltage.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a fixing roller and a control system according to an exemplary embodiment of the present invention.

FIG. 2 is a flowchart showing a lighting / extinguishing control flow of the heater 2 in the same embodiment.

FIG. 3 is a flowchart showing a lighting / extinguishing control flow of the heater 3 in the same embodiment.

FIG. 4 is a waveform diagram showing a waveform of a current flowing through the heater of the same embodiment.

[Explanation of symbols]

1 fixing roller A few heaters 4,5 triac 6, 7 Control driver 8 CPU 9, 10 thermistor 11 drivers 12 transistors 13 cover switch RA1 relay

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Claims (3)

(57) [Claims] 1. A fixing means for fixing a toner image on a sheet by being heated by a plurality of heating means, and a plurality of detecting means for detecting temperatures of a plurality of portions of the fixing means corresponding to the plurality of heating means, respectively. Temperature detection means and heating means points
A heating timer is provided for each heating means and heating
A timer for turning off the means is provided for each of the heating means, and the plurality of heating means are independently controlled based on the temperature detection signals of the plurality of temperature detection means, and to be turned off when turning off each of said plurality of heating means with activating the heating means timer for lighting other than heating means when the lighting of the heating means to be lighted when turning on the respective plurality of heating means off when the heating means timer for turning off the non-heating means is activated in the heating means, said plurality of heating means said heating means timer for lighting to be turned on when lighting the each has timed And heating the heating means to control so that the plurality of heating means are not turned on at the same time, and turn off each of the plurality of heating means. By the heating means off for the timer to be turned off be off the heating means determines that the time is up in time of the control to control so as not to turn off from on the plurality of heating means at the same time And a fixing device. 2. A fixing means for fixing a toner image on a sheet by being heated by a plurality of heating means, and a plurality of detecting means for detecting temperatures of a plurality of portions of the fixing means corresponding to the plurality of heating means, respectively. Temperature detection means and heating means points
A heating timer is provided for each heating means and heating
A timer for turning off the means is provided for each of the heating means, and the plurality of heating means are independently controlled based on the temperature detection signals of the plurality of temperature detection means, and to be turned off when turning off each of said plurality of heating means with activating the heating means timer for lighting other than heating means when the lighting of the heating means to be lighted when turning on the respective plurality of heating means off when the heating means timer for turning off the non-heating means is activated in the heating means, said plurality of heating means said heating means timer for lighting to be turned on when lighting the each has timed And heating the heating means to control so that the plurality of heating means are not turned on at the same time, and turn off each of the plurality of heating means. By the heating means off for the timer to be turned off be off the heating means determines that the time is up in time of controls so as not to said plurality of heating means at the same time from ON to OFF, 2. A fixing device, comprising: a control unit that sets a delay time at a timing of turning on each of the plurality of heating units and a timing of turning on each of the plurality of heating units. 3. A fixing means for fixing a toner image on a sheet by being heated by a plurality of heating means, and a plurality of detecting means for detecting temperatures of a plurality of portions of the fixing means corresponding to the plurality of heating means, respectively. Temperature detection means and heating means points
A heating timer is provided for each heating means and heating
A timer for turning off the means is provided for each of the heating means, and the plurality of heating means are independently controlled based on the temperature detection signals of the plurality of temperature detection means, and to be turned off when turning off each of said plurality of heating means with activating the heating means timer for lighting other than heating means when the lighting of the heating means to be lighted when turning on the respective plurality of heating means off when the heating means timer for turning off the non-heating means is activated in the heating means, said plurality of heating means said heating means timer for lighting to be turned on when lighting the each has timed And heating the heating means to control so that the plurality of heating means are not turned on at the same time, and turn off each of the plurality of heating means. By the heating means off for the timer to be turned off be off the heating means determines that the time is up in time of controls so as not to said plurality of heating means at the same time from ON to OFF, Each of the plurality of heating means is driven with an AC waveform to turn on and off with the AC waveform of 1
A fixing device, comprising: a control unit that delays by a period or more.