JPH1023764A - Output controller, heater apparatus and magnetic induction heating fixing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of power supplied from a power supply circuit even at a low cost with simple circuit structure. SOLUTION: A ripple signal outputted from a power supply circuit 1 is detected by a voltage detection circuit 12. The detected ripple signal is inputted to a pulse width modulation circuit 14 with a power signal which is a control object signal. With this process, a switching control signal Vs whose pulse width is so modulated as to have its switching-on width wider when the amplitude of the ripple signal is lower and have its switching on width narrower when the amplitude of the ripple signal is higher is generated. The ON/OFF of a switching device is controlled by a switching control circuit 17 in accordance with the signal Vs to control and output the power supplied from the power supply circuit 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output control device, a heating device, and a magnetic induction heating fixing device used for a heat fixing device of a developer (toner) formed in an electrophotographic process.

[0002]

2. Description of the Related Art Conventionally, a fixing device in a printer device using an electrophotographic process generally comprises a heating roller (fixing roller) and a pressure roller which presses against this roller. The fixing is performed by passing the recording paper on which the toner is applied.

The principle of operation for fixing a heating roller while controlling the temperature will be described below. As a heat source of the heating roller, a halogen heater made of aluminum metal is generally used. Usually, a halogen heater is disposed in a hollow portion in the center of a heating roller in the form of an elongated rod sealed with glass, and is heated by flowing a current from an AC power supply (line input power supply) via a switching control element. Heat the rollers.

When power is supplied to the halogen heater, the heater emits heat and emits light, and heats the heating roller by radiation and convection. The heat roller made of aluminum metal transfers the received heat to the entire roller without a temperature difference. The heating roller 1 having a uniform temperature distribution in this manner is heated via the heat-resistant rubber coated on the upper layer of the roller.
The unfixed toner is fixed by heating and melting so as to permeate the recording paper.

[0005] The fixing is performed as described above. The temperature of the fixing heating roller is controlled by detecting the temperature of the heating roller by a temperature detecting element (generally, a thermistor thermosensitive element) arranged close to the roller, and connecting to an AC power supply. On / off control of the halogen heater is performed by a switching element (for example, a triac or the like) provided between the halogen heater and the halogen heater, thereby controlling the heating roller to obtain a target constant temperature. Thus, the temperature control of the heating roller is performed.

In such a temperature control system, even if the switch is turned off when the temperature reaches the target temperature, an overshoot occurs far beyond the target temperature due to the large power supplied so far. I will. Such an overshoot occurs about 5% of the target temperature when the simple temperature control means as described above is used.

Here, the cause of the occurrence of overshoot will be considered. In the case of the fixing device described above, the halogen heater is disposed at a central portion far away from the heating roller whose temperature is to be transmitted. Therefore, the heat model (heat model) depends on the heat resistance until the heating roller reaches the heating roller and the heat capacity of the roller. (At least not a simple first-order transfer model) can be very complex and difficult to analyze. This is a configuration in which heat is guided through a loop transmission path of a heater → a heater glass tube → a space inside the tube (radiation, convection) → a fixing roller (heating roller) → heat-resistant rubber. (Fixing roller and heat-resistant rubber).

In a control system in which overshooting occurs as described above, when temperature control is performed by detecting the temperature of the surface of the heating roller, the temperature of the halogen heater and the temperature of the halogen heater are controlled due to a transfer function until heat is conducted to the roller surface. On / off is repeated while generating a temperature difference of several hundred degrees with the surface temperature of the roller, and as a result, control is performed to keep the surface temperature of the heating roller constant. That is, the temperature control is established in such a model because of the above-described loop transmission path (heater → heater glass tube → tube space (radiation, convection) →
(Fixing roller → heat-resistant rubber) performs a sufficient time integration function. As a result, even if the input power is controlled slowly at a relatively temporal level, the operation is performed so that a constant surface temperature can be obtained. is there.

[0009]

However, in the above-described control system, in order to perform ideal temperature control, the usual "interval when paper is not passing", "during paper passing", " Paper quality ",
It is necessary to control in consideration of "ambient temperature" and other various control parameters related to temperature. That is, it is impossible to perform high-precision temperature control without performing complicated control while operating each control parameter by constantly detecting various conditions such as printing, standby, paper quality control, and ambient temperature. As a result, it is difficult to shorten the first print time, and there is a problem that the working efficiency is poor.

In recent years, in order to reduce such a first print time, a cylindrical film is used, and a resistor (metal oxide film resistor) is printed on a ceramic inside the cylindrical film. Fusing rollers have been proposed. In this case, heat is generated by passing an electric current through such a print resistor, and the heat is used to melt and fix the toner via the film. By efficiently supplying power directly to the toner as described above, the first print time is reduced and energy is saved.

[0011] However, the temperature control method in the fixing roller constituted by using such a printing resistor works well in the mono-color fixing, but when performing the color fixing, the synthesis process of each color is performed based on the behavior of the toner. In this case, precise control of temperature and pressurization is required in order to be able to perform the control at the same time, and as a result, there is a problem that a control mechanism is complicated.

Further, as a system configured in consideration of the first print time and the response of sufficient pressurization and temperature, heat generated by a skin current generated on a metal surface by applying a high-frequency current to a coil to generate a high-frequency magnetic field. A fixing roller configured to apply the toner as it is has been devised. However, in such a fixing roller, since the temperature detecting element cannot detect a high-speed temperature rise, there is a problem that the feedback speed cannot catch up and the accuracy of the temperature control is deteriorated.

Further, when the fixing roller is heated by using the above-described method of applying a high-frequency magnetic field to a metal surface, the high-frequency power supply to be driven is large, exceeding 1 kVA in a large-sized apparatus, and the power supply circuit is made compact. There is a problem that can not be.

Further, in some conventional induction heating circuits, heating control of the fixing roller is performed by using a power supply circuit of a type in which an input voltage (pulsating current signal) is switched at a constant cycle by a switching element. In this case, the burden ratio of the switching element in the high voltage portion of the pulsating signal and the burden ratio of the switching element in the low voltage portion of the pulsating signal naturally change. For this reason, it is necessary to always determine the design of the switching device of the power circuit in consideration of the operation state at the time of the maximum voltage of the pulsating signal. As a result, the circuit configuration becomes complicated, and the efficiency of use of the switching element,
As a result, there arises a problem that utilization efficiency of the power supplied from the power supply circuit is low.

It is an object of the present invention to provide an output control device, a heating device, and a magnetic induction heating device capable of improving the efficiency of use of power supplied from a power supply circuit, despite the fact that the circuit configuration is inexpensive and simple. An object of the present invention is to provide a fixing device.

[0016]

According to the present invention, there is provided a drive control element whose drive time is controlled by an input control signal, first means for generating a pulsating signal, and detecting an amplitude of the pulsating signal. A second means, a third means for outputting the control signal for extending the drive time of the drive control element in a region where the amplitude of the pulsation signal is small, and the drive control as the amplitude of the pulsation signal increases. An output control device can be configured by including fourth means for outputting the control signal for shortening the drive time of the element. In this case, the first means may be configured to generate a pulsating signal of a full-wave rectified voltage.

Also, the present invention provides a power supply means for generating a pulsating signal for supplying power, a power control element for controlling the power supplied from the power supplying means, and a detecting means for detecting the pulsating signal. First detecting means, and a second detecting means for detecting a power signal, the pulsating signal and the power signal are input, the driving time of the power control element is long in a region where the amplitude of the pulsating signal is low and Drive control means for outputting a control signal for shortening the drive time of the power control element as the amplitude increases; and power supplied from the power supply means via the power control element driven and controlled by the control signal. And an electric power output means for outputting an output.

In this output control device, the drive control means may include an input terminal to which the power signal is input as a signal for a control object, and an input terminal to which the pulsation signal is input as a signal for adjusting the drive time of the power control element. And a triangular wave having an oblique side having a different slope depending on the amplitude of the pulsating signal, and determining the drive time at a position where the oblique side of the triangular wave intersects with the signal level of the power signal. And a drive control circuit that performs drive control of the power control element based on the control signal.

The power supply means includes: an AC power supply; a line filter to which an AC signal from the power supply is input; a bridge circuit for rectifying the AC signal to generate the pulsating signal; And a power supply circuit including a power supply filter for storing.

The first detecting means detects a pulsating signal of a full-wave rectified voltage, and the second detecting means generates a power signal by a product of a current flowing through the power control element and a voltage of the pulsating signal. It can be configured to calculate.

An electric power output means is constituted by a magnetic field generation means comprising an exciting coil and a capacitor, and an output detection means for detecting a signal (for example, a flyback voltage) generated by the electric power output means; And timing adjustment means for adjusting the drive timing of the power control means based on the signal thus obtained.

As the drive control element, a switching element such as an FET can be used. The drive time of the drive control element or the power control element may be a switching-on width of the switching element.

Further, according to the present invention, a heating device can be constituted by including the above-mentioned output control device and a heat-generating member which generates heat by the power output means. In this case, the heat generating member can be configured as a fixing roller including a magnetic member. Further, a temperature detecting means for detecting the temperature of the heat generating member, and means for inputting the detected temperature to the input terminal for the control target of the drive control means and performing feedback control may be provided. Good.

The present invention also provides a magnetic field generating means including an exciting coil, and a magnetic field generated by the magnetic metal member by generating a magnetic field in the magnetic metal member by the magnetic field generating means. The present invention relates to a magnetic induction heating type heating device for heating a heating material, a means for detecting a voltage supplied to the magnetic field generating means, a current measuring means for measuring an exciting current waveform of the exciting coil, and the exciting coil Means for controlling the exciting power supplied to the exciting coil from the induced voltage induced in the exciting coil, means for detecting the peak value of the induced voltage waveform induced in the exciting coil, and exciting based on the voltage value detected by the means. By providing a means for restricting electric power, a magnetic induction heating fixing device can be configured. In this case, the excitation power may be limited based on a product of the waveform of the voltage supplied to the magnetic field generation unit and the waveform of the excitation current.

[0025]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG.

FIG. 1 shows the overall configuration of the present apparatus. First, in FIG. 1, a power supply circuit 1 is provided with a commercial AC power supply 2, and a line filter 3 is connected to the power supply 2. The line filter 3 is connected to a diode bridge circuit 4 for rectifying an input AC voltage. The power supply line on the output side of the bridge circuit 4 includes:
The filter coil 5 and the filter capacitor 6 are connected. The filter coil 5 gives an impedance to a high frequency switching frequency. Here, as the filter capacitor 6, a film capacitor or the like having a relatively small capacity (several μm to several tens of μF) having good high-frequency characteristics is used instead of a smoothing capacitor used for a normal switching power supply or the like.

The power supply line of the power supply circuit 1 is connected to a magnetic field generating means 7 as power output means and a switching element 8 for controlling power supply from the power supply circuit 1. In this case, the magnetic field generating means 7 includes an excitation coil 9 for supplying a high-frequency switching current to generate a high-frequency magnetic field, and a capacitor 10 connected in parallel to the excitation coil 9. In addition, although an FET is used as the switching element 8, a switching transistor, an electrostatic dielectric transistor corresponding to high power, or the like can be used. Note that, instead of the switching element 8, a configuration using a linear linear element can be used.

At a position close to the exciting coil 9,
A cylindrical (endless) heat resistant film body 11 as a heat generating member is provided. The film body 11 is configured as, for example, a fixing roller described later,
The high frequency magnetic field generated by the exciting coil 9 is arranged to be efficiently coupled. Around the cylindrical film body 11, a member to be heated 11a is provided.
When the fixing roller is used, the heated member 11a is equivalent to a recording sheet for fixing toner.

A voltage detection circuit 12 and a current detection circuit 13 for detecting a current of the switching element 8 are connected to a power supply line between the power supply circuit 1 and the magnetic field generating means 7. ing. Further, a pulse width modulation circuit 14 is provided as a waveform control circuit to which the voltage value detected by the voltage detection circuit 12 and the current value detected by the current detection circuit 13 are input.

The pulse width modulation circuit 14 is connected to a flyback voltage detection circuit 15 as output detection means. The flyback voltage detection circuit 15 detects an induced voltage induced in the exciting coil 2, and the detected induced voltage is input to the pulse width modulation circuit 14. The pulse width modulation circuit 14 includes a temperature detecting means 16.
Are connected, and a signal (voltage or the like) relating to the temperature detected from the heating member 4 is input.

As described above, signals related to voltage, current, and temperature are input to the pulse width modulation circuit 14. This pulse width modulation circuit 14 is connected to a switching control circuit 17 as a drive control circuit to which a switching control signal is input. The signal output from the switching control circuit 17 is input to the gate of the switching element 8. By controlling the driving of the switching element 8, the amount of electric power supplied from the power supply circuit 1 to the magnetic field generating means 7 is controlled.

In FIG. 2, the pulse width modulation circuit 1
4 is connected to a multiplication circuit 18 and a switching circuit 19. As a result, the signal output from the voltage detection circuit 12 and the signal output from the current detection circuit 13 are multiplied by being input to the multiplication circuit 18 to obtain a power value. The switching circuit 19 selects one of the power value signal and the temperature-related signal calculated in this manner, and inputs the selected signal to the pulse width modulation circuit 14.

Next, the operation of the present apparatus will be described. In the power supply circuit 1, when an AC input voltage is applied from the AC power supply 2, a pulsating current signal (see FIG. 5A described later) rectified by the diode bridge 4 via the line filter 3 is obtained, and the filter capacitor 6 is stored. By using this filter capacitor 6, the current distortion input from the power supply line is reduced so that harmonics are not increased more than necessary. The terminal voltage pulsating signal generated in the filter capacitor 6 is applied to the voltage detecting circuit 12.
And is input to the pulse width modulation circuit 14.
The terminal voltage of the filter capacitor 6 is supplied to a parallel circuit of the capacitor 10 and the exciting coil 9 via the switching element 8. Then, the current switched by the switching element 8 is detected by the current detection circuit 13 and input to the pulse width modulation circuit 14.

The pulse width modulation circuit 14 obtains the flyback voltage _Vf applied to the switching element 8 via the flyback voltage detection circuit 15, and determines the timing at which the switching element 8 is turned on according to the voltage. At the same time, the product of the signal of the power supply voltage (pulse current signal) detected by the voltage detection circuit 12 and the signal of the current detected by the current detection circuit 13 is obtained, and the switching power in the magnetic field generation means 7 is controlled.

Next, the pulse width modulation circuit 14 is shown in FIGS.
It will be described based on. First, in FIG. 2, a voltage and a current detection signal detected by the voltage detection circuit 12 and the current detection circuit 13 are supplied through a multiplication circuit 18 as power supplied to a resonance circuit including the capacitor 10 and the exciting coil 9. Input to the pulse width modulation circuit 14. The voltage and current detection signals are input to the pulse width modulation circuit 14, and a temperature detection signal and a power signal obtained by calculating power from the voltage and current detection signals are selectively input to the pulse width modulation circuit 14 via the switching circuit 19. You.

FIG. 3 shows a circuit configuration of the pulse width modulation circuit 14. Reference numeral 20 denotes a terminal to which a signal for a control target such as power or temperature is input. Reference numeral 21 denotes a terminal for inputting a target value for a signal input to the terminal 20. 22 is a terminal to which a voltage detection signal V _b to define the maximum switching ON width T _a switching waveform of the switching element 8 is input. 23 is a terminal for current limiter input current detection signal V _i is inputted. _Reference numeral 24 denotes a terminal to which a trigger pulse (P) when the flyback voltage _Vf crosses the level L in FIG. 4 is input, and the timing of switching is set by the trigger pulse (P). Reference numeral 25 denotes a terminal for outputting a signal for controlling the driving of the switching element 8.

Here, the detection signal input to the terminal 20 will be described. This detection signal is a signal that is input as a control parameter using environmental conditions such as “paper passing”, “paper interval”, and “ambient temperature”. For example, when “recording paper” as a heated member is “passed”, feedback control is performed using electric power (the product of voltage and current) as a feedback signal to be controlled.

In the “sheet interval”, the feedback voltage (comparison voltage between the reference voltage and the control target voltage) is used to monitor the feedback voltage for determining the initial temperature at the time of sheet passing. Performs feedback control as a control target.

In the "paper interval", the temperature detecting means 1
6, the feedback temperature (temperature reference voltage,
Feedback control is performed with the control target voltage (comparison result voltage with the control target voltage).

Next, an example in which a signal to be controlled is input to the terminal 20 to perform feedback control will be described with reference to FIGS. Signals inputted from the terminal 20 that is, the voltage V _a operational amplifier with a reference voltage V ₀ which from the terminal 21,
That is, the voltage is input to the operational amplifier 30, amplified and converted to a required voltage V ₁ by this, and then input to the + terminal of the comparator 31. A constant current I ₀ is supplied to a negative terminal of the comparator 31 by a constant current driving circuit 33 connected to a capacitor 32. As a result, the comparator 31
As shown in FIG. 4, a voltage V ₂ that linearly increases based on the current value I ₀ and the value of the capacitor 32 is input to the − terminal.

[0041] Then, - the voltage V ₂ of the terminal becomes a voltage higher than the voltage V ₁ of the + terminal, the comparator 31 is inverted, RS flip-flop 34 is set, as a result, the transistor 35 is turned on, the comparator 31 -
The charge of the capacitor 32 connected to the terminal is released. At the same time, the transistor 37 via the inverter 36 is turned off, the constant current I ₁ opens the terminals of the capacitor 39 is supplied from the constant current circuit 38. Thus, this time the voltage V ₄ of the capacitor 39 increases linearly as shown in FIG.

Here, a predetermined reference voltage V ₃ is supplied to the + terminal of the comparator 40 by the resistors 41 and 42. As a result, the comparator 40 inverts after a lapse of a predetermined time and switches the RS flip-flop 34. Reset. As a result, the charge of the capacitor 39 is rapidly released, and the terminal of the capacitor 32 is opened via the transistor 35.

The switching voltage V _s to the terminal 25 by repeating such a series of operations is outputted.
ON time of the output voltage V _s is the time to turn on the comparator 31, i.e., an analog voltage value V ₁ obtained by amplifying the voltage V _a of the terminal 20, the capacitor 32
It is determined by the charging voltage V _2. Also, the output voltage V _s
Is determined by the time until the comparator 40 turns on, that is, the reference voltage V ₃ and the charging voltage V _{4 of the} capacitor 39.

[0044] Further, by varying the constant current I ₀ through the transistors 43 and 44 by an analog voltage value V _b of the pulsating signal input from the terminal 22, the maximum switching ON width T _a of the switching elements 8 I have decided. Further, at the terminal 23, the input V exceeding the reference voltage _Vi0
If _i is, rapidly discharges the soft-start capacitor 46 through the diode 45, then V _i of the terminal 23 is restored to the slow switching ON width T _a decreases. As described above, the waveform V ₁ of the signal relating to the power or temperature to be controlled is controlled by the circuits such as the comparators 31 and 34, the capacitors 32 and 39, the RS flip-flop circuit 34, and the voltage detection signal V _b and the current detection by controlling with a signal V _i and the like, it is possible to adjust the maximum switching oN width T _a of the switching element 8.

[0045] Next will be described with reference to FIGS. 4 to 6 the relationship between the switching voltage V _s to the analog input voltage V _b. FIG. 5 (A) shows the waveform of the pulsating signal of the analog input voltage V _b, FIG. 5 (B) shows the waveform of the switching voltage V _s. Thus narrowing the on width T _a is a high voltage V _b portion of the pulsating waveform, the ON width T in a low voltage parts V _b conversely
It performs an operation to widen the _a. Such control method as described above, when (voltage rising waveform V ₂ is controlled triangular wave to produce a switching ON width T _a is high by the voltage detection waveform V _b increases the charging curve, switching ON width T _s is reduced) as a result, the flyback voltage V
_f is the waveform expands the switching ON width T _a of the switching element 8 is in a low part (2 times the input AC frequency) ripple on the input voltage V _b, also in the amplitude of high part of the ripple of the input voltage V _b, It serves to narrow the switching oN width T _a. As a result, the envelope ripple of the flyback voltage _Vf is reduced, and the utilization efficiency of the switching element 8 is improved.

[0046] That is, if explained in FIG. 4, on the width T of the flyback voltage V _f of the waveform and the switching element 8 when switching ON width T _a of the switching element 8 is wide
_Although the waveform of the flyback voltage _Vf when _a is narrow is different, both areas are equal, so that the power to be used is almost equal between a low and a high input voltage,
Thereby, the use efficiency of the switching element can be increased as compared with the conventional case.

FIG. 6 shows an example in which the "utilization efficiency" of the switching element 5 is improved in comparison with a conventional example. A dashed waveform 50 is an output waveform of the switching element 5 according to the conventional method in which the power-on pulsation signal ( _Vb ) is not detected and the switching-on width control is performed only by the temperature feedback signal. The solid line waveform 51 is an output waveform V _ss according to the present system in which the switching-on width control is performed by inputting the power pulsating current signal to the switching-on width control input terminal 22 and inputting the temperature feedback signal to the terminal 20. is there. As can be seen from the output waveform 51, since a large amount of current flows even in a portion where the input voltage is low, the waveform ratio is close to 1, which indicates that the switching element 8 has a high utilization rate.

The "utilization efficiency" as used herein refers to how to efficiently supply a large power to a load with a device having a limited withstand voltage and current. The output can be increased by efficiently supplying power at the power supply. Thereby, the power supply circuit 1
Efficiency of the power supplied from the power supply can be improved.

Here, the “utilization efficiency” will be described with an example. For example, if the waveform of the input voltage of the switching element 8 is 100 V commercial, the switching element 5 performs the operation up to the maximum amplitude of the input voltage, that is, 141V input, whereas the average voltage value of the element 8 is known. About 9
It becomes 0 V, and the utilization efficiency is extremely low. On the contrary,
By using the above-described method, the average voltage value of the element 8 can be controlled by raising the average voltage value to the same level (switching element breakdown voltage) as the input voltage (flyback voltage (maximum amplitude value) 141 V). It is possible to take output up to (crest factor) times. Thereby, the power use efficiency of the power supply circuit 1 can be improved. In fact, if a too large current is taken at a low voltage, an input current distortion occurs, which causes a reduction in input harmonics and a power factor.

Next, a second embodiment of the present invention will be described with reference to FIG. Figure 7 shows a configuration example of the pulse width modulation circuit 14, in the manner described in the first embodiment described above shows a current resonance type high frequency excitation circuit, determines the switching ON width T _a of the switching elements 8 Although a configuration for modulating the charging current of the triangular wave voltage which, in this method, the temperature feedback signal (temperature detection signal V _t of the terminal 20, and a temperature reference voltage V _t0 the terminal 21 compares the amplified voltage) After applying analog amplitude modulation with the pulsating voltage _Vb , pulse width modulation is performed.

[0051] In FIG. 7, the temperature comparison output V ₁ was, by the operational amplifier 47, is input to the pulse width modulation circuit is added to the pulsating voltage V _b of the terminal 22.

Then, the temperature comparison output V ₁ to which the pulsating voltage _Vb is added is supplied to the comparator 31 by the capacitor 3.
Is compared 2 between the voltage V _2, further voltage V ₄ of the capacitor 39 in the comparator 40 is compared with the reference voltage V _3. Thus, to obtain the waveform of the same relationship as Fig. 4 described above, the output voltage V _S of the switching ON width T _s of the switching element 8 is controlled from the terminal 24 is obtained.

The device provided with the pulse width modulation circuit 14 as described above can be applied to a fixing device or the like. For example, to configure the heating element as a cylindrical fixing roller, enter the switching control signal switching ON width T _s is controlled to the switching element 8 performs power control to be supplied to the excitation coil 9. The fixing roller is heated by the magnetic induction heating by the exciting coil 9, and the temperature feedback control is performed so that the surface temperature of the fixing roller is kept constant. By performing such heating control, the toner on the recording paper as the member to be heated can be fixed. In this case, using the magnetic induction heating method,
Since the efficiency of using the power supplied from the power supply circuit 1 is high with the roller ambient temperature and the like as control parameters during the sheet interval, the fixing process can be performed satisfactorily with a circuit configuration almost the same as that of the related art.

[0054]

According to the present invention, the drive of the switching element is controlled over the entire range from the low to the high signal amplitude of the input pulsating signal, so that the current flows to the load. The switching on width is widened in the region where the signal amplitude is low, and the switching on width is adjusted so as to become narrower as the signal amplitude increases, so that the burden on the element is reduced. Can be achieved. Therefore, from the above, it is possible to improve the power use efficiency, and to provide a highly reliable, inexpensive, and simple circuit configuration device using a switching element having a withstand voltage design substantially similar to the conventional one. Can be.

Further, by using such a device, a heating device capable of high-speed thermal response by high-frequency heating of magnetic induction or the like can be obtained, thereby shortening the first print time and saving labor. it can.

Further, by detecting the temperature of the heat generating member as a feedback signal, highly accurate temperature control can be performed in the fixing process, and the image quality can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of an output control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating types of signals input to and output from a waveform control circuit.

FIG. 3 is a circuit diagram showing an internal configuration of a waveform control circuit.

FIG. 4 is a waveform chart showing operation waveforms in each section of the waveform control circuit.

FIG. 5A is a waveform chart showing a pulsating signal, and FIG. 5B is a waveform chart showing a switching control signal whose switching-on width has been converted.

FIG. 6 is a waveform diagram showing a waveform of a switching current of a switching element.

FIG. 7 is a circuit diagram showing a configuration of a waveform control circuit in an output control device according to a second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 power supply means 2 AC power supply 3 line filter 4 bridge circuit 5, 6 power supply filter 7 power output means (magnetic field generating means) 8 switching element (drive control element, power control element) 9 excitation coil 10 capacitor 11 heat generating member 12 first Detection means 14 Pulse width modulation circuit (waveform control circuit, drive control means) 15 Output detection means 16 Temperature detection means 17 Switching control circuit (drive control circuit, drive control means)

Claims (23)

[Claims] A drive control element whose drive time is controlled by an input control signal; first means for generating a pulsation signal; second means for detecting an amplitude of the pulsation signal; Third means for outputting the control signal for extending the drive time of the drive control element in a region where the amplitude of the signal is small; and decreasing the drive time of the drive control element as the amplitude of the pulsating signal increases. An output control device, comprising: fourth means for outputting the control signal. 2. The output control device according to claim 1, wherein said first means generates a pulsating signal of a voltage which is full-wave rectified. 3. The output control device according to claim 1, wherein the drive control element is a switching element. 4. The output control device according to claim 3, wherein said switching element is an FET. 5. The output control device according to claim 3, wherein the drive time of the drive control element is a switching-on width of the switching element. 6. A power supply unit for generating a pulsation signal for supplying power, a power control element for controlling power supplied from the power supply unit, and a first detection for detecting the pulsation signal Means, a second detection means for detecting a power signal, the pulsation signal and the power signal are input, the drive time of the power control element is long and the amplitude is high in a region where the amplitude of the pulsation signal is low Drive control means for outputting a control signal that reduces the drive time of the power control element, and power for outputting power supplied from the power supply means via the power control element that is driven and controlled by the control signal. An output control device comprising output means. 7. The drive control means includes: an input terminal to which the power signal is input as a signal for a control target; and an input terminal to which the pulsating signal is input as a signal for adjusting the drive time of the power control element. A control signal having a triangular wave having a different slope on the hypotenuse depending on the magnitude of the amplitude of the pulsating signal, and the drive time determined at a position where the hypotenuse of the triangular wave intersects with the signal level of the power signal. 7. The output control device according to claim 6, further comprising: a waveform control circuit that generates a signal; and a drive control circuit that performs drive control of the power control element based on the control signal. 8. The output control device according to claim 6, wherein said first detection means detects a pulsating signal of a voltage which has been subjected to full-wave rectification. 9. The power supply device according to claim 6, wherein the second detection means calculates a power signal by a product of a current flowing through the power control element and a voltage of the pulsating signal. Output control device according to the above. 10. The output control device according to claim 6, wherein the power control element is a switching element. 11. The output control device according to claim 10, wherein said switching element is an FET. 12. The output control device according to claim 10, wherein the drive time of the power control element is a switching-on width of the switching element. 13. An AC power supply, a line filter to which an AC signal from the power supply is input, a bridge circuit that rectifies the AC signal to generate the pulsating signal, 13. The output control device according to claim 6, further comprising a power supply circuit including a power supply filter for storing a signal. 14. An output detection means for detecting a signal generated by the power output means, and a timing adjustment means for adjusting a drive timing of the power control means based on the signal detected by the output detection means. The output control device according to any one of claims 6 to 13, further comprising: 15. The output control device according to claim 14, wherein said output detecting means is means for detecting a flyback voltage. 16. The output control device according to claim 6, wherein said power output means comprises a magnetic field generation means. 17. The output control device according to claim 16, wherein said magnetic field generating means has an exciting coil and a capacitor. 18. A heating device, comprising: the output control device according to claim 6; and a heating member that generates heat by the power output unit. 19. The heating device according to claim 18, wherein the heat generating member includes a magnetic member. 20. The heating device according to claim 18, wherein the heat generating member is a fixing roller. 21. A temperature detecting means for detecting the temperature of the heat generating member, and means for performing the feedback control by inputting the detected temperature to the input terminal for the control target of the drive control means. The heating device according to any one of claims 18 to 20, wherein: 22. A magnetic field generating means including an excitation coil, and a magnetic field generated in the magnetic metal member by the magnetic field generating means, whereby the material to be heated is heated by heat generated by the magnetic metal member due to an eddy current generated in the magnetic metal member. A magnetic induction heating type heating device, comprising: means for detecting a voltage supplied to the magnetic field generating means; current measuring means for measuring an exciting current waveform of the exciting coil; and induction induced by the exciting coil. Means for controlling the exciting power supplied to the exciting coil from a voltage; means for detecting the peak value of the induced voltage waveform induced in the exciting coil; and limiting the exciting power based on the voltage value detected by the means. And a magnetic induction heating fixing device. 23. The magnetic induction heating fixing device according to claim 22, wherein the exciting power is limited based on a product of the waveform of the voltage supplied to the magnetic field generating means and the waveform of the exciting current. .