JPH10149050A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which does not require exchange of heat source depending on each country's power specification. SOLUTION: An image forming device includes a fixing device 15A which heats a heating roller 15a to fix a toner image onto a recording medium, and a power supply part 23 for generating power voltage. The fixing device 15A comprises a fixing part 26 which has plural heat sources to which power voltage is supplied and temperature detecting component which detects surface temperature of the heating roller heated by the heat source, a voltage detecting part 24 which detects power voltage, and a control part 25 which controls conductivity to plural sources based on voltage value detected by the voltage detecting component and surface temperature of the heating roller detected by the fixing component 26. This structure provides an image forming device which does not require exchange of heat sources depending on each country's power specification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording sheet, fixing the image, and then discharging the recording sheet outside the apparatus.

[0002]

2. Description of the Related Art Conventionally, various image forming apparatuses have been proposed as output terminals of personal computers and workstations. In recent years, laser beam printers using an electrophotographic process and laser technology, which are superior in terms of recording speed and print quality, have rapidly become widespread. 2. Description of the Related Art An electrophotographic apparatus such as a laser beam printer performs printing on a recording sheet by performing a charging step, an exposure step, a developing step, a transfer step, and a fixing step, and discharges the recording sheet outside the apparatus.

FIG. 10 is a block diagram showing a conventional general image forming apparatus. 10, 1 is a laser beam printer main body, 2 is a display / operation unit, 3 is a controller unit,
4 is a photosensitive drum, 5 is a charger, 6 is an exposure optical system, 7 is a developing device, 8 is a transfer roller, 9 is a static eliminator, 10 is an exposure light beam,
11 is a cassette for recording paper 12, 13 is a paper feed roller, 1
4 is a paper transport path, 15 is a fixing device, 15a is a heating roller,
15b is a pressure roller, 15c is a halogen lamp, 15e
Is a temperature detection unit, 16 is a fan for exhausting heat, 17 is a control unit, 18 is a drive unit, 19 is a face-down transport path, 20
Denotes a face-down discharge tray, 21 denotes a face-up conveyance path, and 22 denotes a face-up discharge tray.

[0004] The function and the like of each part in FIG. 10 will be described.
The display / operation unit 2 is generally provided on the upper surface of the laser beam printer main body 1 and includes a display unit such as a liquid crystal display panel or a light emitting diode and an operation unit such as an input switching unit. . The controller unit 3 is an external host device (not shown)
It controls the input and output of data to and from the printer, performs image processing of the transmitted image data, and sets various operating environments related to printing in accordance with the data input from the display / operation unit 2. The photosensitive drum 4 is obtained by attaching an organic photoconductive substance on an electrode thin film on the surface of a metal drum such as aluminum.

In the printing process, first, the surface of the photosensitive drum 4 is charged by the charger 5 along the rotation direction of the photosensitive drum 4 (charging process). An exposure optical system 6 irradiates an exposure light beam 10 to the surface of the photosensitive drum 4 charged by the charger 5. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 4 by projecting the image of the document as an optical image (exposure process). The developing device 7 adsorbs toner on the electrostatic latent image (developing process).
The transfer roller 8 transfers the toner image formed by the developing device 7 on the surface of the photosensitive drum 4 onto the recording paper 12 (transfer process). The charge eliminator 9 removes the toner remaining on the surface of the photosensitive drum 4 after the transfer roller 8 transfers the toner image to the recording paper 12. The toner image on the recording paper 12 after the transfer is transferred to the recording paper 1 by a heating roller 15a and a pressure roller 15b in the fixing device 15.
2 (fixing process).

The fan 16 radiates heat generated from the heating roller 15a and a drive motor (not shown) to the outside of the machine. The recording paper 12 is stored in the cassette 11. Paper feed roller 13
Feeds the recording paper 12 one by one from the cassette 11 and conveys it to the paper conveyance path 14. Face-down output tray 2
0 is used when the user selects face-down as the paper discharge method, and receives the recording paper 12 that has passed through the face-down transport path 19. On the other hand, when the user selects the face-up discharge mode, the face-up discharge tray 22 is used, and the face-up discharge tray 22 is used.
Receives the recording paper 12 that has passed through the face-up transport path 21.

The operation of the conventional laser beam printer configured as described above will be described. Before printing, the user performs various settings according to the settings of the printing environment displayed on the display / operation unit 2. When the controller unit 3 receives character / image data from an external host device such as a personal computer and performs image processing on the character / image data, the photosensitive drum 4 performs the following charging, exposure, development, transfer, and fixing processes while rotating. The print operation is repeatedly performed. First, in the charging process,
A high voltage is applied to the charging line in the charging device 5 in a DC manner to cause corona discharge, thereby radiating electric charge and electrostatic energy, and the surface of the rotating photosensitive drum 4 is made uniform to about -700 V. Charge. Next, in the exposure step, the laser beam emitted from the exposure optical system 6 is modulated according to the print pattern data transmitted from the controller 3, and the exposure light beam 10 is emitted to the surface of the photosensitive drum 4. Since the portion irradiated with the exposure light beam 10 has increased electric conductivity, the electric charge disappears only in that portion, and an electrostatic latent image is formed on the surface of the photosensitive drum 4. Next, in the developing process, the developing device 7 charges the toner to about -300V. When the photosensitive drum 4 reaches the developing device 7, the negatively charged toner is attracted to the surface portion of the photosensitive drum 4 which has been depleted by the irradiation of the exposure light beam 10, and is developed by the negative-positive process. Next, in the transfer process, the recording paper 12 is fed from the cassette 11 by the feed roller 13 and
4 and is conveyed to the transfer roller 8. +100 on the surface
The toner adsorbed on the surface of the photosensitive drum 4 is transferred to the recording paper 12 by the electrostatic Coulomb force of the transfer roller 8 to which a voltage of about 0 V is applied. After the transfer, the toner remaining on the surface of the photosensitive drum 4 is removed by the charge remover 9.

Next, in the fixing process, when the surface of the recording paper 12 comes into contact with the heating roller 15a whose surface temperature is stabilized at the control temperature, the toner image is melted, and at the same time, the heating roller 15a and the pressing roller 15b are separated. The toner image is fixed semipermanently on the surface of the recording paper 12 by being pressed. The fan 16 emits heat generated from the heating roller 15a and a drive motor (not shown) and ozone generated by corona discharge to the outside of the machine. There are two methods of ejecting the recording paper 12, face-down and face-up. As described above, when the user selects face-down as the paper ejection method, the recording paper 12 is ejected to the face-down ejection tray 20 through the face-down conveyance path 19. On the other hand, when the user selects face-up as the paper discharge method, the recording paper 12 is discharged to the face-up paper discharge tray 22 through the face-up conveyance path 21. The printing operation on one sheet of recording paper 12 is completed by the printing process as described above.

Next, the configuration, operation and control of the fixing device 15 will be described in detail. FIG. 11 is a block diagram showing a fixing unit 15 of a conventional image forming apparatus. In FIG. 11, a halogen lamp 15c, a temperature detecting unit 15e, a control unit 17, and a driving unit 18 constitute the fixing unit 15. Reference numeral 23 denotes a power supply unit that supplies power to the drive unit 18. The fixing device 1
5 also has a heating roller 15a and a pressure roller 15b as shown in FIG. The heating roller 15a has a metal hollow roller surface coated with a thin layer of silicon rubber or the like, and a halogen lamp 15c is disposed inside (see FIG. 10).
The pressure roller 15b is a metal roller having a fluororesin film layer on the outermost surface and a rubber layer in the middle, and is pressed against the heating roller 15a by an urging member (not shown). The temperature detector 15e is disposed near the surface of the heating roller 15a in order to detect the surface temperature of the heating roller 15a.

The portion for controlling the temperature of the fixing device 15 is composed of a halogen lamp 15c, a temperature detecting section 15e, a control section 17, a driving section 18, and a power supply section 23. The halogen lamp 15c is used to heat the halogen by applying electric power to a filament (not shown) in the lamp and to use infrared rays emitted by the heated halogen as a heat source, and is used to heat the heating roller 15a. Can be Temperature detector 15
e can be easily configured with a thermistor (not shown) inside. Since the thermistor has the property that the resistance value greatly changes depending on the outside air temperature, if a voltage is applied across both ends of the thermistor in series with a voltage-dividing resistor (not shown), the potential of the connection portion becomes outside air. Since it changes depending on the temperature, the outside air temperature, that is, the heating roller 15a
Can be detected, and this is output to the control unit 17. The control unit 17 controls the drive unit 18 based on the temperature detected by the temperature detection unit 15e, and controls the halogen lamp 15c
Is adjusted to keep the surface temperature of the heating roller 15a constant. The drive unit 18 drives the halogen lamp 15c under the control of the control unit 17. The power supply unit 23 is an AC power supply for applying a voltage to the halogen lamp 15c.

When a normal fixing process is performed, the heating roller 1
The recording paper 12 carrying the unfixed image is sandwiched between 5a and the pressure roller 15b, and the toner image is fixed on the recording paper 12 by pressure and heat. That is, when the heating roller 15a whose surface temperature is stabilized at the control temperature and the surface of the recording paper 12 come into contact with each other, the toner image is melted. Is fixed on the surface of the recording paper 12 semi-permanently.

When the surface temperature of the heating roller 15a is set near the control temperature, first, the control unit 17 controls the driving unit 18 to connect the power supply unit 23 and the halogen lamp 15c to supply power to the halogen lamp 15c. Then, the heating roller 15a is heated by the generated heat. The surface temperature of the heating roller 15a is detected by the temperature detecting
Is input to When the detected surface temperature of the heating roller 15a is lower than the control temperature, the control unit 17 controls the driving unit 18 to connect the halogen lamp 15c and the power supply unit 23,
Power is supplied to the halogen lamp 15c. This allows
The halogen lamp 15c generates heat, the heating roller 15a is heated, and its surface temperature rises. Conversely, when the detected surface temperature of the heating roller 15a is higher than the control temperature, the control unit 17 controls the driving unit 18 to control the halogen lamp 15c.
And the power supply unit 23 are shut off to supply no power to the halogen lamp 15c. As described above, the control unit 17 includes the driving unit 18
, The connection and disconnection of the halogen lamp 15c and the power supply unit 23 are repeated, and control is performed such that the surface temperature of the heating roller 15a detected by the temperature detection unit 15e is kept near the set temperature.

[0013]

However, in a conventional image forming apparatus such as a laser beam printer, since the power supply specifications such as the voltage in each country of the world are different, the specification of the heat source in the fixing unit 15 is adjusted in accordance with the power supply specification in each country. Has to be changed, and the heat source must be replaced according to each specification. In addition, there is a limitation on the power supply capacity of the outlet to be used, and there is a problem that the breaker is shut off when the power consumption of the image forming apparatus exceeds the power capacity of the outlet. In this case, the user needs to repair the interrupted breaker and connect the power input of the image forming apparatus to an outlet having a power capacity equal to or greater than its maximum power consumption.

In this image forming apparatus, it is not necessary to exchange heat sources in accordance with different power supply specifications in each country, and it is desired that the power consumption of the apparatus can be prevented from exceeding the power capacity of the outlet.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which does not require a heat source to be exchanged according to a different power supply specification in each country, and can prevent the power consumption of the apparatus from exceeding the power capacity of an outlet. I do.

[0016]

In order to solve this problem, an image forming apparatus according to the present invention comprises a fixing device for heating a heating roller to fix a toner image on a recording medium, and a power supply for generating a power supply voltage. A fixing unit having a plurality of heat sources to which a power supply voltage is supplied and a temperature detection unit to detect a surface temperature of a heating roller heated by the heat source; and a power supply voltage detection unit. And a control unit that controls energization to a plurality of heat sources based on the detected voltage value output from the voltage detection unit and the surface temperature value of the heating roller output from the fixing unit.

As a result, it is possible to obtain an image forming apparatus in which it is not necessary to exchange heat sources according to different power supply specifications in each country.

[0018]

DETAILED DESCRIPTION OF THE INVENTION An image forming apparatus according to a first aspect of the present invention has a fixing device for heating a heating roller to fix a toner image on a recording medium, and a power supply for generating a power supply voltage. A fixing unit having a plurality of heat sources to which a power supply voltage is supplied and a temperature detection unit that detects a surface temperature of a heating roller heated by the heat source; and a voltage detection unit that detects a power supply voltage. A control unit that controls the energization of a plurality of heat sources based on the detected voltage value output from the voltage detection unit and the surface temperature value of the heating roller output from the fixing unit. The power supply voltage and the surface temperature value of the heating roller are detected, and the number of heat sources to which power is supplied is set according to the detected power supply voltage value and surface temperature value.

According to a second aspect of the present invention, in the first aspect, the control section reduces the number of heat sources to be energized when the detected voltage value is larger than the predetermined voltage value, so that the detected voltage value is smaller than the predetermined voltage value. If the value is smaller than the value, the number of heat sources to be energized is increased, and the energization control of the heat sources is performed based on the surface temperature value of the heating roller. Has the effect of being set to

According to a third aspect of the present invention, there is provided an image forming apparatus comprising: a fixing device for heating a heating roller to fix a toner image on a recording medium; and a power supply unit for generating a power supply voltage.
The fixing device has a fixing unit having a plurality of heat sources to which a power supply voltage is supplied and a temperature detecting unit for detecting a surface temperature of a heating roller heated by the heat source, and a capacity input unit for setting a capacity value of the power unit. And a control unit that controls energization to a plurality of heat sources based on the set capacity value input from the capacity input unit and the surface temperature value of the heating roller output from the fixing unit. The value and the surface temperature value of the heating roller are detected, and the number of heat sources to which power is supplied is set according to the detected set capacity value and surface temperature value.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the control section increases the number of heat sources to be energized if the set capacity value input from the capacity input section is larger than a predetermined capacity value. If the set capacity value input from the capacity input unit is smaller than the predetermined capacity value, reduce the number of heat sources to be energized,
The control of energization of the heat source is performed based on the surface temperature value of the heating roller, and has an effect that the number of heat sources to which electric power is supplied is set to an optimum number based on the set capacity value.

According to a fifth aspect of the present invention, there is provided an image forming apparatus comprising: a fixing device for heating a heating roller to fix a toner image on a recording medium; and a power supply for generating a power supply voltage.
The fixing device includes a fixing unit having a plurality of heat sources to which a power supply voltage is supplied and a temperature detection unit that detects a surface temperature of a heating roller heated by the heat source; a voltage detection unit that detects a power supply voltage; and a voltage detection unit. To a second control unit that controls the number of heat sources to be energized based on the detected voltage value output from the printer, and to a heat source whose number is controlled by the second control unit based on the surface temperature value of the heating roller output from the fixing unit. And a first control unit that controls whether or not to conduct current.
The number of heat sources to which power is supplied is set based on the detected voltage value, and the power supply control based on the surface temperature value of the heating roller is performed for the set number of heat sources.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the second control section reduces the number of heat sources to be energized when the detected voltage value is larger than a predetermined voltage value. If the value is smaller than the predetermined voltage value, the number of heat sources to be energized is increased, and based on the detected voltage value, the number of heat sources to which power is supplied is set to an optimal number. .

According to a seventh aspect of the present invention, there is provided an image forming apparatus comprising: a fixing device for heating a heating roller to fix a toner image on a recording medium; and a power supply unit for generating a power supply voltage.
The fixing device has a fixing unit having a plurality of heat sources to which a power supply voltage is supplied and a temperature detecting unit for detecting a surface temperature of a heating roller heated by the heat source, and a capacity input unit for setting a capacity value of the power unit. A second control unit that controls the number of heat sources to be energized based on a set capacity value input from the capacity input unit;
A first control unit for controlling whether or not to energize the heat source whose number is controlled in the second control unit based on the surface temperature value of the heating roller output from the fixing unit. There is an effect that the number of heat sources to which electric power is supplied is set by the set capacity value, and the energization control based on the surface temperature value of the heating roller is performed on the set number of heat sources.

According to an eighth aspect of the present invention, in the seventh aspect of the invention, the control section increases the number of heat sources to be energized if the set capacity value input from the capacity input section is larger than a predetermined capacity value. If the set capacity value input from the capacity input unit is smaller than the predetermined capacity value, the number of heat sources to be energized is reduced.Based on the set capacity value, the number of heat sources to which power is supplied is It has the effect of being set to an optimal number.

According to a ninth aspect of the present invention, in the first aspect of the present invention, the heat source is a halogen lamp, and the operation of controlling the energization of the halogen lamp is performed. Having.

According to a tenth aspect of the present invention, in the first aspect of the present invention, the heat source is a heating resistor, and energization control of the heating resistor is performed. It has the action of:

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a block diagram showing a fixing unit 15A of an image forming apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 23 denotes a power supply unit that generates a power supply voltage; 24, a voltage detection unit that detects a power supply voltage generated by the power supply unit 23;
Reference numeral 25 denotes a detection voltage value output from the voltage detection unit 24 and a heating roller 15a (FIG.
Multiple heat sources (not shown) depending on the surface temperature
A control unit 26 for controlling power supply to the power supply unit; a plurality of heat sources to which a power supply voltage is supplied from the power supply unit 23; and a temperature detection unit (not shown) for detecting a surface temperature of the heating roller 15a heated by the heat source. And a voltage detecting unit 24.
The control unit 25 and the fixing unit 26 constitute a fixing device 15A according to the present embodiment. Further, the point that the fixing device 15A has a pressure roller 15a and a pressure roller 15b is the same as the conventional one (see FIG. 10). Further, the fixing unit 26 of FIG.
Corresponding to the halogen lamp 15c and the temperature detector 15e,
The control unit 25 in FIG. 1 corresponds to the control unit 17 in FIG.
Those corresponding to the drive unit 18 of 0 are included in the control unit 25.

Next, the function and the like of each unit will be described. The fixing unit 26 has a plurality of heat sources for heating the internal heating roller 15a, and outputs the surface temperature of the heating roller 15a to the control unit 25 as a surface temperature value t. Power supply unit 23
Is a power supply for applying power to a plurality of heat sources included in the fixing unit 26. The voltage detection unit 24 detects the power supply voltage generated by the power supply unit 23 and sets the detected voltage value as a detected voltage value v.
Output to The control unit 25 turns on a plurality of heat sources of the fixing unit 26 connected to the power supply unit 23 based on the detected voltage value v output from the voltage detection unit 24 and the surface temperature value t output from the fixing unit 26. Performs off control. Voltage detector 2
If the voltage value (detected voltage value) v detected in Step 4 is higher than the predetermined voltage value, the control unit 25 reduces the number of heat sources used in the fixing unit 26 connected to the power supply unit 23, and sets the detected voltage value v Is lower than the predetermined voltage value, the control unit 25 increases the number of heat sources used in the fixing unit 26 connected to the power supply unit 23, and further increases the heating roller 1 output from the fixing unit 26.
On / off control is performed so that the surface temperature value of 5a becomes a predetermined temperature value. In this way, different power supply voltages of the power supply unit 23 (for example, different power supply voltages for each country) are detected, and the number of heat sources included in the fixing unit 26 is switched to supply optimal power to the heat sources. It can be controlled to a predetermined temperature value.

FIG. 2 shows a fixing device 15A according to the first embodiment.
3 is a circuit diagram showing a case where the fixing unit 26 of FIG. In FIG.
3, the voltage detection unit 24, the control unit 25, and the fixing unit 26 are the same as those in FIG.
27 is an AC power supply, 28 is a transformer, 29 is a bridge type rectifier circuit, 30 is a capacitor, 31 is a coil, 32 and 33 are voltage dividing resistors, 34 is a CPU (central processing unit),
5, 36 are transistors; 37, 38 are light-emitting diodes; 39, 40 are limiting resistors; 41, 42 are phototriac couplers; 43, 44 are halogen lamps as heat sources; , 46 is a thermistor constituting a temperature detecting section together with the voltage dividing resistor 45, and N1 is a connecting portion between the voltage dividing resistor 45 and the thermistor 46. The fixing unit 15A in FIG. 1 is obtained by removing the AC power supply 27 from FIG.

Next, the operation of the fixing device 15A shown in FIG. 2 will be described. The voltage detector 24 converts an AC component of the voltage value of the AC power supply 27 into a DC component to generate a DC voltage value, and outputs the DC voltage value to the CPU of the controller 25 as a detected voltage value v.
For this purpose, first, the AC voltage of the AC power supply 27 is
To transform a large voltage value of the AC power supply 27 into a small voltage value. The transformer 28 includes two coils on the input side and the output side. The AC voltage on the input side is transformed in proportion to the ratio of the number of turns of each coil, and is output to the output side. The AC voltage transformed by the transformer 28 is applied to a bridge type rectifier circuit 29.
Is input to The bridge type rectifier circuit 29 is configured by combining four diodes so that the polarity of the AC voltage on the input side is converted in one direction and output, that is, full-wave rectified, and the AC voltage is full-wave rectified. Output to the output side. The voltage output by full-wave rectification by the bridge rectifier circuit 29 (hereinafter referred to as “rectified output voltage”) contains a large amount of ripple components and is not a DC voltage, and therefore is input to the smoothing circuit and included in the rectified output voltage. Remove the alternating current component. This smoothing circuit includes a capacitor 30 and a coil 31. The capacitor 30 has a small reactance with respect to the AC component, and the coil 31 has a large reactance. For this reason, the ripple component of the input rectified output voltage is short-circuited by the capacitor 30 and blocked by the coil 31, so that the output side voltage of the coil 31 is a DC voltage with no AC component (hereinafter referred to as "smoothed DC voltage"). ) Is obtained. When adjusting the value of the smoothed DC voltage, the voltage is divided by the voltage dividing resistors 32 and 33 to a ratio of these values. In this way, the AC voltage of the AC power supply 27 is converted into a smoothed DC voltage, and the converted
To enter. Thus, the value of the power supply voltage generated by the AC power supply 27 can be detected as the detection voltage value v.

The control unit 25 has the CPU 34 as described above.
An AC power supply 27 of the power supply unit 23 is configured based on the smoothed DC voltage value (detected voltage value) v detected by the voltage detection unit 24 and the surface temperature value t of the heating roller 15a output from the fixing unit 26. Of the fixing unit 26 connected to the
On / off control of the two halogen lamps 43 and 44 is performed. On / off control of the two halogen lamps 43 and 44 is performed using phototriac couplers 41 and 42 suitable for switching of an AC circuit. Halogen lamp 43
When power is supplied to the
Is turned on. When the transistor 35 is turned on, the current limited by the limiting resistor 39 flows through the light emitting diode 37 on the input side of the phototriac coupler 41 to emit light, and the gate trigger current flows through the phototriac coupler 41 to be in a conductive state. Electric power is supplied to the halogen lamp 43. Conversely, when power is not supplied to the halogen lamp 43, the CPU 34 turns off the transistor 35. When the transistor 35 is turned off, the current does not flow through the light emitting diode 37 on the input side and the light does not emit. Therefore, the phototriac coupler 41 is cut off because no gate trigger current flows and the power is not supplied to the halogen lamp 43. In this manner, by performing on / off control of the transistor 35, on / off control of the power supplied from the AC power supply 27 to the halogen lamp 43 is performed, the heat output thereof is adjusted, and the surface temperature of the heating roller 15a is reduced. Control is performed to keep the temperature near the set temperature. Similarly, the on / off control of the power supplied to the halogen lamp 44 is also performed by the transistor 36, the light emitting diode 38, and the limiting resistor 4.
0, using a phototriac coupler 42.

The halogen lamps 43 and 44 are connected to the AC power source 2
7 is determined according to the specifications when the power supply voltage value is large and when it is small. That is, when the power supply voltage value of the AC power supply 27 is large, the specification is determined such that only the halogen lamp 43 is driven and a predetermined power is applied. On the other hand, when the power supply voltage value of the AC power supply 27 is small, the specification of the halogen lamp 44 is determined so that a predetermined power is applied when the halogen lamp 44 is driven in addition to the halogen lamp 43.

The surface temperature of the heating roller 15a can be easily detected by providing the voltage dividing resistor 45 and the thermistor 46, and the thermistor 46 is arranged near the surface of the heating roller 15a. The voltage dividing resistor 45 and the thermistor 46 are connected in series, both ends are connected to the power supply and the ground, respectively, and the potential of the connection portion N1 is output to the CPU 34 as a detected surface temperature value. Since the resistance of the thermistor 46 greatly changes depending on the outside air temperature, the potential of the connection portion N1 between the voltage dividing resistor 45 and the thermistor 46 also changes accordingly. From the relative relationship between the outside air temperature and the potential, the CPU 34 can detect the outside air temperature of the thermistor 46, that is, the surface temperature of the heating roller 15a.

Next, the control operation of the halogen lamps 43 and 44 will be described. When the power supply voltage value of the AC power supply 27 is large, the CPU 34 detects the power supply voltage value and the surface temperature value of the heating roller 15a, and performs on / off control of the power applied only to the halogen lamp 43 by the transistor 35, thereby controlling the halogen lamp. The heat output of the heating roller 15a is adjusted so that the surface temperature of the heating roller 15a is maintained near the set temperature. On the other hand, when the power supply voltage value of the AC power supply 27 is small, the predetermined power is not applied only by the halogen lamp 43, and a necessary heat output cannot be obtained. For this reason, the CPU 34 detects the power supply voltage value and the surface temperature value of the heating roller 15a, and makes the halogen lamps 43 and 44
On and off control of the power applied to each of the
The heat output of each of the halogen lamps 43 and 44 is adjusted, and control is performed so that the surface temperature of the heating roller 15a is maintained near the set temperature. In this way, the ON / OFF control of only the halogen lamp 43 and the ON / OFF control of each of the halogen lamps 43 and 44 are performed by the changing power supply voltage of the AC power supply 27 to adjust the applied power. The required heat output can be obtained even if the power supply voltage value of the AC power supply 27 changes.

In the present embodiment, the heat source is a halogen lamp. However, the present invention is not limited to this, and another heat source, for example, a heating resistor may be used.

As described above, according to the present embodiment, when the power supply voltage value of AC power supply 27 is large, transistor 3
5 to control ON / OFF of the power applied to only the halogen lamp 43 by controlling ON and OFF of only the halogen lamp 43, to adjust the heat output of the halogen lamp 43, and to keep the surface temperature of the heating roller 15a near the set temperature. Control and the AC power supply 27
When the power supply voltage value of the transistors 35 and 36 is small, the transistors 35 and 36
Are turned on and off to control the power applied to each of the halogen lamps 43 and 44, thereby adjusting the heat output of each of the halogen lamps 43 and 44 to reduce the surface temperature of the heating roller 15a. Since the control is performed so as to keep the temperature near the set temperature, the power supplied to the heat source is controlled to a predetermined power so that the surface temperature of the heating roller 15a becomes close to the set temperature even if the power supply specification, for example, the power supply voltage value differs in each country. Can be controlled.

(Embodiment 2) FIG. 3 is a block diagram showing a fixing unit 15B of an image forming apparatus according to Embodiment 2 of the present invention. 3, the power supply unit 23, the control unit 25, and the fixing unit 26 are the same as those in FIG.
Description is omitted. Reference numeral 47 denotes a capacitance input unit for setting a capacitance value of the power supply unit 23. The control section 25, the fixing section 26, and the capacity input section 47 constitute the fixing device 15B according to the present embodiment. Further, the point that the fixing device 15B has a pressure roller 15a and a pressure roller 15b is the same as the conventional one (see FIG. 10). Further, the fixing unit 26 in FIG. 3 corresponds to the halogen lamp 15c and the temperature detecting unit 15e in FIG. 10, the control unit 25 in FIG. 3 corresponds to the control unit 17 in FIG.
Those corresponding to 8 are included in the control unit 25.

Next, the function of each unit will be described. The fixing unit 26 has a plurality of heat sources for heating the internal heating roller 15a, and outputs the surface temperature of the heating roller 15a to the control unit 25 as a surface temperature value t. Power supply unit 23
Is a power supply for applying power to a plurality of heat sources included in the fixing unit 26. The capacity input section 47 is provided with a power capacity (power supply section 23) of an outlet (not shown) connected to the power supply section 23.
Is the power capacity of the power supply unit 23 in the case of, for example, a commercial AC power supply supplied from the outside. Here, it is assumed that the power capacity of the power supply unit 23 and the power capacity of the outlet are the same. )
Is input by the user or the like, and the set capacity value is input to the control unit 25. The control unit 25 controls the capacity input unit 4
7 and the power capacity value c of the power supply unit 23 output from the fixing unit 2
On / off control of a plurality of heat sources of the fixing unit 26 connected to the power supply unit 23 is performed based on the surface temperature value t of the heating roller 15a output from the unit 6. If the set capacity value in the capacity input section 47 is larger than a predetermined capacity value, the control section 25
Increases the number of heat sources used in the fixing section 26 connected to the power supply section 23, and if the set capacity value in the capacity input section 47 is smaller than a predetermined capacity value, the control section 25 connects to the power supply section 23. The number of heat sources used in the fixing unit 26 is reduced, and ON / OFF control is performed so that the surface temperature of the heating roller 15a output from the fixing unit 26 becomes a predetermined temperature value. In this manner, the number of heat sources used by the fixing unit 26 is switched according to the set capacity value set in the capacity input unit 47 to adjust the power supplied to the heat sources, and the power consumed by the laser beam printer is changed to the power of the outlet. It is possible to prevent the breaker from being shut off by not exceeding the capacity (the power capacity of the power supply unit 23), and to control the surface temperature of the heating roller 15a to around the set temperature.

FIG. 4 shows a fixing device 15B according to the second embodiment.
3 is a circuit diagram showing a case where the fixing unit 26 of FIG. In FIG.
3, the control unit 25, the fixing unit 26, and the capacity input unit 47 are the same as those in FIG.
Transistors 35 and 36, light emitting diodes 37 and 38,
Limiting resistors 39 and 40, photo triac coupler 4
1, 42, halogen lamps 43, 44, voltage dividing resistor 4
5, the thermistor 46 and the connecting portion N1 are the same as those in FIG. 48 is a switch, and 49 is a pull-up resistor. Fixing device 15 in FIG.
B is the one obtained by removing the AC power supply 27 from FIG.

Next, the operation of the fixing device 15B shown in FIG. 4 will be described. For example, when inputting the power capacity of two types of outlets, the capacity input unit 47 is simply configured with a switch 48 and a pull-up resistor 49, and the set capacity value is input to the control unit 25. When the switch 48 is turned off, the input value to the control unit 25 becomes high level “H” by the pull-up resistor 49, and when the switch 48 is turned on, the input value becomes low level “L” due to the ground potential. If the power capacity of the outlet is large, the switch 48 is turned off and "H" is input to the control unit 25. If the power capacity is small, the switch 48 is turned on and "L" is input to the control unit. Different types of power capacities can be detected separately.

The control unit 25 has the CPU 34 as described above.
The set capacity value c input from the capacity input unit 47 and the heating roller 15 output from the fixing unit 26 are used.
a of the AC power supply 27 of the power supply unit 23 according to the surface temperature value t of
ON / OFF control of the two halogen lamps 43 and 44 of the fixing unit 26 connected to the control unit is performed. The on / off control of the two halogen lamps 43 and 44 is the same as in the first embodiment, and a description thereof will be omitted.

The halogen lamps 43 and 44 are connected to the AC power source 2
7 is determined according to the specifications when the power capacity of the outlet connected to the power supply 7 is large and when the power capacity is small. That is, when the power capacity of the outlet is small, only the halogen lamp 43 is turned on and off to determine the specifications so that the power consumed by the laser beam printer does not exceed the power capacity of the outlet. On the other hand, when the power capacity of the outlet is large, the halogen lamp 44 is driven in addition to the halogen lamp 43, and the specifications of the halogen lamp 44 are determined so that the power consumed by the laser beam printer does not exceed the power capacity of the outlet.

Since the detection of the surface temperature of the heating roller 15a is the same as that of the first embodiment, the description is omitted.

Next, the control operation of the halogen lamps 43 and 44 will be described. When the power capacity of the outlet is small, the switch 48 is turned on by the user or the like and the CPU 3
“L” is input to 4. The CPU 34 has a small power capacity value of the outlet (a set capacity value in the capacity input unit 47).
c and the surface temperature t of the heating roller 15a are detected, and the power applied to only the halogen lamp 43 is turned on and off by the transistor 35, the heat output of the halogen lamp 43 is adjusted, and the surface temperature of the heating roller 15a is adjusted. Is controlled so as to keep the temperature near the set temperature. On the other hand, when the power capacity of the outlet is large, the switch 48 is turned off by the user or the like, and “H” is input to the CPU 34. The CPU 34 detects a large power capacity value (set capacity value in the capacity input section 47) c of the outlet and a surface temperature value of the heating roller 15a.
On / off control of the power applied to each of the lamps 3 and 44 is performed, the heat output of each of the halogen lamps 43 and 44 is adjusted, and control is performed so as to keep the surface temperature of the heating roller 15a near the set temperature. In this way, the ON / OFF control of only the halogen lamp 43 and the ON / OFF control of each of the halogen lamps 43 and 44 are performed by the changing power capacity of the outlet, so that the power consumed by the laser beam printer is reduced by the outlet. By preventing the power from exceeding the power capacity, the breaker can be prevented from being shut off, and the surface temperature of the heating roller 15a can be controlled to be near the set temperature.

In the present embodiment, the heat source is a halogen lamp. However, the present invention is not limited to this, and another heat source, for example, a heating resistor may be used.

As described above, according to the present embodiment, when the set capacitance value c is small, only the transistor 35 is turned on and off, and the power applied to only the halogen lamp 43 is turned on and off. The heat output of the halogen lamp 43 is adjusted to control the surface temperature of the heating roller 15a to be kept close to the set temperature. When the set capacity value c is large, the transistors 35 and 36 are turned on and off, respectively. The on / off control of the power applied to each of the halogen lamps 43 and 44 is performed by
And the heat output of each of the heating rollers 15a
Is controlled so as to keep the surface temperature of the laser beam near the set temperature, so that the power consumed by the laser beam printer does not exceed the power capacity of the outlet to prevent the breaker from being shut off, and the surface of the heating roller 15a The temperature can be controlled around the set temperature.

(Embodiment 3) FIG. 5 is a block diagram showing a fixing unit 15C of an image forming apparatus according to Embodiment 3 of the present invention. In FIG. 5, a power supply unit 23, a voltage detection unit 2
4. Since the fixing section 26 is the same as that in FIG. Reference numeral 50 denotes a second control unit 51 described later.
A first control unit 51 controls the energization of the heat sources, the number of which is controlled by the control unit, and a second control unit 51 controls the number of heat sources to be energized based on the detected voltage value output from the voltage detection unit 24. The voltage detection unit 24, the fixing unit 26, and the first and second control units 50 and 51 constitute a fixing unit 15C according to the present embodiment. Further, the point that the fixing device 15C has a pressure roller 15a and a pressure roller 15b is the same as the conventional one (see FIG. 10). Further, the fixing unit 26 of FIG. 5 corresponds to the halogen lamp 15c and the temperature detecting unit 15e of FIG.
The second control units 50 and 51 correspond to the control unit 17 in FIG. 10, and those corresponding to the drive unit 18 in FIG. 10 are included in the first and second control units 50 and 51.

The function, operation, and the like of the fixing device 15C configured as described above will be described. The fixing unit 26 has a plurality of heat sources for heating the heating roller 15 a therein, and outputs the surface temperature value t of the heating roller 15 a to the first control unit 50. The power supply unit 23 is a power supply for applying power to a plurality of heat sources included in the fixing unit 26. The voltage detection unit 24 detects a power supply voltage generated by the power supply unit 23 and outputs the detected power supply voltage to the second control unit 51 as a detected voltage value v. Second
The control unit 51 controls the number of heat sources of the fixing unit 26 to which power is supplied from the power supply unit 23 based on the detected voltage value v output from the voltage detection unit 24. If the detection voltage value v is higher than the predetermined voltage value, the second control unit 51 reduces the number of heat sources of the fixing unit 26 to which power is supplied from the power supply unit 23, and the detection voltage value v becomes higher than the predetermined voltage value. If lower, the second control unit 5
1 increases the number of heat sources of the fixing unit 26 to which power is supplied from the power supply unit 23. The number of the first control units 50 is controlled by the second control unit 51 based on the surface temperature value t of the heating roller 15a output from the fixing unit 26 so that the surface temperature of the heating roller 15a becomes a predetermined temperature. Control of energization of the heat source. In this manner, the number of heat sources used by the fixing unit 26 is switched according to the power supply voltage value of the power supply unit 23 detected by the voltage detection unit 24, that is, the detected voltage value v, and the power supplied to the heat sources is adjusted. Can control the surface temperature of the heating roller 15a to a predetermined temperature.

FIG. 6 shows a fixing device 15C according to the third embodiment.
3 is a circuit diagram showing a case where the fixing unit 26 of FIG. In FIG. 6, the power supply unit 2
3, the voltage detection unit 24, the fixing unit 26, the first and second control units 50 and 51 are the same as those in FIG. Coil 31, voltage dividing resistors 32, 33, CPU3
4, transistors 35 and 36, light emitting diodes 37 and 3,
8, limiting resistors 39 and 40, phototriac couplers 41 and 42, halogen lamps 43 and 44, voltage dividing resistor 4
5, the thermistor 46 and the connecting portion N1 are the same as those in FIG. 52 is a comparator and 53 is a battery. The fixing device 15C shown in FIG.
From which the AC power supply 27 is excluded.

Next, the operation of the fixing device 15C shown in FIG. 6 will be described. The voltage detection unit 24 converts the AC component of the voltage value of the AC power supply 27 into a DC component to generate a DC voltage value, and uses the converted DC voltage value as a detected voltage value v to output the voltage to the comparator 5 of the second control unit 51.
Output to 2. For this purpose, first, the AC voltage of the AC power supply 27 is input to the transformer 28, and the large voltage value of the AC power supply 27 is reduced. From the transformer 28 to the voltage dividing resistor 32,
The operation of 33 is the same as that of the first embodiment, and a description thereof will be omitted. Thus, the value of the power supply voltage generated by the AC power supply 27 can be detected as the detection voltage value v.

The second control unit 51 includes a transistor 36,
It is configured using a light emitting diode 38, a limiting resistor 40, a phototriac coupler 42, a comparator 52, and a battery 53 for a reference voltage. In the comparator 52, the detected voltage value v detected by the voltage
Is input to the plus terminal, and the reference voltage value from the battery 53 is input, and the comparison result is output to the base of the transistor 36. When the transistor 36 is turned on,
The current restricted by the limiting resistor 40 flows through the light emitting diode 38 on the input side of the phototriac coupler 42 to emit light, and the phototriac coupler 42 becomes conductive due to the flow of a gate trigger, and the halogen lamp 44 is connected in parallel with the halogen lamp 43. Connected. Conversely, when the transistor 36 is turned off, no current flows through the light-emitting diode 38 and no light is emitted, so that the phototriac coupler 42 is cut off without a gate trigger current flowing, and the halogen lamp 44 is not connected in parallel with the halogen lamp.

The first control unit 50 is constituted by the CPU 34 and the like, and the heating roller 15a output from the fixing unit 26
Of the halogen lamp in the fixing unit 26 in which whether or not the heating roller 15a is connected in parallel is controlled by the second control unit 51 so that the surface temperature of the heating roller 15a becomes a predetermined temperature. The power supply by the power supply 27 is controlled. The energization control of the halogen lamp is performed by using a phototriac coupler 41 suitable for switching of an AC circuit. When power is supplied from the AC power supply 27 to the halogen lamp in the fixing unit 26, the CPU 34 turns on the transistor 35. When the transistor 35 is turned on, the light emitting diode 37 on the input side of the phototriac coupler 41 is turned on.
Then, the current limited by the limiting resistor 39 flows, and light is emitted.
The phototriac coupler 41 is turned on when a gate trigger current flows, and power is supplied from the AC power supply 27 to the halogen lamp in the fixing unit 26. Conversely, the fixing unit 26
When power is not supplied to the halogen lamp in the
4 turns the transistor 35 off. When the transistor 35 is turned off, no current flows through the light emitting diode 37 and no light is emitted.
Is in a cut-off state because no gate trigger current flows, and the fixing unit 2
No power is supplied to the halogen lamp in 6. In this way, by performing on / off control of the transistor 35, on / off control of the power supplied from the AC power supply 27 to the halogen lamp in the fixing unit 26 is performed, the heat output thereof is adjusted, and the heating roller 15a is controlled. Is controlled so as to keep the surface temperature near the set temperature (predetermined temperature).

The halogen lamps 43 and 44 are
7 is determined according to the specifications when the power supply voltage value is large and when it is small. That is, when the power supply voltage value of the AC power supply 27 is large, the specification is determined such that only the halogen lamp 43 is driven and a predetermined power is applied. On the other hand, when the power supply voltage value of the AC power supply 27 is small, the specifications of the halogen lamp 44 are determined so that predetermined power is applied when the halogen lamp 43 and the halogen lamp 44 are connected in parallel and driven.

Since the detection of the surface temperature of the heating roller 15a is the same as that of the first embodiment, the description is omitted.

Next, the control operation of the halogen lamps 43 and 44 will be described. When the power supply voltage value of the AC power supply 27 is large, the detection voltage value v detected by the voltage detection unit 24 is input to the minus terminal of the comparator 52, which is larger than the reference voltage value of the battery 53. "L", and the transistor 36 is turned off. When the transistor 36 is turned off, the light emitting diode 3 on the input side of the phototriac coupler 42
Since no current flows through 8 and no light is emitted, the phototriac coupler 42 is cut off without a gate trigger current flowing, and the connection of the halogen lamp 44 is cut off. That is,
The halogen lamp 44 is not connected to the halogen lamp 43 in parallel. The CPU 34 detects the surface temperature value of the heating roller 15a, and uses the transistor 35 to
ON / OFF control of the power applied to only the halogen lamp 43 is performed to control the heat output of the halogen lamp 43 so that the surface temperature of the heating roller 15a is maintained near the set temperature. As described above, when the power supply voltage value of the AC power supply 27 is large, only the halogen lamp 43 is driven, so that a predetermined power is applied to obtain an optimal heat output.

On the other hand, when the power supply voltage value of the AC power supply 27 is small, the detected voltage value v detected by the voltage detection unit 24 is input to the minus terminal of the comparator 52,
3, the output level of the comparator 52 becomes “H”, and the transistor 36 is turned on. When the transistor 36 is turned on, the light emitting diode 38 on the input side of the phototriac coupler 42
Current flows through the photo-triac coupler 42
, A gate trigger current flows to be in a conductive state, and the halogen lamp 44 is connected to the halogen lamp 43 in parallel. CP
U34 detects the surface temperature value t of the heating roller 15a,
The on / off control of the power applied to both the halogen lamps 43 and 44 connected in parallel by the transistor 35 is performed, the heat output of both the halogen lamps 43 and 44 is adjusted, and the surface temperature of the heating roller 15a is set to the set temperature. Control to keep it near. In this manner, the ON / OFF control of only the halogen lamp 43 and the ON / OFF control of both the halogen lamps 43 and 44 are performed by the changing power supply voltage of the AC power supply 27 to adjust the applied power. A predetermined power is applied regardless of the power supply voltage of the AC power supply 27, and an optimum heat output is obtained.

In the present embodiment, the heat source is a halogen lamp. However, the present invention is not limited to this, and another heat source such as a heating resistor may be used.

As described above, according to the present embodiment, when the power supply voltage value of AC power supply 27, that is, the detected voltage value v is large, transistor 36 is turned off and halogen lamp 4 is turned off.
4 is not connected in parallel to 43, the ON / OFF control of the power applied only to the halogen lamp 43 is performed by the transistor 35, the heat output of the halogen lamp 43 is adjusted, and the surface temperature of the heating roller 15a is set near the set temperature. When the power supply voltage value of the AC power supply 27, that is, the detected voltage value v is small, the transistor 36 is turned on, and the halogen lamp 44 is connected in parallel with the halogen lamp 43.
On / off control of the power applied to both the lamps 44 is performed by the transistor 35, the heat output of both the halogen lamps 43 and 44 is adjusted, and the control is performed so that the surface temperature of the heating roller 15a is maintained near the set temperature. I decided to do it,
An optimum heat output can be obtained in the fixing process of the laser beam printer regardless of the power supply voltage value of the AC power supply 27 which changes.

(Embodiment 4) FIG. 7 is a block diagram showing a fixing unit 15D of an image forming apparatus according to Embodiment 4 of the present invention. In FIG. 7, the power supply unit 23, the fixing unit 26, and the capacity input unit 47 are the same as those in FIG. 3, and the first control unit is the same as that in FIG. Reference numeral 51a denotes a second control unit that controls the number of heat sources to be energized based on the set capacity value input from the capacity input unit 47. The fixing unit 26, the capacity input unit 47, and the first and second control units 50 and 51a constitute a fixing unit 15D according to the present embodiment. Further, the point that the fixing device 15D has a pressure roller 15a and a pressure roller 15b is the same as the conventional one (see FIG. 10). Further, the fixing unit 26 in FIG. 7 corresponds to the halogen lamp 15c and the temperature detecting unit 15e in FIG.
The second control units 50 and 51a correspond to the control unit 17 in FIG. 10, and those corresponding to the driving unit 18 in FIG. 10 are included in the first and second control units 50 and 51a.

The function, operation, and the like of the fixing device 15D configured as described above will be described. The fixing unit 26 has a plurality of heat sources for heating the internal heating roller 15a, and outputs the surface temperature of the heating roller 15a to the first control unit 50 as a surface temperature value t. The power supply unit 23 is a power supply for applying power to a plurality of heat sources included in the fixing unit 26. The capacity input section 47 is provided with a power capacity of an outlet (not shown) connected to the power supply section 23 (for example, in the case where the power supply section 23 is supplied from outside, for example, a commercial AC power supply, the power supply section 23 is provided).
Here, it is assumed that the power capacity of the power supply unit 23 and the power capacity of the outlet are the same. ) Is input by the user or the like, and the set capacitance value c is input to the second control unit 51a. The second control unit 51a calculates the power capacity value c of the power supply unit 23 output from the capacity input unit 47.
Controls the number of heat sources of the fixing unit 26 to which power is supplied from the power supply unit 23. Set capacitance value c at capacitance input section 47
Is larger than the predetermined capacitance value, the second control unit 51a
Is to increase the number of heat sources of the fixing unit 26 to which power is supplied from the power supply unit 23, and if the set capacity value at the capacity input unit 47 is smaller than a predetermined capacity value, the fixing power supplied from the power supply unit 23 The number of heat sources in the section 26 is reduced. First control unit 5
0 is a heat source whose number is controlled by the second control unit 51a so that the surface temperature value of the heating roller 15a becomes a predetermined temperature value based on the surface temperature value t of the heating roller 15a output from the fixing unit 26. Is performed. In this way, the second
The control unit 51a controls the power supplied to the heat source by switching the number of heat sources used by the fixing unit 26 according to the set capacity value set by the capacity input unit 47, and the power consumed by the laser beam printer is the power of the outlet. Capacity (power supply unit 23
Power capacity of the heating roller 15a can be prevented from being exceeded, and the surface temperature of the heating roller 15a can be controlled near the set temperature.

FIG. 8 shows a fixing device 15D according to the fourth embodiment.
3 is a circuit diagram showing a case where the fixing unit 26 of FIG. In FIG. 8, the power supply unit 2
3, fixing unit 26, capacity input unit 47, first and second control units 50 and 51a are the same as those in FIG.
7, CPU 34, transistors 35 and 36, light-emitting diodes 37 and 38, limiting resistors 39 and 40, phototriac couplers 41 and 42, halogen lamps 43 and 44,
Since the voltage dividing resistor 45, the thermistor 46, and the connection portion N1 are the same as those in FIG. 4, the same reference numerals are given, and the description is omitted.
The fixing unit 15D in FIG. 7 is obtained by removing the AC power supply 27 from FIG.

Next, the operation of the fixing device 15D shown in FIG. 8 will be described. When inputting the power capacity of, for example, two types of outlets, the capacity input unit 47 is simply configured with a switch 48 and a pull-up resistor 49, and the set capacity value c is input to the second control unit 51a. . When the switch 48 is turned off, the second control unit 51a is operated by the pull-up resistor 49.
When the switch 48 is turned on, the input value becomes low level "L" due to the ground potential. When the power capacity of the outlet is large, the switch 48 is turned off and "H" is input to the second control unit 51a. When the power capacity is small, the switch 48 is turned on and "L" is input to the second control unit 51a. For example, the second control unit 51
“a” can be detected by distinguishing two types of power capacity.

The second control unit 51a includes the transistor 36
And a potential (hereinafter referred to as “setting”) indicating a set capacitance value c (here, a power supply potential or a ground potential) output from the capacitance input unit 47 and configured using the phototriac coupler 42 or the like suitable for switching of the AC circuit. A capacitance potential) is input to the base of the transistor 36. When the set capacitor potential output from the capacitor input unit 47 is “H” and the transistor 36 is turned on, the limiting resistor 4 is connected to the light emitting diode 38 on the input side of the phototriac coupler 42.
When the current limited to 0 flows to emit light, the phototriac coupler 42 becomes conductive due to the flow of the gate trigger current, and the halogen lamp 44 is connected in parallel to the halogen lamp 43. Conversely, when the set capacitance potential output from the capacitance input unit 47 is “L” and the transistor 36 is turned off, no current flows to the light emitting diode 38 on the input side of the phototriac coupler 42 and no light is emitted. Reference numeral 42 denotes a shut-off state in which no gate trigger current flows, and the halogen lamp 44 is not connected to the halogen lamp 43 in parallel.

The first control unit 50 is constituted by using the CPU 34 and the like, and is provided with the heating roller 15 output from the fixing unit 26.
The energization of the halogen lamps whose number is controlled by the second control unit 51a is controlled such that the surface temperature of the heating roller 15a becomes a predetermined temperature based on the surface temperature value t of a. This energization control is performed using a phototriac coupler 41 suitable for switching of an AC circuit. When power is supplied from the AC power supply 27 to the halogen lamp of the fixing unit 26, C
The PU 34 turns on the transistor 35. When the transistor 35 is turned on, the limiting resistor 3 is connected to the light emitting diode 37 on the input side of the phototriac coupler 41.
The current limited at 9 flows to emit light, and the phototriac coupler 41 becomes conductive due to the flow of a gate trigger current, and power is supplied from the AC power supply 27 to the halogen lamp of the fixing unit 26. Conversely, when power is not supplied from the AC power supply 27 to the halogen lamp of the fixing unit 26, the CPU 34 turns off the transistor 35. Transistor 35
Is turned off, no current flows through the light emitting diode 37 on the input side of the phototriac coupler 41 and no light is emitted. Therefore, the gate trigger current does not flow through the phototriac coupler 41 and the phototriac coupler 41 is cut off. Power is not supplied from the power supply 27. In this way, by performing on / off control of the transistor 35, on / off control of the power supplied from the AC power supply 27 to the halogen lamp of the fixing unit 26 is performed, the heat output thereof is adjusted, and the heating roller 15a is controlled. Control is performed to keep the surface temperature near the set temperature.

The halogen lamps 43 and 44 are
7 is determined according to the specifications when the power capacity of the outlet connected to the power supply 7 is large and when the power capacity is small. That is, when the power capacity of the outlet is small, only the halogen lamp 43 is turned on and off to determine the specifications so that the power consumed by the laser beam printer does not exceed the power capacity of the outlet. On the other hand, when the power capacity of the outlet is large, the halogen lamp 44 is driven in addition to the halogen lamp 43, and the specifications of the halogen lamp 44 are determined so that the power consumed by the laser beam printer does not exceed the power capacity of the outlet.

Since the detection of the surface temperature of the heating roller 15a is the same as that of the first embodiment, the description is omitted.

Next, the control operation of the halogen lamps 43 and 44 will be described. When the power capacity of the outlet is large, the switch 48 is turned off by the user or the like, the set capacity potential from the capacity input unit 47 becomes “H”, and the transistor 36 is turned on. When the transistor 36 is turned on, a current flows through the light-emitting diode 38 on the input side of the phototriac coupler 42 to emit light, and the phototriac coupler 42 becomes conductive due to the flow of a gate trigger current, and the halogen lamp 44 is connected to the halogen lamp 43. Connect in parallel. The CPU 34 detects the surface temperature value t of the heating roller 15a, turns on the power applied to the halogen lamps 43 and 44 connected in parallel by the transistor 35,
The off-control is performed to adjust the heat output of both the halogen lamps 43 and 44, and to control the surface temperature of the heating roller 15a to be kept near the set temperature. As described above, when the power capacity of the outlet is large, the halogen lamps 43 and 44 are connected in parallel and driven, and a predetermined power is applied.

On the other hand, when the power capacity of the outlet is small, the switch 48 is turned on by the user or the like, the set capacity potential from the capacity input section 47 is set to the “L” level, and the transistor 36 is turned off. When the transistor 36 is turned off, no current flows to the light emitting diode 38 on the input side of the phototriac coupler 42 and no light is emitted. I do. That is, the halogen lamp 44 is not connected to the halogen lamp 43 in parallel. The CPU 34 detects the surface temperature value t of the heating roller 15a, turns on the power applied only to the halogen lamp 43 by the transistor 35,
OFF control, the heat output is adjusted, and the heat roller 15
Control is performed so that the surface temperature of a is maintained near the set temperature.
Thus, when the power capacity of the outlet is small, the power is applied from the AC power supply 27 to only the halogen lamp 43,
Reduce power consumed by laser beam printers. In this way, the ON / OFF control of only the halogen lamp 43 and the ON / OFF control of both the halogen lamps 43 and 44 are performed by the changing power capacity of the outlet.
By preventing the power consumed by the laser beam printer from exceeding the power capacity of the outlet, the breaker can be prevented from being shut off, and the surface temperature of the heating roller 15a can be controlled near the set temperature.

In this embodiment, the heat source is a halogen lamp. However, the present invention is not limited to this, and another heat source such as a heating resistor may be used.

As described above, according to the present embodiment, when the set capacitance value c is large, the transistor 36 is turned on to perform on / off control of the power applied to both the halogen lamps 43 and 44, The heat output of both the halogen lamps 43 and 44 is adjusted to control the surface temperature of the heating roller 15a to be kept close to the set temperature. If the set capacity value c is small, the transistor 36 is turned off to turn off the halogen lamp 43a. ON / OFF control of the power applied to only the heating roller 15a
The surface temperature of the laser beam is controlled so as to keep it near the set temperature, so that the power consumed by the laser beam printer does not exceed the power capacity of the outlet, so that the breaker can be prevented from being shut off and the heating roller 15a
Can be controlled near the set temperature.

(Embodiment 5) A fixing unit 15E of an image forming apparatus according to Embodiment 5 of the present invention has a block diagram similar to that of FIG. Fixing device 15 according to this embodiment
E differs from the fixing device 15A according to the first embodiment in the connection between the control unit 25 and the fixing unit 26. This will be described later.

FIG. 9 shows a fixing device 15E according to the fifth embodiment.
3 is a circuit diagram showing a case where the fixing unit 26 of FIG. In FIG. 9, the power supply unit 2
3, a voltage detection unit 24, a control unit 25, and a fixing unit 26 are the same as those in FIG. 33, CPU (Central Processing Unit) 34,
Transistors 35 and 36, light emitting diodes 37 and 38,
Limiting resistors 39 and 40, photo triac coupler 4
1, 42, halogen lamps 43, 44, voltage dividing resistor 4
5, the thermistor 46 and the connecting portion N1 are the same as those in FIG. 9 except for the AC power supply 27 is the fixing device 15 according to the present embodiment.
E. Here, the difference in the connection form between FIG. 2 and FIG. 9 will be described. In FIG. 2, the phototriac couplers 41 and 42 are connected in series with the halogen lamps 43 and 44, respectively. In FIG. 9, the phototriac coupler 42 is connected in series with the halogen lamps 44. The triac coupler 41 is connected in series to a parallel connection circuit of a series connection part of the photo triac coupler 42 and the halogen lamp 44 and the halogen lamp 43. That is, a plurality of transistors 35 (two transistors in this case)
3) ON / OFF control of the halogen lamp.

Next, the operation of the fixing device 15E shown in FIG. 9 will be described. Operation of Voltage Detector 24 and Heating Roller 15a
Is the same as that in the first embodiment, and a description thereof will be omitted. The control unit 25 is configured using a CPU 34 and the like, and performs on / off control of the transistor 36 based on the smoothed DC voltage value (detected voltage value) v detected by the voltage detection unit 24. Therefore, the output signal a of the CPU 34 is input to the base of the transistor 36. When the level of the output signal a is “H” and the transistor 36 is turned on,
The current restricted by the limiting resistor 40 flows through the light emitting diode 38 on the input side of the phototriac coupler 42 to emit light, and the phototriac coupler 42 becomes conductive due to the flow of a gate trigger current, and the halogen lamp 44 is connected to the halogen lamp 43. Connected in parallel. Conversely, when the level of the output signal a is "L" and the transistor 36 is turned off,
Since current does not flow through the light emitting diode 38 on the input side of the phototriac coupler 42 and does not emit light, the phototriac coupler 42 does not flow with a gate trigger current, and is in a cutoff state.

The CPU 34 detects the surface temperature value t of the heating roller 15a output from the fixing unit 26, and controls the halogen lamp 43 of the fixing unit 26 so that the surface temperature of the heating roller 15a becomes a predetermined temperature. The energization control of both the lamps 44 or only the halogen lamp 43 is performed. This energization control is performed using a phototriac coupler 41 suitable for switching of an AC circuit. When the halogen lamp is energized by the energization control, power is supplied from the AC power supply 27 to the halogen lamp. When power is supplied from the AC power supply 27 while the halogen lamp of the fixing unit 26 is energized, the CPU 34 sets the level of the output signal b to “H” to turn on the transistor 35. Transistor 3
5 is turned on, the phototriac coupler 41
The current restricted by the limiting resistor 39 flows through the light emitting diode 37 on the input side of the light emitting diode 37 to emit light, the gate trigger current flows through the phototriac coupler 41 and the phototriac coupler 41 becomes conductive, and power is supplied to the halogen lamp of the fixing unit 26. . Conversely, when the halogen lamp of the fixing unit 26 is turned off and the power is not supplied from the AC power supply 27, the CPU 34 outputs the output signal b.
Is set to “L” to turn off the transistor 35. When the transistor 35 is turned off, the current does not flow through the light emitting diode 37 on the input side of the phototriac coupler 41 and the light does not emit. Is not powered. In this way, by performing on / off control of the transistor 35, on / off control of the power supplied from the AC power supply 27 to the halogen lamp of the fixing unit 26 is performed, the heat output thereof is adjusted, and the heating roller 15a is controlled. Control is performed to keep the surface temperature near the set temperature.

The halogen lamps 43 and 44 are
7 is determined according to the specifications when the power supply voltage value is large and when it is small. That is, when the power supply voltage value of the AC power supply 27 is large, the specification is determined such that only the halogen lamp 43 is driven and a predetermined power is applied. On the other hand, when the power supply voltage value of the AC power supply 27 is small, the specification of the halogen lamp 44 is determined so that a predetermined power is applied when the halogen lamp 44 is driven in addition to the halogen lamp 43.

Next, the control operation of the halogen lamps 43 and 44 will be described. When the power supply voltage value of the AC power supply 27 is large, the CPU 34 outputs a large power supply voltage value (detection voltage value).
v is detected, and an output signal a of level “L” is output to the base of the transistor 36 to turn off the transistor 36. When the transistor 36 is turned off, no current flows through the light emitting diode 38 on the input side of the phototriac coupler 42 and no light is emitted. Therefore, the phototriac coupler 42 is shut off without a gate trigger current flowing, and the halogen lamp 44 is Are not connected in parallel. Further, the CPU 34 detects the surface temperature value t of the heating roller 15a, performs on / off control of the power applied only to the halogen lamp 43 by the transistor 35, adjusts the heat output, and adjusts the surface temperature of the heating roller 15a. Is controlled so as to keep the temperature near the set temperature. in this way,
When the power supply voltage value of the AC power supply 27 is large, only the halogen lamp 43 is driven, so that a predetermined power is applied to obtain an optimal heat output.

On the other hand, when the power supply voltage value of the AC power supply 27 is small, the CPU 34 sets the small power supply voltage value (detection voltage value) v
And the output signal “a” of level “H” is
6 and the transistor 36 is turned on. When the transistor 36 is turned on, a current flows through the light-emitting diode 38 on the input side of the phototriac coupler 42 to emit light. The phototriac coupler 42 is turned on by a gate trigger current flowing, and the halogen lamp 44 is connected to the halogen lamp 43. Connected in parallel. Further, the CPU 34 detects the surface temperature value t of the heating roller 15a, performs on / off control of power applied to both of the halogen lamps 43 and 44 connected in parallel by the transistor 35, and adjusts the heat output. , Heating roller 15a
Is controlled so as to keep the surface temperature around the set temperature. As described above, when the power supply voltage value of the AC power supply 27 is small, the halogen lamps 43 and 44 are connected in parallel and driven, so that a predetermined power is applied and an optimal heat output is obtained.
In this manner, the ON / OFF control of only the halogen lamp 43 or the ON / OFF control of both the halogen lamps 43 and 44 is performed in accordance with the changing power supply voltage of the AC power supply 27 to adjust the applied power. Thus, an optimum heat output can be obtained even if the power supply voltage of the AC power supply 27 changes.

In this embodiment, the heat source is a halogen lamp. However, the present invention is not limited to this, and another heat source such as a heating resistor may be used.

As described above, according to the present embodiment, when the power supply voltage of AC power supply 27 is large, transistor 3
6 is turned off and the power applied to only the halogen lamp 43 is turned on and off by the transistor 35, the heat output of the halogen lamp 43 is adjusted, and the surface temperature of the heating roller 15a is controlled so as to be kept near the set temperature. When the power supply voltage value of the AC power supply 27 is small, the transistor 3
6 to turn on and off the power applied to both the halogen lamps 43 and 44 by the transistor 35, adjust the heat output of both the halogen lamps 43 and 44, and set the surface temperature of the heating roller 15a. Since the control is performed so as to keep the temperature near the temperature, even if the power supply specification, for example, the power supply voltage value differs in each country, the heating roller 1 is controlled by the heat source.
The power supplied to the heating roller 1a is controlled to a predetermined power.
The surface temperature of 5a can be controlled near the set temperature.

[0081]

As described above, according to the image forming apparatus of the present invention, the power supply voltage value and the surface temperature value of the heating roller for each country are detected, and according to the detected power supply voltage value and surface temperature value, Since the number of heat sources to which power is supplied can be set, the power supplied to the heating roller by the heat source is controlled to a predetermined power to control the surface temperature of the heating roller even if the power supply specification is different for each country, for example, the power supply voltage value is different. An advantageous effect that control can be performed near the set temperature is obtained.

If the detected voltage value is larger than a predetermined voltage value, the number of heat sources to be energized is reduced. If the detected voltage value is smaller than the predetermined voltage value, the number of heat sources to be energized is increased. By controlling the energization of the heat sources, the number of heat sources to be power-controlled can be set to an optimal number according to the detected voltage value, so that the power supplied to the heating roller can be accurately controlled to a predetermined power. As a result, the advantageous effect that the surface temperature of the heating roller can be accurately controlled to around the set temperature can be obtained.

Further, a fixing unit having a plurality of heat sources to which a power supply voltage is supplied and a temperature detecting unit for detecting a surface temperature of a heating roller heated by the heat source, and a capacity input for setting a capacity value of the power supply unit. Unit, and a control unit that controls energization to a plurality of heat sources based on the set capacity value input from the capacity input unit and the surface temperature value of the heating roller output from the fixing unit, thereby setting the set capacity value and heating. The number of heat sources to which power is supplied can be set according to the detected set capacity value and the detected surface temperature value of the roller, so that the roller can be consumed by an image forming apparatus such as a laser beam printer. Power can be controlled so as not to exceed the power capacity of the power supply unit, breaker breakage can be prevented, and the surface temperature of the heating roller can be set to a predetermined temperature. Cormorant advantageous effect can be obtained.

Further, if the set capacity value input from the capacity input section is larger than the predetermined capacity value, the number of heat sources to be energized is increased, and if the set capacity value input from the capacity input section is smaller than the predetermined capacity value, the power is turned on. By reducing the number of heat sources and controlling the energization of the heat sources based on the surface temperature value, the number of heat sources to which electric power is supplied can be set to an optimal number based on the set capacity value. The power can be accurately controlled to a predetermined power, and the advantageous effect that the power consumed by the image forming apparatus such as a laser beam printer can be accurately controlled so as not to exceed the power capacity of the power supply unit can be obtained. Can be

Further, a fixing section having a plurality of heat sources to which a power supply voltage is supplied and a temperature detection section for detecting a surface temperature of a heating roller heated by the heat source; a voltage detection section for detecting a power supply voltage; A second control unit that controls the number of heat sources to be energized based on the detected voltage value output from the fixing unit, and a second control unit that controls the number of heat sources output from the fixing unit based on the surface temperature value of the heating roller.
And a first control unit for controlling whether or not to energize the heat sources whose number is controlled in the control unit, wherein the number of heat sources to which power is supplied is determined by a detected voltage value. It is possible to set and perform energization control based on the surface temperature value of the heating roller for the set number of heat sources,
Even if the power supply specification is different for each country, for example, the power supply voltage value is different, the advantageous effect that the power supplied to the heating roller by the heat source can be controlled to a predetermined power and the surface temperature of the heating roller can be controlled near the set temperature can be obtained. .

Further, the second control unit reduces the number of heat sources to be energized when the detected voltage value is larger than the predetermined voltage value, and increases the number of heat sources to be energized when the detected voltage value is smaller than the predetermined voltage value. By doing so, based on the detected voltage value,
Since the number of heat sources to which electric power is supplied can be set to an optimum number, the electric power supplied to the heating roller by the heat source can be accurately controlled to a predetermined electric power, and the surface temperature of the heating roller is set near the set temperature. The advantageous effect that accurate control can be obtained is obtained.

Further, a fixing unit having a plurality of heat sources to which a power supply voltage is supplied and a temperature detecting unit for detecting a surface temperature of a heating roller heated by the heat sources, and a capacity input for setting a capacity value of the power supply unit Unit, a second control unit for controlling the number of heat sources to be energized by the set capacity value input from the capacity input unit, and a second control unit for controlling the number of heat sources output from the fixing unit by the surface temperature value of the heating roller. And a first control unit that controls whether or not the controlled heat source is energized, so that the number of heat sources to which power is supplied is set by a set capacity value, and the set number of heat sources is set. Can be controlled based on the surface temperature value of the heating roller, so that the power supplied to the heat source can be accurately controlled to a predetermined power and consumed by an image forming apparatus such as a laser beam printer. Be done Force beneficial effect is obtained that can be accurately controlled so as not to exceed the power capacity of the power supply unit.

Further, if the set capacity value input from the capacity input section is larger than the predetermined capacity value, the number of heat sources to be energized is increased, and if the set capacity value input from the capacity input section is smaller than the predetermined capacity value, the power supply By reducing the number of heat sources to perform the above, the number of heat sources to which power is supplied can be set to an optimal number based on the set capacity value, so that the power supplied to the heat sources is accurately controlled to a predetermined power. Therefore, the advantageous effect that the power consumed by the image forming apparatus such as a laser beam printer or the like can be accurately controlled so as not to exceed the power capacity of the power supply unit can be obtained.

Further, since the heat source is a halogen lamp, there is an advantageous effect that the power supplied to the halogen lamp can be controlled to a predetermined power by controlling the energization of the halogen lamp.

Further, since the heat source is a heating resistor, there is an advantageous effect that the power supply to the heating resistor can be controlled to a predetermined power by controlling the conduction of the heating resistor.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a fixing device of an image forming apparatus according to a first embodiment of the present invention;

FIG. 2 is a circuit diagram showing a case where the fixing unit of the fixing device according to the first embodiment includes two halogen lamps as heat sources.

FIG. 3 is a block diagram illustrating a fixing device of an image forming apparatus according to a second embodiment of the present invention;

FIG. 4 is a circuit diagram showing a case where the fixing unit of the fixing device according to the second embodiment includes two halogen lamps as heat sources.

FIG. 5 is a block diagram illustrating a fixing device of an image forming apparatus according to a third embodiment of the present invention.

FIG. 6 is a circuit diagram showing a case where the fixing unit of the fixing device according to the third embodiment includes two halogen lamps as heat sources.

FIG. 7 is a block diagram illustrating a fixing device of an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 8 is a circuit diagram showing a case where the fixing unit of the fixing device according to the fourth embodiment includes two halogen lamps as heat sources.

FIG. 9 is a circuit diagram showing a case where the fixing unit of the fixing device according to the fifth embodiment includes two halogen lamps as heat sources.

FIG. 10 is a configuration diagram showing a conventional general image forming apparatus.

FIG. 11 is a block diagram showing a fixing device of a conventional image forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Laser beam printer main body 2 Display / operation part 3 Controller part 4 Photosensitive drum 5 Charger 6 Exposure optical system 7 Developing device 8 Transfer roller 9 Static eliminator 10 Exposure light beam 11 Cassette 12 Recording paper 13 Feed roller 14 Paper transport path 15, 15A, 15B, 15C, 15D, 15E Fixing unit 15a Heating roller 15b Pressure roller 15c Halogen lamp 15e Temperature detecting unit 16 Fan 17 Control unit 18 Drive unit 19 Face-down transport path 20 Face-down discharge tray 21 Face-up transport path 22 Face-up paper discharge tray 23 Power supply unit 24 Voltage detection unit 25 Control unit 26 Fixing unit 27 AC power supply 28 Transformer 29 Bridge type rectifier circuit 30 Capacitor 31 Coil 32, 33, 45 Voltage dividing resistor 34 CPU 35, 36 Transistor 37, 38 luminescence Diodes 39 and 40 limit resistor 41 and the photo-triac coupler 43 halogen lamp 46 Thermistor 47 volume input unit 48 switch 49 pullup resistor 50 first controller 51,51a second controller N1 connecting portion

Claims (10)

[Claims] 1. An image forming apparatus comprising: a fixing device that heats a heating roller to fix a toner image on a recording medium; and a power supply unit that generates a power supply voltage. A fixing unit having a plurality of heat sources and a temperature detection unit for detecting a surface temperature of the heating roller heated by the heat source, and a voltage detection unit for detecting the power supply voltage,
An image forming apparatus comprising: a control unit configured to control energization to the plurality of heat sources based on a detected voltage value output from the voltage detection unit and a surface temperature value of the heating roller output from the fixing unit. apparatus. 2. The control section decreases the number of heat sources to be energized when the detected voltage value is larger than a predetermined voltage value, and increases the number of heat sources to be energized when the detected voltage value is smaller than a predetermined voltage value. The image forming apparatus according to claim 1, wherein energization control of the heat source is performed based on a surface temperature value of the heating roller. 3. An image forming apparatus comprising: a fixing device for heating a heating roller to fix a toner image on a recording medium; and a power supply for generating a power supply voltage, wherein the fixing device is supplied with the power supply voltage. A fixing unit having a plurality of heat sources to be heated and a temperature detecting unit for detecting a surface temperature of the heating roller heated by the heat source; a capacity input unit for setting a capacity value of the power supply unit; and the capacity input. An image forming apparatus comprising: a control unit configured to control energization to the plurality of heat sources based on the set capacity value input from a unit and a surface temperature value of the heating roller output from the fixing unit. 4. The control section, if the set capacity value input from the capacity input section is larger than a predetermined capacity value, increases the number of the heat sources to be energized, and increases the set capacity input from the capacity input section. 4. The image forming apparatus according to claim 3, wherein when the value is smaller than a predetermined capacity value, the number of the heat sources to be energized is reduced, and energization control of the heat source is performed based on a surface temperature value of the heating roller. 5. An image forming apparatus comprising: a fixing device for heating a heating roller to fix a toner image on a recording medium; and a power supply unit for generating a power supply voltage, wherein the fixing device is supplied with the power supply voltage. A fixing unit having a plurality of heat sources and a temperature detection unit for detecting a surface temperature of the heating roller heated by the heat source, a voltage detection unit for detecting the power supply voltage,
A second controller configured to control the number of heat sources to be energized based on a detected voltage value output from the voltage detector, and a second controller configured to control a surface temperature value of the heating roller output from the fixing unit; And a first control unit for controlling whether or not to energize the heat source whose number is controlled in (1). 6. The second control section reduces the number of heat sources to be energized when the detected voltage value is larger than a predetermined voltage value, and performs the energization when the detected voltage value is smaller than a predetermined voltage value. The image forming apparatus according to claim 5, wherein the number of heat sources is increased. 7. An image forming apparatus comprising: a fixing device for heating a heating roller to fix a toner image on a recording medium; and a power supply unit for generating a power supply voltage, wherein the fixing device is supplied with the power supply voltage. A fixing unit having a plurality of heat sources to be heated and a temperature detecting unit for detecting a surface temperature of the heating roller heated by the heat source; a capacity input unit for setting a capacity value of the power supply unit; and the capacity input. A second control unit that controls the number of heat sources to be energized according to a set capacity value input from the unit, and a number in the second control unit based on a surface temperature value of the heating roller output from the fixing unit. An image forming apparatus comprising: a first control unit configured to control whether or not the controlled power supply to the heat source is performed. 8. The control section, if the set capacity value input from the capacity input section is larger than a predetermined capacity value, increases the number of heat sources to be energized to increase the number of heat sources to be supplied. The image forming apparatus according to claim 7, wherein if the capacitance value is smaller than a predetermined capacitance value, the number of heat sources to be energized is reduced. 9. The heat source according to claim 1, wherein said heat source is a halogen lamp.
9. The image forming apparatus according to any one of claims 1 to 8, wherein 10. The image forming apparatus according to claim 1, wherein said heat source is a heating resistor.