JP2020204719A - Power supply device and image forming apparatus - Google Patents

Abstract

To maintain the quality of an image without increasing the circuit scale of a power supply device.SOLUTION: A power supply device comprises: a high voltage power supply circuit for charging 202; a coupling capacitor 204 that is connected at one end to the high voltage power supply circuit for charging 202; a high voltage power supply circuit 203 for fixing; and a high voltage power supply circuit 201 for transfer. When a fixing film 109 and a transfer roller 103 are electrically connected, the coupling capacitor 204 blocks output of a DC voltage from the high voltage power supply circuit 201 for transfer to the high voltage power supply circuit 202 for charging.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power supply device and an image forming apparatus, and more particularly to an image forming apparatus such as an electrophotographic copying machine and an electrophotographic printer.

Most image forming devices such as a laser beam printer are composed of a charging device, a developing device, a transfer device, and a fixing device. The charging device is a device for charging an electric charge on a photosensitive drum. The developing device is a device for developing a latent image formed by laser light or the like on a photosensitive drum as a toner image. The transfer device is a device for transferring the developed toner image to a transfer material. The fuser is a device provided with a heater or the like driven by an AC power source in order to fix the transferred unfixed toner image on the transfer material. A high voltage of several hundred to several thousand V is applied to these charging devices, developing devices, and transfer devices, and a high-voltage power supply having a high-voltage power supply circuit provided on a printed circuit board to output these high voltages. A board is provided.

A superposed voltage obtained by superimposing an AC voltage on a negative DC voltage is applied as a charging voltage to the charging roller in the charging device by a high voltage power supply board. When the superimposed voltage applied to the charging roller becomes equal to or higher than the discharge start voltage, the charging roller discharges the photosensitive drum and the photosensitive drum begins to be charged. Finally, the surface potential of the photosensitive drum converges to the potential of the DC voltage and is uniformly charged. At this time, if the photosensitive drum cannot be uniformly charged for some reason, image defects may occur. For example, Patent Document 1 shows that when the photosensitive drum is locally poorly charged due to dirt, image defects such as a high density in a halftone image or the like occur as a problem. A method for suppressing poor charging is disclosed. Further, a direct current positive voltage is applied as a transfer voltage to the transfer roller in the transfer device from the high voltage power supply circuit. As a result, the negative electrode toner is attracted from the photosensitive drum toward the recording paper and transferred onto the recording paper.

A negative DC voltage is applied to the fixing film in the fixing device as a fixing voltage, so that the negative electrode toner is attracted to the recording paper side. This pulling force is effective against image defects called the fixing tail pulling phenomenon. The fixing tailing phenomenon is an image defect caused by scattering of unfixed toner images when the water content contained in the recording paper is heated and converted into water vapor. For example, in Patent Document 2, when printing is performed with a recording material that has absorbed moisture under a configuration in which an AC voltage is applied to a glass-coated heater, image defects due to fixing tail trailing and image defects due to fluctuations in transfer voltage occur. It is shown that. For example, Patent Document 2 discloses a method for improving image defects due to fixing and tailing and image defects due to fluctuations in transfer voltage.

Further, as a high voltage output means for generating a fixing voltage, a high voltage power supply circuit for generating a charging voltage, a developing voltage, or the like may be shared. For example, in Patent Document 3, the high-voltage power supply circuit of the charging device and the fixing device is shared by a method of separating the charging voltage and the fixing voltage by a resistor, and the fixing tailing phenomenon is achieved while reducing the size and cost of the device. Is disclosed how to improve. Further, for example, Patent Document 4 discloses a circuit configuration example in which a high-voltage power supply circuit is generated by superimposing an AC voltage on a DC voltage with a single transformer. In this circuit, there is also a simple configuration in which the information of the output voltage value is not fed back from the secondary side of the transformer to the primary side. This is a mechanism in which the output voltage is determined based on the ratio of the constants of the two resistors configured on the secondary side of the transformer and the duty ratio of the PWM signal input to the control circuit unit on the primary side.

JP-A-2007-093922 Japanese Unexamined Patent Publication No. 2006-195003 Japanese Unexamined Patent Publication No. 2005-107237 Japanese Unexamined Patent Publication No. 2004-040891

There is a situation where one sheet of recording paper comes into contact with both the fixing film to which the fixing voltage is applied at the time of printing and the transfer roller to which the transfer voltage is applied. At this time, the transfer roller and the fixing film are electrically connected by the resistance component of the recording paper, and a path through which a current flows is generated. When the high voltage power supply circuit that outputs the charging voltage, etc. is shared as the high voltage power supply circuit that outputs the fixing voltage, in the conventional circuit configuration, the charging voltage, etc. shared with the fixing voltage, etc. from the transfer roller through the recording paper. The current flows to the high voltage power supply circuit that outputs. In the high-voltage power supply circuit having a simple configuration that does not feed back the information of the output voltage value described above, this current flows through the resistor in the high-voltage power supply circuit that determines the output voltage value. When a current flows through this resistor, the voltage value of the charging voltage changes. The factors that determine the amount of current that flows are not only the voltage values of the charging voltage and the fixing voltage, but also the period and timing at which the recording paper contacts both voltages, the material of the recording paper, the amount of water contained in the recording paper, etc. It also depends on the parameters you have. Therefore, it is difficult to fix or predict the amount of flowing current to a unique value. If the voltage value of the charging voltage changes due to a change in the amount of current, the photosensitive drum cannot be charged uniformly, so that the photosensitive drum may have a charging failure. As described above, in the state of poor charging, there is a possibility that image defects such as a high density may occur in a halftone image or the like. Such a problem can be solved if a feedback circuit is arranged in a voltage generation circuit such as a charging voltage and the voltage value of the charging voltage can be stabilized at a design value. However, there is a problem that the circuit scale becomes large by arranging the feedback circuit, and the original purpose of miniaturization of the device cannot be achieved.

The present invention has been made under such circumstances, and an object of the present invention is to maintain image quality without increasing the circuit scale of the power supply device.

In order to solve the above-mentioned problems, the present invention includes the following configurations.

(1) A first power supply that has an AC power supply that outputs an AC voltage and a DC power supply that outputs a DC voltage, and outputs a first voltage obtained by superimposing the AC voltage and the DC voltage to a first load. And, one end is connected to the first capacitor connected to the first power supply and the other end of the first capacitor, and the AC voltage output from the other end of the first capacitor is rectified and smoothed. A second power source that outputs the second voltage to the second load and a third power source that outputs the DC voltage to the third load are provided, and the first capacitor is the second load. A power supply device characterized in that when the third load and the third load are electrically connected, the DC voltage of the third power supply is cut off from being output to the first power supply.

(2) The photoconductor, the charging means which is the first load for charging the photoconductor, the exposure means which exposes the photoconductor to form an electrostatic latent image, and the electrostatic latent image are developed. The developing means for forming the toner image, the transfer means which is the third load for transferring the toner image to the recording paper, and the second load for fixing the toner image of the recording paper. An image forming apparatus including the fixing means and the power supply device according to (1) above.

According to the present invention, the image quality can be maintained without increasing the circuit scale of the power supply device.

Cross-sectional view showing the image forming apparatus of Examples 1 to 3 and schematic cross-sectional view of a main part showing paper at the time of printing. Block diagram showing circuit functions of Examples 1 to 3 Circuit diagram of the power supply device of the first embodiment Circuit diagram of the power supply device of the second embodiment Circuit diagram of another power supply device of the second embodiment Circuit diagram of the power supply device of the third embodiment

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Rough configuration example of image forming apparatus]
FIG. 1A is a cross-sectional view of an image forming apparatus 100 using an electrophotographic recording technique. Only one sheet of paper 112, which is the recording paper loaded on the paper feed cassette 118, is sent out from the paper feed cassette 118 by the pickup roller 113, and is directed toward the registration roller (hereinafter referred to as the registration roller) 115 by the paper feed roller 114. Be transported. Further, the paper 112 is conveyed to the cartridge 106 by the resist roller 115 at a predetermined timing. The cartridge 106 is integrally composed of a charging roller 101 which is a charging means, a developing roller 102 which is a developing means, a cleaner 105 which is a cleaning means, and a photosensitive drum 104 which is an electrophotographic photosensitive member (photoreceptor). An unfixed toner image is formed on the paper 112 by a series of known electrophotographic processes. The surface of the photosensitive drum 104 is uniformly charged by the charging roller 101, and then the image exposure based on the image signal is performed by the scanner unit 107, which is an exposure means. The laser beam 108 emitted from the scanner unit 107 is scanned by the photosensitive drum 104, and a two-dimensional latent image (electrostatic latent image) is formed on the surface of the photosensitive drum 104. The latent image of the photosensitive drum 104 is visualized as a toner image by the developing roller 102, and the toner image is transferred onto the paper 112 conveyed from the resist roller 115 by the transfer roller 103 which is a transfer means.

Subsequently, when the paper 112 on which the toner image is transferred is conveyed to the fixing device 111 which is a fixing means, it is heat-pressurized and the unfixed toner image on the paper 112 is fixed to the paper 112. The fixing device 111 has a fixing film 109 and a fixing pressure roller 110. The paper 112 is further discharged to the outside of the main body of the image forming apparatus 100 by the intermediate discharge roller 116 and the discharge roller 117, and a series of printing operations is completed.

The image forming apparatus 100 has a power supply device 119, and the electric power supply device 119 supplies electric power used in the image forming apparatus 100 to each part. The AC voltage supplied from the AC power supply or the like is connected to the power supply device 119 via a power cable (not shown). The power supply device 119 converts the power obtained from the AC power supply or the like into a voltage value and a voltage waveform used by the high voltage power supply board, the fixing device 111, or the like, and supplies the power. The high-voltage power supply board further converts the power supplied from the power supply device 119 to generate a high voltage of several hundred V to several kiloV, which is applied to the charging roller 101, the developing roller 102, the transfer roller 103, and the like. ..

[High-voltage power supply configuration and schematic configuration example of voltage]
FIG. 2 is a block diagram showing the circuit function of the first embodiment. In FIG. 2, transfer, charging, and fixing are shown as representatives of a plurality of voltages existing in the high-voltage power supply board 200, which is a power supply device, but other high-voltage power supply circuits such as developing and cleaning blades ( (Not shown) exists. In FIG. 2, for example, a DC voltage of 24 V is supplied to the high voltage power supply board 200 from the power supply device 119, and the transfer high voltage power supply circuit 201 and the charging high voltage power supply circuit 202 boost the DC voltage 24 V. , Generate a voltage suitable for each voltage. A coupling capacitor 204 is connected in parallel with the charging roller 101 to the output of the charging high-voltage power supply circuit 202. The other terminal of the coupling capacitor 204 is connected to the input portion of the fixing high voltage power supply circuit 203. With such a connection configuration, a high voltage for the charging voltage is supplied to the fixing high voltage power supply circuit 203, and a high voltage for the fixing voltage is generated.

The high voltage generated by the high-voltage power supply circuit 201 for transfer is supplied as a transfer voltage to the transfer roller 103 via the contact 205 provided on the high-voltage power supply board 200. The high voltage generated by the high-voltage power supply circuit 202 for charging is supplied as a charging voltage to the charging roller 101 via the contact 206 provided on the high-voltage power supply board 200. The high voltage generated by the high-voltage power supply circuit 203 for fixing is supplied to the fixing film 109 as a fixing voltage via the contact 207 provided on the high-voltage power supply board 200.

Further, the resistance 208 represents the resistance component of the paper 112, and will be hereinafter referred to as the resistance component 208 of the paper 112. The broken line in FIG. 2 represents a situation in which the transfer roller 103 and the fixing film 109 are electrically connected by the resistance component 208 of the paper 112. That is, FIG. 2 shows that the transfer roller 103 and the fixing film 109 are electrically connected when one end of the paper 112 is in contact with the transfer roller 103 and the other end of the paper 112 is in contact with the fixing film 109. ing.

Next, FIG. 1B is a schematic cross-sectional view at the time of printing showing a situation in which a part of the configuration of the image forming apparatus 100 is extracted and the paper 112 is being conveyed. High voltage output from each high voltage power supply circuit on the high voltage power supply board 200 is applied to the charging roller 101, the developing roller 102, the transfer roller 103, the fixing film 109, and the cleaner 105 of FIG. 1 (b). ing. In FIG. 1B, one end of the paper 112 (hereinafter referred to as one end) is sandwiched between the photosensitive drum 104 and the transfer roller 103. The other end (hereinafter referred to as the other end) of the end of the paper 112 is sandwiched between the fixing film 109 and the fixing pressure roller 110. The nip portion between the photosensitive drum 104 and the transfer roller 103 is referred to as a transfer portion, and the nip portion between the fixing film 109 and the fixing pressure roller 110 is referred to as a fixing portion.

[Circuit configuration]
FIG. 3 is a circuit diagram showing the circuit configuration of the first embodiment. The charging high-voltage power supply circuit 202, which is the first power supply, has an AC power supply 401 and a DC power supply 400. The AC power supply 401 outputs an AC component (hereinafter referred to as AC voltage) of the output voltage of the charging high voltage power supply circuit 202, and the DC power supply 400 outputs a DC component of the output voltage of the charging high voltage power supply circuit 202 (hereinafter referred to as DC voltage). ) Is output. As described above, the charging high-voltage power supply circuit 202 has a circuit configuration for outputting a first voltage (hereinafter, referred to as an output voltage) having a waveform in which a DC voltage and an AC voltage are superimposed. The output voltage of the charging high-voltage power supply circuit 202 is supplied to the charging roller 101, which is the first load, and the fixing high-voltage power supply circuit 203, which is the second power supply.

A coupling capacitor 204, which is a first capacitor, is arranged in series on the path where the voltage is supplied to the fixing high-voltage power supply circuit 203. That is, the coupling capacitor 204 is connected between the charging high-voltage power supply circuit 202 and the fixing high-voltage power supply circuit 203. Therefore, when the output voltage of the charging high-voltage power supply circuit 202 is transmitted to the fixing high-voltage power supply circuit 203, capacitive coupling occurs. When the capacitive coupling occurs, the DC voltage of the output voltage of the high-voltage power supply circuit 202 for charging is cut off, and the AC voltage passes through. As a result, only the AC voltage, which is an AC component of the output voltage of the charging high-voltage power supply circuit 202, is input to the fixing high-voltage power supply circuit 203 via the coupling capacitor 204.

(High voltage power supply circuit for fixing)
The fixing high-voltage power supply circuit 203 includes a rectifying diode 402 on the ground (hereinafter referred to as GND) side, a rectifying diode 403, a protection resistor 404, and a smoothing capacitor (hereinafter referred to as a smoothing capacitor) 405. Specifically, in the rectifying diode 402 on the GND side, which is the second diode, the coupling capacitor 204 is connected to the anode terminal, and the cathode terminal is grounded. In the rectifying diode 403, which is the first diode, the coupling capacitor 204 is connected to the cathode terminal, and one end of the resistor 404, which is the first resistor, is connected to the anode terminal. One end of a smoothing capacitor 405, which is a second capacitor, is connected to the other end of the resistor 404. The other end of the smoothing capacitor 405 is grounded.

The fixing high-voltage power supply circuit 203 rectifies and smoothes the AC voltage input from the charging high-voltage power supply circuit 202 via the coupling capacitor 204 by the rectifying diode 403 and the smoothing capacitor 405, and converts it into a DC voltage. .. As a result, the fixing high-voltage power supply circuit 203 can supply a second voltage, a DC voltage, to the fixing film 109, which is a second load, without being interrupted by the coupling capacitor 204.

(High voltage power supply circuit for transfer)
The transfer high-voltage power supply circuit 201, which is a third power supply, has a DC power supply 406, and the DC power supply 406 outputs a DC voltage. The transfer high voltage power supply circuit 201 supplies a DC voltage to the transfer roller 103, which is a third load. As described above, when one sheet of paper 112 is sandwiched between the transfer portion and the fixing portion (see FIG. 1B), as shown in FIG. 3, a high-voltage power supply for transfer is provided via the resistance component 208 of the paper 112. The circuit 201 and the fixing high voltage power supply circuit 203 are connected. Even in such a case, the DC voltage which is the DC component of the output voltage of the transfer high voltage power supply circuit 201 is the same as the DC voltage which is the DC component of the output voltage of the charging high voltage power supply circuit 202. Is blocked by. As a result, even when the transfer roller 103 and the fixing film 109 are connected by the paper 112, no current flows from the transfer high voltage power supply circuit 201 to the charging high voltage power supply circuit 202. Since the current does not flow into the high-voltage power supply circuit 202 for charging, the output voltage can be stabilized without providing the feedback means, and it is possible to prevent the occurrence of charging failure with a simple configuration.

In the first embodiment, a rectifying diode 403, a rectifying diode 402 on the GND side, and a smoothing capacitor 405 are used in a portion of the fixing high voltage power supply circuit 203 for smoothing the AC component. In this configuration, by arranging the directions of the rectifying diodes 402 and 403 as shown in FIG. 3, a full-wave rectifying circuit is formed in which a negative voltage corresponding to the voltage amplitude value of the passing AC voltage is output as a fixing voltage. There is. The voltage output as the fixing voltage is the voltage obtained by subtracting the voltage value consumed by the protection resistor 404 and the forward voltage of the rectifying diodes 402 and 403 from the voltage amplitude value on the negative side of the passing AC voltage. .. Further, the protection resistor 404 is for protecting the rectifying diodes 402 and 403, the smoothing capacitor 405, and the charging high voltage power supply circuit 202 from the lightning surge of external noise applied to the fixing film 109.

As described above, when the high-voltage power supply circuit that outputs the charging voltage or the like is shared as the high-voltage power supply circuit that outputs the fixing voltage, the high-voltage power supply circuit that is shared from the transfer roller via the recording paper is used. The amount of current flowing in can be suppressed. As a result, it is possible to suppress the occurrence of image defects such as density unevenness due to poor charging with a simple configuration.

As described above, according to the first embodiment, the image quality can be maintained without increasing the circuit scale of the power supply device.

[Circuit configuration]
The configuration of the second embodiment is obtained by replacing the rectifying diode 402 on the GND side of the configuration of the first embodiment with a rectifying resistor 500. FIG. 4 is a circuit diagram showing the circuit configuration of the second embodiment, and the same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted. A coupling capacitor 204 is connected to one end of the rectifying resistor 500, which is the second resistor, and the other end is grounded. By replacing the rectifying diode 402 on the GND side with the rectifying resistor 500, the fixing high-voltage power supply circuit 203 changes from full-wave rectification to half-wave rectification. As a result, the absolute value of the fixing voltage is lowered, but the expensive high-voltage diode can be reduced, which has the effect of reducing the cost of the circuit.

Further, in the configuration of the first embodiment, a current flows from the coupling capacitor 204 via the rectifying diode 402 on the GND side, but since the impedance of the path is low, it rushes when the rectifying diode 402 on the GND side is turned on. Current flows. Sudden fluctuations in current such as inrush current may cause an increase in radioactive noise and image defects depending on the current path. Therefore, it is desirable to prevent sudden fluctuations in current. In the configuration of the second embodiment, the rectifying diode 402 on the GND side of such an inrush current path has a rectifying resistor 500. Therefore, in the configuration of the second embodiment, the impedance is high and it is difficult for a sudden fluctuation of the current to occur. Therefore, the increase in radioactive noise and image defects are less likely to occur.

[Circuit configuration of modified example]
The content of the second embodiment is not limited to the replacement with a resistor, and may be used in combination with the configuration of the first embodiment, for example. For example, FIG. 5 is a diagram showing a circuit configuration in which the configuration of the first embodiment and the configuration of the second embodiment are combined, and the same reference numerals are given to the same configurations as the circuit configuration of the first embodiment, and the description thereof will be omitted. As shown in FIG. 5, the rectifying resistor 500 and the rectifying diode 402 on the GND side may be connected in series. Specifically, in the rectifying diode 402 on the GND side, a coupling capacitor 204 is connected to the anode terminal, and one end of the rectifying resistor 500 is connected to the cathode terminal. The other end of the rectifying resistor 500 is grounded. With such a configuration, the peak value of the inrush current that flows when the rectifying diode 402 on the GND side is turned on (conducting) is relaxed by the rectifying resistor 500, and the rectification is performed by the rectifying diode 402 on the GND side. It can be carried out. As a result, the generation of inrush current can be mitigated while securing the required fixing voltage.

As described above, according to the second embodiment, the image quality can be maintained without increasing the circuit scale of the power supply device.

[Circuit configuration]
The third embodiment is a configuration in which the position of the smoothing capacitor 405 is changed from the configurations of the first and second embodiments, and a protective capacitor (hereinafter referred to as a protective capacitor) 700 is added. FIG. 6 shows a circuit diagram of the third embodiment, and the same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted. The third embodiment is characterized in that the protective capacitor 700 is arranged between the anode side of the diode and the GND potential. Specifically, the smoothing capacitor 405 has a connection point between the anode terminal of the rectifying diode 403 and one end of the protection resistor 404 connected to one end thereof, and the other end is grounded. In the protection capacitor 700, which is the third capacitor, the other end of the protection resistor 404 is connected to one end, and the other end is grounded.

As described above, when a glass-coated heater is used in the fixing device 111, the protective capacitor 700 connected to the line having the same potential as the fixing voltage plays the role of a protective element when a lightning surge is applied. There may be. When the protective capacitor 700 plays the role of a protective element, the capacitance value may be limited accordingly. Therefore, if priority is given to protection from lightning surges, the capacitance value may be insufficient to smooth the ripple voltage caused by AC output such as charging, depending on the specifications of the fixing device 111 and the amount of current consumed. It may end up. When an excessive ripple voltage is applied to the fixing voltage, the effect of suppressing the fixing tail trail is reduced, and image defects may occur.

Therefore, the smoothing capacitor 405 is arranged at a position from the fixing voltage via the protection resistor 404, and the protection capacitor 700 plays a role of protecting the fixing device 111 from lightning surge. As a result, the capacitance value of the smoothing capacitor 405 can be set regardless of the specifications of the fixing device 111. As a result, it is possible to smooth the ripple voltage and suppress the occurrence of image defects while having the function of protecting from lightning surges. The arrangement of the smoothing capacitor 405 and the configuration of the protective capacitor 700 of the third embodiment can also be applied to the second embodiment.

As described above, according to the third embodiment, the image quality can be maintained without increasing the circuit scale of the power supply device.

201 High-voltage power supply circuit for transfer 202 High-voltage power supply circuit for charging 203 High-voltage power supply circuit for fixing 204 Coupling capacitor

Claims (8)

A first power supply that has an AC power supply that outputs an AC voltage and a DC power supply that outputs a DC voltage, and outputs a first voltage obtained by superimposing the AC voltage and the DC voltage to a first load.
A first capacitor whose one end is connected to the first power supply,
A second power supply connected to the other end of the first capacitor and outputting a second voltage obtained by rectifying and smoothing the AC voltage output from the other end of the first capacitor to a second load.
A third power supply that outputs DC voltage to a third load,
With
The first capacitor cuts off the DC voltage of the third power supply being output to the first power supply when the second load and the third load are electrically connected. A power supply that is characterized by The second power source is
A first diode for rectification in which one end of the first capacitor is connected to the cathode terminal,
A second diode for rectification, in which one end of the first capacitor is connected to the anode terminal and the cathode terminal is grounded,
A first resistor with one end connected to the anode terminal of the first diode,
A second capacitor for smoothing with the other end grounded,
The power supply device according to claim 1, wherein the power supply device comprises. The second power source is
A first diode for rectification in which one end of the first capacitor is connected to the cathode terminal,
A second resistor for rectification, in which one end of the first capacitor is connected to one end and the other end is grounded,
A first resistor with one end connected to the anode terminal of the first diode,
A second capacitor for smoothing with the other end grounded,
The power supply device according to claim 1, wherein the power supply device comprises. The second power source is
A first diode for rectification in which one end of the first capacitor is connected to the cathode terminal,
A second diode for rectification, in which one end of the first capacitor is connected to the anode terminal,
A first resistor with one end connected to the anode terminal of the first diode,
A second resistor for rectification, in which the cathode terminal of the second diode is connected to one end and the other end is grounded,
A second capacitor for smoothing with the other end grounded,
The power supply device according to claim 1, wherein the power supply device comprises. The power supply device according to any one of claims 2 to 4, wherein one end of the second capacitor is connected to the other end of the first resistor. One end of the second capacitor is connected to the connection point between the first diode and the first resistor.
The power supply according to any one of claims 2 to 4, wherein the other end of the first resistor is connected to one end and the other end has a grounded protective third capacitor. apparatus. Photoreceptor and
The charging means, which is the first load for charging the photoconductor,
An exposure means that exposes the photoconductor to form an electrostatic latent image,
A developing means for developing the electrostatic latent image to form a toner image,
The transfer means, which is the third load for transferring the toner image to the recording paper,
The fixing means, which is the second load for fixing the toner image of the recording paper,
The power supply device according to any one of claims 1 to 6.
An image forming apparatus comprising. A claim characterized in that the transfer means and the fixing means are electrically connected when one end of the recording paper is in contact with the transfer means and the other end of the recording paper is in contact with the fixing means. Item 7. The image forming apparatus according to item 7.

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