JP6311448B2 - High voltage power supply - Google Patents

Description

  The present invention relates to a high-voltage power supply used in a surface modification technique for a recording medium on which an image is formed by an inkjet image forming apparatus, a printing apparatus, or the like.

  In an inkjet image forming apparatus, an image is formed by adhering ink to a recording medium such as paper or film. However, depending on the combination of ink and recording medium, the ink may not adhere to the recording medium. Image formation with this is impossible. However, it is possible to form an image by changing the ink of the image forming apparatus according to the recording medium. However, considering the case where many types of recording media are used, the ink filled in the image forming apparatus can be removed and other inks can be removed. It is virtually impossible to replace it. However, there is a great demand for image formation on a recording medium to which ink such as paper or film coated with resin is difficult to adhere, and it is necessary to cope with it by improving the wettability of the recording medium itself. For this reason, it is common to perform image formation by applying a precoat liquid to a recording medium. However, when a liquid is applied, drying is necessary, and the energy for drying and the gas and odor generated during drying of the precoat liquid are avoided. There are many cases.

  In recent years, in consideration of the environment, attention has also been paid to a method for improving the wettability of a recording medium by using a functional group that improves the wettability with respect to ink by modifying the recording medium itself by using a discharge phenomenon without generating gas or the like. There is a known technique for improving wettability by generating hydrophilic functional groups by dielectric barrier discharge using a push-pull or full-bridge AC inverter type high-voltage power supply. For the purpose of minimizing transformer loss, it is possible to suppress the temperature rise of the transformer by making the self-resonant frequency of the secondary winding measured with the primary side open close to the drive frequency of the drive circuit. Therefore, a technique is known in which a relatively inexpensive transformer winding wire can be used (see, for example, “Patent Document 1”).

  In the conventional surface modification technology using dielectric barrier discharge, plasma is generated by creating a uniform electric field by applying an alternating high voltage and recording is performed by creating a hydrophilic functional group. Modifications were made to improve the wettability of the medium. An ideal dielectric barrier discharge does not generate arcs, but in reality, the oscillation period is shifted due to load fluctuations due to load fluctuations, changes in the dielectric constant of the recording medium, environmental changes such as temperature, humidity, and atmospheric pressure. The oscillation cycle of the control circuit adjusted to the constant to be controlled is not suitable, and it is necessary to install a cooling device as a countermeasure against problems such as deterioration in efficiency, heat generation, and failure due to increased circuit loss.

  Usually, in the case of a discharge that is not a dielectric barrier discharge, dielectric breakdown occurs, and an arc or spark discharge is generated at the site of dielectric breakdown. In that case, since the insulation at the site where the dielectric breakdown has occurred is lowered, the discharge is sustained only at that site, and unevenness occurs in the modification of the recording medium. In other words, in order to obtain a uniform image, a high-precision high-voltage power supply, atmospheric pressure, humidity, and the type and concentration of gas around the discharge unit must be finely controlled to maintain a uniform discharge state. Since discharge and spark discharge occur, it is difficult to realize with a simple device.

  The dielectric is electrically polarized when an electric field is applied, and electric charges move, that is, current flows until the polarization is stabilized. A discharge using this characteristic is a dielectric barrier discharge. In addition, since the dielectric itself is an insulator, and unlike other discharges, the insulation does not depend on space or gas, so the dielectric barrier discharge is a uniform and stable discharge technology against dielectric breakdown. In dielectric barrier discharge, a dielectric and a gap are provided between electrodes, and when a voltage is applied between the electrodes, a charge flows in the gap and discharge occurs. Since the dielectric is sandwiched, if the dielectric is polarized, the charge will not flow, and if a discharge occurs at a certain location, the dielectric at that location will polarize and the discharge will stop, and the discharge will move to the undischarged location. To do. Since this phenomenon occurs repeatedly between the electrodes, a uniform discharge is generated in a short time across the electrodes sandwiching the dielectric.

  Specifically, when a dielectric barrier discharge is generated by applying a high voltage between electrodes facing each other across a space between a dielectric having a certain area and a dielectric, the dielectric has a discharge plasma and a discharge path. Since it does not spread in the orthogonal direction, the discharge has a small diameter. Once the portion is discharged, the dielectric is polarized and the charge cannot move, so the discharge does not occur again, and the discharge moves to the undischarged portion with a small diameter. That is, many discharge plasmas having a small diameter are uniformly generated on the dielectric. However, since the dielectric once polarized in series with respect to the discharge path exists at the site once discharged, the discharge ends when the discharge occurs on the entire dielectric surface and the electric charge is accumulated.

  At this time, if the electric field is applied in the reverse direction, the dielectric polarization direction is also reversed, so that discharge in the reverse direction can occur. Therefore, the dielectric barrier discharge can be continued repeatedly by using an AC high voltage power source whose electric field direction is periodically reversed. However, although the discharge is a discharge between two electrodes, the dielectric treatment applied to the conductor is costly, so that the surface of one electrode of the electrode pair is covered with a dielectric. Approximately, the dielectric barrier discharge electrode is a capacitor, and an AC high-voltage power supply is required to pass a current. However, the AC high-voltage power supply requires a complicated circuit and a large transformer and is large. Further, since the electrode for dielectric barrier discharge is a capacitor, the capacitance changes depending on the environment, the dielectric constant of the recording medium, the size of the recording medium between the electrodes, the deterioration of the electrode due to use, and the like. The change in capacity is not a desirable phenomenon for an AC high-voltage power supply, and the inherent oscillation frequency determined by the discharge electrode capacity and other factors changes. Therefore, an AC high-voltage power supply driven at the assumed operating frequency generates heat and loss. There is a problem that it becomes an undesired state such as an increase and deterioration of efficiency.

  In the technology disclosed in “Patent Document 1”, the push-pull type AC high-voltage power supply has a large transformer, and the oscillation period is adjusted in advance to the load assumed in the design stage. It is not possible to deal with such changes, and the problem of the effects of load fluctuations cannot be solved. Moreover, since control of electric power also depends on resonance, it is difficult to control with arbitrary electric power.

  The present invention solves the above-described problems, and a conventional high-voltage power source for performing surface modification of a recording medium by dielectric barrier discharge is inexpensive and compact without impairing efficiency and reliability even when there is a load fluctuation. The dielectric barrier discharge reformer, which has existed as a large facility that cannot be moved, can be built in the image forming apparatus, and it is environmental factors and deterioration over time compared to conventional high voltage power supply for dielectric barrier discharge An object of the present invention is to provide a high-voltage power supply that can cope with load fluctuations affected by a recording medium and the like and can easily adjust power.

  In the first aspect of the invention, the primary side is driven by a switching element, the secondary side is provided with an electrode having capacitance forming a resonance circuit with the inductor, and the primary winding has an output transformer having no neutral point; Current detecting means for detecting the current of the switching element, the regenerative current or the current of the primary winding, and detecting that the voltage on the primary side is 0 V or a low voltage negligible due to the switching loss of the switching element. The voltage detecting means and the switching element when the voltage detecting means detects 0 V or a low voltage that can be ignored by the switching loss of the switching element, or when the current detecting means detects that a regenerative current is flowing. When the current of the switching element reaches a predetermined value by the current detecting means, the switching element is non-conductive. And having a control means for the.

  According to the present invention, since the charge amount of the dielectric changes when the electric field changes, a dielectric barrier discharge can be generated even with a DC high-voltage power supply, and an inexpensive and small power supply that does not impair efficiency and reliability even when a load fluctuates. The charging control apparatus provided can be provided. As a result, the dielectric barrier discharge reforming apparatus can be built in the image forming apparatus, so that a significant reduction in size can be achieved and power adjustment can be easily performed in response to changes in various factors. A high-voltage power supply for dielectric barrier discharge can be provided.

1 is a schematic view of a high voltage power supply for dielectric barrier discharge to which an embodiment of the present invention can be applied. It is the schematic explaining the behavior of the electric current and voltage in one Embodiment of this invention. It is a flowchart explaining operation | movement of the control circuit in one Embodiment of this invention. It is a flowchart explaining operation | movement of the control circuit in the modification of one Embodiment of this invention. It is the schematic explaining the control circuit used for one Embodiment of this invention.

  First, the outline of the present invention will be described. The present invention relates to a charge control device including a high-voltage power supply for performing surface modification of a recording medium by dielectric barrier discharge. Specifically, as a high-voltage power supply for modifying the surface of the recording medium by dielectric barrier discharge, a flyback type DC high-voltage power supply whose output varies periodically without using an AC high-voltage power supply is used. A dielectric barrier discharge has a capacitor structure with a dielectric sandwiched between them. When an electric field is applied to the dielectric, electric charge flows through the dielectric, but current flows when the dielectric is charged and polarized and electrically balanced. Disappear. When the polarity of the electric field is changed in this equilibrium state, a current for charging the dielectric in the reverse direction flows, and the current continues to flow until the dielectric is charged and balanced.

  In the technique disclosed in “Patent Document 1” and the surface modification method using ordinary dielectric barrier discharge, when electric charge is accumulated on the dielectric surface, it cannot be discharged, and the direction of the electric field needs to be switched, so that alternating current is required. Use a high-voltage power supply. In addition, an AC high-voltage power supply that operates at a fixed frequency determined in accordance with a resonance frequency determined by a discharge electrode and other factors at the design stage has been used.

  However, even if the dielectric is not alternating current and the direction of the electric field does not change, if there is a change in the electric field strength, a current corresponding to the change in the electric field strength flows, and it responds to changes in the positive and negative asymmetrical alternating current and direct current fields. A current can be passed, and a dielectric barrier discharge can be generated. Therefore, a flyback type high voltage power supply is used with a DC pulse that is easy to control instead of AC or a DC high voltage power supply that is asymmetrical in positive and negative directions, and the efficiency that is automatically determined by the load even when the capacitance of the electrode changes. Use a high-voltage power supply with a good frequency. And, as a flyback type using resonance due to the load and other factors without determining the frequency by itself, the loss of not only the transformer but also the drive circuit can be reduced by making it a high voltage power supply that performs soft switching, It is characterized in that it can be miniaturized. Hereinafter, it explains in detail using a drawing.

  FIG. 1 shows a non-AC type high-voltage power source that generates a dielectric barrier discharge to which an embodiment of the present invention can be applied. In the figure, a high-voltage power supply 11 includes diodes 2, 3, 4, and 5 that rectify an AC power supply 1 and convert it to DC, and a capacitor 6 that smoothes the rectified DC ripple. The high-voltage power supply 11 includes inductors 12 and 13 that form an output transformer 41 that is electrically coupled to each other and does not have a neutral point. The high-voltage power supply 11 includes an FET gate drive circuit 7 for passing an electric current to excite the inductor 12. The FET gate drive circuit 7 controls the FET 9, the regenerative diode 10, the current detection resistor 17, and a control for controlling the circuit. The control circuit 8 is a means. The FET gate drive circuit 7 is controlled to operate and stop by a control signal 23. Further, the high-voltage power supply 11 has an electrode 14 and an electrode 15 having a dielectric 16 formed on the surface thereof and performing dielectric barrier discharge with the electrode 14.

  Next, an example of the control circuit 8 will be described with reference to FIG. The control signal 23 is connected to a one-shot multivibrator 24, an inverter 25, and an OR circuit 27. The drain voltage 22 is input from a terminal 44 and is connected to a drain voltage drop detection unit including a comparator 43 and resistors 38 and 39 via a differentiation circuit including a capacitor 40 and a resistor 37. The terminal 44 is connected to a drain voltage inverting amplifier composed of resistors 47 and 48 and an OP amplifier 49. The current detection terminal 45 is connected to the current detection resistor 17, is connected to a regenerative current detector composed of resistors 33, 34 and an OP amplifier 28, and is connected to a drain current detector composed of resistors 35, 36 and a comparator 29. It is connected. The OP amplifier 28 and the comparator 29 constitute current detection means, and the comparator 43 and the OP amplifier 49 constitute voltage detection means.

  The outputs of the control signal 23 and the one-shot multivibrator 24 are connected to the AND circuit 42, and the output of the AND circuit 42 is connected to the OR circuit 27. The control signal 23, the drain voltage drop detection unit output, and the drain voltage inverting amplifier The output and the regenerative current detector output are input to the AND circuit 26. The output of the control signal 23 via the inverter 25 and the drain current detector output are input to the OR circuit 30. The output of the OR circuit 27 is connected to the set (S) terminal of the RS flip-flop 31, and the output of the OR circuit 30 is connected to the reset (R) terminal of the RS flip-flop 31. The output Q of the RS flip-flop 31 is connected to the input of the FET gate drive circuit 27, and the output terminal 46 of the FET gate drive circuit 32 is a signal connected to the gate of the FET 9.

  Next, the circuit operation of the high-voltage power supply 11 shown in FIG. 1 will be described with reference to FIGS. The AC power source 1 is rectified by the diodes 2, 3, 4, and 5 and applies a voltage to the inductor 12. When the control signal 23 is input (ST01), the control circuit 8 conducts the FET 9, which is a switching element, and current flows into the FET 9 via the inductor 12 (ST02). When the FET 9 becomes conductive, the drain current 19 of the FET 9 shown in FIG. 2 rises with time as shown in the period A. At this time, the current 19 flowing through the inductor 12 is equal to the drain current flowing through the FET 9. When the current 19 flowing through the inductor 12 reaches a preset current value calculated from the required power (ST03), the FET 9 becomes non-conductive as at the end of the period A (ST04), and the 19 flowing through the inductor 12 is cut. Turned off. This set value of the current affects not only the drain current of the FET 9 but also the voltage of the inductor 13 at the time of voltage resonance.

  In the period B shown in FIG. 2 after the current 19 flowing through the inductor 12 is cut off, the drain voltage 22 of the FET 9 and the electrode 15 generated by the inductor 13 are generated by resonance between the capacitor formed by the electrodes 14 and 15 and the inductor 13. A voltage is generated as shown in FIG. At this time, the current 18 flowing through the inductor 13 is 90% out of phase with the voltage 21 of the electrode 15 generated by the inductor 13, so that no electric power is consumed, and the current lost due to the gas being turned into plasma by the discharge phenomenon. Only small power.

  In the voltage resonance, the drain voltage 22 rises once (ST05) but gradually falls with a peak of 1.0 kV (ST06). At this time, the control circuit 8 detects the fall of the drain voltage 22 exceeding the peak, and monitors whether the drain voltage 22 becomes 0 V after the fall. Next, when the voltage resonance is completed and the drain voltage 22 becomes 0 V in the period C of FIG. 2 (ST07), the current 20 of the inductor 12 is regenerated through the regenerative diode 10. The regenerative current 20 flowing through the regenerative diode 10 is the regenerative current of the inductor 12, and the current 20 flowing through the inductor 12 flows in a direction opposite to the direction of the current 19 flowing through the inductor 12 when the drain current is flowing. The control circuit 8 detects that the regenerative current is flowing with the resistor 17 (ST08), and after confirming that the control signal 23 is not turned off (ST09), the FET 9 is turned on again while the regenerative current is flowing. Conduction is made (ST02). The regenerative current 20 of the inductor 12 decreases with time and eventually becomes 0, but the FET 9 is conducting when the regenerative current 20 of the inductor 12 becomes 0. A drain current 19 flows from the FET 9 to the FET 9. Thereafter, the cycles of the periods A, B, and C shown in FIG. 2 are repeated, and when the control signal 23 is turned off, the FET 9 is turned off and stopped (ST10).

  Since no current flows when the FET 9 is non-conductive, no loss occurs, and no voltage is generated between the drain and source in the conductive state, so no power loss occurs, and at the time of transition from conductive to non-conductive or from non-conductive to conductive. A loss occurs because a voltage is generated and a current flows. In the present invention, at the time of transition from the period C to the period A in the above-described operation, the drain voltage 22 is 0 V at the moment when the FET 9 becomes conductive. For this reason, the loss power of the FET 9 = the drain voltage × the drain current is theoretically 0, the switching loss of the FET 9 does not occur, the loss of power and the heat generation of the FET 9 do not occur. Further, the FET 9 is switched from conduction to non-conduction at the time of transition from the period A to the period B. However, since the drain voltage 22 is 0 V, the switching loss of the FET 9 does not occur, and no loss of power and no heat generation of the FET 9 occur. Thus, in this circuit, the loss in the FET 9 is reduced, the durability of the FET 9 is improved, the reliability is improved, and there is no loss of power and energy is saved. Further, since there is no switching loss, the cooling of the FET 9 can be simplified or unnecessary, and the circuit can be made small and inexpensive. Secondary switching with a drain voltage of 0V does not cause a sudden change in voltage, and no pulsed current or voltage is generated. Does not occur. As described above, the oscillation using the resonance can be continued by repeating the operations in the periods A, B, and C, and the efficient continuous discharge can be maintained.

  The role of the control circuit 8 that performs switching of the FET 9 is to repeatedly perform conduction and non-conduction of the FET 9 at an appropriate timing. As in the prior art, generally, when the resonance frequency such as load fluctuation does not fluctuate, the control circuit 8 is provided with a transmitter, and the FET 9 is made to conduct for a certain period of time with a fixed period like PWM control at a fixed frequency. Can be achieved. However, in general, the capacity created by the electrodes 14 and 15 that are loads varies. For example, the electrodes 14 and 15 such that the electrodes are worn due to discharge, the dielectric is deteriorated to change the dielectric constant, the size of the recording medium to be modified is changed, and there is a difference in the dielectric depending on the material of the recording medium. There are many factors that affect the capacitance of the. In general, there is a change in capacitance, but in this case, the above-described resonance period is shifted, and the FET 9 cannot be conducted at the point where the drain voltage 22 which is a feature of the present invention is 0V. In that case, the FET 9 becomes conductive when a high voltage is applied to the drain of the FET 9, so that the switching loss of the FET 9 increases, and the FET 9 breaks down and burns out in the worst case.

  In the present invention, when the resonance frequency is shifted due to the load capacitance variation described above, the control circuit 8 performs control corresponding to the capacitance change in order not to cause a problem. First, the control circuit 8 reads the voltage of the current detection resistor 17 connected to the source of the FET 9 and detects the current flowing through the FET 9 except that the FET 9 becomes conductive in the period A and the current flows through the inductor 12. The control circuit 8 operates to turn off the FET 9 when the current flowing through the FET 9 becomes equal to or greater than a set value. In this embodiment, the set value is 14A. The FET 9 becomes non-conductive when the drain current 19 becomes 14 A, and shifts to the period B.

  In the period B, the drain voltage 22 and the voltage 21 of the electrode 15 are generated by voltage resonance. Although the drain voltage 22 and the voltage 21 increase once due to resonance, the voltage resonance shown in the period B ends when the drain voltage 22 decreases again and the drain voltage 22 becomes 0V. Next, in the period C, when the drain voltage 22 becomes 0 V or less due to voltage resonance, the regenerative diode 10 becomes conductive and starts to flow the regenerative current 20 from the inductor 12. The regenerative current 20 flowing through the inductor 12 flows in the opposite direction to the current 19 flowing through the inductor 12 when the FET 9 is conducting. The regenerative current flowing through the regenerative diode 10 is large when it starts to flow like the current 20, and decays with time to finally reach 0A. At this time, the control circuit 8 detects that the drain voltage 22 has decreased to 0 V, and that the period B of voltage resonance has ended due to the regenerative current flowing in the current detection resistor 17, and makes the FET 9 conductive. Let When there is no fear of malfunction due to noise and the detection is stable, the conduction condition of the FET 9 may be as shown in the flowchart shown in FIG. That is, the drop of the drain current 19 and the detection of 0V of the drain voltage 22 are omitted, and the period of voltage resonance is detected only by detecting that the regenerative current flows through the current detection resistor 17 or that the drain voltage 22 is 0V. The FET 9 may be turned on by determining that B has ended.

  Next, the regenerative current that has reached 0 V repeats the same operation as in period A again, so that the discharge between the electrodes 14 and 15 continues. The FET 9 changes from conduction to non-conduction at the time of transition from the period A to the period B, but since the drain voltage 22 at this time is 0 V, no switching loss occurs. At the time of transition from the period C to the period A, the FET 9 becomes conductive in the period C, so that the drain voltage 22 is 0 V, and the regenerative current also flows through the regenerative diode 10, so that no switching loss occurs. Accordingly, since the switching power loss in the FET 9 is small, there is little energy consumption and there is an energy saving effect, and since there is no power loss, the heat generation of the inverter 25 is small, and the heat sink and the cooling fan are simplified. Can be omitted.

  Next, the operation of the control circuit 8 will be described. A general AC high-voltage power supply generates a discharge in a load by performing PWM control at a constant cycle. If the oscillation cycle is shifted at that time, the switching element is turned on or off at a timing when the voltage is not 0V. A hard switching state for switching is made. Then, power loss and heat generation of the FET 9 are caused, and in the worst case, burning is caused. A feature of the present invention is that the FET 9 is switched between conducting and non-conducting only by the current and voltage flowing through the FET 9 and the regenerative diode 10. For this reason, for example, when the capacitance of the capacitor formed by the electrodes 14 and 15 changes with time, when the environmental factor changes, even when the dielectric constant of the recording medium to be processed changes, switching is performed at an optimal timing. Become. The above operation is as shown in the flowchart of FIG. Further, although the same operation is performed in the flowchart shown in FIG. 4, there are many determination factors in the case of malfunction due to noise or the like, and therefore the flowchart shown in FIG. 3 is more reliable. The flowchart shown in FIG. 4 is sufficient in a favorable environment free from malfunction factors such as noise.

  Next, an example of the control circuit 8 will be described with reference to FIG. The control signal 23 is a drive signal for the inverter 25, and the operation of the inverter 25 can be controlled by setting it to L when stopped and H during operation. When the control signal 23 changes from L to H, the one-shot multivibrator 24 outputs only one pulse, the AND circuit 42 creates the control signal 23 and the AND signal, and the RS flip-flop 31 via the OR circuit 27. Set to. When the RS flip-flop 31 is set, the FET gate driving circuit 32 drives the gate of the FET 9 to keep the FET 9 conductive in order to maintain the state.

  When the FET 9 becomes conductive, the voltage of the current detection resistor 17 that monitors the drain current 19 is monitored by the current detection terminal 45. When the drain current 19 reaches the reference voltage 50 set to the control current value, the comparator 29 is inverted. When the reset terminal of the RS flip-flop 31 is reset and the RS flip-flop 31 is in a reset state, the FET gate drive circuit 32 switches the FET 9 to non-conduction. When the FET 9 becomes non-conductive, the comparator 29 becomes L again, but the RS flip-flop 31 maintains the reset state. Thereafter, LC resonance occurs and the control circuit 8 holds the FET 9 in a non-conducting state. However, when the resonance voltage starts to drop after the peak, the differential circuit of the capacitor 40 and the resistor 37 is negative from the voltage at the terminal 44. A voltage in the direction is generated, and the comparator 43 becomes H.

  Further, when the voltage at the terminal 44 decreases to 0 V due to resonance, the amplifier circuit including the resistors 47 and 48 and the OP amplifier 28 also becomes H, and when the regenerative current next flows through the regenerative diode 10, the current detection terminal 45 becomes negative. . Therefore, the OP amplifier 28 becomes H, and AND of the outputs of the control signal 23, the comparator 43, the OP amplifier 49, and the OP amplifier 28 is taken, and the AND circuit 26 becomes H, and the RS flip-flop 31 is set via the OR circuit 27. Let it be in a state. Then, the FET gate drive circuit 32 is set to H to make the FET 9 conductive, and the operation cycle is repeated from this state until the drain current 19 rises and the voltage of the resistor 17 reaches the reference voltage 50 set to the control current value. This cycle can be stopped by setting the control signal 23 to L.

  With the above configuration, according to the present invention, if the electric field changes, the amount of charge of the dielectric changes. Therefore, a dielectric barrier discharge can be generated even with a DC high-voltage power supply, and the efficiency and reliability are not impaired even if load fluctuation occurs. A small high-voltage power supply for dielectric barrier discharge can be provided. As a result, the dielectric barrier discharge reforming apparatus can be built in the image forming apparatus, so that a significant reduction in size can be achieved and power adjustment can be easily performed in response to changes in various factors. A charge control device can be provided.

  In addition, since the switching element is switched to conduction when voltage is not applied by using voltage resonance, it can provide a power source with less energy loss and heat generation, improve reliability and life, and reduce noise. can do. Also, by adopting the flyback converter method, the circuit configuration is simple and downsizing can be achieved, the size and weight of the transformer can be halved, and the current value can be set arbitrarily, which is difficult with other methods. Output adjustment can be easily performed. Further, since the high-voltage power supply uses the capacitance of the discharge electrode as a resonance element of the resonance circuit, an optimum operation can be automatically performed even when there is a load change.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments described above, and is described in the claims unless specifically limited by the above description. Various modifications and changes can be made within the scope of the present invention.
For example, the image forming apparatus to which the present invention is applied is not limited to the type of image forming apparatus described above, and may be another type of image forming apparatus. In other words, the image forming apparatus to which the present invention is applied may be a printer, a single facsimile, or a complex machine thereof, or a complex machine such as a monochrome machine or a color machine related thereto. In addition, the image forming apparatus to which the present invention is applied may be an image forming apparatus used for forming an electric circuit or an image forming apparatus used for forming a predetermined image in the biotechnology field.
The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention. .

8 Control means (control circuit)
9 Switching element (FET)
11 High Voltage Power Supply 12, 13 Inductor 14, 15 Electrode 41 Output Transformer

Japanese Patent No. 3910210

Claims (4)

The primary side is driven by a switching element, the secondary side is provided with an electrode having a capacitance forming a resonance circuit with an inductor, the primary side winding has an output transformer having no neutral point,
Current detection means for detecting the current of the switching element, the regenerative current or the current of the primary winding;
Voltage detecting means for detecting that the primary side voltage is 0 V or a low voltage negligible due to the switching loss of the switching element;
When the voltage detection means detects 0 V or a low voltage that can be ignored by the switching loss of the switching element, or when the current detection means detects that a regenerative current is flowing, the switching element is turned on, A high voltage power supply comprising: a control unit configured to turn off the switching element when the current of the switching element reaches a predetermined value by the current detection unit. The high-voltage power supply according to claim 1,
The high-voltage power supply, wherein the switching element is switched to conduction when voltage is not applied using voltage resonance. The high-voltage power supply according to claim 1 or 2,
A high-voltage power supply characterized by a flyback converter system. The high-voltage power source according to any one of claims 1 to 3,
A high-voltage power supply characterized in that the capacitance of a discharge electrode is used as a resonance element of a resonance circuit.

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