JPH03253919A - High voltage power source - Google Patents

Abstract

PURPOSE:To prevent the abnormality of an output high voltage to be caused by the fluctuation of a load by determining energization of a switching means by a constant current control means, when an output voltage is below a set value, and determining an energization of a switching means by a constant- voltage control means, when the output voltage exceeds the set value. CONSTITUTION:When an output voltage is below a set value, a control switching means IOC determines energization of a switching means Q10 by a constant- current control means IOC, and the constant-current control means IOC energizes the switching means Q10 so that an output current becomes a target current value. On the other hand, when the output voltage exceeds the set value, the control switching means IOC determines an energization of the switching means Q10 by a constant-voltage control means IOC, and the constant-voltage control means IOC energizes the switching means Q10 so that the output voltage comes to a target voltage value. In such a way, the output voltage is controlled to the target voltage value, an abnormal wise of the output voltage does not occur, and a malfunction of a recorder, and an electronic device IC of a high voltage power source unit caused by a noise does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a high voltage power supply device that outputs constant current and constant voltage high voltage power, and particularly relates to a high voltage power supply device that outputs high voltage for corona discharge.

[Conventional technology]

For example, the photoreceptor is uniformly charged with a corona charger.

A high-voltage power supply device that applies a high voltage to a corona charger of a recording device that exposes a charged surface to image light to form an electrostatic latent image and develops this electrostatic latent image with a developer, a so-called electrophotographic device. However, JP-A-60-153518 and JP-A-61-
It is disclosed in Japanese Patent No. 236363.

The high-voltage power supply device disclosed in Japanese Patent Application Laid-open No. 60-153518 applies high voltage to a corona electric device for charging a photoreceptor and a transfer charger for transferring a toner image on the photoreceptor to recording paper. A microcomputer (
A microcomputer (hereinafter abbreviated as a microcomputer) turns on/off (PWM control) the switching means of the high voltage power supply circuit so that the output current is at a predetermined value.

The high-voltage power supply device disclosed in Japanese Patent Application Laid-Open No. 61-236363 outputs a high voltage and a low voltage in a time-division manner by switching and outputting the high voltage to a corona charger and the low voltage to a bias electrode of a developing device.

[Problem that the invention seeks to solve]

By the way, in electrophotographic devices that record large recording sizes, the corona charger is also large (long), and the charge wire (corona, discharge wire) is long, and corona discharge causes problems in the recording device. The charge wire vibrates with the vibration.

This vibration causes the load on the high-voltage power supply to fluctuate, causing its output voltage to fluctuate. Since the corona charger is designed with a withstand voltage of 7 to 8 V, if the output high voltage of the high voltage power supply exceeds this voltage range due to load fluctuation, the corona charger shifts from corona discharge to arc discharge. Arc discharge is a type of spark discharge and has an extremely high current value. This spark discharge may damage the charge wire (high voltage electrode) 9 of the corona charger, the grounded casing (low voltage electrode), the photoreceptor, or the high voltage power supply, and the noise may cause damage to the recording device and/or electronic equipment of the high voltage power supply. There are problems such as the (IC) malfunctioning.

None of the above-mentioned conventional techniques can avoid this problem.

An object of the present invention is to prevent abnormalities in the output high voltage due to fluctuations in a load (for example, a corona charger) to which the output high voltage is applied.

[Means to solve the problem]

The high voltage power supply device of the present invention includes a step-up transformer (TRIO) connected to a DC power supply;
A switching means (QIO
) ; Current detection means (R14) that detects the output current of the output circuit connected to the secondary winding of the step-up transformer (TRIO)
) ; Constant current control means (I
OC); Voltage detection means (R13, R15) for detecting the output voltage of the output circuit; Constant voltage control means (IOC) for energizing the switching means (QIO) so that the output voltage becomes the target voltage value. ; and when the output voltage is below the set value (RV), the constant current control means (IOC
) determines the energization of the switching means (QIO) by 1
2When the voltage exceeds the constant value (RV), the constant voltage control means CI
DC) determines the energization of the switching means (1:110). A control switching means (IOC) is provided.

Note that symbols in parentheses indicate corresponding elements or corresponding matters in the embodiments shown in the drawings and described later.

[Effect]

When the output voltage is below the set value (RV), the control switching means (IOC) determines the energization of the switching means (Q10) by the constant current control means (IOC). , energizes the switching means (QIO) so as to set the output current to the target current value.

Therefore, while the output voltage is below the set value (RV).

The switching means (QIO) is controlled so that the load current (photoreceptor charge amount when the load is a corona charger) becomes a predetermined value, and the predetermined current flows through the load.

For example, when the load is a corona charger and the output voltage exceeds the set value (RV) due to the vibration of the charge wire, the control switching means (IOC) switches on the switching means (QIO) by the constant voltage control means (IOC). Decide the force.

As a result, the constant voltage control means (IOC) energizes the switching means (QIO) so as to set the output voltage to the target voltage value.

Therefore, when the output voltage exceeds the set value (RV), the output voltage is controlled to the target voltage value, there is no abnormal increase in the output voltage, the corona charger does not move to spark discharge, and the charge wire of the corona charger (high voltage electrode).

Damage to the equipment's grounded casing (low-voltage electrode), photoreceptor or high-voltage power supply or electronic equipment of the recording device and/or high-voltage power supply due to noise! (IC) will no longer malfunction.

During this constant voltage control, the output current value deviates slightly from the target current value, but because this constant voltage control is temporary and does not lead to spark discharge, the photoreceptor is sufficiently charged by the corona charger. Achieved without causing any particularly large disturbances in quantity.

Image formation processing can be stably continued without any particular disturbance in image formation.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

〔Example〕

FIG. 1 shows one embodiment of the present invention. In Figure 1, a photoreceptor PC is uniformly charged with a corona charger M, an electrostatic latent image is formed by exposing the charged surface to image light (not shown), and this electrostatic latent image is developed. The main elements around the photoreceptor 20 of a recording device, a so-called electrophotographic device, which is used for development in device B are shown.

A constant current DC high voltage is supplied from the first power supply circuit HM to the charge wire of the main charger M.
C is uniformly charged by corona discharge.

A constant voltage DC high voltage is supplied to the developing device B from the second power supply circuit HB, and the developing device B performs optimum development based on this voltage. A transfer paper (not shown) is sent to the image on the photoconductor PC, which is applied with toner and visualized by the developer B, and the transfer paper is charged with corona discharge by the transfer charger T, and the image on the photoconductor PC is transferred to the transfer paper (not shown). The toner image is transferred to transfer paper. Transfer charger T
A constant current DC high voltage is supplied from the third power supply circuit HT. After the transfer is completed, the surface of the photoreceptor is neutralized by a static eliminating lamp QL.

FIG. 2 shows the configuration of the first power supply circuit HM. The output controller IOC gives a pulse signal (PIIM signal) to the switching transistor QIO inserted in the primary circuit of the step-up transformer TR10 of the power supply circuit HM. The switching transistor QIO turns on/off in response to this pulse signal, and this turning on/off turns the step-up transformer TR
A high voltage pulse is generated in the secondary winding of l0. This high pressure pulse.

Diode DI O, DI 1. Capacitor C10°C
1l converts to DC and doubles the voltage. This boosted DC voltage is connected to the output protection resistor R12 and the output current detection resistor R1.
4 to the main charger M. The output current is converted into a voltage by the resistor R14 and input to the A/D conversion input terminal AO of the output controller IOC.

In the constant current control mode, the output controller E○C converts the detected current into digital data, reads it, and uses PWM to match the latter with the former based on the current target value and the detected current value.
The pulse time data is calculated, and based on the calculated pulse time data, a PWM signal (pulse) is applied from the output port To to the switching transistor QIO of the first power supply circuit HM. Thereby, the first power supply circuit HM is subjected to constant current control and outputs a current substantially equal to the target current value.

The output voltage of the first power supply circuit HM is determined by the voltage dividing resistors R13 and R13.
The voltage is stepped down at 15 and detected, and this is the output controller IO
It is applied to the A/D conversion input terminal A1 of C.

The output controller IOC compares this output voltage with a predetermined level value RV, and executes constant voltage control mode when the former is greater than the latter. In other words, "D current control" described later
8M in (subroutine DC3 shown in FIG. 11)
The detected value of the output voltage is set as a target value (M voltage target value), and "M output control" (subroutine MC5 shown in FIG. 12), which will be described later, is performed.
), during the copy cycle, the pulse width of the PWM signal that drives the first power supply circuit HM is determined by calculation from this target value and the detected value of the output voltage, and the PWM signal with the pulse width is sent from the output port To to the switching Output to transistor QIO. As a result, when the output voltage of the first power supply circuit HM becomes abnormally high due to vibration of the charge wire or the like, the constant current control mode is automatically switched to the constant voltage control mode, thereby preventing an abnormal increase in the output high voltage.

FIG. 3 shows the configuration of the second power supply circuit HB. The configuration of the second power supply circuit HB is similar to the first power supply circuit HM, and the only difference is that there is no resistor for detecting the output current and that the output voltage value is different.

The output voltage of the second power supply circuit HB is determined by the output controller IOC.
is applied to the A/D conversion input terminal A2 of. The output controller IOC controls the output voltage of the second power supply circuit HB to the target voltage value using a process similar to the constant voltage control mode of the first power supply circuit HM described above.

FIG. 4 shows the configuration of the third power supply circuit HT. This third power supply circuit HT is configured to output a constant current. When the output controller IOC outputs a low level L to its output port PO, the switching transistor Q21 of the third power supply circuit HT becomes conductive, and power is supplied to the switching regulator IC20. Switching regulator IC20 drives transistor Q20 at an oscillation frequency determined by the capacitance of capacitor C21, thereby obtaining a high voltage pulse on the secondary side of transformer TR20. Connect this to diode D21. D22. The converter C22 and C23 perform voltage double rectification to obtain high voltage direct current. This high voltage direct current is applied to the transfer charger T via the output protection resistor R27. The output current is sensed by resistor R29, and a voltage proportional to the output current is applied to the non-inverting input of the internal comparator of regulator IC20. A constant voltage of the stabilized power supply circuit in the regulator IC20 is connected to the inverting input terminal of the comparator through a resistor R22.
, R23 provide the divided voltage (target current value).

Regulator IC20 changes the width of the pulse that drives switching transistor Q20 in response to the deviation of the output current from the target current value. As a result, the output current of the third power supply circuit HT is constant current controlled to the target value.

A current flowing through the photoconductor PC in its thickness direction is detected by a current detector Id, and is applied to an A/D conversion input terminal A3 of an output controller IOC. The output controller E○C is
The output current of the main charger HM is adjusted so that the current flowing through the photoconductor PC becomes a predetermined value. Output controller I
The OC stores the output current of the first power supply circuit HM at this time, and controls the first power supply circuit HM with a constant current, using the stored current value as a target current value until the next predetermined timing (
However, while the output voltage is below the set value RV).

Figure 6 shows the main parts of the output controller IOC, the main body of which is the microcomputer IC30, and the main microcomputer MAIN.
Communication with C, control of each power supply circuit, and on/off sequence control of motors, solenoids, etc. (not shown).
A programmable interval timer IC31 is connected to the microcomputer IC30. The input terminal GATEO~2 of the timer IC31 is connected to the microcomputer IC30 to 20.
A KHz pulse signal is given. The input terminal CLK O~2 of the timer IC31 receives 8KHz from the oscillator IC32.
pulse is given. The timer IC31 has a built-in timer of 311, and has a terminal C3゜0. The timer designation and the timer count value are designated by the data of At, RD, IIR, and DO-D7.

Each timer counts the clock signal CLK and inverts the output OUT when the count value reaches a designated value. This output O
The UT is reset by the signal GATE. Repeat the same operation until the count value is changed. That is frequency 2
A pulse signal with variable duty at 0 KHz with a resolution of 8 KHz is generated. The crystal oscillator 05C30 connected to the microcomputer IC30 sends clock pulses to the microcomputer I.
Give to C30. IC33 to IC35 are operational amplifiers, which invert the detection voltage of negative polarity to positive polarity.

Figure 6 shows the microcomputer IC30 of the output controller IOC.
The outline of the control operation (main routine) is shown below. When the power is turned on (Step 1: below, the words "step" and "subroutine" are omitted and only the numbers are written in parentheses), the microcomputer IC30 , various mode settings,
Execute the "initial settings" (2) such as clearing the RAM, and then perform the "D current setting J (DCS
).

"M output control J (MC3) that controls the output (current or voltage) of the first power supply circuit HM to the target value, the second power supply circuit H
rB output control J (
BC3), which controls the on/off of the third power supply circuit HT.
Subroutines such as T output control J (Te3) are executed sequentially.

Figure 7 shows the main microcomputer MAIN of microcomputer IC30.
The microcomputer IC30, which shows the serial communication operation with C,
When a communication interrupt is received from the main microcomputer MAIN C, the main microcomputer MAIN C receives the data sent, and if a communication error occurs, the retransmission request "Error processing J (14)
Execute. If communication is successful, send the received data to R.
AM and return to the main routine. Fig. 8 shows an outline of the specifications of communication data, No. 2 shown in Fig. 8.
is the output current target value of the first power supply circuit, and the optimum value matching the copy processing conditions is sent. No. 3 is a target value of the current flowing through the photoconductor PC, and No. 3 is a target value of the output voltage of the second power supply circuit HB, and optimal values of these are also sent in accordance with the copy process conditions. No. 4 is flag data, and bit O of TON is 1, which is the third flag data.
The power supply circuit HT is turned on and O is turned off.

Bit 1 of GSET instructs to execute "D current control J (DC3)" which sets the current of the photoconductor PC, and O instructs not to execute it. 1 was sent and the microcomputer I
In response, C30 corrects the output of the first power supply circuit HM (
DC8) is executed, and the output current of the first power supply circuit HM at this time is set to the target current value, and the output voltage is set to the target voltage value.

FIG. 9 shows interrupt processing by the internal timer of the microcomputer IC 30. In this embodiment, the microcomputer IC30 is
A flag MCAL that generates an interrupt by an internal timer every 5m5ec and executes a control routine for each power supply circuit.
and set BCAL to 1. Each flag is reset to 0 in each control routine.

FIG. 10 shows rP I operation J (PASI to PAS5) (
7) Indicates the content, in which the value obtained by multiplying the previous output value (result) by the current deviation of the detected value from the target value by a certain coefficient KP, that is, the deviation correction value (P term) is added. and output this. Since this calculation process is repeated, the output value (result) includes the output integral value (I term). Note that the output value (result) is time data that indicates the pulse width of the PWM pulse output to the switching transistor of the power supply @N (HM, HB), and is calculated using the calculation formula (Kp of
) is "D current control J (DC8), rM output control J (M
C5) and "B output control J (BO2)."

FIG. 11 shows "D current control J (D OS
). When the microcomputer IC 30 proceeds to this subroutine, it checks the contents of the flag GSET (4).
1) If it is 0, return to the main routine, but if it is work, first clear the flag GSET to O (42)
, Next, write the target value (M current target value) of the first power supply circuit HM to the target value register (43), read the output current of the first power supply circuit HM and write it to the measured value register (44),
Perform the PI operation (PASI) that introduces these, write the obtained PWM (time) data to the output register MPW, and then write the obtained PWM (time) data to the switching transistor Q of the first power supply circuit HM.
10 is turned on/off based on this data.

This loop is repeated KM times to raise the output of the first power supply circuit HM.

Next, the output of the 111g circuit HM is adjusted so that the current flowing through the photoreceptor pc becomes a predetermined value. That is, the target value of the photoreceptor current (D current target value) is written to the target value register (47), the photoreceptor current signal is digitally converted and read, and written to the measured value register (48), and the current PWM output pulse is Write the pulse width data to the integral value register (
49), write the result of PI calculation from these to register MPW as new PWM data (PAS2, 50)
, based on this data, turns on/off the switching transistor QIO of the first power supply circuit HM. This loop is repeated KD times to set the photoreceptor current to a predetermined value. The measured values (M current detection value and M voltage detection value) of the output voltage and output current of the first power supply circuit at this time are used as the target current value (target value in constant current control mode) of the first power supply circuit and the target value. Please set the voltage value (target value in constant voltage control mode).
3.54), updates the data in register MPW to the lowest value 1 (55) and returns to the main routine. Note that KM and KD are 5 to 20, and it takes 25 to 100 seconds to repeat KM and KD times, but these are completely negligible times compared to the ON period of the main charger M during one copy cycle. It is.

Figure 12 shows the contents of the M output control J (MC8) that controls the output of the first power supply circuit HM.
0, check the flag MCAL (61) and see if it is 0.
When , the process returns to the main routine, but when ■, the flag MCAL is cleared to 0 (62A), and the contents of the flag FRV, which is set only within this subroutine and cleared every time one copy process ends, are checked (62B).
). When it is O (constant current control mode specified), constant current control (63 to 68) is executed, and when it is 1 (constant voltage control mode specified), constant voltage control (70 to 73) is executed. Note that while constant current control is being performed.

When the output voltage of the first power supply circuit HM exceeds RV, the flag FRV is set to 1 to switch to constant voltage control (68.
69-73).

In constant current control, first the target current value (M current target value) is written to the target value register (63), the output current value of the first power supply circuit HM is digitally converted and written to the measured value register (64), and the current value is The pulse width data of the PWM pulse is written to the integral value register (65), and a PI operation is executed based on these data (P, AS3) to calculate the PWM pulse width data, and this is written to the output register MPW (67). Then, the output voltage of the first power supply circuit HM is digitally converted and read (67), and it is checked whether it exceeds the set value RV (constant voltage control is required) or not (not necessary) (68). If not, a PWM pulse based on the data in the output register MPW is output.

When the output voltage exceeds the set value RV, 1 is written to the flag FRV (69) and constant voltage control is executed. That is, write the target voltage value (M voltage target value) to the target value register (
70), digitally converts the output voltage value of the first power supply circuit HM and writes it into the measured value register (71), and writes the pulse width data of the current PWM pulse into the integral value register (71).
2), with these, P1 calculation is executed PAS4) and P
Calculate WM pulse width data and send it to output register MP
Write to W (73).

Then, a PWM signal based on this data is output. Note that since the flag FRV is cleared every time one copy cycle ends, constant current control is always started at the beginning of charging the photoreceptor for one copy process. Then, by the time the charging for - sheets is completed, the output voltage of the first power supply circuit HM is set to RV.
When the value exceeds 1, the constant voltage control is switched to the constant voltage control, and this constant voltage control is performed until the charging of -the number of sheets is completed. - When the output voltage does not exceed RV until the charging for the number of sheets is completed, constant voltage control is not performed and only constant current control is continuously performed.

Therefore, when the charge wire of the main charger M vibrates due to corona discharge or vibration of the copying machine, and the output voltage of the first power supply circuit HM exceeds the set value RV, the output voltage changes to the target voltage value (M voltage target value ), the first power supply circuit HM is controlled at a constant voltage, and an abnormal increase in the output voltage is prevented, so that the charge wire does not generate spark discharge.

The target voltage during this constant voltage control is the “D current control J” mentioned above.
(DC8) is determined to be a value that conforms to the set copy conditions, so no particularly large deterioration in copy quality occurs.

FIG. 13 shows the contents of the subroutine "B output control J (BO2)" for controlling the developing bias voltage.

The microcomputer IC 30 first checks the contents of the flag BCAL (74), and if it is 0, it returns to the main routine, but if it is 1, it first clears the flag BCAL (75) and sets the developing bias in the target value register. Write the target value (B voltage target value) (76), and write the second power supply circuit HB.
Digitally converts the output voltage, reads it, and writes it to the measured value register (77), and writes the current PWM output data (contents of output register BPII) to the integral value register (78), and calculates the PI based on these values. By calculation, PW
Calculate the M output data (PAS5), write it to the output register BPV (79), and calculate the P based on this data.
The WM pulse is output to the second power supply circuit HB.

Note that during the output on period of the first power supply circuit HM (main charger M energization period) and the output on period of the second power supply circuit HB (developing device B energization period), the flag MC is set every 5 m5ec.
Since AL and BCAL are set to 1, the above
The M output control J (62A or less of MC3) and the B output control J (75 or less of BO2) are repeated at a 5-see cycle.

FIG. 14 shows the contents of the subroutine "T output control J (Te3)" that controls the on/off of the third power supply circuit HT. Check (81) and if it is 0, the microcomputer IC30
The third power supply circuit HT is turned off by outputting a high level 1 to the output port PO (84).

When TON is 1, first clear it (2
2), and outputs a low level O to the output port PO to turn on the third power supply circuit HT (83).

According to the embodiment described above, when the output voltage of the first power supply circuit HM is detected and exceeds the set value RV,
Since the control mode of the first power supply circuit HM is switched from constant current control to constant voltage control, the voltage of the charge wire is maintained at a constant voltage even if there is load fluctuation due to vibration of the charge wire of the main charger M. , an abnormally high voltage will not occur and spark discharge will not occur, and the safety and reliability of the main charger M will be improved.

Even when switching from constant current control to constant voltage control, the target voltage value of constant voltage control is set to the M voltage detection value that maintains the copy process with sufficient quality, and in constant voltage control, the output of the first power supply circuit is set to this voltage. Since the voltage is controlled, there will be no stoppage of the copy process or copy loss.

Once the output voltage of the first power supply circuit HM exceeds the set value RV, constant voltage control is continued during the main charging period until the end of one copy cycle, so the copy process is stabilized and the copy process control does not fluctuate greatly. The copying machine has high operating stability, with no errors or irregularities.

M at which the photoreceptor current remains at a predetermined value even during constant voltage control
Since the output voltage of the first power supply circuit is controlled using the detected voltage value as the target voltage value, high-quality copies can be obtained.

〔Effect of the invention〕

As described above, the high voltage power supply device of the present invention! (HM + l0
According to C), when the output voltage is below the set value (RV), the control switching means (IOC) switches the constant current control means (IOC) to the constant current control means (IOC).
), and thereby the constant current control means (IOC) energizes the switching means (QIO) so that the output current reaches the target current value. Therefore, while the output voltage is below the set value (RV), the switching means (QIO
) is controlled, and a predetermined current flows to the load.

For example, when the load is a corona charger and the output voltage exceeds the set value (RV) due to the vibration of the charge wire, the control switching means (IOC) switches on the switching means (QIO) by the constant voltage control means (IOC). Based on this, the constant voltage control means (IOC) energizes the switching means (QIO) so as to set the output voltage to the target voltage value.

Therefore, when the output voltage exceeds the set value (RV), the output voltage is controlled to the target voltage value, there is no abnormal increase in the output voltage, the corona charger does not move to spark discharge, and the charge wire of the corona charger (high voltage electrode).

Damage to the device grounded casing (low-voltage electrode), photoreceptor, or high-voltage power supply device, and malfunction of the recording device and/or the electronic device (RC) of the high-voltage power supply device due to noise are eliminated.

During this constant voltage control, the output current value deviates slightly from the target current value, but because this constant voltage control is temporary and does not lead to spark discharge, the photoreceptor is sufficiently charged by the corona charger. Achieved without causing any particularly large disturbances in quantity.

Image formation processing can be stably continued without any particular disturbance in image formation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an overview of an embodiment of the present invention. FIG. 2 is an electrical circuit diagram showing the configuration of the first power supply circuit HM shown in FIG. 1. FIG. 3 is an electrical circuit diagram showing the configuration of the second power supply circuit HB shown in FIG. 1. FIG. 4 is an electrical circuit diagram showing the configuration of the third power supply circuit HT shown in FIG. 1. FIG. 5 is an electrical circuit diagram showing the main components of the output controller IOC shown in FIG. 1. 6, 7, 9, 10, and 11. FIGS. 12, 13, and 14 are flowcharts showing control operations of the microcomputer IC 30 shown in FIG. FIG. 8 is a plan view showing the contents of communication data transmitted from the main microcomputer MAIN C shown in FIG. 1 to the output controller IOC. PC: Photoconductor Old main charger B: Developer T: Transfer charger QL: Static neutralization lamp HM: First power supply circuit TR10: Step-up transformer (step-up transformer) QIO switching transistor (switching means) R14: Resistor (current Detection means) R13, R15: Resistor (voltage detection means) HB: Second power supply circuit H = Third power supply circuit IOC: Output controller MAIN C: Main microcomputer IC30: Output controller IOC microcomputer (constant current control means Voltage control means, control switching means) IC31: Written amendment to timer procedure (voluntary) April 4, 1990 1, Indication of case 1990 Patent Application No. 53136 2
, Title of the invention: High-voltage power supply device 3, Relationship to the case of the person making the amendment Patent applicant address: 1-3-6 Nakamagome, Ota-ku, Tokyo
Name (674) Ricoh Co., Ltd. Representative Hama 1) Hiro 4, Agent 103 Telephone 03-864-60
52 Address: 2-27-6-6 Higashi Nihonbashi, Chuo-ku, Tokyo Details of the amendment All drawings will be corrected as per the attached appendix (no changes to the engraving or content of the drawings).

Claims (1)

[Scope of Claims] A step-up transformer connected to a DC power supply; a switching means inserted in the current-carrying path of the primary winding of the step-up transformer; an output of an output circuit connected to the secondary winding of the step-up transformer; Current detection means for detecting current; Constant current control means for energizing the switching means so that the output current is a target current value; Voltage detection means for detecting the output voltage of the output circuit; constant voltage control means for energizing the switching means to achieve a target voltage value; and, when the output voltage is below a set value, determining the energization of the switching means by the constant current control means; A high-voltage power supply device comprising: control switching means for determining the energization of the switching means by the constant voltage control means when the voltage exceeds the voltage.