US20140036546A1 - Power supply apparatus, image forming apparatus, and integrated circuit - Google Patents

Power supply apparatus, image forming apparatus, and integrated circuit Download PDF

Info

Publication number
US20140036546A1
US20140036546A1 US13/951,746 US201313951746A US2014036546A1 US 20140036546 A1 US20140036546 A1 US 20140036546A1 US 201313951746 A US201313951746 A US 201313951746A US 2014036546 A1 US2014036546 A1 US 2014036546A1
Authority
US
United States
Prior art keywords
signal
voltage
output
target voltage
piezoelectric transformer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/951,746
Other languages
English (en)
Inventor
Taro Minobe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Assigned to CANON KABUSHIKI KAISHA reassignment CANON KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MINOBE, TARO
Publication of US20140036546A1 publication Critical patent/US20140036546A1/en
Priority to US15/466,312 priority Critical patent/US10228649B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/80—Details relating to power supplies, circuits boards, electrical connections
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/40—Piezoelectric or electrostrictive devices with electrical input and electrical output, e.g. functioning as transformers

Definitions

  • the present invention relates to a power supply apparatus, an image forming apparatus, and an integrated circuit and, more particularly, to a high-voltage power supply using a piezoelectric transformer.
  • the image forming apparatus using the electrophotographic method includes a developing member that develops a latent image formed on an image bearing member using toner serving as a developing material, a charging member that uniformly charges the image bearing member, and a transfer member that transfers the toner image formed on the image bearing member to a recording material.
  • a high voltage is applied to the developing member, the charging member, and the transfer member, thereby performing image formation.
  • a power supply apparatus using a piezoelectric transformer made of a ceramic can generate a high voltage at an efficiency higher than an electromagnetic transformer and also increase the distance between the electrode on the primary side and that on the secondary side.
  • the image forming apparatus can be made compact and lightweight.
  • FIG. 5A is a schematic view of a conventional high-voltage power supply apparatus using a piezoelectric transformer. Note that the same reference numerals as in a high-voltage power supply apparatus to be described later in the embodiments denote the same parts, and a detailed description thereof will be made in the embodiments. Since a piezoelectric transformer 101 generally has a characteristic with tails extending so that the output voltage is maximized at a resonance frequency FO, as shown in FIG. 5B , voltage control using a frequency is possible. The graph of FIG. 5B plots the driving frequency (Hz) of the piezoelectric transformer 101 along the abscissa and the output voltage (V) along the ordinate.
  • Hz driving frequency
  • a frequency generation block 2015 first outputs a pulse signal of a frequency Fmax much higher than the resonance frequency FO. After that, the frequency of the piezoelectric transformer 101 is changed between the frequency Fmax and the resonance frequency FO, thereby controlling the output voltage. That is, the output voltage of the piezoelectric transformer 101 can be increased by changing the frequency from the higher side to the lower side.
  • a high voltage control unit 201 raises or lowers the frequency of the pulse signal of the frequency generation block 2015 , thereby controlling the voltage of an output terminal Vout to the target voltage.
  • the conventional digital control circuit arrangement has the following problem because the frequency generation block 2015 uses a general digital counter circuit (for example, Japanese Patent Application Laid-Open No. 2009-038892).
  • a control calculation block 2014 executes calculation using a predetermined formula based on a difference calculation result from a difference calculation block 2013 , and outputs the preset value to the frequency generation block 2015 that is a digital counter circuit at the subsequent stage.
  • the frequency generation block 2015 formed from the digital counter circuit generates a pulse signal in accordance with the input preset value. That is, the frequency generation block 2015 is configured to raise or lower the frequency of the pulse signal in accordance with the preset value. For this reason, when frequency control is performed for the piezoelectric transformer 101 that exhibits a nonlinear characteristic as shown in FIG.
  • the relationship between the preset value and the output voltage is represented by a nonlinear characteristic as shown in FIG. 5C . More specifically, when the piezoelectric transformer 101 is controlled near the resonance frequency FO, the output voltage exhibits a steep characteristic with respect to the frequency. Hence, the output voltage exhibits a steep characteristic with respect to the preset value. On the other hand, when the piezoelectric transformer 101 is controlled at a frequency much higher than the resonance frequency FO, the output voltage exhibits a moderate characteristic with respect to the frequency. Hence, the output voltage exhibits a moderate characteristic with respect to the preset value.
  • the frequency generation block 2015 formed from a digital counter circuit performs frequency control of the piezoelectric transformer 101 , the preset value (abscissa) and the output voltage (ordinate) have a nonlinear relationship, as shown in FIG. 5C .
  • the difference calculation result of the difference calculation block 2013 becomes small, and the amount of increase in the preset value of the control calculation block 2014 also becomes small.
  • the preset value is increased many times until the target voltage, resulting in a long rise time.
  • the rise time can be shortened by switching the control gain in accordance with the voltage of the output terminal Vout, like a high-voltage power supply apparatus described in, for example, Japanese Patent Application Laid-Open No. 2007-189880.
  • the system of an engine controller 501 becomes complex with this technique.
  • the high voltage control unit 201 the number of operations of sequentially storing the voltage of the output terminal Vout in an output voltage register 2022 of a memory unit 2011 and transmitting the information of the output voltage register 2022 to a CPU 301 increases.
  • the number of operations of determining the control gain based on the sequentially transmitted information of the output voltage register 2022 and storing the gain in the memory unit 2011 increases.
  • the system for controlling the high-voltage power supply apparatus becomes complex, resulting in, for example, increases in the development cost and the cost of the engine controller 501 .
  • the present invention enables to stably obtain the output of a power supply apparatus and shorten the rise time until the target voltage in a power supply apparatus using a piezoelectric transformer.
  • the present invention provides a power supply apparatus including a piezoelectric transformer, a signal generation unit configured to generate a signal to drive the piezoelectric transformer, a detection unit configured to detect an output voltage of the piezoelectric transformer, and a frequency determination unit configured to determine a frequency of the signal from the signal generation unit by a feed back control based on a feedback signal corresponding to the output voltage detected by the detection unit and a target voltage signal corresponding to a target voltage, wherein the frequency determination unit determines the frequency of the signal based on a gain of the feedback signal switched in correspondence with the target voltage signal.
  • the present invention also provides an image forming apparatus comprising an image forming unit, and a power supply configured to supply a high voltage to the image forming unit, wherein the power supply includes a piezoelectric transformer, a signal generation unit configured to generate a signal to drive the piezoelectric transformer, a detection unit configured to detect an output voltage of the piezoelectric transformer, and a frequency determination unit configured to determine a frequency of the signal from the signal generation unit by a feed back control based on a feedback signal corresponding to the output voltage detected by the detection unit and a target voltage signal corresponding to a target voltage, wherein the frequency determination unit determines the frequency of the signal based on a gain of the feedback signal switched in correspondence with the target voltage signal.
  • the power supply includes a piezoelectric transformer, a signal generation unit configured to generate a signal to drive the piezoelectric transformer, a detection unit configured to detect an output voltage of the piezoelectric transformer, and a frequency determination unit configured to determine a frequency of the signal from the signal generation unit by a
  • the present invention also provides an integrated circuit for controlling an operation of a power supply apparatus including a piezoelectric transformer, including a signal generation unit configured to generate a signal to drive the piezoelectric transformer, and a frequency determination unit configured to determine a frequency of the signal from the signal generation unit by a feed back control based on a feedback signal corresponding to an output voltage of the piezoelectric transformer and a target voltage signal corresponding to a target voltage, wherein the frequency determination unit determines the frequency of the signal based on a gain of the feedback signal switched in correspondence with the target voltage signal.
  • FIG. 1A is a view showing a section of an image forming apparatus according to the first and second embodiments.
  • FIG. 1B is a block diagram showing the constituent blocks of the image forming apparatus indicating an application example of a high-voltage power supply apparatus according to the first and second embodiments.
  • FIG. 2 is a block diagram showing the circuit arrangement of the high-voltage power supply apparatus according to the first embodiment.
  • FIG. 3A is a block diagram showing the arrangement of a frequency generator block according to the first embodiment.
  • FIG. 3B is a view showing a table used to set a control gain parameter group.
  • FIG. 4A is a block diagram showing a modification of the circuit arrangement of the high-voltage power supply apparatus according to the first embodiment.
  • FIG. 4B is a block diagram showing the circuit arrangement of the high-voltage power supply apparatus according to the second embodiment.
  • FIG. 5A is a block diagram showing the circuit arrangement of a conventional high-voltage power supply apparatus.
  • FIG. 5B is a graph showing the driving frequency vs. output voltage characteristic of a piezoelectric transformer.
  • FIG. 5C is a graph showing the relationship between a preset value and the output voltage.
  • FIG. 1A is a schematic sectional view of the color laser printer serving as the image forming apparatus according to this embodiment.
  • a laser beam printer 10 includes a pickup roller 12 that picks up a recording sheet 11 (recording medium) stored in a tray (not shown), and sheet feeding rollers 13 that convey the recording sheet 11 picked up by the pickup roller 12 .
  • a secondary transfer unit 26 and an intermediate transfer belt 24 are provided downstream of the sheet feeding rollers 13 in the conveyance direction of the recording sheet 11 .
  • the secondary transfer unit 26 transfers a toner image (developing material image) transferred to the intermediate transfer belt 24 to the recording sheet 11 fed by the sheet feeding rollers 13 so as to form a color image.
  • the toner image is formed by an image forming unit.
  • the image forming unit includes photosensitive drums 21 a to 21 d each serving as an image bearing member on which an electrostatic latent image is formed, and charging units 22 a to 22 d that uniformly charge the photosensitive drums 21 a to 21 d , respectively.
  • the image forming unit also includes developing units 23 a to 23 d that develop the electrostatic latent images formed on the photosensitive drums 21 a to 21 d by toners, and primary transfer units 25 a to 25 d that transfer the toner images developed on the photosensitive drums 21 a to 21 d to the intermediate transfer belt 24 .
  • suffixes a to d in the image forming unit represent, for example, yellow, magenta, cyan, and black, and will be omitted hereinafter except when necessary.
  • a fixing unit 27 that incorporates a heater and a pressure roller to thermally fix the toner images transferred to the recording sheet 11 is provided downstream in the conveyance direction of the recording sheet 11 .
  • the image forming apparatus including the power supply apparatus of this embodiment is not limited to the image forming apparatus having the above-described arrangement.
  • FIG. 1B is a block diagram showing the constituent blocks of a plurality of high-voltage power supply apparatuses provided in the laser beam printer 10 , and a charging unit 22 , a developing unit 23 , a primary transfer unit 25 , and the secondary transfer unit 26 that are loads to which high voltages are applied.
  • the loads shown in FIG. 1B correspond to the image forming apparatus having the arrangement shown in FIG. 1A .
  • the power supply apparatus according to this embodiment is applied to an image forming apparatus having another arrangement, the voltages are applied to loads corresponding to the image forming apparatus.
  • An engine controller 501 includes a CPU 301 , and high voltage control units 201 a to 201 d . To perform the respective processes of image formation, it is necessary to apply predetermined high voltages from the high-voltage power supply apparatus to the charging unit 22 , the developing unit 23 , the primary transfer unit 25 , and the secondary transfer unit 26 .
  • the high voltage control unit 201 a causes a voltage detection circuit 108 a (see FIG. 2 to be described later, and the same shall apply hereinafter) to detect a high voltage applied to the charging unit 22 , and controls a booster circuit 114 a to make the detected voltage equal to a target voltage set by the CPU 301 .
  • the high voltage control unit 201 b causes a voltage detection circuit 108 b to detect a high voltage applied to the developing unit 23 , and controls a booster circuit 114 b to make the detected voltage equal to a target voltage set by the CPU 301 .
  • the high voltage control unit 201 c causes a voltage detection circuit 108 c to detect a high voltage applied to the primary transfer unit 25 , and controls a booster circuit 114 c to make the detected voltage equal to a target voltage set by the CPU 301 .
  • the high voltage control unit 201 d causes a voltage detection circuit 108 d to detect a high voltage applied to the secondary transfer unit 26 , and controls a booster circuit 114 d to make the detected voltage equal to a target voltage set by the CPU 301 .
  • FIG. 2 is a block diagram showing the high-voltage power supply apparatus according to this embodiment.
  • the high-voltage power supply apparatus incudes a booster circuit 114 , a voltage detection circuit 108 (detection means), and the engine controller 501 .
  • the booster circuit 114 corresponds to the booster circuits 114 a to 114 d described with reference to FIG. 1B
  • the voltage detection circuit 108 corresponds to the voltage detection circuits 108 a to 108 d also described with reference to FIG. 1B .
  • the booster circuit 114 includes the piezoelectric transformer 101 , rectifier diodes 102 and 103 , a rectifier capacitor 104 , a field effect transistor 111 , a voltage resonance inductor 112 , and a voltage resonance capacitor 113 .
  • the field effect transistor 111 performs a switching operation based on a pulse signal supplied from a high voltage control unit 201 to be described later.
  • An LC resonance circuit formed from the inductor 112 and the capacitor 113 amplifies the pulse signal.
  • the piezoelectric transformer 101 vibrates in accordance with the pulse signal supplied to its primary-side terminal, and generates, at its secondary-side terminal, an AC voltage amplified at a boost ratio corresponding to the size of the piezoelectric transformer 101 .
  • a rectifying circuit is connected to the subsequent stage of the piezoelectric transformer 101 . That is, the secondary-side terminal of the piezoelectric transformer 101 is connected to the cathode terminal of the diode 102 and the anode terminal of the diode 103 .
  • One terminal of the capacitor 104 is connected to the cathode terminal of the diode 103 and also to an output terminal Vout.
  • the other terminal of the capacitor 104 is connected to the anode terminal of the diode 102 and also grounded.
  • the diodes 102 and 103 and the capacitor 104 form a rectifying circuit.
  • the AC voltage output from the secondary-side terminal of the piezoelectric transformer 101 is rectified and smoothed to a positive voltage by the rectifying circuit and supplied from the output terminal Vout to the load (not shown).
  • the voltage detection circuit 108 includes resistors 105 , 106 , and 107 .
  • the voltage of the output terminal Vout is divided by the voltage detection circuit 108 , and the divided voltage is input to an A/D converter 2012 of the high voltage control unit 201 to be described later.
  • the engine controller 501 includes the high voltage control unit 201 (control means), the CPU 301 , and a clock generation unit 401 .
  • the high voltage control unit 201 corresponds to the high voltage control units 201 a to 201 d described with reference to FIG. 1B , and performs constant voltage control of the voltage of the output terminal Vout.
  • the CPU 301 sets the target voltage in the high voltage control unit 201 .
  • the clock generation unit 401 supplies a clock to the high voltage control unit 201 and the CPU 301 .
  • the high voltage control unit 201 includes a memory unit 2011 (memory means) that is a volatile memory, the A/D converter 2012 , a difference calculation block 2013 , a control calculation block 2014 , and a frequency generation block 2015 using a digital counter circuit.
  • the memory unit 2011 includes a target value setting block 2021 , an output voltage register 2022 , and a gain setting register 2023 .
  • the high-voltage power supply apparatus according to this embodiment is different from the conventional high-voltage power supply apparatus shown in FIG. 5A in that the memory unit 2011 includes the gain setting register 2023 .
  • the output of the output terminal Vout input to the A/D converter 2012 is digitally converted and stored in the output voltage register 2022 of the memory unit 2011 .
  • the target voltage is stored from the CPU 301 in the target value setting block 2021 and the gain setting register 2023 of the memory unit 2011 .
  • the difference calculation block 2013 calculates the difference between the values stored in the output voltage register 2022 and the target value setting block 2021 , and outputs it to the control calculation block 2014 .
  • the control calculation block 2014 performs proportional-integral-derivative(PID) control based on the difference calculation result of the difference calculation block 2013 , calculates a preset value that is a value to determine the frequency of the pulse signal to be generated by the frequency generation block 2015 , and outputs the preset value to the frequency generation block 2015 .
  • PID proportional-integral-derivative
  • the frequency generation block 2015 includes an N-bit programmable counter 20151 , a 1-bit counter 20153 , and an AND gate 20154 .
  • the clock generation unit 401 supplies an input pulse (for example, a clock of several MHz) to the N-bit programmable counter 20151 (to be referred to as the N-bit counter 20151 hereinafter).
  • the N-bit counter 20151 increments the count value by one every time the input pulse goes high (to be referred to as H hereinafter), thereby performing count.
  • H the number of bits
  • the output of the N-bit counter 20151 is inverted, and the above-described count value is cleared to zero (0).
  • the output of the N-bit counter 20151 is output to the 1-bit counter 20153 to be described later.
  • L low-level (to be referred to as L hereinafter) signal serving as a reset signal
  • the N-bit counter 20151 is reset, and the count value becomes zero (0).
  • the reset signal to be input to the N-bit counter 20151 is supplied from the CPU 301 .
  • the 1-bit counter 20153 inverts the output voltage every time the output signal from the N-bit counter 20151 changes to the H signal; it generates a pulse signal of a frequency corresponding to the information of the preset value input via the N-bit counter 20151 .
  • the 1-bit counter 20153 is reset when a reset signal is input to the reset terminal RESET.
  • the reset signal to be input to the 1-bit counter 20153 is supplied from the CPU 301 .
  • the inversion period of the signal output from the N-bit counter 20151 shortens. Hence, the frequency of the pulse signal output from the frequency generation block 2015 rises.
  • the preset value input from the control calculation block 2014 becomes large, the inversion period of the signal output from the N-bit counter 20151 lengthens. Hence, the frequency of the pulse signal output from the frequency generation block 2015 lowers.
  • the AND gate 20154 on/off-controls the output of the high-voltage power supply apparatus in accordance with an ENABLE signal output from the CPU 301 . More specifically, when the ENABLE signal is an L output, the AND gate 20154 outputs a pulse signal corresponding to the output of the 1-bit counter 20153 . On the other hand, when the ENABLE signal is an H output, the output of the AND gate 20154 is forcibly changed to an L signal, and the AND gate 20154 outputs the L signal. Hence, since the pulse signal output from the high voltage control unit 201 can be on/off-controlled in accordance with the ENABLE signal output from the CPU 301 , the output of the high-voltage power supply apparatus can be on/off-controlled.
  • the limit values Fmax and FO are provided for the preset value of the control calculation block 2014 . That is, when the preset value has reached the limit value Fmax or FO, the calculation operation of PID control of the control calculation block 2014 is stopped (the calculation result is held). At this time, the limit values Fmax and FO can be stored in the memory unit 2011 , set by the CPU 301 , or fixed.
  • FIG. 3B is a view showing a table 800 used to set the control gain in accordance with the setting voltage value according to this embodiment.
  • the table 800 is an example of a lookup table that defines the correspondence between the setting voltage value (Tgt[V]) of the high-voltage power supply apparatus and the control gain parameter group (to be also referred to as a gain or control gain hereinafter) of the control calculation block 2014 .
  • the table 800 that associates the high-voltage power supply apparatus and the gain is stored in advance in the ROM included in the CPU 301 .
  • control gain parameter group in the table 800 includes the parameters of the gains of the proportional (P term), integral (I term), and derivative (D term) of PID control as an example of feedback control. That is, the control gain parameter group includes the set values of control parameters for performing PID control, which are optimized for each setting voltage value in view of elements of the time delay in the high-voltage power supply circuit and the A/D converter 2012 of the high voltage control unit 201 .
  • the table 800 may define a relation defining the correspondence between the setting voltage value of the high-voltage power supply apparatus and the control gain parameter group of the control calculation block 2014 .
  • the frequency generation block 2015 drives the piezoelectric transformer 101 in a region where the output voltage with respect to the frequency is moderate (see FIG. 5B ).
  • the output voltage exhibits a moderate characteristic (see FIG. 5C ) with respect to the preset value of the control calculation block 2014 .
  • the CPU 301 increases the gain of PID control of the control calculation block 2014 and largely changes the preset value of the control calculation block 2014 , thereby largely changing the frequency of the pulse signal. That is, the CPU 301 sets the setting voltage value and the control gain parameter group (in FIG. 3B , a parameter group corresponding to G 1 ) corresponding to the setting voltage value in each of the target value setting block 2021 and the gain setting register 2023 of the memory unit 2011 .
  • G 1 is a gain group optimized to obtain a low target voltage lower than, for example, 1,000 V (Tgt ⁇ 1000).
  • the PID control of the control calculation block 2014 can largely change the preset value of the control calculation block 2014 by changing the gains used in the proportional (P term), integral (I term), and derivative (D term). As a result, even when the piezoelectric transformer 101 is driven in the region where the output voltage is moderate with respect to the frequency, the preset value can largely be changed. It is therefore possible to quickly output the target voltage.
  • the frequency generation block 2015 drives the piezoelectric transformer 101 in a region where the output voltage is steep with respect to the frequency (see FIG. 5B ). Hence, the output voltage exhibits a steep characteristic (see FIG. 5C ) with respect to the preset value of the control calculation block 2014 .
  • the CPU 301 changes the gain of PID control of the control calculation block 2014 and finely changes the preset value of the control calculation block 2014 , thereby finely changing the frequency of the pulse signal. That is, the CPU 301 sets the setting voltage value and the control gain parameter group (in FIG. 3B , a parameter group corresponding to G 5 ) corresponding to the setting voltage value in each of the target value setting block 2021 and the gain setting register 2023 of the memory unit 2011 .
  • the PID control of the control calculation block 2014 can change the preset value of the control calculation block 2014 to be finer than terms in G 1 by changing the gains used in the proportional (P term), integral (I term), and derivative (D term). As a result, even when the piezoelectric transformer 101 is driven in the region where the output voltage is steep with respect to the frequency, calculation can be done using the conventional PID control gain. This makes it possible to output the target voltage in a time equal to the conventional rise time and also output a stable voltage without overshoot.
  • the gain of PID control is switched in accordance with the setting voltage value. This allows the high-voltage power supply apparatus using the piezoelectric transformer to quickly output the target voltage even when outputting a low voltage.
  • the voltage of the output terminal Vout is divided by the voltage detection circuit 108 , and the divided voltage is input to the A/D converter 2012 of the high voltage control unit 201 .
  • the difference calculation block 2013 may be formed as an analog circuit, as indicated by 125 in FIG. 4A . That is, reference numeral 125 denotes a differential amplification circuit including an operational amplifier 120 and resistors 121 , 122 , 123 , and 124 , which will be referred to as the differential amplification circuit 125 (output means) hereinafter.
  • the voltage of the output terminal Vout is divided by the voltage detection circuit 108 , and the divided voltage is input to the inverting input terminal ( ⁇ terminal) of the operational amplifier 120 via the resistor 121 .
  • the setting voltage value (target voltage value) set in the target value setting block 2021 by the CPU 301 is output to a D/A converter 2016 .
  • the setting voltage value output from the D/A converter 2016 is input to the noninverting input terminal (+terminal) of the operational amplifier 120 via the resistor 123 .
  • the operational amplifier 120 outputs the signal such that the inverting input terminal and the noninverting input terminal form a virtual short.
  • the output of the operational amplifier 120 is input to the control calculation block 2014 via the A/D converter 2012 .
  • the differential amplification circuit 125 can output the difference between the setting voltage value and the voltage of the output terminal Vout, like the difference calculation block 2013 .
  • the control calculation block 2014 outputs the preset value based on a value obtained by causing the A/D converter 2012 to digitally convert the difference output from the differential amplification circuit 125 .
  • the same reference numerals as in FIG. 2 denote the same parts in FIG. 4A , and a description thereof will be omitted.
  • the table 800 is stored in advance in the ROM included in the CPU 301 , and the CPU 301 sets the control gain parameter group in the gain setting register 2023 of the memory unit 2011 .
  • the second embodiment is different in that a table 800 (see FIG. 3B ), which is stored in the CPU 301 in the first embodiment, is stored in a memory unit 2011 of a high voltage control unit 201 .
  • a description of the same parts as in the first embodiment will be omitted, and the arrangement that stores the table 800 in the memory unit 2011 of the high voltage control unit 201 and its operation will be described in detail.
  • FIG. 4B is a block diagram showing a high-voltage power supply apparatus according to this embodiment.
  • a gain setting table 2017 stores the table 800 of the first embodiment.
  • the gain setting table 2017 is an example of a lookup table that defines the correspondence between the setting voltage value (target voltage value) and the PID control gain parameters of a control calculation block 2014 .
  • the PID control gain parameter group in the table 800 is optimized for each setting voltage value, as in the first embodiment.
  • the table 800 may define a relation defining the correspondence between the setting voltage value of the high-voltage power supply apparatus and the control gain parameter group of the control calculation block 2014 , as in the first embodiment.
  • the control calculation block 2014 can perform PID control calculation using the control gain parameter group corresponding to the setting voltage value from the gain setting table 2017 .
  • switching the control gain in accordance with the setting voltage value makes it possible to stably obtain the output of the high-voltage power supply apparatus and quickly output the target voltage even when outputting a low voltage.
  • the CPU 301 sets only the target voltage in the memory unit 2011 of the high voltage control unit 201 . For this reason, the number of registers in the high voltage control unit 201 can be decreased. In addition, control can be done without intervening the CPU 301 .
  • the difference calculation block 2013 may be changed to a differential amplification circuit 125 formed from an analog circuit, as in the first embodiment.
  • the present invention is not restricted by this relationship term.
  • the impedance variation of the member to which the high voltage power supply supplies a high voltage can be considered as the values G 1 , G 2 , G 3 , G 4 , and G 5 in the table 800 . That is, since the relationship between the frequency and the output voltage shown in FIG.
  • the output value of the high voltage power supply can be stably obtained by detecting the impedance of the member, considering the characteristic variation between the frequency and the output voltage and optimizing the values G 1 , G 2 , G 3 , G 4 , and G 5 in the control gain parameter group in the table 800 .
  • PID control has been exemplified as the feedback control of the control calculation block 2014 .
  • feedback control of any other form is usable if the gain of the feedback control can be changed.
  • the high voltage control unit 201 described in the first and second embodiments may be formed as an integrated circuit.
  • the high voltage control unit 201 can be formed as, for example, an ASIC (Application Specific Integrated Circuit).
  • the integrated circuit can reduce the circuit scale of the power supply apparatus, leading to size reduction of the circuit board of the power supply apparatus.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dc-Dc Converters (AREA)
  • Control Or Security For Electrophotography (AREA)
US13/951,746 2012-08-01 2013-07-26 Power supply apparatus, image forming apparatus, and integrated circuit Abandoned US20140036546A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US15/466,312 US10228649B2 (en) 2012-08-01 2017-03-22 Power supply apparatus, image forming apparatus, and integrated circuit

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2012171146 2012-08-01
JP2012-171146 2012-08-01
JP2013126546A JP6433114B2 (ja) 2012-08-01 2013-06-17 電源装置、画像形成装置及びｉｃ
JP2013-126546 2013-06-17

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US15/466,312 Continuation US10228649B2 (en) 2012-08-01 2017-03-22 Power supply apparatus, image forming apparatus, and integrated circuit

Publications (1)

Publication Number Publication Date
US20140036546A1 true US20140036546A1 (en) 2014-02-06

Family

ID=48906130

Family Applications (2)

Application Number Title Priority Date Filing Date
US13/951,746 Abandoned US20140036546A1 (en) 2012-08-01 2013-07-26 Power supply apparatus, image forming apparatus, and integrated circuit
US15/466,312 Active US10228649B2 (en) 2012-08-01 2017-03-22 Power supply apparatus, image forming apparatus, and integrated circuit

Family Applications After (1)

Application Number Title Priority Date Filing Date
US15/466,312 Active US10228649B2 (en) 2012-08-01 2017-03-22 Power supply apparatus, image forming apparatus, and integrated circuit

Country Status (4)

Country Link
US (2) US20140036546A1 (ja)
EP (1) EP2693621B1 (ja)
JP (1) JP6433114B2 (ja)
KR (2) KR102010595B1 (ja)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180145242A1 (en) * 2015-07-28 2018-05-24 Murata Manufacturing Co., Ltd. Power supply circuit and ac adaptor
US10671009B2 (en) 2017-02-13 2020-06-02 Canon Kabushiki Kaisha Printed circuit board mounting piezoelectric transformer
US11195985B2 (en) * 2016-06-14 2021-12-07 Koninklijke Philips N.V. Electroactive polymer actuator device and driving method

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20160026600A (ko) 2014-09-01 2016-03-09 주식회사 솔루엠 전원 공급 장치 및 방법
US10250252B2 (en) * 2016-11-03 2019-04-02 Semiconductor Components Industries, Llc Control circuit and method therefor
CN109856961B (zh) * 2019-03-11 2022-02-11 深圳市安健科技股份有限公司 一种球管电压控制方法、装置及计算机可读存储介质

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110097100A1 (en) * 2009-10-27 2011-04-28 Canon Kabushiki Kaisha Technology for reducing circuit oscillations and ripple in a high-voltage power supply using a piezoelectric transformer
US20110188878A1 (en) * 2010-02-04 2011-08-04 Canon Kabushiki Kaisha Power supply apparatus and image forming apparatus

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007189880A (ja) * 2006-01-16 2007-07-26 Canon Inc 高圧電源装置及びこれを備えた画像形成装置
JP4848853B2 (ja) * 2006-06-16 2011-12-28 セイコーエプソン株式会社 圧電アクチュエータの駆動方法、圧電アクチュエータの駆動装置、電子機器
JP5207643B2 (ja) 2007-03-08 2013-06-12 キヤノン株式会社 画像形成装置、電圧電源装置、それらの制御方法
JP5559456B2 (ja) * 2007-08-01 2014-07-23 三星電子株式会社 圧電トランス方式高圧電源装置および画像形成装置
US7973520B2 (en) 2007-08-01 2011-07-05 Samsung Electronics Co., Ltd. Piezoelectric transformer type high-voltage power apparatus and image forming apparatus
US8040018B2 (en) * 2007-08-01 2011-10-18 Samsung Electronics Co., Ltd. Piezoelectric transformer type high-voltage power apparatus and image forming apparatus
JP2009128416A (ja) * 2007-11-20 2009-06-11 Canon Inc 画像形成装置及びその制御方法
KR100966873B1 (ko) * 2008-05-26 2010-06-29 (주)아이엠 압전 변압기를 이용한 고전압 발생 장치
JP5322536B2 (ja) 2008-08-27 2013-10-23 キヤノン株式会社 電源装置、画像形成装置、及び電源装置の制御方法
US8265511B2 (en) 2008-10-29 2012-09-11 Oki Data Corporation Power source device and image forming apparatus
JP2010124601A (ja) 2008-11-19 2010-06-03 Canon Inc 高圧電源装置
JP4902693B2 (ja) 2009-05-28 2012-03-21 株式会社沖データ 圧電トランス駆動装置及び画像形成装置
JP5394164B2 (ja) 2009-08-18 2014-01-22 株式会社沖データ 電源装置及び画像形成装置
JP4902708B2 (ja) 2009-08-27 2012-03-21 株式会社沖データ 電源装置及び画像形成装置
JP5735758B2 (ja) * 2010-05-25 2015-06-17 キヤノン株式会社 電圧トランス式高圧電源装置、高圧電源装置、及び画像形成装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110097100A1 (en) * 2009-10-27 2011-04-28 Canon Kabushiki Kaisha Technology for reducing circuit oscillations and ripple in a high-voltage power supply using a piezoelectric transformer
US20110188878A1 (en) * 2010-02-04 2011-08-04 Canon Kabushiki Kaisha Power supply apparatus and image forming apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180145242A1 (en) * 2015-07-28 2018-05-24 Murata Manufacturing Co., Ltd. Power supply circuit and ac adaptor
US11195985B2 (en) * 2016-06-14 2021-12-07 Koninklijke Philips N.V. Electroactive polymer actuator device and driving method
US10671009B2 (en) 2017-02-13 2020-06-02 Canon Kabushiki Kaisha Printed circuit board mounting piezoelectric transformer
US11307525B2 (en) 2017-02-13 2022-04-19 Canon Kabushiki Kaisha Printed circuit board mounting piezoelectric transformer

Also Published As

Publication number Publication date
US20170194876A1 (en) 2017-07-06
EP2693621A2 (en) 2014-02-05
EP2693621A3 (en) 2017-07-12
JP2014045645A (ja) 2014-03-13
KR102010595B1 (ko) 2019-08-13
KR20140017450A (ko) 2014-02-11
EP2693621B1 (en) 2019-11-06
KR20170015860A (ko) 2017-02-09
US10228649B2 (en) 2019-03-12
JP6433114B2 (ja) 2018-12-05
KR101908217B1 (ko) 2018-10-15

Similar Documents

Publication Publication Date Title
US10228649B2 (en) Power supply apparatus, image forming apparatus, and integrated circuit
US7265479B2 (en) Power supply apparatus, and image forming apparatus having the same
JP5247908B2 (ja) 電源、制御回路、画像形成装置の電源
US8750744B2 (en) Technology for reducing circuit oscillations and ripple in a high-voltage power supply using a piezoelectric transformer
US9904232B2 (en) Power supply apparatus and image forming apparatus
JP2006340588A (ja) 電源装置、画像形成装置
US8213823B2 (en) High-voltage power supply device and image forming apparatus including the same
US10564588B2 (en) High-voltage power supply apparatus and image forming apparatus
JP2008224778A (ja) 画像形成装置、電圧電源装置及びそれらの方法
US8983329B2 (en) Piezoelectric transformer type high-voltage power supply device and image forming apparatus
US8513834B2 (en) Power supply apparatus and image forming apparatus
US9235184B2 (en) High-voltage power supply apparatus and image forming apparatus
JP2008299292A (ja) 電圧電源装置及び画像形成装置
JP2010158149A (ja) 電源装置及び画像形成装置
US10547242B2 (en) Power supply apparatus and image forming apparatus
JP4981323B2 (ja) 画像形成装置の電源
JP5188022B2 (ja) 画像形成装置
JP2006201351A (ja) 画像形成装置
JP2024031576A (ja) 高圧電源装置及び画像形成装置
JP2021056360A (ja) 画像形成装置
JP2008301691A (ja) 画像形成装置及びその電源装置
JP2013219894A (ja) 電源装置及び画像形成装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: CANON KABUSHIKI KAISHA, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MINOBE, TARO;REEL/FRAME:031691/0420

Effective date: 20130722

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION