WO2005008873A1 - 電流検出回路 - Google Patents
電流検出回路 Download PDFInfo
- Publication number
- WO2005008873A1 WO2005008873A1 PCT/JP2004/007476 JP2004007476W WO2005008873A1 WO 2005008873 A1 WO2005008873 A1 WO 2005008873A1 JP 2004007476 W JP2004007476 W JP 2004007476W WO 2005008873 A1 WO2005008873 A1 WO 2005008873A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- circuit
- current
- capacitor
- switch element
- voltage
- Prior art date
Links
Classifications
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
- H02M1/4225—Arrangements for improving power factor of AC input using a non-isolated boost converter
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0009—Devices or circuits for detecting current in a converter
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Definitions
- the present invention relates to a current detection circuit that detects a current flowing through a switch element.
- a circuit for turning on and off a switch element to control a current value flowing through the switch element for example, there is a step-up chopper circuit using an active filter as shown in FIG. As shown in Fig. 7, there is a half-bridge type HID lighting circuit. In this type of circuit, it is necessary to detect the current flowing through the switch element, and to control the switching element to be turned on and off based on the detected current value, and how to detect the current flowing through the switch element. It becomes a problem.
- a DC power supply 84 is composed of an AC power supply 81 and a full-wave rectifier circuit 82, and a yoke coil 85 and a switch are connected between output terminals of the DC power supply 84.
- An element (semiconductor switch) 86 is connected in series, and a series circuit of a diode 87 and a capacitor 88 is connected in parallel to both ends of the switch element 86.
- the electromagnetic energy is applied to the choke coil 85 by the on / off operation of the switch element 86. And discharges the energy to the capacitor 88 via the diode 87.
- the switch control circuit 89 detects a current flowing through the switch element 86 by a resistor (for example, 1 ⁇ ) 90, outputs an ON signal S that becomes a high voltage (H) to the switch element 86, and outputs the ON signal S
- the switch element 86 is turned on while S is output (the output signal becomes high voltage (H)), and the switch element 86 is turned off by stopping the on signal S (the output signal becomes low voltage (L)). Is turned off.
- the switch control circuit 89 starts to output the ON signal S (turns on the switch element 86), and the switch element 86 detects the switch element 86 via the resistor 90.
- the flowing current is the peak current of the desired choke coil 85.
- the on-signal S is stopped (switch element 86 is turned off), thereby controlling switch element 86 on and off at a high frequency to obtain a stable DC voltage on capacitor 88 side. It has become.
- a series circuit of a pair of switch elements 92 and 93 is connected between the output terminals of a DC power supply 91 and a series circuit of a pair of capacitors 94 and 95 is connected.
- a circuit is connected, and a choke finole 97, a HID lamp 98, a choke finole 99, and a capacitor 100 are connected between a pair of switch elements 92 and 93 and between a pair of capacitors 94 and 95.
- a resistor (for example, 1 ⁇ ) 103 is connected between the capacitor 100 and the pair of capacitors 94 and 95, and the current flowing through the pair of switch elements 92 and 93 is detected by the resistor 103, and based on the detected current,
- the HID lamp 98 is turned on by alternately repeating the on / off operation of the pair of switch elements 92 and 93 by the switch control circuit 104.
- the current flowing through the switch element 86 is detected by the resistor 90 connected in series with the switch element 86, and the current flowing through the switch element 86 is detected by the resistor 90. Because of the presence of an inductance component, there is a problem that spike-like noise is generated, which may cause erroneous detection, and that power loss occurs.
- the current flowing through the switch element 86 is a voltage V generated across the resistor 90 and the resistance value of the resistor 90 is R
- the current flowing through the pair of switch elements 92 and 93 is detected by the resistor 103, and in addition to having the same problems as the circuit of FIG. It is necessary to provide a current detection circuit 105 having a comparison circuit 106 and the like. Further, in order to transmit a current detection signal to the switch control circuit 104, a photocoupler 108 is connected between the current detection circuit 105 and the switch control circuit 104. It was necessary to insulate using such as.
- FIG. 11 As another method for detecting the current flowing through the switch element, as shown in FIG. It is conceivable that a current transformer 111 having a winding 11 la and a secondary winding 11 lb is provided, and current is detected at both ends of a resistor 112 provided on the secondary winding 11 lb of the current transformer 111. In this case, by making the number of turns of the secondary winding 11 lb larger than the number of turns of the primary winding 11 la, the current can be detected in a form in which a low current is insulated with a high voltage and a low power loss. However, there is a problem that the DC component cannot be detected.
- the present invention has been made in view of the above problems, and provides a current detection circuit capable of detecting a current flowing through a switch element with high accuracy at a high voltage with little power loss and in an insulated form.
- the purpose is to:
- Patent Document 1 JP-A-7-231650
- the present invention has taken the following technical measures to achieve the above object.
- a charging circuit that charges the capacitor with a current proportional to the voltage generated in the choke coil is provided.
- a discharging circuit for changing the voltage of the capacitor to OV is provided, and the voltage of the capacitor is detected as a value proportional to the current flowing through the switch element.
- a choke coil and a switch element are connected in series between output terminals of a DC power supply, and a series circuit of a diode and a capacitor is provided at both ends of the switch element.
- a circuit that is connected in parallel and stores electromagnetic energy in the choke coil by the on / off operation of the switch element and discharges the energy to the capacitor through the diode to obtain a DC voltage, the voltage generated in the choke coil
- a charging circuit that charges the capacitor with a current proportional to the current; a discharging circuit that sets the voltage of the capacitor to OV when the current flowing through the switch element is 0; The point is that the voltage of the capacitor is detected as a value proportional to the current flowing through the switch element.
- a series circuit of a pair of switch elements is connected between output terminals of a DC power supply, and a series circuit of a pair of capacitors is connected.
- a half-bridge type in which a choke coil and an HID lamp are connected between the switch elements and between the pair of capacitors, and the HID lamps are turned on at a high frequency by alternately turning on and off the pair of switch elements.
- a charging circuit is provided to charge the capacitor with a current proportional to the voltage generated in the choke coil, and a discharging circuit that sets the voltage of the capacitor to 0 V when both of the switch elements are turned off. And that the voltage of the capacitor is detected as a value proportional to the current flowing through the switch element.
- FIG. 1 is a circuit diagram showing an embodiment of the present invention.
- FIG. 2 is a waveform diagram for explaining the operation.
- FIG. 3 is a circuit diagram showing another embodiment.
- FIG. 4 is a waveform diagram for explaining the operation.
- FIG. 5 is another waveform diagram for explaining the operation.
- FIG. 6 is a circuit diagram showing a conventional example.
- FIG. 7 is a circuit diagram showing another conventional example.
- FIG. 8 is a circuit diagram showing another conventional example.
- FIG. 9 is a circuit diagram showing another conventional example.
- FIG. 1 shows an embodiment in which the present invention is applied to a step-up chopper circuit using an active filter.
- 1 is a commercial AC power supply
- 2 is a full-wave rectifier circuit for full-wave rectification of the AC power supply 1, and is configured by a diode bridge.
- the AC power supply 1 and the full-wave rectifier circuit 2 constitute a DC power supply 4.
- 5 is a choke coil
- 6 is a switch element (semiconductor switch), for example, a metal oxide film It consists of a field effect transistor (MOSFET).
- the choke coil 5 and the switch element 6 are connected in series between output terminals of the DC power supply 4.
- a series circuit of a diode 7 and a capacitor 8 is connected in parallel to both ends of the switch element 6.
- An active filter is formed by the DC power supply 4, the choke coil 5, the switch element 6, the diode 7, and the capacitor 8, and the switch element 6 is turned on and off at a high frequency, so that electromagnetic energy is stored in the yoke coil 5.
- the energy is released to the capacitor 8 via the diode 7, whereby the AC power supply 1 is stored in the capacitor 8 by the full-wave rectifier circuit 2 at a voltage higher than the voltage obtained by full-wave rectification.
- a discharge lamp lighting device for lighting the discharge lamp 12 at high frequency is configured.
- the choke coil 5 is provided with a secondary winding 5b.
- the switch control circuit 15 outputs an ON signal S that becomes a high voltage (H) to the switch element 6, and outputs an ON signal S (while the output signal becomes a high voltage (H)). In addition to turning on the switch 6, the switch element 6 is turned off by stopping the ON signal S (the output signal becomes low voltage (L)).
- the switch control circuit 15 has a comparison circuit 19 and the like.As shown in FIG. 2, when the current I of the choke coil 5 becomes 0, the switch control circuit 15 starts outputting an ON signal S (turns on the switch element 6). ), The current I flowing through the switch element 6 detected via the charging circuit 17 is compared with a reference voltage V having a sine wave shape at a predetermined frequency, and the current I flowing through the switch element 6 is determined by the reference voltage V
- the on-signal S is stopped (switch element 6 is turned off), whereby the switch element 6 is controlled on and off at a high frequency so that a stable DC voltage is obtained on the capacitor 8 side.
- FIG. 2A shows a current waveform of the current I flowing through the switch element 6, and FIG. 2B shows a gate voltage waveform of the switch element 6, and FIG. ) Is the switch element 6
- the charging circuit 18 includes a capacitor 16 and a pair of switch elements (transistors) 21 and 22 forming a mirror circuit, and another pair of switch elements (transistors) 23 and 24 forming a mirror circuit, a DC power supply 25 and a resistor 26, 27 with
- the discharge circuit 18 includes a transistor 28 and a NOT circuit 29, and is configured such that when the switch control circuit 15 stops the ON signal S, the transistor 28 turns on and discharges the capacitor 16. .
- the pair of switch elements 21 and 22 of the charging circuit 17 are mirror circuits, the current I flowing through the switch element 21 and the current I flowing through the switch element 22 are equal.
- the current I flowing through the switch element 21 is the same as the current flowing through the secondary winding 5b of the choke coil 5, and is proportional to the current I flowing through the choke coil 5 and the switch element 6.
- the current I flowing through the capacitor 16 is the current I flowing through the choke coil 5 and the switch element 6.
- the person in charge is as follows.
- V J (l X C) dt / C
- V Ldi / dt
- V dt Ldi
- the voltage V of the capacitor 16 has a value proportional to the current I flowing through the switch element 6.
- the transistor 28 is turned on until the switch element 6 is turned on, the voltage V of the capacitor 16 is set to 0V, and when the switch element 6 is turned on, c
- the current I flowing through the choke coil 5 is a value obtained by adding a constant to the value obtained by integrating the choke voltage, but when the current I starts flowing through the choke coil 5, the integrated value is cleared to 0.
- the constant becomes 0 and the voltage of the capacitor 16
- V can be used as the value of the current I flowing through the switch element 6. Also, Chiyo c
- the integral value can be reset each time the current starts flowing through the work coil 5, so that errors do not accumulate.
- the current I flowing through the switch element 6 can be detected with high accuracy, at a high voltage with little power loss, and in an insulated form via the secondary winding 5b of the choke coil 5.
- FIG. 3 shows another embodiment in which the present invention is applied to a half-bridge HID lighting circuit.
- reference numeral 41 denotes a DC power supply.
- a series circuit of a pair of switch elements 42 and 43 and a series circuit of a pair of capacitors 44 and 45 are connected between output terminals of the DC power supply 41.
- a choke pin 47, a tilD lamp 48, a choke pin 49, a capacitor 50, and a force S are connected between a pair of switch elements 42, 43 and a pair of capacitors 44, 45.
- the HID lamp is an abbreviation for high intensity discharge lamp, and is a general term for high pressure mercury lamps, metal halide lamps, and high pressure sodium lamps. HID lamps, also called high-intensity discharge lamps, are characterized by their small size, high output, high efficiency and long life.
- the switch control circuit 55 outputs the high-voltage (H) ON signals SI and S2 to the switch elements 42 and 43 and outputs the ON signal S1 (the output signal to the switch element 42 becomes the high voltage (H)).
- Switch element 42 is turned on during this time, and the on signal S1 is stopped (the output signal to the switch element 42 becomes low voltage (L)), so that the switch element 42 is turned off, and the on signal S2 is turned off.
- the switch element 43 is turned on and the ON signal S2 is stopped (the output signal to the switch element 43 becomes low voltage (L)). That is, the switch element 43 is turned off.
- the ON signal S1 or the ON signal S2 is stopped (the switch element 42 or the switch element 43 is turned off).
- FIG. 5A shows the current waveform of the current I flowing through the switch element 42 (or the switch element 43)
- FIG. 5B shows the current waveform of the switch element 42 (or the switch element 43).
- I in FIG. 5 (a) indicates the current I flowing through the switch element 42 (or the switch element 43).
- the current I is the current input from the DC power supply 41 to the HID lamp 48.
- the pump current The pump current.
- the switch control circuit 55 controls so that the period A for outputting the ON signal S1 and the period B for outputting the ON signal S2 are alternately repeated, thereby turning on and off the switch element 42.
- the operation and the on / off operation of the switch element 43 are alternately repeated to apply the AC lamp voltage Via to the HID lamp 48 and the AC lamp current Ila as shown in FIGS. 4 (c) and 4 (d).
- the HID lamp 48 is stably turned on.
- FIG. 4 ( a ) shows the voltage waveform of the switch element 42
- FIG. 4 (b) shows the voltage waveform of the switch element 43
- FIG. 4 (c) shows the HID lamp 48.
- the waveform of the lamp voltage Via is shown
- FIG. 4D shows the waveform of the lamp voltage Ila of the HID lamp 48.
- the charging circuit 57 includes a capacitor 56, a pair of switch elements (transistors) 61 and 62 forming a mirror circuit, a pair of switch elements 63 and 64 forming another mirror circuit, a DC power supply 65, and a resistor 66. I have. Both ends of the secondary winding 42b are connected via diodes 71 and 72, respectively.
- the resistor 66 of the charging circuit 57 is connected.
- the discharge circuit 58 includes a transistor 68, a NOT circuit 69, and an OR circuit 70, and when the ON signals Sl and S2 from the switch control circuit 55 are both stopped (the switch elements 42 and 43 are both OFF). Then, the transistor 68 is turned on to discharge the capacitor 56.
- the current I flowing through the switch elements 42 and 43 is converted to a high voltage with a high accuracy and a small power loss via the secondary winding 5b of the choke coil 47 and the like. And it can be detected in an insulated form.
- the present invention can be used as a current detection circuit for detecting a current flowing through a switch element.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Circuit Arrangements For Discharge Lamps (AREA)
- Rectifiers (AREA)
- Inverter Devices (AREA)
- Measurement Of Current Or Voltage (AREA)
- Dc-Dc Converters (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/558,304 US7425799B2 (en) | 2003-06-13 | 2004-05-31 | Current detecting circuit |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003169719A JP4280116B2 (ja) | 2003-06-13 | 2003-06-13 | 電流検出回路 |
JP2003-169719 | 2003-06-13 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005008873A1 true WO2005008873A1 (ja) | 2005-01-27 |
Family
ID=34074235
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2004/007476 WO2005008873A1 (ja) | 2003-06-13 | 2004-05-31 | 電流検出回路 |
Country Status (3)
Country | Link |
---|---|
US (1) | US7425799B2 (ja) |
JP (1) | JP4280116B2 (ja) |
WO (1) | WO2005008873A1 (ja) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100134028A1 (en) * | 2005-02-25 | 2010-06-03 | Koninklijke Philips Electronics, N.V. | Light source |
DE102008004399A1 (de) * | 2008-01-14 | 2009-07-16 | HÜCO electronic GmbH | Elektronisches Vorschaltgerät mit Strommesseinrichtung, Verfahren zu seiner Steuerung und Beleuchtungsgerät |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10125484A (ja) * | 1996-10-16 | 1998-05-15 | Matsushita Electric Works Ltd | 放電灯点灯装置 |
JP2000184702A (ja) * | 1998-12-18 | 2000-06-30 | Toko Inc | 電源装置 |
JP2003125582A (ja) * | 2001-10-15 | 2003-04-25 | Sanken Electric Co Ltd | 電源装置 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR960010713B1 (ko) * | 1993-08-17 | 1996-08-07 | 삼성전자 주식회사 | 공진형 컨버터의 영전압 스위칭 제어장치 및 이를 이용한 전자식 안정기 |
JPH07231650A (ja) | 1994-02-21 | 1995-08-29 | Ikeda Electric Co Ltd | 昇圧チョッパー回路 |
US5572735A (en) * | 1994-05-27 | 1996-11-05 | Ast Research, Inc. | Method and apparatus for discharging the output voltage of a DC power supply |
US5689155A (en) * | 1996-10-25 | 1997-11-18 | Yao Shung Electronic Co., Ltd. | Electronic stabilizer having a variable frequency soft start circuit |
US6429604B2 (en) * | 2000-01-21 | 2002-08-06 | Koninklijke Philips Electronics N.V. | Power feedback power factor correction scheme for multiple lamp operation |
JP2002328416A (ja) * | 2001-05-02 | 2002-11-15 | Fuji Photo Film Co Ltd | ストロボ装置 |
US6469917B1 (en) * | 2001-08-16 | 2002-10-22 | Green Power Technologies Ltd. | PFC apparatus for a converter operating in the borderline conduction mode |
-
2003
- 2003-06-13 JP JP2003169719A patent/JP4280116B2/ja not_active Expired - Fee Related
-
2004
- 2004-05-31 WO PCT/JP2004/007476 patent/WO2005008873A1/ja active Application Filing
- 2004-05-31 US US10/558,304 patent/US7425799B2/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10125484A (ja) * | 1996-10-16 | 1998-05-15 | Matsushita Electric Works Ltd | 放電灯点灯装置 |
JP2000184702A (ja) * | 1998-12-18 | 2000-06-30 | Toko Inc | 電源装置 |
JP2003125582A (ja) * | 2001-10-15 | 2003-04-25 | Sanken Electric Co Ltd | 電源装置 |
Also Published As
Publication number | Publication date |
---|---|
US7425799B2 (en) | 2008-09-16 |
US20070007904A1 (en) | 2007-01-11 |
JP4280116B2 (ja) | 2009-06-17 |
JP2005006465A (ja) | 2005-01-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6181079B1 (en) | High power electronic ballast with an integrated magnetic component | |
US5677602A (en) | High efficiency electronic ballast for high intensity discharge lamps | |
US6927544B2 (en) | Lighting control system with variable arc control including start-up circuit for providing a bias voltage supply | |
KR100345589B1 (ko) | 회로장치 | |
CA2735805A1 (en) | Electronic ballast having a partially self-oscillating inverter circuit | |
WO2010027392A1 (en) | Electronic ballast having asymmetric resonant circuit topology | |
WO2010027390A2 (en) | Measurement circuit for an electronic ballast | |
KR20030076565A (ko) | 단일-스테이지 pfc + 밸러스트 제어 회로/범용 전력변환기 | |
JP3760074B2 (ja) | 放電灯点灯回路 | |
JP2001006890A (ja) | 放電灯点灯回路 | |
KR19990083245A (ko) | 방전램프점등장치및조명장치 | |
WO2005008873A1 (ja) | 電流検出回路 | |
GB2452261A (en) | Discharge lamp controller with SEPIC and push-pull stage | |
JPH0947022A (ja) | 直流コンバータ装置 | |
JP2001211658A (ja) | 相補形スイッチを有するハロゲン電力変換器 | |
JP3404874B2 (ja) | 負荷制御装置 | |
US7733031B2 (en) | Starting fluorescent lamps with a voltage fed inverter | |
JP4836587B2 (ja) | 高圧放電灯点灯装置 | |
JP3514603B2 (ja) | 高力率高輝度放電灯点灯装置及びその駆動方法 | |
JP3188994B2 (ja) | 放電灯点灯装置 | |
US20220232681A1 (en) | Driver Circuit with Reduced Current Ripple | |
JP3482784B2 (ja) | 無電極放電灯点灯装置 | |
JP2010056042A (ja) | 放電灯点灯装置 | |
JPH0878171A (ja) | 放電灯点灯装置 | |
JP4304743B2 (ja) | 補助電源なしでオンオフ制御を可能にするスイッチング電源装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2007007904 Country of ref document: US Ref document number: 10558304 Country of ref document: US |
|
122 | Ep: pct application non-entry in european phase | ||
WWP | Wipo information: published in national office |
Ref document number: 10558304 Country of ref document: US |