Plural Periodic Switches Or Multiple Contact Periodic Switch Patents (Class 315/226)
  • Patent number: 10295894
    Abstract: In a discharge lamp driver, a control section is configured to alternately repeat a first period in which an AC current is supplied and a second period in which a DC current is supplied, and when a first drive power lower than a rated power of the discharge lamp is supplied and an accumulated lighting time of the discharge lamp is shorter than a predetermined time, the control section is configured to set the length of the first period to be greater than that in a case where the first drive power is supplied and the accumulated lighting time is equal to or longer than the predetermined time, and set the frequency of the AC current during the first period to be higher than that in the case where the first drive power is supplied and the accumulated lighting time is equal to or longer than the predetermined time.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: May 21, 2019
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Shun Sato
  • Patent number: 10278262
    Abstract: A sensor, such as a motion sensor and/or an occupancy sensor, a soft switch relay controller, or a power pack can significantly reduce the in-rush current and thereby extend the life of relays and other electrical components susceptible to damage caused by in-rush current or voltage surges. The sensor, soft switch relay controller, and/or power pack can reduce the in-rush current when enabling or disabling a light source.
    Type: Grant
    Filed: April 19, 2018
    Date of Patent: April 30, 2019
    Assignee: McWong International, Inc.
    Inventors: Blane Goettle, Yan Zhou, Michael Darren Musgrove, Andrew Judy, Jesse James Graham
  • Patent number: 10186857
    Abstract: Multiple relays are connected in parallel by including one or more semiconductor devices connected across the relay contacts. The semiconductor devices are triggered to conduct and shunt transient currents during the opening and closing of the relay contacts to protect the relay contacts from overcurrent and to eliminate arcing during relay switching. This permits a combination of smaller relays to replace a larger and more expensive relay in applications that require switching of large load currents.
    Type: Grant
    Filed: May 16, 2016
    Date of Patent: January 22, 2019
    Assignee: Astronics Advanced Electronic Systems Corp.
    Inventors: Frederick J. Potter, Massoud Vaziri, Patrick Wellington Mills
  • Patent number: 9948147
    Abstract: The present disclosure provides a magnetic resonance type wireless charging circuit, and belongs to the field of wireless charging technology. The magnetic resonance type wireless charging circuit comprises: a high frequency oscillation circuit configured to generate an initial oscillation signal; and a driving circuit configured to generate a transmission signal using the initial oscillation signal; wherein the driving circuit comprises one stage of driving sub-circuit or n stages of driving sub-circuits with (n?1) stages of Direct Current (DC) blocking circuits serially connected thereamong in an alternate manner, where n?2 and n is an integer, and each stage of driving sub-circuit comprises a frequency doubling circuit and a first frequency selection circuit which are connected in series.
    Type: Grant
    Filed: October 16, 2015
    Date of Patent: April 17, 2018
    Assignee: BOE TECHNOLOGY GROUP CO., LTD.
    Inventor: Xuewen Lv
  • Patent number: 9420650
    Abstract: Some embodiments relate to dimmer control circuitry for LED lighting, comprising: phase control circuitry to control the supply of voltage to at least one LED load, wherein the phase control circuitry comprises an AC switch to selectively provide voltage to the LED load for a first portion of a half cycle of an AC supply voltage, and a drive component to drive the AC switch so that the AC switch remains on for the first portion of the half cycle; and load switching circuitry to couple a dissipative load to an output of the AC switch during a second portion of the half cycle, wherein the second portion overlaps with the first portion.
    Type: Grant
    Filed: December 3, 2014
    Date of Patent: August 16, 2016
    Assignee: LSC Lighting Systems (Aust) Pty. Ltd.
    Inventors: Trevor James Sykes, Gary Steven Pritchard, Dejan Deletic, David Lawrence Burchell
  • Patent number: 8994284
    Abstract: A high intensity discharge lamp (HID) control circuit and method are provided in the present invention. The circuit includes a first winding and a second winding, both of which are coupled with a series-connected inductor of an HID lamp circuit; a current zero point detector for detecting an inductor current zero crossing signal in the HID lamp circuit; an inductor current signal generator for generating an inductor current signal in the circuit to indicate a current value of the HID lamp; a modulator having input terminals connected to the current zero point detector and the inductor current signal generator, respectively, and an output terminal connected to a driving circuit for the HID lamp; and the driving circuit for driving switches in the HID lamp control circuit.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: March 31, 2015
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Qi Zhang, Weiqiang Zhang, Jianping Ying
  • Patent number: 8987995
    Abstract: The lighting circuit comprises an AC input connectable to receive an AC input voltage, a switched LED array comprising a plurality of LEDs reconfigurable into a plurality of configurations and having an input for receiving a LED driving voltage, a switched capacitor array having an input for receiving a charging voltage and an output selectively connectable to the input of the switched LED array and comprising a plurality of capacitors and switches connected to selectively couple the capacitors across the input or output, a first switched rectifier connected between the AC input and the switched LED array, a second switched rectifier connected between the AC input and the switched capacitor array, and, a control system configured to monitor the AC input voltage and control the switched LED array, the switched capacitor array and the first and second switched rectifiers based on the AC input voltage and a desired light output.
    Type: Grant
    Filed: October 26, 2010
    Date of Patent: March 24, 2015
    Assignee: Koninklijke Philips N.V.
    Inventors: Milen Moussakov, Thomas George Foxall
  • Publication number: 20150061533
    Abstract: A light-emitting device in which variation in luminance among pixels is suppressed. The light-emitting device includes a pixel; a first circuit configured to generate a signal containing information on a value of current extracted from the pixel; and a second circuit configured to correct an image signal in accordance with the signal. The pixel includes a light-emitting element; a transistor for controlling supply of the current to the light-emitting element in accordance with the image signal; a first switch configured to control connection between a gate and a drain of the transistor or between the gate of the transistor and a wiring; and a second switch configured to control extraction of the current from the pixel.
    Type: Application
    Filed: August 26, 2014
    Publication date: March 5, 2015
    Inventors: Hiroyuki MIYAKE, Shunpei YAMAZAKI
  • Patent number: 8963441
    Abstract: The present disclosure discloses a pixel unit driving circuit and method, and a pixel unit of an Active Matrix Organic Light Emitting Diode AMOLED panel and a display apparatus.
    Type: Grant
    Filed: August 23, 2012
    Date of Patent: February 24, 2015
    Assignees: Boe Technology Group Co., Ltd., Chengdu Boe Optoelectronics Technology Co., Ltd.
    Inventors: Wen Tan, Xiaojing Qi
  • Patent number: 8941315
    Abstract: A luminary dimming system having a three terminal dimming unit. The dimming unit includes a power controller and a receiver and is responsive to dimming directives received by the receiver. The power controller controls a buck switch and a freewheel switch in a manner that allows reduction of alternating current voltages. Such voltage reduction is accomplished in a manner that preserves the waveform of the source voltage and the power factor exhibited by the luminary.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: January 27, 2015
    Inventor: Jack Ivan Jmaev
  • Patent number: 8937433
    Abstract: LED controllers, LED lighting systems and control methods capable of providing an average luminance intensity independent from the variation of an AC voltage. A string of LEDs are divided into LED groups electrically connected in series between a power source and a ground. A LED controller has path switches, each for coupling a corresponding LED group to the ground. A management center controls the path switches, for making an input current from the power source to the string substantially approach a target value. A line waveform sensor coupled to the power source holds a representative signal during a cycle time of the power source. The representative signal is in response to an attribute of the power source, and substantially determines the target value.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: January 20, 2015
    Assignee: Analog Integrations Corporation
    Inventors: Jing-Chyi Wang, Chang-Yu Wang, Wei-Ming Chen
  • Patent number: 8928248
    Abstract: Provided is a step up/down converter, in which the inductor current can be easily detected by a simple configuration in any connecting mode of the switches.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: January 6, 2015
    Assignee: Panasonic Corporation
    Inventors: Takuya Ishii, Takeshi Azuma
  • Patent number: 8912729
    Abstract: A backlight module and a liquid crystal display (LCD) device thereof are proposed. The backlight module includes a DC/DC converter producing a positive/negative voltage level. The backlight module can output the positive and negative levels of driving voltage from an output end of the inverter to drive LEDs through alternately switching. Besides, a constant current can be obtained with designs of power on/off periods and energy-storing inductors to prevent LEDs employing current limiting resistors from having too low current efficiency and from being burnt out.
    Type: Grant
    Filed: September 1, 2010
    Date of Patent: December 16, 2014
    Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd.
    Inventors: Chengming He, Chingyuan Yang
  • Publication number: 20140354171
    Abstract: An image display device including a light-emitting element configured to emit light corresponding to a current flowing therethrough; a driving element that is connected to the light-emitting element and configured to control light emission of the light-emitting element; and a control unit configured to apply a reverse bias voltage to a first n-type driving element whose the threshold voltage determined at a specific time is equal to or higher than a positive predetermined voltage level for shifting the threshold voltage of the first n-type driving element in a negative direction, and not apply the reverse bias voltage to a second n-type driving element whose the threshold voltage determined at the specific time is lower than the positive predetermined voltage level for shifting the threshold voltage of the second n-type driving element in a positive direction when the light-emitting element does not emit light.
    Type: Application
    Filed: August 14, 2014
    Publication date: December 4, 2014
    Inventors: Shinji TAKASUGI, Taro HASUMI
  • Patent number: 8878449
    Abstract: There is provided an LED drive circuit that can be connected to an alternating-current power supply through a phase control dimmer and that drives an LED load, the LED drive circuit including: an LED current control circuit; a capacitance component and a resistance component that are connected in series between an input of the LED current control circuit and a reference potential; a switch element that is connected to both ends of the resistance component; and a switch control portion that turns off the switch element for a given period of time after a timing when the phase control dimmer is turned on and that turns on the switch element after the given period of time elapses.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: November 4, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Atsushi Kanamori, Hirohisa Warita, Takayuki Shimizu
  • Patent number: 8860328
    Abstract: A method and apparatus for controlling a light string is provided. A controller is coupled to the light string and is used to bias one or more of the multicolor LEDs within each bulb on the light string. Using a prearranged determination of 1) the multicolor LEDs within each bulb, 2) the placement of the bulbs within the light string, and 3) the proper biasing of the plurality of leads within the light string, the controller can be used to change the entire light string from one complex holiday color scheme to another using a simple switching mechanism to select from one a of a plurality of desired color schemes.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: October 14, 2014
    Inventor: Michael M. McRae
  • Patent number: 8836225
    Abstract: A dimmable LED driver circuit comprises a resonant DC-DC converter coupled to an output circuit. The converter comprises a half bridge or full bridge switching circuit coupled to a resonant circuit. An output of the resonant circuit is rectified and fed to the output circuit. The output circuit may comprise at least one LED series or shunt switch for switching an LED unit on and off. A control circuit controls the switches of the switching circuit at a variable switching frequency. The control circuit is also configured for controlling the switching circuit for amplitude modulating the converter and for pulse-width modulating the converter at a first pulse-width modulation frequency lower than the switching frequency. The control circuit is may further be configured for controlling the switching of the LED switch at a second pulse-width modulation frequency lower than the switching frequency.
    Type: Grant
    Filed: September 21, 2010
    Date of Patent: September 16, 2014
    Assignee: Koninklijke Philips N.V.
    Inventors: Jeroen Snelten, Geert Willem Van Der Veen
  • Patent number: 8830405
    Abstract: A DC/DC converter 10 has a high-side transistor QH as a switching element and a low-side transistor QL as a synchronous rectifier element. A first primary electrode D and secondary primary electrode S of the high-side transistor QH are connected to an input voltage VIN and an external terminal T1, respectively. A detection transistor QD is provided in a row with the high-side transistor QH, and the ON voltage of the high-side transistor QH when ON is output as detection voltage VQD from the detection transistor QD. The output detection voltage VQD is added to a feedback voltage VFB1 by an adder CB, and inputted to a comparator CMP1. The ON period of a one-shot pulse PS1 outputted from the comparator CMP1 is regulated so as to be in direct proportion to the sum of the detection voltage VQD and the feedback voltage VFB1.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: September 9, 2014
    Assignee: Rohm Co., Ltd.
    Inventor: Kazuhiro Murakami
  • Patent number: 8729816
    Abstract: In one embodiment, a charge-pump controller is formed to control a value of current supplied to a load.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: May 20, 2014
    Assignee: Semiconductor Components Industries, LLC
    Inventor: Pierre Andre Genest
  • Patent number: 8723449
    Abstract: An LED drive circuit (10) for driving an LED circuit (220) includes: a constant current driver (110) including transistors (111-114) whose collector terminals are respectively connected with LED rows (221-224) connected with each other in parallel and whose emitter terminals are grounded; and an LED drive control section (120) for setting a voltage to be commonly applied on the LED rows (221-224), the setting being performed in accordance with a maximum base current out of base currents of the transistors (111-114).
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: May 13, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masahiro Ide, Hideki Shioe
  • Patent number: 8716946
    Abstract: Disclosed is an improved light-emitting device for an AC power operation. A conventional light emitting device employs an AC light-emitting diode having arrays of light emitting cells connected in reverse parallel. The arrays in the prior art alternately repeat on/off in response to a phase change of an AC power source, resulting in short light emission time during a ½ cycle and the occurrence of a flicker effect. An AC light-emitting device according to the present invention employs a variety of means by which light emission time is prolonged during a ½ cycle in response to a phase change of an AC power source and a flicker effect can be reduced. For example, the means may be switching blocks respectively connected to nodes between the light emitting cells, switching blocks connected to a plurality of arrays, or a delay phosphor.
    Type: Grant
    Filed: October 20, 2010
    Date of Patent: May 6, 2014
    Assignee: Seoul Opto Device Co., Ltd.
    Inventors: Chung Hoon Lee, James S. Speck, Hong San Kim, Jae Jo Kim, Sung Han Kim, Jae Ho Lee
  • Patent number: 8716949
    Abstract: A lighting device for lighting a solid-state light source includes: a DC power circuit unit for converting a power of an input DC power source using a switching element and flowing a current through a solid-state light source; and a control unit for performing a first switching control in which the switching element is turned on/off at a first high frequency and a second switching control in which an ON/OFF operation of the switching element is intermittently stopped at a second frequency lower than the first frequency of the first switching control. When the current flowing through the solid-state light source is changed, the second frequency is varied.
    Type: Grant
    Filed: April 26, 2012
    Date of Patent: May 6, 2014
    Assignee: Panasonic Corporation
    Inventors: Koji Watanabe, Hiromitsu Mizukawa
  • Patent number: 8710758
    Abstract: A damper circuit is operable to dampen resonance of an electromagnetic interference filter when a phase dimmer activates. The damper circuit includes a capacitor and a bipolar junction transistor (BJT). The capacitor includes a first terminal and a second terminal. The BJT includes a control terminal, a collector terminal, and an emitter terminal. The control terminal of the BJT receives a control signal to make the BJT operate in the amplified area, and the collector terminal of the BJT is electrically connected to the second terminal of the capacitor. The first terminal of the capacitor receives the resonance generated to by the electromagnetic interference filter, and the BJT and the capacitor cooperate to dampen the resonance generated by the electromagnetic interference filter when the BJT operates in the amplified area.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: April 29, 2014
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Li-Zhi Xu, Wei-Qiang Zhang, Qi Zhang
  • Patent number: 8686667
    Abstract: A lighting power source provides AC or DC power as needed to power an electric light source. A first switching element and a diode are coupled in series across output ends of a DC power source, with a second switching element coupled across the diode. An inductor forms an output loop with the diode. A driving capacitor has a first end coupled to a node between the first switching element and the diode. A charging power source is coupled to a second end of the driving capacitor and supplied with power from the DC power source. During a charging operation, a control circuit charges the driving capacitor by turning on the second switching element while maintaining the first switching element in an OFF state. During a normal operation which follows the charging operation the control circuit repeatedly turns on/off the first switching element while maintaining the second switching element in the OFF state.
    Type: Grant
    Filed: January 26, 2011
    Date of Patent: April 1, 2014
    Assignee: Panasonic Corporation
    Inventors: Masanori Mishima, Katunobu Hamamoto
  • Publication number: 20140084804
    Abstract: According to one embodiment, a power supply device includes a switching circuit and a control circuit. The switching circuit adjusts, according to ON-OFF control for an input voltage, electric power supplied to a lighting load. The control circuit controls ON and OFF of the switching circuit such that the electric power supplied to the lighting load coincides with target power. The control circuit that operates at a frequency equal to or higher than a switching frequency of the switching circuit is used. That is, a control frequency of the control circuit for the switching circuit is equal to or higher than the switching frequency of the switching circuit.
    Type: Application
    Filed: March 11, 2013
    Publication date: March 27, 2014
    Applicant: Toshiba Lighting & Technology Corporation
    Inventors: Go Kato, Hirokazu OTAKE, Noriyuki KITAMURA, Hiroto NAKAMURA
  • Publication number: 20140077714
    Abstract: A driving device includes a switching power supply circuit to convert input power to output power; a first switching element which opens and closes a circuit of a load; an output capacitor connected in parallel to the load and the first switching element; a selection switch disposed between the inductor and the output capacitor, the selection switch switching between a first selection state where the load is electrically connected to the inductor and the second selection state where a reference potential portion is electrically connected to the inductor; a timing controller which operates the switching power supply circuit while the first switching element is closed; and a controller which puts the selection switch into the second selection state before the first switching element is closed.
    Type: Application
    Filed: September 17, 2013
    Publication date: March 20, 2014
    Applicant: CASIO COMPUTER CO., LTD.
    Inventor: Hideo SUZUKI
  • Publication number: 20140062331
    Abstract: An organic light emitting display comprises: a driving TFT comprising a gate connected to a node B, a drain connected to an input terminal of high-potential cell driving voltage, and a source connected to the organic light emitting diode through a node C; a first switching TFT for switching the current path between a node A and the node B in response to a light emission control signal; a second switching TFT for initializing the node C in response to an initialization signal; a third switching TFT for initializing either the node A or the node B in response to the initialization signal; a fourth switching TFT for switching the current path between a data line and the node B in response to a scan signal; a compensation capacitor connected between the node B and the node C.
    Type: Application
    Filed: November 2, 2012
    Publication date: March 6, 2014
    Applicant: LG DISPLAY CO., LTD.
    Inventors: Woojin NAM, Jongsik SHIM, Hongjae SHIN, Minkyu CHANG
  • Patent number: 8604707
    Abstract: A power supply includes: a step-down chopper unit for stepping down a DC voltage from a DC power source to a voltage required for lighting; and a dimming control unit which dims the light source by alternately repeating a switching ON period during which a drive signal having a frequency higher than that of the dimming signal is supplied to the switching element and a switching OFF period during which the supply of the drive signal to the switching element is stopped. Further, the power supply includes an inrush current prevention unit for preventing an inrush current occurring when the DC power source is turned on, and a compensation unit which applies a drive voltage to the thyristor in the switching OFF period.
    Type: Grant
    Filed: April 18, 2012
    Date of Patent: December 10, 2013
    Assignee: Panasonic Corporation
    Inventors: Kazuhiro Kumada, Yosikazu Kado, Satoru Nagata, Kazuhiro Nisimoto
  • Patent number: 8593072
    Abstract: A circuit arrangement for operating a high-pressure discharge lamp with an operating circuit for the high-pressure discharge lamp with an input for receiving a switch-on/switch-off signal for the high-pressure discharge lamp and at least one output for providing an operating signal to the high-pressure discharge lamp, wherein the operating circuit is designed to reduce the power of the operating signal provided at the at least one output once a switch-off signal has been received at its input, wherein the operating circuit furthermore designed to provide the operating signal as an AC signal above a predeterminable power threshold value and as a quasi DC signal below the predeterminable power threshold value.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: November 26, 2013
    Assignee: OSRAM Gesellschaft mit beschraenkter Haftung
    Inventors: Christian Breuer, Andreas Huber, Bernhard Reiter
  • Patent number: 8593068
    Abstract: A two-wire AC switch suppressing heat from a bidirectional switch element inside the switch is provided. The two-wire AC switch 100a connected between an AC power supply 101 and a load 102 includes: a bidirectional switch element 103 which flows passing current bi-directionally, selects whether to flow or block the current, is connected in series with the AC power supply 101 and the load 102 to form a closed-loop circuit, and is made of a group-III nitride semiconductor; a full-wave rectifier 104 performing full-wave rectification on power supplied from the AC power supply 101; a power supply circuit 105 smoothing a voltage after the full-wave rectification to generate DC power; a first gate drive circuit 107 and a second gate drive circuit 108 each outputting a control signal to the bidirectional switch element 103; and a control circuit 106 controlling the first and second gate drive circuits 107 and 108.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: November 26, 2013
    Assignee: Panasonic Corporation
    Inventors: Shingo Hashizume, Ayanori Ikoshi, Hiroto Yamagiwa, Yasuhiro Uemoto, Manabu Yanagihara
  • Patent number: 8564216
    Abstract: An asymmetric end-of-life protection circuit with single-point voltage measurement is provided for an electronic ballast having two lamp connection terminals. A grounding circuit includes a capacitor and a first resistor coupled in parallel between a first lamp connection terminal and ground, and is effective to drain the second lamp connection terminal to ground. A lamp voltage detection circuit is coupled between the first lamp connection terminal and ground and measures the lamp voltage from the first lamp connection terminal. A controller is effective to shut down the ballast based on an output signal from the lamp voltage detection circuit being greater than a first predetermined threshold value or less than a second predetermined threshold value.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: October 22, 2013
    Assignee: Universal Lighting Technologies, Inc.
    Inventors: Giovanni Gallegos, James Koehler
  • Patent number: 8513903
    Abstract: A discharge lamp lighting device capable of preventing magnetic saturation of an inductor connected with an output of an inverter. An inverter 12 comprises a first set of switching elements 32, 33 for switching an output voltage of the inverter 12 to a positive polarity and a second set of switching elements 31, 34 for switching the output voltage thereof to a negative polarity. At the start-up of a lamp 20, each of the switching elements 31 to 34 is allowed to perform switching operations in such a pattern that after turning on and off the first set of the switching elements 32, 33 more than once, the second set of switching elements 31, 34 are allowed to turn or and off more than once. Accordingly, energy stored in the inductor 37 is discharged during a temporary off-period, thus permitting the inductor 37 to be prevented from being magnetically saturated.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: August 20, 2013
    Assignees: TDK-Lambda Corporation, Seiko Epson Corporation
    Inventors: Takumi Horikawa, Kikuro Sasayama, Kenichi Kitagawa
  • Patent number: 8508143
    Abstract: In a driving circuit for controlling a brightness of a light emitting diode based on a duty ratio of a pulse-width modulation signal, an integration circuit is disposed on a connecting line between a gate of a first transistor coupled with a constant current source and a gate of a second transistor coupled in series with a light emitting diode. The integration circuit smoothes a change in a gate voltage of the first transistor and transmit a smoothed change in the gate voltage to the gate of the second transistor. A third transistor is coupled between a ground and a portion of the connecting line located between the gate of the first transistor and the integration circuit. The third transistor is activated and deactivated based on the duty ratio, thereby changing the gate voltages of the first transistor and the second transistor.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: August 13, 2013
    Assignee: Denso Corporation
    Inventor: Takuya Okubo
  • Patent number: 8502475
    Abstract: A discharge lamp ballast is provided with a feedback control operation to provide optimal lamp current flow during an electrode heating operation. A startup circuit coupled together with a discharge lamp between output terminals of a DC-AC power converter having a plurality of switches. The startup circuit generates a high voltage to ignite the lamp. A lamp current sensor detects an amplitude of an output current to the lamp. A control circuit controls the switches in accordance with each of a plurality of control operations including a startup operation to ignite the lamp using the high voltage generated by the startup circuit, an electrode heating operation wherein an operating frequency of the switches is controlled to set the amplitude of the detected output current to a predetermined target current amplitude, and a normal operation wherein the operating frequency is reduced to maintain stable lighting of the lamp.
    Type: Grant
    Filed: February 24, 2010
    Date of Patent: August 6, 2013
    Assignee: Panasonic Corporation
    Inventors: Nobutoshi Matsuzaki, Jun Kumagai, Satoru Nagata
  • Patent number: 8497636
    Abstract: Drivers and ballast circuits are presented having a boost converter with a triac compatibility circuit providing regulated current load to accommodate phase-cutting triac circuit holding current requirements, including auto switching driver circuit with overvoltage protection and an auto leveling circuit to regulate against thermal and load fluctuations.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: July 30, 2013
    Assignee: General Electric Company
    Inventor: Louis Robert Nerone
  • Patent number: 8492998
    Abstract: A driver circuit is configured to drive light-emitting elements. The driver circuit includes a light-emitting element, a power switching element, a control circuit, and a charge pump circuit. The power switching element includes a first terminal connected to the light-emitting element and turns on and off the light-emitting element. The control circuit is connected to a second terminal of the power switching element and controls a switching operation of the power switching element. The charge pump circuit is connected between the control circuit and a power source for the light-emitting element and supplies current to the control circuit for driving the control circuit.
    Type: Grant
    Filed: August 9, 2011
    Date of Patent: July 23, 2013
    Assignee: Dongbu HiTek Co., Ltd.
    Inventors: Jong Tae Hwang, Seong Joon Park, Dae Ho Kim, Moon Sang Jung
  • Patent number: 8487542
    Abstract: A load driving apparatus is disclosed. The load driving apparatus includes a driving signal generator and a controller. The driving signal generator is used for providing a driving signal to a load. The controller is used for generating and providing a control signal to the driving signal generator. The driving signal generator generates N integer signals and M fractional signals in a driving period to form the driving signal according to the control signal. N and M are positive integers, and an amplitude of the integer signals is greater than an amplitude of each of the fractional signals.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: July 16, 2013
    Assignee: ITE Tech. Inc.
    Inventor: Hsu-Min Chen
  • Publication number: 20130175941
    Abstract: A voltage-driven pixel circuit, a driving method thereof and a display panel including the voltage-driven pixel circuit are disclosed. The voltage-driven pixel circuit comprises a driving transistor, a retaining transistor, a switching transistor, a compensating transistor, a storage capacitance and an OLED device. The technical solutions disclosed here compensate for the unevenness of the threshold voltage of the N-type TFT transistors and OLED efficiently.
    Type: Application
    Filed: September 5, 2012
    Publication date: July 11, 2013
    Applicant: BOE TECHNOLOGY GROUP CO., LTD.
    Inventors: Zhongyuan Wu, Gang Wang
  • Publication number: 20130147386
    Abstract: The present disclosure discloses an AMOLED pixel unit driving circuit and method, an AMOLED pixel unit and a display apparatus, the AMOLED pixel unit driving circuit includes: a switching unit with a first input terminal connected to a current source for supplying a charging current and a second input terminal connected to an OLED; a storage capacitor with a first terminal connected to an output terminal of the switching unit and a second terminal connected to a low level; a driving TFT with a gate electrode connected to the first terminal of the storage capacitor and a source electrode connected to the low level; and a current dividing unit with a first terminal connected to the low level. The embodiments of the present disclosure enable a relatively large scale to exist between the charging current Idata and the current loled flowing through the OLED.
    Type: Application
    Filed: August 23, 2012
    Publication date: June 13, 2013
    Applicants: CHENGDU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD., BOE TECHNOLOGY GROUP CO., LTD.
    Inventors: Wen Tan, Xiaojing Qi
  • Publication number: 20130134897
    Abstract: The present disclosure discloses a pixel unit driving circuit and method, and a pixel unit of an Active Matrix Organic Light Emitting Diode AMOLED panel and a display apparatus.
    Type: Application
    Filed: August 23, 2012
    Publication date: May 30, 2013
    Applicants: CHENGDU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD., BOE TECHNOLOGY GROUP CO., LTD.
    Inventors: Wen Tan, Xiaojing Qi
  • Patent number: 8441200
    Abstract: An electronic ballast for operating at least two discharge lamps is provided, which may include a starting detection apparatus for detecting whether one of the discharge lamps has been started; wherein a drive circuit includes an input, which is coupled to a starting detection apparatus, wherein a threshold value entry apparatus is designed to enter a second threshold value for a setpoint value of a total current through at least two inductances, wherein the second threshold value has a smaller magnitude than a first threshold value; and wherein the drive circuit is designed to drive a first electronic switch and a second electronic switch taking into consideration the first threshold value as setpoint value prior to detection of the starting of a discharge lamp by the starting detection apparatus, and taking into consideration the second threshold value as setpoint value.
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: May 14, 2013
    Assignee: OSRAM Gesellschaft mit beschraenkter Haftung
    Inventors: Olaf Busse, Siegfried Mayer, Arwed Storm
  • Patent number: 8415893
    Abstract: Provided is a discharge lamp lighting device, which can control a load precisely while improving the practicability. When the difference of a count number (Nn) becomes a predetermined threshold value or less, a predictor circuit (35) predicts the timing, at which a current value (iQ1) becomes a peak value, on the basis of the rate of change of the difference. A switch selecting circuit (38), which is driven with a clock frequency higher than the sampling frequency of a first converter unit (32), turns off a field effect transistor (Q1) at the turn-off timing, and turns on a field effect transistor (Q2). A plurality of A/D converters (37a) are subjected to a multi-rate control, thereby to correct the threshold value of the predictor circuit (35) on the basis of the peak value of a lamp current (iOUT).
    Type: Grant
    Filed: October 17, 2008
    Date of Patent: April 9, 2013
    Assignee: Nagasaki University
    Inventor: Fujio Kurokawa
  • Patent number: 8378962
    Abstract: An LCD backlight driving device with an isolating transformer comprises a DC power supply, a square wave generator, a square wave controller, said isolating transformer and a driver transformer; wherein said isolating transformer has a primary side connected to said square wave generator and a secondary side connected to said driver transformer, since said isolating transformer is placed between said square wave generator and said driver transformer, it helps to effectively shorten a safety distance required for setting up said driver transformer; the present invention uses said isolating transformer to shorten the safety distance required than that of using said driver transformer directly and to decrease an area in implementing a circuit board and to cut cost of said device.
    Type: Grant
    Filed: July 8, 2010
    Date of Patent: February 19, 2013
    Assignee: Logah Technology Corp.
    Inventors: Cheng-Chia Hsu, Yu-Cheng Pan, Ho-Wen Chen
  • Patent number: 8363037
    Abstract: A circuit for resetting a display having at least one driver outputting a driving voltage through an output channel to a corresponding data line of a panel comprises a first switch and a second switch. The first switch is actuated by a control pulse to transfer a reset voltage to the data line of the panel. The second switch is actuated by the control pulse to electrically isolate the output channel of the driver from the data line of the panel, wherein the control pulse is asserted during transient periods resulting from power-on and power-off of the display.
    Type: Grant
    Filed: August 7, 2007
    Date of Patent: January 29, 2013
    Assignee: Himax Technologies Limited
    Inventors: Ying Lieh Chen, Kai Lan Chuang, Tsung Yu Wu, Chien Ru Chen, Chin Tien Chang, Chuan Che Lee, Wen Teng Fan
  • Patent number: 8314567
    Abstract: A circuit for controlling illumination means in a display includes illumination means arranged in a series-connection that are supplied with an essentially constant current. For individually controlling the illumination means, switches are provided for bypassing individual illumination means, maintaining the essentially constant current in the series-connection. The switches are floating with respect to a ground potential. A coupling means is thus provided for proper control of the switches. In a development of the invention a floating local power supply is provided with each illumination means and switch for operating the switch. The local power supply is, in one embodiment, powered by the control signal that is used for controlling the bypass switch. In another embodiment provision is made for supplying power to the floating local power supply. A driving method according to the embodiments of the circuit is also described.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: November 20, 2012
    Assignee: Thomson Licensing
    Inventors: Didier Ploquin, Philippe Marchand, Gerard Morizot
  • Publication number: 20120287097
    Abstract: The semiconductor device is included in the LED driving circuit (current regulator) of driving the LED array (with series-connected number m×parallel-connected number n), and is formed of a plurality (n pieces) of LED driving devices of controlling a current (constant-current driving) flowing in each string. A vertical semiconductor device, for example, a vertical MOSFET is used as the LED driving device. Both of a main device functioning as a constant-current driving device and a subsidiary device functioning as a circuit-breaking switch during dimming are formed inside a chip of the device, which are formed of the vertical semiconductor devices. In a first surface of the device, each source region of the main device and the subsidiary device is formed so as to be insulated from each other through an isolation region.
    Type: Application
    Filed: July 27, 2012
    Publication date: November 15, 2012
    Applicant: Renesas Electronics Corporation
    Inventors: Noboru AKIYAMA, Takayuki HASHIMOTO, Takashi HIRAO, Nobuyoshi MATSUURA, Hideo ISHII
  • Publication number: 20120286686
    Abstract: A lighting device for lighting a solid-state light source includes: a DC power circuit unit for converting a power of an input DC power source using a switching element and flowing a current through a solid-state light source; and a control unit for performing a first switching control in which the switching element is turned on/off at a first high frequency and a second switching control in which an ON/OFF operation of the switching element is intermittently stopped at a second frequency lower than the first frequency of the first switching control. When the current flowing through the solid-state light source is changed, the second frequency is varied.
    Type: Application
    Filed: April 26, 2012
    Publication date: November 15, 2012
    Applicant: Panasonic Corporation
    Inventors: Koji WATANABE, Hiromitsu Mizukawa
  • Publication number: 20120268028
    Abstract: A power supply includes: a step-down chopper unit for stepping down a DC voltage from a DC power source to a voltage required for lighting; and a dimming control unit which dims the light source by alternately repeating a switching ON period during which a drive signal having a frequency higher than that of the dimming signal is supplied to the switching element and a switching OFF period during which the supply of the drive signal to the switching element is stopped. Further, the power supply includes an inrush current prevention unit for preventing an inrush current occurring when the DC power source is turned on, and a compensation unit which applies a drive voltage to the thyristor in the switching OFF period.
    Type: Application
    Filed: April 18, 2012
    Publication date: October 25, 2012
    Applicant: Panasonic Corporation
    Inventors: Kazuhiro KUMADA, Yosikazu Kado, Satoru Nagata, Kazuhiro Nisimoto
  • Patent number: 8278843
    Abstract: A method for operating a switching power supply is provided. A switching element is switched on and off by a switching signal with a variable switching frequency. A frequency bandwidth is predefined for determining average levels of a frequency spectrum of the switching signal. The switching frequency is modulated by a modulation frequency greater than a frequency bandwidth.
    Type: Grant
    Filed: October 6, 2008
    Date of Patent: October 2, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventors: Harald Demoulin, Ewald Lohninger
  • Patent number: 8274232
    Abstract: A communications apparatus and techniques are presented for communicating with ballasts or drivers through lighting system power connections in which the power connections are energized with low levels of power to power communications components in the ballast/drivers while the light sources are off and low frequency AC communications signals are transmitted through the power connections.
    Type: Grant
    Filed: August 3, 2010
    Date of Patent: September 25, 2012
    Assignee: General Electric Company
    Inventor: Louis Robert Nerone