Current Generator Control Patents (Class 315/300)
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Patent number: 11862097Abstract: A display device includes a display panel including a pixel circuit, a display panel driving circuit that drives the display panel, a voltage generating circuit that receives an input power supply voltage when the display device is powered on and generates display panel voltages and driving circuit voltages based on the input power supply voltage, and an over-current protecting circuit that monitors an over-current generated inside the display device and generates a shut-down request signal when the over-current is detected. The voltage generating circuit outputs an initialization voltage at a first time point corresponding to a time point at which the input power supply voltage is received. The display panel driving circuit outputs a scan clock signal at a second time point. The over-current protecting circuit performs a first over-current protecting operation in a power-on monitoring period set between the first time point and the second time point.Type: GrantFiled: December 23, 2022Date of Patent: January 2, 2024Assignee: Samsung Display Co., Ltd.Inventors: Sanghyun Lee, Dae-Sik Lee, Keunoh Kang, Siduk Sung, Songyi Han
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Patent number: 11783788Abstract: A display apparatus and a display control method are disclosed. The display apparatus includes a backlight module and a display panel. The backlight module comprises a controller, a plurality of power sources, and a plurality of lamp areas corresponding to the plurality of power sources. The plurality of power sources include a first power source for providing a positive power supply signal to the controller and driving a lamp area, and a second power source for driving a lamp area. The plurality of power sources are configured to output negative power supply signals and negative reference signals; the controller is configured to output a driving signal through negative voltage driving based on a control signal, the negative power supply signals and the negative reference signals.Type: GrantFiled: April 26, 2022Date of Patent: October 10, 2023Assignee: Hisense Visual Technology Co., Ltd.Inventors: Zhenhua Pang, Guangxue Liu, Yuxin Zhang, Caixia Zhao, Aichen Xu
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Patent number: 11678419Abstract: A Light-Emitting Diode (LED) light system has a plurality of LED groups connected in parallel with each of the plurality of LED groups having one or more LEDs connected in series, a power circuit having a plurality of outputs with each output of the power circuit is electrically coupled to a respective one of the plurality of LED groups, and a control subsystem electrically coupled to the power circuit for individually controlling each output of the power circuit for controlling the operation of the corresponding LED group and adapting to the characteristics thereof. In some embodiments, at least one LED group may further have a switch and/or a light-angle controlling structure connected with the one or more LEDs in series and controlled by the control subsystem for selectively enabling or disabling the LED group and/or adjusting the light angle thereof.Type: GrantFiled: July 15, 2019Date of Patent: June 13, 2023Assignee: 10644137 CANADA INC.Inventors: Majid Pahlevaninezhad, Sam Scherwitz
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Patent number: 11668442Abstract: A lighting system is disclosed. The lighting system has a plurality of lighting assemblies; a first controller coupled to a power source at a first connection and at least one of the plurality of lighting assemblies at a second connection, each of said plurality of lighting assemblies including a plurality of lighting elements, each of said plurality of lighting elements including a plurality of pairs of different colored lights, each of said plurality of pairs including a first light and a second light, said first light of said light pair activated via a first voltage polarity and said second light of said light pair activated via a second voltage polarity, said first controller having a switch with a plurality of switch positions.Type: GrantFiled: September 21, 2021Date of Patent: June 6, 2023Assignee: NATIONAL CHRISTMAS PRODUCTS LLCInventor: Michael M. McRae
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Patent number: 11172558Abstract: Various embodiments include apparatuses and methods enabling a dim-to-warm circuit operation of an LED multi-colored array. In one example, an apparatus includes a hybrid driving-circuit coupled to the LED array and to a single control-device to receive an indication of a luminous flux desired from the LED array. A color temperature for the LED array is determined based on the desired luminous flux of the LED array. In various embodiments, the hybrid driving-circuit includes an analog current-division circuit to produce current for at least two LED current-driving sources and a multiplexer array coupled between the analog current-division circuit and the LED to provide periodically, for a predetermined amount of time, current from at least one of the at least two LED current-driving sources to at least two colors of the LED array. Other apparatuses and methods are described.Type: GrantFiled: April 9, 2020Date of Patent: November 9, 2021Assignee: Lumileds LLCInventor: Yifeng Qiu
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Patent number: 10999911Abstract: An LED driver with ability to operate at low input voltages is disclosed. The LED driver comprises a boost converter to boost an input voltage to a desired output voltage to power one or more LED strings. The boost converter incorporates a first controllable switch, such as a metal-oxide-semiconductor field-effect transistor (MOSFET), IGBT, etc., for output voltage control. The boost converter receives input from an external source, such as a battery voltage, as power source for voltage boost operation. The first controllable switch couples to a gate driver powered by a linear regulator, which switchably couples to different voltage sources via a second switch to ensure that the gate driver is able to provide enough voltage for switching the first controllable switch.Type: GrantFiled: August 2, 2019Date of Patent: May 4, 2021Assignee: Maxim Integrated Products, Inc.Inventor: Philip Anthony Murphy
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Patent number: 10819393Abstract: An electromagnetically-coupled state detection circuit including a detection unit that measures a primary side Q value of a circuit containing a primary side coil electromagnetically coupled with a secondary side coil and power transmission efficiency to the secondary side coil, corrects the power transmission efficiency based on the Q value of the primary side coil, and detects a state of electromagnetic coupling with the secondary side coil based on an obtained corrected value of the power transmission efficiency.Type: GrantFiled: September 27, 2017Date of Patent: October 27, 2020Assignee: SONY CORPORATIONInventors: Hiroaki Nakano, Tomomichi Murakami, Shinichi Fukuda, Osamu Kozakai, Kenichi Fujimaki
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Patent number: 10327296Abstract: There is provided a dimming circuit, a dimming method and a LED driving circuit. On the basis of the dimming of a dimmer, the circuit according to the disclosure generates a plurality of current reference signals corresponding to a plurality of loads in accordance with a dimming signal, to change a ratio of load currents of the plurality of loads, so that, the adjustment of color temperature is implemented, wherein the dimming signal represents the changes of switching operation or dimming speed of the dimmer, and the ratio of current load currents of the plurality of loads is latched or a predetermined ratio of load currents is latched. According to the disclosure, the dimmer can be used for directly adjusting color temperature, without the need for a MCU, so that, the system compatibility is improved and the cost is decreased.Type: GrantFiled: December 13, 2017Date of Patent: June 18, 2019Assignee: JOULWATT TECHNOLOGY (HANGZHOU)CO., LTD.Inventors: Guoqiang Liu, Pitleong Wong, Yingyan He, Yuancheng Ren, Xunwei Zhou
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Patent number: 9713212Abstract: Provided is a current mirror circuit (1) for balancing respective currents in a plurality of parallel circuit branches (2) in a target circuit (3), the current mirror circuit (1) including: a plurality of balancing transistors (4), each having a connector (5), an emitter (6), and a base (7), the collector (5) and emitter (6) of each balancing transistor (4) connected in series with a respective circuit branch (2); a selection circuit (8) that connects the circuit branch (2) having the smallest current amongst the circuit branches (2) to the bases (7) of each balancing transistor; and an isolation circuit (9) that isolates circuit branches (2) having an open circuit fault from the rest of the target circuit (3). An associated method of balancing respective currents in a plurality of parallel circuit branches (2) in a target circuit (3) is also provided.Type: GrantFiled: November 21, 2012Date of Patent: July 18, 2017Inventors: Ron Shu Yuen Hui, Sinan Li
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Patent number: 9603218Abstract: A method of iteratively adjusting a color of light emitted by a light source includes setting a weighted target color to an initial color of a light emitted by a light source. The method further includes determining a target color of the light by a color controller to iteratively adjust a color of the light to the target color of the light. The method also includes determining an updated weighted target color as a combination of a portion of the weighted target color and a portion of the target color. The method further includes adjusting the color of the light by the color controller to the weighted target color.Type: GrantFiled: March 13, 2015Date of Patent: March 21, 2017Assignee: COOPER TECHNOLOGIES COMPANYInventors: Christopher Lee Bohler, Li Li
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Patent number: 9502958Abstract: During a start-up phase, each corresponding test current is delivered to a corresponding chain of loads of a plurality of chain of loads. Each chain of loads is coupled between a common node and a corresponding output node. Each chain of loads includes N series-coupled loads, where N is an integer greater than one. A maximum voltage is determined from among the output voltages, where the output voltages are the voltages at the output nodes. Also, a minimum voltage is determined from among the output voltages. The maximum voltage from among the output voltages is compared with the minimum voltage from among the output voltages to make a determination as to whether the maximum voltage exceeds the minimum voltage by a threshold. An indication is output based on a result of the determination.Type: GrantFiled: January 30, 2015Date of Patent: November 22, 2016Assignee: Infineon Technologies AGInventors: Marco Pamato, Damiano Sartori, Maurizio Galvano
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Patent number: 9380673Abstract: The present invention provides LED backlight source of liquid crystal display device. The LED backlight source includes: a boost converter, boosting input DC voltage and outputting boosted DC voltage; a plurality of LED strings connected in parallel, with each LED string including a plurality of LEDs in series and receiving boosted DC voltage from boost converter; a plurality of constant-current drivers, controlling current of each LED string, each constant-current driver controlling at least an LED string and first constant-current driver controlling connection/disconnection of boost converter; an under-voltage protection control circuit, outputting under-voltage protection voltage to constant-current drivers and constant-current drivers determining whether to stop operating based on received under-voltage protection voltage, wherein under-voltage protection voltage outputted to first constant-current driver less than under-voltage protection voltages outputted to other constant-current drivers.Type: GrantFiled: June 25, 2013Date of Patent: June 28, 2016Assignee: Shenzhen China Star Optoelectronics Technology Co., LtdInventor: Hua Zhang
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Patent number: 9041643Abstract: A light emitting element drive apparatus capable of outputting the lowest voltage satisfying drive conditions and having high light emitting efficiency and low power loss, and a portable apparatus using the same, comprising an LED drive apparatus to which LEDs of different drive voltages required for emitting light are connected in parallel and driving one or more LEDs, wherein the LED drive apparatus 10 has drive circuits connected to the corresponding LEDs among a plurality of LEDs and driving the corresponding LEDs with luminances based on set values and power supply circuits for deciding a drive voltage value required for the highest light emission among one or more LEDs driven to emit light based on drive states of drive circuits (for example terminal voltages of the current source) and supplying a drive voltage having at least the decided value to LEDs in parallel.Type: GrantFiled: April 21, 2014Date of Patent: May 26, 2015Assignees: Sony Corporation, Sony Mobile Communications Inc.Inventors: Kazuhito Tsuchida, Junji Saito, Kazuo Sudo
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Patent number: 9000684Abstract: A system including a selection module to select one of a plurality of templates corresponding to a plurality of light emitting diodes, where the selected template includes one or more of temperature, current, and voltage characteristics of the plurality of light emitting diodes. A control module measures a voltage across one of the plurality of light emitting diodes; determines a temperature of the plurality of light emitting diodes based on the voltage measured across the one of the plurality of light emitting diodes and the selected template; and in order to maintain a luminosity of the plurality of light emitting diodes at a predetermined luminosity, adjusts current through the plurality of light emitting diodes based on the temperature, the selected template, and calibration data. The calibration data include current through the plurality of light emitting diodes and corresponding luminosities of the plurality of light emitting diodes.Type: GrantFiled: May 16, 2013Date of Patent: April 7, 2015Assignee: Marvell World Trade Ltd.Inventors: Wanfeng Zhang, Radu Pitigoi-Aron
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Patent number: 8941581Abstract: A light emitting element drive apparatus capable of outputting the lowest voltage satisfying drive conditions and having high light emitting efficiency and low power loss, and a portable apparatus using the same, comprising an LED drive apparatus to which LEDs of different drive voltages required for emitting light are connected in parallel and driving one or more LEDs, wherein the LED drive apparatus 10 has drive circuits connected to the corresponding LEDs among a plurality of LEDs and driving the corresponding LEDs with luminances based on set values and power supply circuits for deciding a drive voltage value required for the highest light emission among one or more LEDs driven to emit light based on drive states of drive circuits (for example terminal voltages of the current source) and supplying a drive voltage having at least the decided value to LEDs in parallel.Type: GrantFiled: November 21, 2013Date of Patent: January 27, 2015Assignees: Sony Corporation, Sony Mobile Communications Inc.Inventors: Kazuhito Tsuchida, Junji Saito, Kazuo Sudo
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Patent number: 8901851Abstract: The present invention provides a controller used in a TRIAC dimmer compatible LED driver and method thereof. The controller comprises a dimming signal generator, a dimming signal processor and a switch control circuit. The dimming signal generator receives an AC chopped voltage from a TRIAC dimmer and generates a dimming signal with regulated duty cycle in accordance with the AC chopped voltage. The dimming signal processor is coupled to the dimming signal generator and generates a processed dimming signal in accordance with the dimming signal. The duty cycle of the processed dimming signal is a sum of a predetermined duty cycle and the duty cycle of the dimming signal. Based on the processed dimming signal and a feedback signal indicative of the current flowing through LED, the switch control circuit generates a control signal to control at least one switch in a switching converter.Type: GrantFiled: February 17, 2012Date of Patent: December 2, 2014Assignee: Chengdu Monolithic Power Systems Co., Ltd.Inventors: Naixing Kuang, Jiali Cai, Hongxia Yu
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Patent number: 8853964Abstract: A system including a first transistor, a second transistor, and a comparator. The first transistor is configured to supply a first current to a first load connected to a first terminal of the first transistor. The second transistor is configured to supply a second current to a second load connected to a first terminal of the second transistor, wherein the first current and the second current have a predetermined ratio. The comparator is configured to compare a voltage at the first terminal of the first transistor or a voltage at the first terminal of the second transistor to a reference voltage, and to adjust, based on the comparison, biasing of the first transistor and the second transistor to maintain the predetermined ratio between the first current and the second current.Type: GrantFiled: December 14, 2012Date of Patent: October 7, 2014Assignee: Marvell World Trade Ltd.Inventors: Sehat Sutardja, Ravishanker Krishnamoorthy
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Patent number: 8749171Abstract: A lighting apparatus includes a lighting unit, a converting circuit, a sensing circuit, and a current control circuit. The lighting unit includes at least one light emitting diode and a switching device connected with each other in series. The converting circuit has an output end electrically connected to the lighting unit for driving it. The sensing circuit includes a sensing element capable of indirectly detecting the current flowing through the light emitting diode and outputting a feedback signal. The current control circuit receives a reference current, the feedback signal and a dimming command, and sends a dimming control signal to the lighting unit and a current control signal to the converting circuit, capable of controlling the amplitude of the current flowing through the light emitting diode.Type: GrantFiled: March 11, 2011Date of Patent: June 10, 2014Assignee: Delta Electronics Inc.Inventors: Wei-Qiang Zhang, Li-Zhi Xu, Qi Zhang, Jian-Ping Ying
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Patent number: 8749169Abstract: An LED device with voltage-limiting unit and voltage-equalizing and current-limiting resistances includes an LED connected in parallel with a voltage-limiting unit, and a current-limiting resistance connected in series between the LED and the voltage-limiting unit. Two ends of each LED are connected in parallel with a voltage-equalizing resistance for forming a light-emitting unit, so that a light-emitting unit set can be structured through connecting two or more than two of the mentioned light-emitting units in series or in series-parallel in the same polarity. With the two ends of each LED being connected in parallel with the voltage-equalizing resistance, the end voltage of each light-emitting unit can be evenly stabilized; and the current-limiting resistance connected in series between the connection joints of the LED and the voltage-limiting unit for limiting the shunt current passing through the voltage-limiting unit.Type: GrantFiled: February 11, 2011Date of Patent: June 10, 2014Inventor: Tai-Her Yang
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Patent number: 8716951Abstract: The invention discloses an illumination controlling circuit coupled between a household electricity input and an illumination lamp. The illumination controlling circuit includes a dimmer module, a sampling-and-holding circuit, a differential circuit, an integrator circuit and a clamping circuit. The dimmer circuit is used for generating a dimming signal which includes a plurality of waveform pulses. The sampling-and-holding circuit samples from the dimming signal, so as to obtain an average waveform pulse. The differential circuit is used for extracting a voltage difference of the average waveform pulse. The integrator circuit performs integration on the average waveform pulse according to the voltage difference, so as to generate a direct current voltage signal. When a level of the direct current voltage signal exceeds a threshold voltage level of the clamping circuit, the direct current voltage signal is used for driving the illumination lamp.Type: GrantFiled: June 25, 2012Date of Patent: May 6, 2014Assignee: Lextar Electronics CorporationInventors: Chun-Kuang Chen, Po-Shen Chen, Feng-Ling Lin, Hui-Ying Chen
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Patent number: 8618745Abstract: A light emitting element drive apparatus capable of outputting the lowest voltage satisfying drive conditions and having high light emitting efficiency and low power loss, and a portable apparatus using the same, comprising an LED drive apparatus to which LEDs of different drive voltages required for emitting light are connected in parallel and driving one or more LEDs, wherein the LED drive apparatus has drive circuits connected to the corresponding LEDs among a plurality of LEDs and driving the corresponding LEDs with luminances based on set values and power supply circuits for deciding a drive voltage value required for the highest light emission among one or more LEDs driven to emit light based on drive states of drive circuits (for example terminal voltages of the current source) and supplying a drive voltage having at least the decided value to LEDs in parallel.Type: GrantFiled: August 28, 2012Date of Patent: December 31, 2013Assignees: Sony Corporation, Sony Mobile Communications Inc.Inventors: Kazuhito Tsuchida, Junji Saito, Kazuo Sudo
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Patent number: 8575860Abstract: The light emitting device control circuit device 100 in accordance with the disclosure includes a power source V1, a transistor TR1, a light emitting unit EU1, switches S1 to S17, constant current sources CC1 to CC17, and a controller 110. A switching voltage Vs1 is supplied from the controller 110 to turn ON or turn OFF the transistor TR intermittently, a pulse voltage is supplied to a pulse voltage supplying line Y1 connected to a drain terminal D of the transistor TR1. The driving signals SP1 to SP17 are sequentially supplied to the switches S1 to S17 to turn ON or turn OFF them (i.e., time division drive). The light emitting devices A1 to A17 are driven sequentially by a pulse current (i.e., time division drive) when a high voltage is supplied to the pulse voltage supplying line Y1 and when the driving signals SP1 to SP17 are turned ON.Type: GrantFiled: April 8, 2011Date of Patent: November 5, 2013Assignee: Rohm Co., Ltd.Inventors: Hidekazu Kikuchi, Akinobu Sawada
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Patent number: 8525435Abstract: In order to further develop a circuit arrangement and a method for controlling at least one light emitting component, to which a threshold current is applied, with the circuit arrangement being supplied with voltage by means of at least one supply element, and with the light emitting component being controlled by means of at least one switching element arranged between at least one current limiting element and the light emitting component using at least one switching controller, in such a way that the power efficiency is significantly increased in comparison to prior art, it is proposed that a maximum value of the current is provided by means of the current limiting element, and that the logical “1” of the data to be transmitted by means of the light emitting component is represented by periodic switching between the zero value of the current and the maximum value of the current supplied to the light emitting component.Type: GrantFiled: November 19, 2010Date of Patent: September 3, 2013Assignee: Silicon Line GmbHInventors: Martin Groepl, Holger Hoeltke
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Patent number: 8476841Abstract: An apparatus for driving a voltage source such as a discharge or LED lamp using a power booster receiving an AC voltage source configured through an inductor to turn on and off periodically in response to a duty cycle of a dimming control signal or a transformer starting a new cycle, for regulating a low voltage AC signal. The booster control circuitry adjusting the current feed to a determined target boost voltage according to sensed input from primarily a single comparator which compares any one of (but not limited to) a) the output boosted voltage, b) the globe current, or c) the inductor input current.Type: GrantFiled: April 24, 2009Date of Patent: July 2, 2013Assignee: Indice Pty LtdInventors: Aaron Brown, James Hamond, Alex Knott
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Patent number: 8446108Abstract: A system including a calibration module, a selection module, and a control module. The calibration module is configured to generate calibration data for a plurality of light emitting diodes (LEDs). The calibration data include current through the LEDs and corresponding luminosities of the LEDs. The selection module is configured to select one of a plurality of templates corresponding to the LEDs. The selected template includes at least one of temperature, current, and voltage characteristics of the LEDs. The control module is configured to determine a temperature of the LEDs and adjust current through the LEDs based on the temperature, the selected template, and the calibration data to maintain a luminosity of the LEDs at a predetermined luminosity.Type: GrantFiled: April 1, 2011Date of Patent: May 21, 2013Assignee: Marvell World Trade Ltd.Inventors: Wanfeng Zhang, Radu Pitigoi-Aron
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Patent number: 8421371Abstract: An LED drive circuit in which an alternating voltage is input and an LED is driven, and which can be connected to a phase control dimmer The LED drive circuit is provided with an edge detector for detecting an edge of the output voltage of the phase control dimmer; and a current extractor for extracting a current from a current feed line for feeding an LED drive current to the LED; wherein the value of the current extracted from the current feed line by the current extractor is varied in accordance with the detection results of the edge detector.Type: GrantFiled: January 10, 2011Date of Patent: April 16, 2013Assignee: Sharp Kabushiki KaishaInventors: Takayuki Shimizu, Hirohisa Warita, Atsushi Kanamori, Mitsuru Mariyama
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Patent number: 8373448Abstract: An electronic load for a semiconductor element is provided. The electronic load includes at least two slope generating circuits, each of which generates a current according to a current for the electronic load corresponding to an output voltage of a power supply. Each slope generating circuit comprises at least a first slope generating circuit that simulates a first slope when the output voltage of the power supply is between 0V to a rated voltage, and a second slope generating circuit that simulates a second slope when the output voltage of the power supply is higher than the conducting state voltage of the semiconductor element by subtracting the forward bias voltage from the output voltage of the power supply.Type: GrantFiled: June 14, 2011Date of Patent: February 12, 2013Assignee: Prodigit Electronics Co., Ltd.Inventor: Ying-Chang Liu
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Patent number: 8334662Abstract: An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.Type: GrantFiled: September 11, 2009Date of Patent: December 18, 2012Assignee: iWatt Inc.Inventors: Xuecheng Jin, Yu Cheng Chang, Yang Li, Maofeng Lan, John W. Kesterson, Xiaoyan Wang, Chenghung Pan
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Patent number: 8314570Abstract: A high pressure discharge lamp light source device is provided having a quartz glass discharge vessel enclosing two opposed electrodes that are spaced apart by at most 2.0 mm, each electrode having a projection formed at a tip end thereof, at least 0.20 mg/mm3 of mercury and a halogen; and a power supply device for supplying alternating current to the lamp, The power supply device is adapted to switch between a nominal electric power lighting mode and a low electric power lighting mode having a defined current value in a range of 40 to 70% of a nominal electric power consumption. In the low power mode, the power supply alternately supplies a base current in a range between 100 Hz and 5 kHz a boost current having a higher current value than that of the base current.Type: GrantFiled: March 30, 2010Date of Patent: November 20, 2012Assignee: Ushio Denki Kabushiki KaishaInventors: Takuya Tsukamoto, Minoru Fukuda, Tomoyoshi Arimoto
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Patent number: 8258720Abstract: A lighting apparatus includes a solid state lamp including one or more solid state lighting elements, and a power circuit including a current limiting device electrically connected to the lamp. The current limiting device configured to impose a maximum threshold on the current delivered to the lamp, wherein the current limiting device functions as essentially a constant current source. The lighting apparatus includes a housing for the power circuit and lamp, as a module unit.Type: GrantFiled: June 6, 2011Date of Patent: September 4, 2012Assignee: American Bright Lighting, Inc.Inventors: George Lee, Arthur Young
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Patent number: 8258717Abstract: In order to maintain a stable arc and avoid wear of the projections of electrode tip ends even if the lamp is lighted with a lamp power of at most 70% of the nominal electric power, a high pressure discharge lamp light source device is provided with a power supply device for supplying alternating current to the high pressure discharge lamp in a low electric power lighting mode having a defined current value in the range of 40 to 70% of a nominal electric power consumption, and wherein the power supply device, in the low electric power lighting mode supplies an alternating current with a low frequency which is lower than the steady-state lighting frequency, and supplies a boost current at least two times during a half cycle of the alternating current with a low frequency which is larger than the alternating current with a low frequency.Type: GrantFiled: March 30, 2010Date of Patent: September 4, 2012Assignee: Ushio Denki Kabushiki KaishaInventor: Koji Yamada
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Patent number: 8242709Abstract: An optical transmitter includes a light-emitting device and an optical modulator that modulates light output from the light-emitting device by using an input signal. The optical transmitter includes a drive current switching controller that performs an ON/OFF switching control of a drive current of the light-emitting device, by using an ON/OFF signal as an input that controls ON/OFF of an optical output of the light-emitting device, in response to a switching of the ON/OFF signal. The optical transmitter also includes a drive current adjusting and generating unit that detects an ambient temperature, and generates a drive current that is adjusted according to the ambient temperature detected thereby. The drive current switching controller includes a differential circuit that is supplied a drive current that is generated by the drive current adjusting and generating unit and controls the drive current that is output to the light-emitting device, according to the ON/OFF signal.Type: GrantFiled: July 13, 2007Date of Patent: August 14, 2012Assignee: Mitsubishi Electric CorporationInventors: Masamichi Nogami, Masaki Noda, Naoki Suzuki
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Patent number: 8188682Abstract: The present invention contemplates a variety of improved techniques for the fast switching of current through, among others, LED loads. A current shunting device is utilized to divert current away from a load at high speed when activated, thus enabling the control of the amount current that flows through the load.Type: GrantFiled: June 22, 2007Date of Patent: May 29, 2012Assignee: Maxim Integrated Products, Inc.Inventor: Mehmet Nalbant
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Patent number: 8188681Abstract: The proposed circuit makes it possible to operate a plurality of gas discharge lamps, particularly cold cathode tubes, across a common voltage source. The circuit reduces the resistance tolerance of the lamp characteristic curves through controlled debalancing of the lamp currents with the aid of debalancing modules. Through the active reduction in the resistance tolerance, the requirements placed on the electric strength of the balancing transistors as well as energy losses of the balancing circuit are reduced.Type: GrantFiled: January 22, 2009Date of Patent: May 29, 2012Assignee: Minebea Co., Ltd.Inventor: Robert Weger
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Patent number: 8183796Abstract: A drive device that drives a discharge lamp including first and second electrodes includes a lighting circuit, a current control unit, a deformation detection unit, a current modulation unit, and a modulation enhancement unit. The lighting circuit supplies alternating current to the electrodes. The current control unit regulates the lighting circuit to control the alternating current. The deformation detection unit detects deformation of the surface shape of the electrodes. The current modulation unit modulates the controlled alternating current when the deformation is detected. The modulation enhancement unit increases a modulation ratio when the deformation is detected while modulating the alternating current.Type: GrantFiled: December 18, 2008Date of Patent: May 22, 2012Assignee: Seiko Epson CorporationInventors: Tetsuo Terashima, Kentaro Yamauchi, Shigeyasu Soma
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Patent number: 8183795Abstract: A LED current-controlling circuit includes a first magnetic amplifier, a first current detecting circuit, a first magnetic amplifier controller and a first diode. The first magnetic amplifier is connected to an input terminal of the LED current-controlling circuit and the first LED string. The first current detecting circuit is connected to the first LED string in series for detecting the first current flowing through the first LED string. The first magnetic amplifier controller is used for controlling on/off statuses of the first magnetic amplifier. The first diode is connected to an output terminal of the first magnetic amplifier, the first LED string and the first magnetic amplifier controller. The first magnetic amplifier controller controls on/off statuses of the first magnetic amplifier according to the magnitude of the first current, thereby maintaining the first current at a specified DC current level.Type: GrantFiled: June 23, 2009Date of Patent: May 22, 2012Assignee: Delta Electronics, Inc.Inventors: Chung-Tsai Huang, Shang-Jin Yan, Po-Yi Lee
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Patent number: 8138684Abstract: A discharge lamp lighting device includes: a power control circuit outputting DC current; an AC conversion circuit being supplied with the DC current and generating and outputting discharge-lamp driving AC current by inverting the polarity of the DC current at a predetermined time; and a control unit performing a duty ratio control process of controlling a duty ratio on the basis of a polarity inversion time of the discharge-lamp driving AC current on the AC conversion circuit and performing an interval current control process of controlling a current value of the DC current every polarity inversion time interval on the power control circuit. Here, the control unit performs the interval current control process so as to control a difference between an average value and a maximum value of the DC current of each polarity inversion time interval on the basis of a difference between the duty ratio and a predetermined reference duty ratio.Type: GrantFiled: March 11, 2009Date of Patent: March 20, 2012Assignee: Seiko Epson CorporationInventors: Kazuhiro Tanaka, Kentaro Yamauchi, Tetsuo Terashima, Takeshi Takezawa
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Patent number: 7982415Abstract: A discharge lamp lighting apparatus includes a switch circuit for DC/AC converting, a discharge lamp connected to a secondary winding of a transformer, a current detector detecting an AC output current of the discharge lamp, an error amplifier outputting an error signal to a detected current, a control circuit generating control signals that turn on/off the switching elements in such a way as to control the AC output current at a predetermined value, and a time division signal generator generating a time division signal at the start of an ON/OFF operation of the switching elements, wherein the time division signal delays a change in a burst dimming signal or has a predetermined inclination on the burst dimming signal. The error amplifier changes the error signal according to the time division signal from the time division signal generator.Type: GrantFiled: November 18, 2008Date of Patent: July 19, 2011Assignee: Sanken Electric Co., Ltd.Inventor: Kengo Kimura
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Patent number: 7977892Abstract: A lighting apparatus includes a solid state lamp including one or more solid state lighting elements, and a power circuit including a current limiting device electrically connected to the lamp. The current limiting device configured to impose a maximum threshold on the current delivered to the lamp, wherein the current limiting device functions as essentially a constant current source. The lighting apparatus includes a housing for the power circuit and lamp, as a module unit.Type: GrantFiled: December 27, 2010Date of Patent: July 12, 2011Assignee: American Bright Lighting, Inc.Inventors: George Lee, Arthur Young
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Patent number: 7868562Abstract: The present invention provides a system and method for controlling one or more light-emitting elements which are driven by forward currents to generate mixed light for use, for example, through a luminaire. The system has one or more light sensors for acquiring feedback optical sensor data and a user interface for providing reference data representative of a desired mixed light. The system also has a controller for transforming either the sensor data or the reference data into the coordinate space of the other and to determine a difference between the sensor and the reference data in that coordinate space. The controller is configured to adjust the forward currents during operating conditions so that the sensor data matches the setpoint data. The present invention also provides a system and method that can at least partially compensate certain temperature induced effects when transforming the optical sensor or the reference data.Type: GrantFiled: December 11, 2007Date of Patent: January 11, 2011Assignee: Koninklijke Philips Electronics N.V.Inventors: Marc Salsbury, Ian Ashdown, Duncan L. B. Smith, Shane P. Robinson, Ingo Speier
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Patent number: 7859196Abstract: A lighting apparatus includes a solid state lamp including one or more solid state lighting elements, and a power circuit including a current limiting device electrically connected to the lamp. The current limiting device configured to impose a maximum threshold on the current delivered to the lamp, wherein the current limiting device functions as essentially a constant current source. The lighting apparatus includes a housing for the power circuit and lamp, as a module unit.Type: GrantFiled: August 7, 2007Date of Patent: December 28, 2010Assignee: American Bright Lighting, Inc.Inventors: George Lee, Arthur Young
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Patent number: 7701148Abstract: A circuit arrangement and associated method for splitting current in a predetermined ratio between N sub-circuits, comprising means for splitting current at one end of a each sub-circuit and at least one device at the other end of each sub-circuit adapted to become forward biased and acts as a short to ground.Type: GrantFiled: May 6, 2008Date of Patent: April 20, 2010Inventor: Alain Comeau
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Patent number: 7541748Abstract: Disclosed herein is a discharge lamp lighting device which realizes the minute control of the lighting sequence and electric power of a high-pressure discharge lamp and the control of various anti-error protecting functions by mounting a microcomputer. However, since microcomputer processing typically progresses in accordance with the programs previously recorded on a ROM, various actions of the discharge lamp are controlled in accordance with ROM-recorded data settings. To modify these settings, the contents of the ROM need to be updated. Therefore, a function for communicating with an external device is assigned to the microcomputer so that various data settings can be modified.Type: GrantFiled: October 11, 2005Date of Patent: June 2, 2009Assignees: Hitachi, Ltd., Hitachi Media Electronics Co., Ltd.Inventors: Fumio Haruna, Masaru Shimizu, Kouji Kitou, Tetsunosuke Nakamura
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Publication number: 20090026980Abstract: A dimming system and method of operating the same are provided. The dimming system includes a first terminal configured to operatively connect to a first conductive line, a second terminal configured to operatively connect to a second conductive line, and a third terminal configured to operatively connect to a third conductive line. The first conductive line is configured to connect to a load, the second conductive line is configured to supply an alternating current, and the third conductive line is configured to connect to a current path. The dimming system further includes a controller operatively connected to at least one of the first, second and third terminals for controlling operation of the dimming system. The first and second terminals are configured for electrically connecting to a primary power supply and the first and third terminals are configured for electrically connecting to a secondary power supply.Type: ApplicationFiled: October 29, 2007Publication date: January 29, 2009Inventors: Michael Ostrovsky, Parimal R. Patel, Eugene Frid
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Patent number: 7439687Abstract: A discharge lamp lighting circuit 1 includes an electric power supply part and a control part. The control part generates a control signal (Sc) for controlling the magnitude of electric power based on a lamp voltage (VL) of a discharge lamp. The electric power supply part supplies the electric power based on the control signal (Sc) from the control part to the discharge lamp. The control part has a differential computation part for differentiating a lamp voltage corresponding signal (VS) with respect to time and generating a first differential signal Sd1 (=dVS/dt), and an integral computation part for integrating a second differential signal (Sd2) which monotonously increases and decreases as the first differential signal (Sd1) increases and decreases with respect to time and generating a first integral signal (Si1), and generates the control signal (Sc) so that the electric power decreases with an increase in the first integral signal (Si1).Type: GrantFiled: May 25, 2007Date of Patent: October 21, 2008Assignee: Koito Manufacturing Co., Ltd.Inventors: Kotaro Matsui, Tomoyuki Ichikawa
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Publication number: 20080191643Abstract: Provided are systems and methods for controlling a solid state lighting panel. A system according to some embodiments of the invention includes a first microprocessor operative to perform color management data processing and generate emitter control data values. The system also includes a second microprocessor operative to receive the emitter control data values from the first processor to control a plurality of light emitters.Type: ApplicationFiled: February 14, 2007Publication date: August 14, 2008Inventors: John K. Roberts, Keith J. Vadas
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Publication number: 20080164828Abstract: An electronic circuit includes circuit portions for identifying a largest voltage drop through one of a plurality of series connected diode strings and for controlling a boost switching regulator according to the largest voltage drop. The electronic circuit can sense an open circuit series connected diode string, which would otherwise have the largest voltage drop, and can disconnect that open circuit series connected diode string from control of the boost switching regulator. Another electronic circuit includes a current limiting circuit coupled to or within a boost switching regulator and configured to operate with a diode load. Another electronic circuit includes a pulse width modulation circuit configured to dim a series connected string of light emitting diodes.Type: ApplicationFiled: January 4, 2007Publication date: July 10, 2008Inventors: Gregory Szczeszynski, Shashank Wekhande, Vijay Mangtani
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Patent number: 7384163Abstract: A lamp socket includes a first shell, a second shell combined with the first shell, a separation plate rested on a bottom of the first shell and the second shell, a base secured to the separation plate, an electronic unit mounted in the first shell and electrically connected to the base to supply an electric current to the base, a light-regulating unit mounted in the second shell and electrically connected to the electronic unit to regulate the electric current from the electronic unit to the base. Thus, the electronic unit is used to provide a current to light the electric bulb, and the light-regulating unit is used to regulate the current value of the electric bulb, so that the lamp socket has a stageless light-regulating function.Type: GrantFiled: May 23, 2006Date of Patent: June 10, 2008Assignee: Sun-Lite Sockets Industry Inc.Inventor: Wen-Ho Yang
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Patent number: 7323825Abstract: A ballast integrated circuit (IC) for driving a first switching element and a second switching element includes: a variable gain amplifier (VGA) connected to a first input terminal connected to a resistor, for generating an output current signal according to a resistance value of the resistor and a gain control signal; a preheating/ignition controller connected to a second input terminal connected to a capacitor, for generating an output current signal and an output voltage signal acting as the gain control signal according to a voltage of the second input terminal; an active zero-voltage controller for generating a hard-switching current signal and an active zero-voltage switching current signal, such that it adjusts the voltage of the second input terminal according to switching states of the first switching element and the second switching element; an oscillator for generating an oscillation signal upon receiving the output current signal from the variable gain amplifier (VGA); and a dead-time controller fType: GrantFiled: December 1, 2006Date of Patent: January 29, 2008Assignee: Fairchild Korea Semiconductor, Ltd.Inventors: Jong-Tae Hwang, Dae-Ho Kim, Moon-Sang Jung, Dong-Hwan Kim
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Patent number: 7312780Abstract: A lamp driver system is provided that facilitates improved efficiency and brightness control for an optical display system. The lamp driver system provides this improved efficiency and brightness control through the precise control of the plasma in the lamp. The lamp driver system excites the electrons in the plasma such that their obtained velocity is optimized to increase the probability of collision with the mercury atoms in the lamp. Collisions with mercury atoms release ultra-violet photons, which in turn excites the phosphor coating in the lamp. The resulting relaxation of the phosphor atoms releases photons in the visible spectrum, thus providing light with the required frequency components to illuminate the display.Type: GrantFiled: February 27, 2004Date of Patent: December 25, 2007Assignee: Honeywell International, Inc.Inventors: Scot Olson, Bruce Pitman