Class / Patent application number | Description | Number of patent applications / Date published |
315226000 | Plural periodic switches or multiple contact periodic switch | 24 |
20080278090 | Reset Circuit for Power-On and Power-Off - 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. | 11-13-2008 |
20080297063 | Power gating of circuits - A control device for controlling power supplied to circuitry is disclosed. The circuitry comprises a plurality of portions, each of said plurality of circuit portions being arranged between a first voltage level source and a second voltage level source, said first and second voltage level sources being adapted to output different voltage levels; said control device being adapted to control power supplied to each of said plurality of circuit portions. The control device comprises: a plurality of power switching devices corresponding to said plurality of circuit portions, each power switching device being arranged between said first voltage level source and a corresponding circuit portion such that when one of said plurality of power switching devices is switched on a voltage level close to a voltage level output by said first voltage level source is supplied to said corresponding circuit portion and said corresponding circuit portion is powered up and when switched off said corresponding circuit portion is isolated from said first voltage level source and said corresponding circuit portion is powered down, said control device further comprising: at least one voltage equalisation switching device arranged between two power switching devices to provide a low resistance path between said two power switching devices when they are both turned on and to isolate said two power switching devices from each other when either are turned off. | 12-04-2008 |
20080309247 | Backlight control circuit having frequency setting circuit and method for controlling lighting of a lamp - An exemplary backlight control circuit includes an inverter, a pulse width modulation (PWM) circuit, and a frequency setting circuit. The inverter is configured to provide an alternating current voltage to a lamp. The PWM circuit is configured to provide a pulse control signal to the inverter. The frequency setting circuit is configured to regulate a frequency of the pulse control signal provided by the PWM circuit according to a temperature of the lamp. | 12-18-2008 |
20080309248 | Backlight control circuit having frequency setting circuit and method for controlling lighting of a lamp - An exemplary backlight control circuit includes an inverter, a pulse width modulation (PWM) circuit, and a frequency setting circuit. The inverter is configured to provide an alternating current voltage to a lamp. The PWM circuit is configured to provide a pulse control signal to the inverter. The frequency setting circuit configured to regulate a frequency of the pulse control signal provided by the PWM circuit according to an environment temperature. | 12-18-2008 |
20090128048 | Organic light emitting diode power converter - A power converter circuit converts an AC line signal to a DC signal for powering an organic light emitting diode. The circuit uses only capacitive elements to limit current to the LED. Inductive and resistive elements are not included in the circuit to limit current. The absence of inductive components eliminates electromagnetic interference generated by the circuit and avoids circuit components magnetically coupling to one another. The circuit includes complementary MOSFET switches that alternately conduct to convert the AC line voltage into a DC current for powering the LED. | 05-21-2009 |
20090267528 | LAMP DRIVING CIRCUIT - A lamp driving circuit ( | 10-29-2009 |
20090289566 | Lighting Device for a Discharge Lamp - The lighting device for a discharge lamp includes a bridge type rectifying and converting circuit CR | 11-26-2009 |
20090295302 | Circuit Arrangement and Method for Operating a High-Pressure Discharge Lamp - A circuit arrangement for operating a high pressure discharge lamp includes a bridge circuit with at least two switches, a control device controlling the switches. The bridge circuit is a half-bridge circuit having exactly two switches. The control device switches on and off in an alternating manner, the first switch and the second switch of the bridge circuit having a first frequency. When the first switch is switched off for controlling the other switch with a rectangular signal of a second frequency which is greater than the first frequency and a predeterminable connection duration. The circuit also includes a tension measuring device measuring an actual value of tension over the high pressure discharge lamp. A reference device provides at least one upper threshold value for the voltage via the high pressure discharge lamp. A comparison device compares the actual voltage over the high pressure discharge lamp with the threshold value. | 12-03-2009 |
20100277086 | CIRCUIT FOR DRIVING LED - A circuit for driving a light emitting diode (LED), the circuit includes a timer, first to third electronic switches, and a regulator. The timer provides a pulse signal to switch the first and second electronic switches. The first electronic switch provides a first level signal to one end of the LED. The second electronic switch switches the third electronic switch on and off. The third electronic switch provides a third level signal to another end of the LED. The regulator adjusts the pulse signal to be at a predetermined frequency to control the first, second, and the third level signals to alternate between a high voltage level and a low voltage level at the predetermined frequency. The LED is driven to be on and off at the predetermined frequency by the first and third level signals. | 11-04-2010 |
20100289421 | STARTING AN ELECTRONIC BALLAST - A ballast including an H-bridge type inverter for driving a lamp and a filter circuit that includes a buck inductor is disclosed. The buck inductor is a primary winding of a transformer, and a secondary winding of the transformer provides power to a controller of the ballast. The controller operates the inverter in various pre-ignition modes of operation such that prior to ignition, the open circuit voltage (OCV) (i.e., voltage across the lamp) and buck inductor current are controlled to transfer sufficient power from the primary of the transformer to the secondary winding of the transformer to power the controller. No switches of the inverter are turned on while there is a non-zero current through the filter circuit. | 11-18-2010 |
20110006698 | OVERLOAD PROTECTION - An overload protection circuit and method for a fluorescent lamp drive circuit is presented, the fluorescent lamp drive circuit having first and second switches connected in series and a controller adapted to switch the switches on and off alternately. The overload protection circuit is adapted to detect a voltage across the first switch, and to turn off the first switch based on whether the detected voltage exceeds a first threshold voltage. | 01-13-2011 |
20110018455 | DISCHARGE LAMP LIGHTING APPARATUS - A discharge lamp lighting apparatus includes a resonant circuit ( | 01-27-2011 |
20110260635 | METHOD OF IGNITING A LAMP, CONTROLLER FOR A LAMP, AND A LAMP CONTROLLED BY A CONTROLLER - A method of igniting a lamp is disclosed. The lamp may be a compact fluorescent lamp. The method is directed in particular to reducing or eliminating hard-switching of half-bridge switches driving a lamp. The method operates by reducing the on-time of at least one of the switches, in response to saturation of the ballast inductor. The method can operate immediately upon saturation of the ballast inductor, or allow a predetermined level of saturation. The method operates by increasing the slope of the sawtooth timing circuit. | 10-27-2011 |
20120043905 | Method of Controlling an Operating Frequency of an Inverter Circuit in an Electronic Dimming Ballast - An electronic ballast having an inverter circuit for driving a gas discharge lamp prevents allows some hard switching to occur in the inverter circuit in order to ensure adequate ballasting impedance to provide stable operation of the lamp, but not enough hard switching to generate excessive power loss in the inverter circuit. The inverter circuit comprises two switching devices that are coupled in series between a DC bus voltage and circuit common and are rendered conductive on a complementary basis, such that a high-frequency output voltage is generated at the junction of the switching devices. When the intensity of the lamp is at or near a low-end intensity, an operating frequency of the high-frequency output voltage is controlled to a low-end frequency that is low enough to ensure stable operation of the lamp and to allow some hard switching to occur in the switching devices, but high enough to prevent excessive power loss due to the hard switching in the switching devices. | 02-23-2012 |
20120062137 | Method for Detection of Non-Zero-Voltage Switching Operation of a Ballast of Fluorescent Lamps, and Ballast - A method for use in a lamp ballast includes obtaining a measurement signal representative of a voltage at an output of a half-bridge circuit. The half-bridge circuit includes first and second semiconductor switching elements, a resonant circuit connected to the half-bridge circuit, and a snubber capacitance connected in parallel with one of the semiconductor switching elements. The method also includes providing a comparison sinal by comparing heeasurem ment signal with a reference value. The method further includes detecting one of a first type of non-zero-voltage switching operation and a second type of non-zero-voltage switching operation based on evaluations of the comparison signal, wherein the evaluations of the comparison signal occurs in each case before the first semiconductor element is switched on and in each case before the second semiconductor element is switched on. | 03-15-2012 |
20120161658 | SOLAR SIMULATOR - A solar simulator includes a flash lamp | 06-28-2012 |
20120268028 | POWER SUPPLY - 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. | 10-25-2012 |
20130134897 | PIXEL UNIT DRIVING CIRCUIT AND METHOD, PIXEL UNIT OF AMOLED PIXEL UNIT PANEL AND DISPLAY APPARATUS - 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. The pixel unit driving circuit of the AMOLED panel comprises: a switching unit, a first input terminal of which is connected to a current source for providing a charging current, a second input terminal of which is connected to an Organic Light-Emitting Diode, and an output terminal of which is connected to a first terminal of a storage capacitor to provide the charging current; the storage capacitor, a first terminal of which is connected to the output terminal of the switching unit, and a second terminal of which is connected to a low level; a driving Thin Film Transistor and a current mirror Thin Film Transistor, gates of which are connected to the first terminal of the storage capacitor, and sources of which are connected to the low level; a voltage-dividing Thin Film Transistor, gate of which is connected to the first terminal of the storage capacitor, a source of which is connected to a drain of the driving Thin Film Transistor, and a drain of which is connected to the Organic Light-Emitting Diode. | 05-30-2013 |
20130147386 | AMOLED PIXEL UNIT DRIVING CIRCUIT AND METHOD, AMOLED PIXEL UNIT AND DISPLAY APPARATUS - 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. | 06-13-2013 |
20130175941 | VOLTAGE-DRIVEN PIXEL CIRCUIT, DRIVING METHOD THEREOF AND DISPLAY PANEL - 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. | 07-11-2013 |
20140062331 | ORGANIC LIGHT EMITTING DISPLAY AND DRIVING METHOD THEREOF - 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. | 03-06-2014 |
20140084804 | POWER SUPPLY DEVICE - 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. | 03-27-2014 |
20140354171 | IMAGE DISPLAY DEVICE AND DRIVING METHOD OF THE SAME - 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. | 12-04-2014 |
20150061533 | LIGHT-EMITTING DEVICE - 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. | 03-05-2015 |