Patent application number | Description | Published |
20080231207 | DISCHARGE LAMP LIGHTING APPARATUS AND SEMICONDUCTOR INTEGRATED CIRCUIT - A discharge lamp lighting apparatus includes switching elements to pass a current to a primary winding of a transformer and a capacitor, an oscillator to generate a triangular signal, an error amplifier to amplify an error voltage of a voltage corresponding to a current passed through a discharge lamp and receive a burst dimming signal that is a pulse signal to intermittently supply power to the discharge lamp, comparators to compare the error voltage with the triangular signal and generate PWM control signals that turn on/off the switching elements, respectively, a clamp circuit to clamp an output from the error amplifier so that the output from the error amplifier may not drop below a lower limit value of the triangular signal during an OFF period of the burst dimming signal, and breaking circuits to block the PWM control signals during the OFF period of the burst dimming signal. | 09-25-2008 |
20080231208 | DISCHARGE LAMP LIGHTING APPARATUS AND SEMICONDUCTOR INTEGRATED CIRCUIT - A discharge lamp lighting apparatus includes a triangular signal oscillator, a first control part to compare the triangular signal with an error voltage between a reference voltage and a voltage corresponding to a first current passed through a secondary winding of a transformer and generate a first PWM control signal for turning on/off switching elements Qp | 09-25-2008 |
20090045757 | DISCHARGE LAMP LIGHTER - A discharge lamp lighter has an abnormality detecting circuit | 02-19-2009 |
20090128049 | DISCHARGE LAMP LIGHTING APPARATUS - 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. | 05-21-2009 |
20090184671 | DISCHARGE LAMP LIGHTING APPARATUS AND SEMICONDUCTOR INTEGRATED CIRCUIT - A discharge lamp lighting apparatus has a switch circuit to convert a DC voltage into an AC voltage, a transformer, a discharge lamp, an error amplifier of a reference voltage and a voltage representative of a lamp current, a control circuit generating a PWM control signal, and a soft start circuit to carry out, at the start of a lighting operation, a soft start operation that gradually extends ON intervals of the PWM control signal to gradually increase the lamp current upto a target lamp current. The soft start circuit carries out the soft start operation in such a way that an increment in ON intervals of the PWM control signal in a period from when the discharge lamp lights to when the target lamp current is attained is smaller than that in a period from when the lighting operation starts to when the discharge lamp lights. | 07-23-2009 |
20090230877 | DISCHARGE LAMP LIGHTING APPARATUS - A discharge lamp lighting apparatus is mounted on a single circuit board. The apparatus converts a direct current into an alternating current, applies voltages of opposite phases to both ends of a discharge lamp. The apparatus includes two resonant circuits. Each of the resonant circuits includes a transformer having a primary winding and a secondary winding, a resonant reactor, and resonant capacitors. Output terminals of the two resonant circuits are connected to the ends of the discharge lamp, to apply the voltages of opposite phases to the ends of the discharge lamp, respectively. Resonant characteristics of the two resonant circuits are equalized with each other by determining values of the resonant reactors of the two resonant circuits according to values of stray capacitances determined by the lengths of high-voltage output lines extended from the two resonant circuits to the ends of the discharge lamp. | 09-17-2009 |
20100019692 | POWER CONVERSION APPARATUS - A power conversion apparatus includes a first DC converter to convert an AC voltage from an AC power source into a DC voltage and correct a power factor, a light emitting load to emit light under a predetermined DC voltage, a second DC converter to electrically insulate the first DC converter and the light emitting load from each other, convert the DC voltage from the first DC converter into the predetermined DC voltage, and supply the predetermined DC voltage to the light emitting load, a plurality of loads to operate under low DC voltages, and a third DC converter to electrically insulate the first DC converter and the plurality of loads from each other, convert the DC voltage from the first DC converter into low DC voltages, and supply the low DC voltages to the plurality of loads. | 01-28-2010 |
20100019696 | POWER CONVERTER - The present invention includes a first DC converter converting AC voltage, into DC voltage while correcting a power factor, and a second DC converter electrically isolating the first DC converter from an LED group load, and converting the DC voltage, into a predetermined DC voltage and supply the resultant voltage to the LED group load. The second DC converter includes a current detection circuit disposed on the secondary side, and detecting current flowing into the LED group load, an error amplifier amplifying an error between a detected current value detected and a reference current value, a signal transmission isolation element transmitting a control signal based on an output signal from the error amplifier, to the primary side, and a switching element transferring power to the secondary side through the transformer by being turned on/off according to the control signal. | 01-28-2010 |
20100052552 | APPARATUS FOR LIGHTING LEDS - An apparatus for lighting LEDs includes an LED group load having the LEDs, a converter to generate a voltage applied to the LED group load, a current controller to control a current of the LED group load, a voltage controller to control an output voltage provided by the converter, a time division circuit to intermittently pass a current through the LED group load, and a selector. The selector, during a period in which the time division circuit passes a current through the LED group load, selects the current controller to control a current of the LED group load and thereby control an output voltage provided by the converter, and during a period in which the time division circuit passes no current through the LED group load, selects the voltage controller to control an output voltage provided by the converter. | 03-04-2010 |
20100066261 | DC/AC CONVERTER AND CONTROLLER THEREOF - A DC/AC converter includes a resonant circuit having a first capacitor connected to at least one of a primary winding and a secondary winding of a transformer and an output end connected to a load, the resonant circuit receiving an alternating signal having a predetermined frequency and amplitude to pass a current, a variable impedance element connected in parallel with a part of the output end of the resonant circuit, the variable impedance element changing the impedance value thereof according to a current passing through the load, and a controller to control the current passing through the load to a predetermined value by changing the resonant frequency of the resonant circuit according to the changed impedance value of the variable impedance element. | 03-18-2010 |
20100073976 | DC/AC CONVERTER - A DC/AC converter includes: a resonant circuit including a transformer having a primary winding and a secondary winding and at least one capacitor, in which the capacitor is connected to at least one of the primary winding and secondary winding of the transformer, and an output terminal to which the load is to be connected is provided on the secondary winding side; a switching circuit connected to both ends of a direct current power supply and having a bridge configuration composed of switching elements for flowing a current through the primary winding of the transformer and the capacitor in the resonant circuit; and a control circuit that turns on/off the switching elements by a pair of drive signals, and flows a current through the load bidirectionally, thereby performs a PWM control for the current flowing through the load, wherein the control circuit includes step drive circuits which turn on the switching elements in steps, and the step drive circuits are provided so as to individually correspond to the switching elements. | 03-25-2010 |
20100090541 | SWITCHING CONTROL CIRCUIT - It is possible to reliably prevent two switching elements comprising a half-bridge circuit from turning ON simultaneously even when two pulse signals allowing both the two switching elements to turn ON are input thereto. | 04-15-2010 |
20100194199 | CURRENT BALANCING APPARATUS, CURRENT BALANCING METHOD, AND POWER SUPPLY APPARATUS - A current balancing apparatus includes a first transformer having a first primary winding and a first secondary winding electromagnetically coupled with the first primary winding, the first primary winding having a first end connected to a first load that passes a first current; a second transformer having a second primary winding and a second secondary winding electromagnetically coupled with the second primary winding, the second primary winding having a first end connected to a second load that passes a second current having an AC component substantially having a 180-degree phase difference with respect to the first current; and a series circuit including the first secondary winding, the second secondary winding, and a current smoother, to balance the first current and second current with each other. | 08-05-2010 |
20100214210 | CURRENT BALANCING DEVICE, LED LIGHTING APPARATUS, LCD BACKLIGHT MODULE, AND LCD DISPLAY UNIT - The present invention includes: a power supply unit | 08-26-2010 |
20100231827 | LIQUID CRYSTAL DISPLAY APPARATUS AND ILLUMINATING APPARATUS THEREFOR - An LCD apparatus includes an LCD panel to display an image and an LED backlight to illuminate the LCD panel from behind. The LCD panel has first sections divided in a vertical direction and second sections divided in a horizontal direction. The LED backlight includes an LED light source and an edge-type light guide. The LED light source includes LEDs that are arranged along at least one of upper and lower sides of the light guide and are allocated to the second sections, respectively. A brightness of an image displayed in a given second section is used to control a light quantity of the corresponding LED. Each LED radially emits light so that light beams from adjacent ones of the LEDs intersect each other. | 09-16-2010 |
20100237802 | CURRENT BALANCING DEVICE, LED LIGHTING DEVICE, AND LCD B/L MODULE - A current balancing device includes: a power supply that outputs sinusoidal alternating-current; and a plurality of series circuits, each of the series circuits including a full-wave rectifier, one or more of windings, and one or more of loads in series connection, the full-wave rectifier connected to an output of the power supply and performing full-wave rectification for the alternating-current of the power supply. Currents flowing in the respective series circuits are balanced based on an electromagnetic force generated in one or more of the windings. | 09-23-2010 |
20110069510 | PLANAR LIGHT SOURCE DEVICE - A planar light source device ( | 03-24-2011 |
20110235383 | FREQUENCY SYNCHRONIZING METHOD FOR DISCHARGE TUBE LIGHTING APPARATUS, DISCHARGE TUBE LIGHTING APPARATUS, AND SEMICONDUCTOR INTEGRATED CIRCUIT - An oscillator generates a triangular wave signal whose inclination for charging a capacitor and inclination for discharging the same are the same and which is used to turn on/off FETs Qp | 09-29-2011 |
20110285307 | LED LIGHTING APPARATUS - An LED lighting apparatus includes a triac dimmer | 11-24-2011 |
20110299310 | SYNCHRONOUS OPERATING SYSTEM FOR DISCHARGE TUBE LIGHTING APPARATUSES, DISCHARGE TUBE LIGHTING APPARATUS, AND SEMICONDUCTOR INTEGRATED CIRCUIT - A synchronous operating system for operating a plurality of discharge tube lighting apparatuses at the same frequency and same phase includes (1) an oscillator of a triangular wave signal whose inclination for charging a capacitor C | 12-08-2011 |
20120025725 | POWER CONVERTER - The present invention includes a first DC converter converting AC voltage, into DC voltage while correcting a power factor, and a second DC converter electrically isolating the first DC converter from an LED group load, and converting the DC voltage, into a predetermined DC voltage and supply the resultant voltage to the LED group load. The second DC converter includes a current detection circuit disposed on the secondary side, and detecting current flowing into the LED group load, an error amplifier amplifying an error between a detected current value detected and a reference current value, a signal transmission isolation element transmitting a control signal based on an output signal from the error amplifier, to the primary side, and a switching element transferring power to the secondary side through the transformer by being turned on/off according to the control signal. | 02-02-2012 |
20120181941 | LED DRIVING APPARATUS AND LED LIGHTING APPARATUS - An LED driving apparatus converts AC input power into predetermined DC output power and supplies the DC output power to an LED load. The LED driving apparatus includes a switching element Q | 07-19-2012 |
20130334968 | Power Supply for LED Illumination - An LED illumination system includes: a load including an LED lamp; and a power supply device, the LED lamp configured to be physically mounted on and demounted from the power supply device, the power supply device comprising: a current feedback control unit; a first voltage comparison unit configured to determine whether the load is in a mounted state; a voltage feedback control unit configured to decrease the voltage of the power supply device to a safe voltage when demounting, and to increase the voltage of the power supply device to perform the constant current control when mounting; and a semiconductor switch element connected in series between the load and the detection resistor, wherein the mounted and demounted states of the load is detected by a voltage of a main electrode of a high potential side of the semiconductor switch element. | 12-19-2013 |
20140021876 | POWER CONVERTER - The present invention includes a first DC converter converting AC voltage, into DC voltage while correcting a power factor, and a second DC converter electrically isolating the first DC converter from an LED group load, and converting the DC voltage, into a predetermined DC voltage and supply the resultant voltage to the LED group load. The second DC converter includes a current detection circuit disposed on the secondary side, and detecting current flowing into the LED group load, an error amplifier amplifying an error between a detected current value detected and a reference current value, a signal transmission isolation element transmitting a control signal based on an output signal from the error amplifier, to the primary side, and a switching element transferring power to the secondary side through the transformer by being turned on/off according to the control signal. | 01-23-2014 |
20140184095 | DC Power-Supply Apparatus - A DC power-supply apparatus of converting an AC input voltage rectified to a DC voltage and supplying it to a load, by performing on-and-off control of a switching element connected in series to a reactor, includes a control circuit, which operates in floating state with respect to a after-rectified ground line and controls an on-width of the switching element based on a value of current flowing through the reactor and the load connected in series with the reactor; and an oscillation circuit, which controls a switching frequency of the on-and-off control by the control circuit, asynchronously with energy release timing of the reactor. | 07-03-2014 |
20140232270 | LED DRIVING DEVICE AND LED LIGHTING APPARATUS - The present invention supplies desired DC output power to a first LED load and a second LED load whose color temperature is different from that of the first LED load, includes a switching element, ripple current reducers series-connected to the respective LED loads and for reducing current ripples flowing through the LED loads, and a control circuit for controlling the DC output power so that it has a predetermined value, by performing on-off control of the switching element based on a feedback voltage at a connecting point between each of the LED loads and a corresponding one of the ripple current reducers. Each ripple current reducer has feedback-type constant current control circuits for performing control for varying impedance, and the present invention also includes color controllers for performing color control by maintaining a total LED current value of the first and second LED loads at a certain value. | 08-21-2014 |
20140233273 | SWITCHING POWER SOURCE DEVICE AND CONTROL IC WHICH ARE CAPABLE OF PERFORMING CONSTANT POWER CONTROL - The present invention is a switching power source device which converts AC power of an AC power source into DC power and outputs the DC power, the device including: a rectifying-smoothing circuit configured to output a rectified-smoothed voltage signal obtained by rectifying and smoothing an AC voltage of the AC power source; a transformer having a primary winding, a secondary winding, and an auxiliary winding; a switching element connected to the primary winding of the transformer; and a control circuit configured to turn the switching element on and off based on a voltage signal which is based on an average value of current flowing through the switching element and the rectified-smoothed voltage signal from the rectifying-smoothing circuit. | 08-21-2014 |