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Daisuke Yamahara
Daisuke Yamahara, Shijonawate-Shi JP
| Patent application number | Description | Published |
|---|---|---|
| 20100039039 | High pressure discharge lamp lighting device and luminaire - A high pressure discharge lamp lighting device, includes: a DC/DC converter for converting a power source voltage of a DC power source into a desired DC voltage and stably lighting a high pressure discharge lamp; a DC/AC inverter for inverting the DC voltage into an AC voltage; and a starting pulse generating circuit for generating a high voltage required for the start-up of the high pressure discharge lamp. Further, the high pressure discharge lamp lighting device includes a lighting state decision unit for deciding a lighted/unlighted state of the high pressure discharge lamp; and an operating state switching control unit for switching the operating state of at least one of the DC/DC converter, the DC/AC inverter, and the starting pulse generating circuit to another operating state, depending on a predetermined operation phase out of the start-up, stable lighting and power interrupt phases of the high pressure discharge lamp. | 02-18-2010 |
| 20100072913 | High pressure discharge lamp lighting device and luminaire using same - A high pressure discharge lamp lighting device includes a DC power source circuit; a power supply circuit for converting an output from the DC power source circuit into a square wave AC output to be supplied to a high pressure discharge lamp; a starting circuit for applying a high voltage output for lamp startup to the high pressure discharge lamp; a control circuit; and a half-wave discharge detection circuit for detecting a half-wave discharge. The detection circuit detects the half-wave discharge at an initial stage of the lamp startup and the control circuit controls the magnitude of a voltage of a square wave half period of one polarity having a load voltage of a larger magnitude and that of a square wave half period of the other polarity having a load voltage of a smaller magnitude to approximate to each other. | 03-25-2010 |
| 20100327775 | HIGH PRESSURE DISCHARGE LAMP LIGHTING DEVICE AND LIGHTING FIXTURE USING THE SAME - A high pressure discharge lamp lighting device comprising an inverter, an igniter, a controller, a pulse voltage detection circuit, and the starting pulse voltage regulation circuit. The inverter applies a lighting voltage to a high pressure discharge lamp. The controller applies the starting pulse voltage generated by the igniter to the high pressure discharge lamp. The pulse voltage detection circuit is configured to detect a voltage indicative of the starting pulse voltage to output a detection signal. The starting pulse voltage regulation circuit is configured to regulate the starting pulse voltage to a desired value of the starting pulse voltage on the basis of the detection signal. The pulse voltage detection circuit is configured to detect either one of the voltage developed in the specified circuit component of the igniter and the starting pulse voltage as the voltage indicative of the voltage indicative of the starting pulse voltage. | 12-30-2010 |
| 20100327776 | HIGH PRESSURE DISCHARGE LAMP LIGHTING DEVICE AND LIGHTING FIXTURE USING THE SAME - A high pressure discharge lamp lighting device in this invention comprises a converter, an inverter, an igniter, a controller, and a pulse voltage detection circuit. The converter outputs the direct current voltage. The inverter converts the direct current voltage into the lighting voltage which is alternating current voltage, and applies the lighting voltage to the high pressure discharge lamp through an output terminal. The igniter is configured to output the pulse voltage superimposed on the lighting voltage, whereby the starting voltage is applied to the high pressure discharge lamp. The controller is configured to control the igniter to allow the igniter to superimpose the pulse voltage on the lighting voltage. The pulse voltage detection circuit detects the starting voltage to output the detection signal. The starting voltage regulation circuit regulates the starting voltage to the desired voltage value of the voltage on the basis of the detection signal. | 12-30-2010 |
| 20110037406 | HIGH PRESSURE DISCHARGE LAMP LIGHTING APPARATUS AND LIGHTING FIXTURE - The high pressure discharge lamp lighting apparatus ( | 02-17-2011 |
Daisuke Yamahara, Shijounawate JP
| Patent application number | Description | Published |
|---|---|---|
| 20100244716 | HIGH PRESSURE DISCHARGE LAMP BALLAST WITH ADAPTIVE FILAMENT HEATING CONTROL BASED ON LAMP AGE - A high pressure discharge lamp ballast is provided with adaptive power control during a filament heating period. A starting circuit is coupled along with a high pressure discharge lamp to output terminals of a DC-AC power converter and generates a high voltage for dielectric breakdown in the lamp. A control circuit controls output power from the power converter to the lamp during the filament heating period after dielectric breakdown of the lamp. The output power is controlled in accordance with a power output parameter which is further determined by the control circuit in accordance with one or more lamp parameters detected by a lamp status detection circuit. The lamp parameters may be cumulative lamp parameters or electrical characteristics associated with the lamp. | 09-30-2010 |
Daisuke Yamahara, Shijonawate JP
| Patent application number | Description | Published |
|---|---|---|
| 20100109534 | ELECTRONIC BALLAST WITH CONTROLLED FILAMENT PREHEATING USING HALF-WAVE LAMP CURRENT DETECTION - An electronic ballast is provided for controlled preheating of filaments in a discharge lamp. A power converter has a plurality of switching elements and converts DC power from a DC power source into AC power for the lamp. A starting circuit generates a high voltage for starting the lamp. A half-wave discharge detecting circuit detects an absolute value for each polarity peak of a lamp current, calculates an asymmetrical current value from the detected peaks with respect to a predetermined current threshold, and detects a half-wave discharge of the lamp wherein an absolute value of the asymmetrical current value is equal to or more than the current threshold for a predetermined determination time. A control circuit regulates on-times for the switching elements in an filament heating operation wherein the power converting circuit provides a high output frequency for heating each filament of the discharge lamp, and further regulates the on-times to reduce half-wave discharge detected during the filament heating operation. | 05-06-2010 |
| 20100109542 | ELECTRONIC BALLAST WITH CONTROLLED LAMP PREHEATING - An electronic ballast provides controlled preheating for a discharge lamp. A power converting circuit receives a DC power input and converts it into an AC power output. A starting circuit coupled to the power converting circuit generates a high voltage for starting the lamp. A control circuit controls the power converting circuit to generate AC power output to the lamp dependent on a mode of operation. A symmetry detecting circuit determines a positive-negative symmetrical state of the output power provided to the discharge lamp with respect to ground. The control circuit has a starting mode wherein the discharge lamp is triggered to start with a high voltage generated by the starting circuit, an electrode heating mode wherein the AC power output of the power converting circuit is controlled to a first frequency for heating each lamp electrode, and a steady-state mode wherein the AC power output of the power converting circuit is controlled to a second frequency for maintaining lighting of the discharge lamp. The control circuit shifts from the electrode heating mode to the steady-state mode when the symmetry detecting circuit determines that the AC power output is in a positive-negative symmetrical state in the electrode heating operation. | 05-06-2010 |
Daisuke Yamahara, Osaka JP
| Patent application number | Description | Published |
|---|---|---|
| 20100013398 | High Voltage Discharge Lamp Lighting Device - A high-voltage discharge lamp lighting device provides a starting pulse voltage sufficient to turn on a high-voltage discharge lamp having terminal wire connections of variable length. A power conversion circuit is coupled to a commercial AC power source input and rectifies the AC input into a predetermined DC voltage output. A charging capacitor is coupled to the power conversion circuit. A full bridge circuit is coupled to the power conversion circuit and the charging capacitor and provides a rectangular wave AC output signal to a transformer primary winding circuit of at least a capacitor, a single switching element and a primary winding of a transformer. A low pulse voltage is induced in the primary winding and a transformer secondary winding is connected on one end to the high-voltage discharge lamp, wherein the low pulse voltage is stepped up to a high pulse voltage and applied to the high-voltage discharge lamp. A reference voltage is generated in a reference transformer winding representative of the high pulse voltage. A starting pulse equivalent value detection circuit is connected to the reference winding and detects a value associated with the reference voltage. A control circuit receives said value from said detection circuit, and variably controls at least one of a frequency of the single switching element or an ON impedance of the single switching element in association with said value, wherein said frequency or ON impedance is further associated with a starting pulse voltage sufficient to start the high-voltage discharge lamp. | 01-21-2010 |