Abstract: An illumination apparatus is provided for outputting a light of mixed colors in a desired color temperature by controlling light outputs from light sources. The illumination apparatus includes a light output setting unit for outputting a set signal presenting a set value for adjusting an output of the light of mixed colors, and a first filter for smoothing the set signal from the light output setting unit. The illumination apparatus further includes a light output adjustment unit for adjusting the light outputs from the respective light sources based on the set signal smoothed by the first filter, and a plurality of second filters smoothing signals outputted from the light output adjustment unit to the light sources, respectively. Each of time constants of the second filters is lower than that of the first filter.

Abstract: A lighting device includes: a lighting unit for supplying a lighting power to a light source unit; and a controller, for controlling the lighting unit. The lighting unit has an inductor and a switching element, and a diode for flowing a flyback current of the inductor to the light source unit during an OFF period of the switching element, and the controller has a unit for intermittently driving an ON/OFF operation of the switching element by a PWM signal and a unit for driving the switching element by a frequency higher than that of the PWM signal during an ON period of the PWM signal, and when the PWM signal falls, the controller reduces a peak value of a load current flowing through the light source unit during a certain period.

Abstract: The lighting device in accordance with the present invention includes: a switching regulator including a switching element and an inductor and configured to supply a direct current to a DC light source; a control circuit unit for controlling the switching element in accordance with a dimming signal for determining an on period in which the DC light source is kept turned on and an off period in which the DC light source is kept turned off to adjust luminance of the DC light source; a current detection unit configured to output a detection value indicative of a current flowing through the inductor; and a superimposing circuit unit. The circuit control unit, in the on period, turns off the switching element when an input value received via the input terminal for receiving the detection value exceeds a first threshold, and turns on the switching element when the input value falls below a second threshold, and keeps turning off the switching element in the off period.

Abstract: A solid-state light-emitting element drive device includes a switching regulator and a control circuit. The switching regulator includes a series circuit of a switching element and an inductor, a regenerative element configured to allow a regenerative current to flow therethrough from the inductor when the switching element is turned off, and output terminals configured so that a solid-state light-emitting element is connected therebetween. The control circuit is configured to control a switching operation of the switching element of the switching regulator. The control circuit is configured to suppress an output power of the switching regulator if a parameter obtained from at least one of an ON-period and an OFF-period of the switching element is out of a prescribed range.

Abstract: In a conventional example, even if a duty cycle of the burst dimming is changed during an OFF-period of a switching element, current flowing to an LED is maintained constant. On the other hand, in the present embodiment, an accumulated value of ON-periods of a switching element is increased or decreased so as to be linked to a minimum variation width for a duty cycle (a dimming level) of a dimming signal, regardless of a timing of when the duty cycle is changed. Therefore, a lighting system (an LED drive device) according to the present embodiment can change smoothly a light output of a solid-state light-emitting element (a light source) with respect to a change in a duty cycle of the burst dimming while preventing the switching frequency from increasing.

Abstract: An illumination apparatus, for outputting a light of mixed colors in a desired color temperature by controlling light outputs from light sources, includes: a light output setting unit for outputting a set signal presenting a set value for adjusting an output of the light of mixed colors; a first filter for smoothing the set signal from the light output setting unit; a light output adjustment unit for adjusting the light outputs from the respective light sources based on the set signal smoothed by the first filter; and a plurality of second filters smoothing signals outputted from the light output adjustment unit to the light sources, respectively. Each of time constants of the second filters is lower than that of the first filter.

Abstract: A lighting device includes lighting control units respectively provided for controlling lighting of solid state light emitting element groups irradiating light of different chromaticities and a color ratio setting unit for setting a target output ratio of the solid state light emitting element groups. In an xy chromaticity diagram of an XYZ color system, a straight line connecting chromaticity coordinates of lights irradiated by a first and a second solid state light emitting element group intersects a black body locus. Further, the lighting control units include a first and a second lighting control unit for controlling lighting of the first and the second solid state light emitting element group, and the first and the second control unit perform a feedback control such that an output ratio of the second to the first solid state light emitting element group becomes equal to the target output ratio thereof.

Abstract: A light emitting device includes a set of light source units including multiple types of solid state light emitting elements having different light colors, each of the light source units comprising the same type of the solid state light emitting elements connected in series and; and an information storage unit which stores information about electrical characteristic of the set of light source units. The information stored in the information storage unit represents a relationship between a light output and a drive current in the set of light source units.

Abstract: A lighting device includes: a lighting unit for supplying a lighting power to a light source unit; and a controller, for controlling the lighting unit. The lighting unit has an inductor and a switching element, and a diode for flowing a flyback current of the inductor to the light source unit during an OFF period of the switching element, and the controller has a unit for intermittently driving an ON/OFF operation of the switching element by a PWM signal and a unit for driving the switching element by a frequency higher than that of the PWM signal during an ON period of the PWM signal, and when the PWM signal falls, the controller reduces a peak value of a load current flowing through the light source unit during a certain period.

Abstract: A lighting device includes: a series circuit of an inductor and a switching element; a diode which regenerates and supplies an energy of the inductor; and a control circuit which controls on/off of the switching element. The control circuit includes a drive signal generator which outputs a high frequency pulse drive signal; and a drive control section which turns on and off the switching element based on the high frequency drive signal and a PWM signal. The drive signal generator changes an ON time of the high frequency drive signal such that, after the PWM signal is changed from OFF to ON, a peak value of the load current gradually drops along an envelope of a specific slope, and the specific slope of the envelope is changed based on a duty ratio of the PWM signal.

Abstract: An illumination system includes a lighting apparatus having a solid-state light emitting element as a light source; and a dimmer including a bidirectional switching element having a self-sustaining function and connected to a serial circuit of the lighting apparatus and an external power source. The dimmer varies a conduction angle of the bidirectional switching element by controlling a phase of an AC voltage of the external power source, wherein the lighting apparatus performs dimming of the light source based on the conduction angle of the bidirectional switching element, and the dimmer continues to apply driving current to the bidirectional switching element during a first period, which is a part of a second period, the bidirectional switching element being allowed to conduct throughout the second period.

Abstract: A series circuit comprising a diode and a resistance is connected in parallel to a filament, and a series circuit comprising a diode and a resistance is connected in parallel to a filament. The filaments are preheated by a preheating current supplied from secondary windings of a preheating transformer, via preheating capacitors. Detection circuits detect DC voltage components of the preheating capacitors. Comparators compare the DC voltage components of the preheating capacitors with a reference voltage. The comparators cause a control circuit to protect the inverter circuit if an abnormality of the filaments is detected.

Abstract: A burst dimming signal to determine a ratio between an ON period and an OFF period is inputted. In the OFF period of the burst dimming signal, a lamp current Ila is stopped from flowing to a discharge lamp FL, while a lamp voltage Vla is applied to both ends of the discharge lamp FL, and preheating currents If1 and If2 are supplied to hot cathodes of the discharge lamp FL. In the ON period of the burst dimming signal, the discharge lamp FL is electrically broken down and is supplied with the lamp current Ila.

Abstract: A series circuit comprising a diode and a resistance is connected in parallel to a filament, and a series circuit comprising a diode and a resistance is connected in parallel to a filament. The filaments are preheated by a preheating current supplied from secondary windings of a preheating transformer, via preheating capacitors. Detection circuits detect DC voltage components of the preheating capacitors. Comparators compare the DC voltage components of the preheating capacitors with a reference voltage. The comparators cause a control circuit to protect the inverter circuit if an abnormality of the filaments is detected.

Abstract: A burst dimming signal to determine a ratio between an ON period and an OFF period is inputted. In the OFF period of the burst dimming signal, a lamp current Ila is stopped from flowing to a discharge lamp FL, while a lamp voltage Vla is applied to both ends of the discharge lamp FL, and preheating currents If1 and If2 are supplied to hot cathodes of the discharge lamp FL. In the ON period of the burst dimming signal, the discharge lamp FL is electrically broken down and is supplied with the lamp current Ila.

Abstract: A power source device includes a control circuit which controls switching elements in full-bridge arrangement so as, in decreasing an output to a load, to substantially equalize ON timing of one of two switching elements at diagonal position to the other of them with ON period of the one switching element shortened, that is, with ON duty ratio of the one switching element decreased. Switching operation of the elements in this event is not made to be in the hard switching operation, and a range in which the output to load can be controlled without increasing any stress or noise is thereby broadened, whereby it is enabled to minimize varying width of switching frequency and to attain a wide range control of the output to load without causing any one of the switching elements to be in the hard switching operation.

Abstract: A discharge lamp lighting device includes a rectifier, a first diode connected at the anode in forward direction to a positive polarity output terminal of the rectifier, a smoothing capacitor connected between the cathode of the first diode and a negative polarity output terminal of the rectifier, a second diode connected at the anode in forward direction to the cathod of the first diode, a pair of switching elements connected in series between the cathode of the second diode and the negative polarity output terminal of the rectifier, a first capacitor connected in parallel to one of the first diode and the rectifier, a second capacitor connected in parallel to the second diode, and a control circuit for controlling ON/OFF operation of these switching elements, and a transformer having a primary winding n11 connected between a junction point of the pair of switching elements and one of output terminals of the rectifier and a secondary winding connected to a load circuit including a discharge lamp, and their a

Abstract: An electronic ballast for discharge lamps comprises a main resonance circuit for applying a voltage necessary for operating of a discharge lamp having filaments to both ends of the discharge lamp and a filament resonance circuit for supplying a filament current to the filaments, wherein the main resonance circuit and filament resonance circuit have resonance circuits having different resonance characteristics in an output path leading to the discharge lamp and also change their outputs depending on an operating frequency of switching elements. Thereby a filament current and a voltage across the discharge lamp can be set at suitable one of respective operational modes of the discharge lamp according to an operational state of the discharge lamp.

Abstract: A discharge lamp lighting device includes first voltage source of a high voltage capable of increasing lamp current, the voltage value of which being sequentially variable, and second voltage source of a low voltage capable of decreasing the lamp current, the voltage value of which being sequentially variable, lighting connection of the first and second voltages sources to a discharge lamp being alternately changed over for its stable lighting, whereby the stable lighting of the lamp can be made with any current limiting element minimized and a response to variation in outputs over a wide range as well as any radiant noise can be effectively improved.

Abstract: A power converter apparatus in which a switched capacitor circuit includes one or more sets of cells connected in series each having a capacitor as a voltage supply source and a bridge circuit for inverting the polarities of the capacitor, the switched capacitor circuit is connected to a load, there is provided a means for parallelly charging the capacitors of the cells with a D.C. voltage source, any number of the cell capacitors are connected in series with any polarity to control supply of an A.C. output to the load. Whereby the power converter apparatus using the switched capacitor circuit can supply A.C. power with less distortion to the load without increasing the withstand voltage of the switching elements and without any need for provision of large inductors or capacitors.