Abstract: A lighting apparatus includes a red LED; a green LED; a blue LED; and a white LED made up of a blue light-emitting element and a yellow phosphor, wherein the red LED, the green LED, the blue LED, and the white LED generate 26 to 38%, 35 to 50%, 0 to 2%, and 12 to 33% of light, respectively, and white light obtained by additive color mixing of light from the red, green, blue, and white LEDs has a correlated color temperature of 2800 K or more to less than 3500 K, a deviation of 0.02 or below in absolute value, and a color gamut area ratio of 120% or more to 140% or less. Consequently, the lighting apparatus can radiate an illuminating light which makes colors look vivid.

Abstract: A receiver includes a light-receiving portion which receives an infrared remote control signal from a transmitter, an A/D converter which converts a signal received by the light-receiving portion into a digital signal at a frequency much higher than a carrier wave, and a digital filter having the band-pass function of a pass band containing the carrier band of the infrared remote control signal for the digital signal output from the A/D converter. The digital filter reduces the influence of variations in argon spectrum intensity over time.

Abstract: When a discharge lamp is preheated, impedance of a filament electrode of the discharge lamp is computed. In accordance with the computed impedance, preheating and lighting of the discharge lamp are controlled.

Abstract: When a discharge lamp is preheated, impedance of a filament electrode of the discharge lamp is computed. In accordance with the computed impedance, preheating and lighting of the discharge lamp are controlled.

Abstract: A high-pressure discharge lamp lighting apparatus including a DC power source, an inverter, and a resonator is presented. The apparatus also includes an inverter controller for controlling the inverter according to its variable frequency oscillation function by selectively impressing a first frequency in a stable operation window free from causing acoustic resonance in the high-pressure discharge lamp, and a second frequency higher than the first frequency to the inverter, a lamp wattage detector, and a time ratio controller for controlling a time ratio of an operation time at the first frequency and an operation time at the second frequency so that the inverter outputs are alternately impressed to the high-pressure discharge lamp at an adequate time at the first frequency and the second frequency. The time ratio is based on a lamp voltage of the discharge lamp detected in the steady lighting state using the lamp wattage detector.

Abstract: A receiver includes a light-receiving portion which receives an infrared remote control signal from a transmitter, an A/D converter which converts a signal received by the light-receiving portion into a digital signal at a frequency much higher than a carrier wave, and a digital filter having the band-pass function of a pass band containing the carrier band of the infrared remote control signal for the digital signal output from the A/D converter. The digital filter reduces the influence of variations in argon spectrum intensity over time.

Abstract: A high-pressure discharge lamp lighting apparatus, comprises an LC resonance circuit, a DC power source, an inverter circuit, an inverter circuit and an inverter control circuit. The resonance frequency of the LC resonance circuit is set in two to three times the oscillation frequency in the steady lighting operation of the high-pressure discharge lamp. Until the high-pressure discharge lamp is started and steadily lit up, the starting control circuit controls to operate the inverter circuit at a frequency lower than the resonance frequency and not causing acoustic resonance.

Abstract: A high-intensity discharge lamp lighting apparatus, including a main circuit, which contains an LC oscillation circuit, and to which a high-intensity discharge lamp is coupled, and an electronic ballast for starting up into a lighting state the high-intensity discharge lamp via the main circuit which is coupled to its output side, and it is operated at a resonance frequency of the LC resonance circuit in the main circuit at a no-load time.

Abstract: A high-pressure discharge lamp lighting apparatus, comprises an LC resonance circuit, a DC power source, an inverter circuit, an inverter circuit and an inverter control circuit. The resonance frequency of the LC resonance circuit is set in two to three times the oscillation frequency in the steady lighting operation of the high-pressure discharge lamp. Until the high-pressure discharge lamp is started and steadily lit up, the starting control circuit controls to operate the inverter circuit at a frequency lower than the resonance frequency and not causing acoustic resonance.

Abstract: An electronic ballast comprises a direct current power supply configured to provide a direct current voltage, an inverter circuit for converting the direct current voltage to a high-frequency alternating current and a load circuit. The inverter circuit includes a switching element and a resonance circuit, and is connected in parallel to the direct current power supply. The resonance circuit includes a resonance inductor, a resonance capacitor, and a first winding of an electrical insulating transformer having first and second windings.

Abstract: A high-intensity discharge lamp lighting apparatus, including a main circuit, which contains an LC oscillation circuit, and to which a high-intensity discharge lamp is coupled, and an electronic ballast for starting up into a lighting state the high-intensity discharge lamp via the main circuit which is coupled to its output side, and it is operated at a resonance frequency of the LC resonance circuit in the main circuit at a no-load time.

Abstract: A high-intensity discharge lamp lighting device includes a high-intensity discharge lamp containing a light-transmissive discharge enclosure having an envelope defining a discharge space and a hollow member having an inner diameter smaller than the envelope, an elongate electrode being inserted into the hollow member of the light-transmissive discharge enclosure in leaving a narrow gap from the inner wall of the hollow member and having leading end protruding into the hollow member of the light-transmissive discharge enclosure, a lead-conductor having a leading end coupled to an base end of the electrode, a middle portion attached to the light-transmissive discharge enclosure and a base end exposing outward from the light-transmissive discharge enclosure, and discharge agent including at least neon and argon and filled into the light-transmissive discharge enclosure, and lighting circuit means having a load characteristics continuous from a secondary open-circuit voltage to a secondary short-circuit current f

Abstract: A lighting apparatus of the present invention includes a discharge lamp incorporating a detecting element having a predetermined electrical characteristic, a detector circuit to discriminate the electrical characteristic of the detecting element and a lighting circuit to light the discharge lamp according to the output from the detector circuit. According to the lighting apparatus of the present invention, it is possible to detect whether a discharge lamp mounted in the socket is an adapted lamp without necessity for lighting the discharge lamp.

Abstract: A discharge lamp lighting apparatus of the present invention includes an inverter to convert input DC voltage into high frequency voltage and supply the converted high frequency voltage to a discharge lamp having filaments, a preheating circuit to preheat the filaments of the discharge lamp, filament voltage detecting circuits to detect voltage applied between both ends of the filaments of the discharge lamp, and an output control circuit to control the inverter to stop or lower the output of high frequency voltage when the detected result of the filament voltage detecting circuit exceeds a specified value.

Abstract: A power supply apparatus has a rectifier for outputting a non-smoothed DC. A switching circuit alternately shut off output of the rectifier at a high frequency, which includes first and second switches. A first capacitor couples to the first and second switches for smoothing output of the rectifier. A series resonance circuit includes a second capacitor and an inductor so that the voltage across the first capacitor becomes lower by the resonance voltage than that of the output of the rectifier. The switches are coupled to a feedback circuit including a saturatable current transformer having a primary winding and secondary winding. A control means varies the saturation time of the saturatable current transformer.

Abstract: Apparatus for operating a discharge lamp comprising a high frequency circuit, sensing means for sensing the absence of an electrical connection between the circuit and the lamp and control means for receiving a non-connection signal and for sending a decrease control signal to the high frequency circuit for decreasing the high frequency power supplied to the lamp in response to the non-connection signal. The sensing means senses the absence of an electrical connection between the circuit terminal to which an electric potential is applied which is less than that applied to the other circuit terminal. By sensing the electrical non-connection between the circuit terminal having the lower potential, it is not necessary to sense the absence of a connection at the other end of the lamp.

Abstract: A discharge lamp lighting apparatus of this invention includes an inverter circuit and a control circuit connected to a power source rectifier for supplying a D.C. voltage. The inverter circuit includes a parallel voltage resonance circuit of an output transformer and a resonance capacitor and the output side of the output transformer is connected to a discharge lamp and a timer circuit. The inverter circuit further includes a switching transistor for switching the D.C. power source and a voltage detection circuit for detecting a voltage V.sub.CE between the collector and emitter of the switching transistor. In the start-up operation of the discharge lamp, the control circuit raises the control level of V.sub.CE of the switching transistor so as to set the output voltage of the inverter circuit high until it receives a signal which is output after a preset time determined by the timer circuit has elapsed, and under this condition, the discharge lamp is started.