LIGHTING DEVICE AND LIGHTING APPARATUS USING THE SAME

• Main Author: NAKASHIRO AKIRA
• Format: Patent
• Language: English
• Published: 08.03.2012
• Subjects: ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY

PROBLEM TO BE SOLVED: To provide a compact lighting device low in power losses and noise, and a lighting apparatus using the same.SOLUTION: An electrodeless-discharge-lamp lighting device comprises an electrodeless discharge lamp 4, an induction coil 3 for inducing an induction magnetic field at the electrodeless discharge lamp 4, a pulse width modulation (PWM) oscillator circuit 5 for outputting a PWM signal according to an external light control signal, and a high-frequency power supply circuit 2 for outputting high-frequency power at the electrodeless discharge lamp 4 responding to the PWM signal from the PWM oscillator circuit 5. The high-frequency power supply circuit 2 comprises a series circuit of switching elements Q2 and Q3 across which an output voltage of a DC power supply circuit 1 is applied, and a driving circuit 20 for alternately turning on and off the switching elements Q2 and Q3 at high frequencies. The switching elements Q2 and Q3 are made of wide bandgap semiconductor devices.