Matsushita Electric Industrial Co., Ltd.

Kenichirou Takahashi

Satoshi Kominami

Toshiaki Kurachi

Kouji Miyazaki

Mamoru Takeda

Kenichi Sasaki

Koji Miyazaki

Masayoshi Gyoten

Nobuyoshi Nagagata

An electrode-less discharge lamp lighting apparatus which is electrically connected to a dimming unit () is provided with: an electrode-less fluorescent lamp (); and a lighting circuit () operable to apply a high-frequency voltage to the electrode-less fluorescent lamp (), wherein the lighting circuit () includes: an AC/DC converting unit () operable to convert a phase-controlled AC voltage outputted from the dimming unit () into a DC voltage; a DC/AC converting unit () operable to convert the DC voltage into a high-frequency voltage; and a dimming controlling unit () that includes a resistor (), a switching element (), and a timer circuit () so as to detect a timing of a turn-on of the phase-controlled AC voltage and to, based on the detected timing, allow a current whose value is at least a threshold to flow across output terminals of the AC/DC converting unit () for at least a duration of a time lag between the turn-on of the phase-controlled AC voltage and the generation of the high-frequency voltage by the DC/AC converting unit ().

Electrode-less discharge lamp lighting apparatus, bulb-shaped electrode-less fluorescent lamp, and discharge lamp lighting apparatus

A ballast for a discharge lamp includes a fluorescent lamp, an AC/DC conversion portion, a dimming control portion, and a DC/AC conversion portion. The AC/DC conversion portion converts a phase-controlled input AC voltage to a DC voltage. The dimming control portion calculates a dimming control signal from the input AC voltage. The DC/AC conversion portion converts the DC voltage from the AC/DC conversion portion to a high frequency AC voltage to be applied to the fluorescent lamp and lights and dims the lamp in response to the dimming control signal. The DC/AC conversion portion has a first operation mode for maintaining the lighting of the fluorescent lamp and for lighting and dimming the same and a second operation mode for supplying the fluorescent lamp with a voltage lower than the starting voltage of the lamp in its non-operating state. The conducting period of the phase-controlled AC voltage can be detected even in the non-operating state of the fluorescent lamp so as to restart the lamp.

Ballast for discharge lamp

An electrodeless discharge lamp includes: a bulb filled with discharge gas; an induction coil; a power supply circuit including a plurality of electric components; a case for accommodating the plurality of electric components; a stick-shaped heat conducting member; a first planar heat conducting member thermally connected to the stick-shaped heat conducting member; a second heat conducting member thermally connected to the first heat conducting member; and a third heat conducting member for thermally connecting at least two of the plurality of electric components, wherein the second heat conducting member is thermally connected to the case, and the thermal conductivity of the first heat conducting member is lower than the thermal conductivity of the stick-shaped heat conducting member and the thermal conductivity of the second heat conducting member.

Electrodeless discharge lamp

Growing community of inventors

Katano, Japan

Kenichirou Takahashi