Matsushita Electric Industrial Co., Ltd.

Kohhei Iwase

Kenji Itaya

Akiko Nakanishi

Kenji Nakano

Shiro Iida

Hiroki Kitagawa

Noriyuki Uchida

Hiroki Nakagawa

Yasushige Tomiyoshi

Yuji Tsuneto

Seidou Tani

An arc tube includes an arc tube body and a pair of electrodes. The arc tube body is formed from a glass tube which is double-spirally wound from a middle portion to both ends around a spiral axis. The pair of electrodes are sealed at both ends of the arc tube body. Mercury is enclosed in the arc tube substantially in a single form. Each of the electrodes includes a multiple-coiled filament which is wound substantially one turn in a last coiling stage.

Arc tube and low-pressure mercury lamp that can be reduced in size

A compact self-ballasted fluorescent lamp has an arc tube in a double-spiral configuration, the arc tube being formed by bending a glass tube around an axis of spiral up to both ends of the glass tube, and a holder that is made of resin and holds this arc tube. Electrodes, each being equipped with a filament coil, are sealed at respective ends of the glass tube. The holder is made up of a holding resin member with a cylindrical shape having a closed bottom and a resin cover in a cone shape, the holder including a circumferential wall and an end wall that is at the edge of the circumferential wall. A heat-dissipating plate is provided inside the holding resin member, at a position corresponding to where the filament coils within the glass tube are.

Compact self-ballasted fluorescent lamp resistant to heat deformation

Growing community of inventors

Takatsuki, Japan

Kohhei Iwase