Matsushita Electric Industrial Co., Ltd.

Matsushita Electronics Corporation

Toshifumi Kondoh

Yutaka Koyamada

Katsuaki Iwama

Toshiyoshi Oga

Masaru Saitoh

Masatoshi Sudou

Hisatoshi Uchiyama

A fluorescent lamp includes two glass outer tubes ( ), a bridge junction ( ), and first glass inner tubes ( ). One end of each of the glass outer tubes is closed, and the other end is sealed with stems ( ) for supporting electrodes ( ). A phosphor is applied to the inside surface of each of the glass outer tubes. The bridge junction connects the glass outer tubes at the other end portion to form a discharge space inside the glass outer tubes. The first glass inner tubes are provided in the glass outer tubes, respectively. A phosphor is applied to the surface of each of the first glass inner tubes. One end of each of the first glass inner tubes is open and disposed at the closed ends of the glass outer tubes, and the other end is sealed with the tips of the stems so that the electrodes are positioned in the first glass inner tubes.

Fluorescent lamp

For environmental protection, a glass composition for lamps that can suppress the consumption of mercury by the glass is provided. An embodiment of the glass composition consists essentially of, expressed in percentages by weight: SiO : 65-75, Al O : 0.5-4, Na O: 1-8, K O: 1-8, Li O: 0-2, MgO: 0.5-5, CaO: 1-8, SrO: 1-7, BaO: 3.5-7, B O : 0-3, Sb O : 0-1, Fe O : 0-0.2, TiO : 0-1, CeO : 0-1; and the total amount of Na O, K O and Li O is not more than 13 weight %. The glass composition is substantially free of lead.

Glass composition, stem and bulb for lamps

A fluorescent lamp includes a glass bulb whose inner surface is coated with a fluorescent substance, a glass bead attached to an end of the glass bulb so as to seal the glass bulb, an exhaust tube provided in the glass bead and sealed, a filament coil arranged in an internal portion of the glass bulb, and an electrode terminal member electrically connected to the filament coil. The glass bead controls a position of the electrode terminal member. The glass bulb preferably contains 5 to 10 wt % of Na,O. The glass bulb, the glass bead and the exhaust tube preferably have a lead-free composition.

Fluorescent lamp sealed with glass bead

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Kagawa, Japan

Toshifumi Kondoh