Wedge base bulb
AssigneeNipro Corporation
InventorYoshihisa Ishihara
Life of this patent
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Abstract
The wedge base bulb includes a bulb body having a colored glass bulb and a press-sealed portion. Further, a tubular insulation collar is mounted to cover press-sealed portion. Bulb body is formed in a process in that a molding section of a glass tube including a color-developing compound or a color-developing element is heat-melted under a reducing atmosphere in a predetermined temperature region, placed in a mold and expanded in the mold, and also develops color with colloid generated by the heat-melting. As a result, a wedge base bulb developed a color and chromaticity satisfying a predetermined standard can be provided at a lower cost.
Claims8
A wedge base bulb, comprising:
- a bulb body including a colored glass bulb, a filament housed in said colored glass bulb and a lead connected to said filament at a tip-end side thereof, said bulb body being press-sealed so as to expose a proximal-end side of said lead from said colored glass bulb;
- and
- a tubular insulation collar attached to cover a press-sealed portion of said bulb body;
- characterized in that
- said colored glass bulb is formed by a process in that a molding section of a glass tube including a color-developing compound or a color-developing element is heat-melted under a reducing atmosphere in a predetermined temperature region and thereafter said glass tube is placed in a mold and expanded in the mold, and develops color with colloid generated by the heat-melting.
Dependencies are inferred from the claim text.