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.
Claims16
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 having a press-sealed portion that is 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 said press-sealed portion of said bulb body;
- wherein said colored glass bulb is made of a glass which itself develops a color of said colored glass bulb, and does not include a colored coating on an outer surface of said glass bulb.
A wedge base bulb comprising:
- a bulb body integrally including a colored glass bulb enclosing a sealed space therein and a press-sealed portion;
- at least one filament arranged in said sealed space;
- two respective electrical leads respectively connected to a respective one of said at least one filament in said sealed space and extending out of said bulb body through said press-sealed portion;
- and
- a tubular insulation collar fitted externally onto said press-sealed portion of said bulb body;
- wherein said colored glass bulb consists of a glass material that contains a colloid formed by a color-developing agent that develops a color directly in said glass material of said colored glass bulb.
Dependencies are inferred from the claim text.