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US 5,402,036 AGranted
Low pressure mercury vapor discharge lamp having double layers
AssigneeToshiba Lighting & Technology Corporation
InventorHidenori Ito
Life of this patent
Estimating the term…
Abstract
A low pressure mercury vapor discharge lamp is operated at a power more than 550 W/m.sup.2. The lamp has a first layer comprising first grains coated on the inner surface of the tube thereof and a second layer comprising second grains coated on the first layer. The second grains are more positive in contact electrification than the first grains. The lamp reduces an early decrease in luminous flux.
Claims14
A low pressure mercury vapor discharge lamp having a wall load of more than 550 W/m.sup.2, comprising:
- a glass tube having an inner surface and defining a discharge space;
- a gas mixture including mercury and a rare gas filling said discharge space;
- a pair of electrodes provided in said glass tube for generating a discharge in said discharge space;
- a first layer comprising first grains and being coated inside said inner surface;
- and
- a second layer comprising second grains and being coated on said first layers, wherein said second grains are more positive in contact electrification than said first grains so that contact between said first and second layers causes said second layer to have a positive charge with respect to said first layer.
3 more elements
Dependencies are inferred from the claim text.