Apparatus for manufacturing fluorescent lamps
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsHitoshi Yamazaki, Hiroshi Ito, Sadaharu Doi, Jun Imai, Hiroshi Takada
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Abstract
A phosphor suspension is prepared by adding to an aqueous solution of a polyethylene oxide, a phosphor, a phosphate or a borate of an alkali metal and a phosphor bonding agent. After having passed through a filter, the phosphor suspension flows down on the inner surface of a glass bulb of a fluorescent lamp to form a phosphor layer on it. The coated bulb is heated to a temperature which is not higher than its softening temperature while it is transported along two opposite guide rails by two endless conveyors by having both end portions supported by associated guide tips on the conveyors projecting above the guide rails.
Claims34
An apparatus for manufacturing a fluorescent lamp comprising:
- a coating unit including:
- an upper tank;
- a coating nozzle disposed on said upper tank for causing a phosphor suspension to flow down on the inner surface of a glass bulb therethrough to form a phosphor layer thereon;
- a lower tank for recovering and accommodating a surplus of said phosphor suspension flowing down from said upper tank;
- a suspension supply pipe for supplying said phosphor suspension to said upper tank from said lower tank therethrough;
- and a filter unit for removing bubbles in said phosphor suspension and disposed within at least one of said upper and lower tanks;
- and a baking unit disposed adjacent said coating unit for baking said phosphor layer on said glass bulb and including:
- a pair of guide rails for guiding said glass bulb coating with said phosphor layer;
- a pair of endless conveyors juxtaposed with said guide rails;
- a plurality of guide tips affixed at predetermined equal intervals on each of said endless conveyors to project above its mating guide rail;
- and a heating furnace for heating and baking said phosphor layer on said inner surface of said glass bulb while said glass is transported along said guide rails by means of said endless conveyors and an associated one of said plurality guide tips;
- said coating nozzle including a stationary injection port disposed at an extremity of said coating nozzle so as to inject the phosphor suspension through a flow passageway disposed within said coating nozzle to reach the extremity thereof, an opening and closing valve disposed within said flow passageway to open and close said flow passageway through vertical movement thereof, and a liquid reservoir portion disposed between said opening and closing valve and said stationary injection port and arranged so as to be always filled with the phosphor suspension.
Dependencies are inferred from the claim text.