Combustion flashbulb
AssigneeU.S. Philips Corporation
InventorAloysius M. M. van Laarhoven
Life of this patent
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Abstract
A flashbulb in which a filament and paste are not required. The flashbulb is not only cheaper but is faster in operation. This is primarily achieved by ensuring that the mass of finely-shredded combustible metal strips provided in such flashbulbs are in contact with the lead-in current conductors in the bulb. Due to the oxidizing atmosphere, the strips have an electrically-insulating skin. It has been found that this skin can readily be broken down by the momentary application of a voltage, whereupon the strips form a current-conducting path between the electrodes and ignition can then be affected with a voltage lower than the breakdown voltage.
Claims10
A combustion flashbulb having a sealed vacuum-tight tubular light transmissive envelope which is filled with an oxidizing gas and contains a mass of finely shredded actinically combustible metal strips, in which spaced current conductors extend from the exterior through and into the envelope wherein each is in contact with the mass of metal strips, said flashbulb having means to ignite the flashbulb in response to the application of a voltage thereto, characterized in that the ignition means solely consisting of the current conductors and part of said mass, said part being in contact with the current conductors.
Dependencies are inferred from the claim text.