Luminescent screen devices
AssigneeEnglish Electric Valve Company Limited
InventorJohn E. U. Ashton
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Abstract
The aluminium-backed phosphor layer on the output window of conventional image intensifier tubes of the photoemissive/luminescent screen type can be seriously damaged by the extremely high energy density pulse of electrons resulting from exposure of the tube to very bright light (such as a shell flash). The invention prevents or minimises the damage by placing in between and in contact with the phospher layer and the aluminium layer a layer of material (for example, potassium silicate) whose thermal properties are such as to cause it to act as a heat sink and so absorb most, if not all, of the thermal energy released by the electron pulse.
Claims6
A light image-forming device of the sort wherein a source of electrons is stimulated to produce electrons which are then accelerated into contact with a luminescent screen which includes a layer of luminescent material constituting the electron-sensitive, light-emitting section thereof, which layer of luminescent material is provided with a backing layer of metal, so as to form a light image corresponding to the original stimulation of the electron source, wherein between and in contact with both said layer of luminescent material and said backing layer of metal is a layer of material whose thermal properties are such that it tends to act as a heat sink to absorb energy from high energy density pulses of electrons impinging thereon.
A device as claimed in claim 4 and wherein said silicate is potassium silicate.
Dependencies are inferred from the claim text.