Indicator lamps

摘要

An indicator lamp comprising a tubular housing which is closed at one end and has a light source disposed within it at a position remote from its open end. A diffusing screen is disposed within the tubular housing in front of the light source and again remote from the open end of the housing. The internal surfaces of the tubular housing between the location of the light source and the open end of the housing are blackened. A transparent lens is disposed adjacent the open end of the tubular housing and carries on its side closest to the light source an infra-red suppressing filter, and, on its side remote from the light source, an anti-reflection coating.