Long-range signal light for roadway - has intense pinpoint source with luminescent device opposite aperture

摘要

The light is mounted in an opaque housing with one or more apertures, and has an intense and virtually pinpoint source, placed in the centre of a focussing device, and a luminescent device capable of rendering an appreciable area luminous. The latter two devices are opposite the aperture. The luminescent device can be a discharge tube of ring or spiral shape. The light is partic. for signally use on motorways etc., and produces no blind spots, the combination of the two sources giving a substantially constant illumination.