GAS -DISCHARGE LAMP WITH A PARTIALLY COATED VESSEL; AND REFLECTOR WITH A BEAM- SHAPING REGION

摘要

The invention describes a gas-discharge lamp (1) comprising a vessel (5), which vessel is partially coated with an essentially rectangular stripe (Sv) arranged circumferentially on a surface of the vessel, and wherein a first long side (14) of the stripe is situated close to a base (6) of the lamp, and the width (wv) of the stripe is such that a first angle (a?2) subtended at a lamp centre between a radius (r) and a point on the first long side (14) of the stripe comprises at most 55°, and a second angle (av1) subtended at the lamp centre between the radius and a point on a second long side (15) of the stripe comprises at most 50°. The invention also describes a reflector for a lamp, comprising a reflective interior surface realised to deflect light originating from the lamp outward to give a specific beam profile with a bright/dark cutoff line and a shoulder, and wherein the lamp, in particular a lamp as described above, is positioned horizontally in the reflector, and wherein the reflective interior surface comprises at least one beam-shaping region realised to deflect a portion of the light emitted from the lamp between 7.5° and 15° below a horizontal plane, at a specific region within the beam profile.