Partially coated vehicle halogen lamp capsule for projector headlight

An automotive vehicle projector headlamp (12) comprising:

• a primary light engine (20) comprising a partially coated lamp capsule (212);
• a reflector (28) configured to reflect visible light emitted from the lamp capsule (212);
• a projector lens (30) configured to project at least a portion of said reflected visible light from said reflector (28);
• and wherein
• the coated lamp capsule (212) comprises:
• a capsule envelope (220) having an upper region (225), a lower capsule base (226), and defining a longitudinal optical axis (O);
• a filament (224) mounted within the capsule envelope (220) for emitting light when energized by electrical energy, said filament (224) mechanically supported by and electrically coupled to filament supports (300, 320) located within said capsule (212) and electrically connected to leads (340, 360) extending from said capsule base (226);
• the filament (224) having a filament axial extent (280) along said capsule optical axis (O), the filament (224) defining a filament distal end (227) proximate the capsule upper region (225) and a filament proximal end (229) located proximate the capsule base (226), the filament axial extent (280) extending between the filament distal end (227) and the filament proximal end (229);
• the capsule envelope (220) having a light-transmissive coating (60) uniformly covering the capsule upper region (225), the coating (60) extending circumferentially about the capsule envelope (220) in a direction of the lower capsule base (226) to an axial location adjacent the filament distal end (227);
• and
• the capsule envelope (220) being devoid of the coating (60) at optically active regions of the capsule envelope (220) adjacent the lower capsule base (226).