Abstract: The invention relates to a beacon lamp which includes a point source of light located at F and surrounded by a transparent cap (20) which is in the shape of a solid of revolution about an axis zz' which passes through F and which forms at least one annular lens (L1, L2) whose focus is F. The profiles of the optical surfaces of the lens(es) are such that they produce a cap which can easily be moulded and which is anastigmatic for the point F and infinity, i.e. which concentrates much of the light from the point F into a plane (25) through the point F. Application to lamps for indicating the survivors at sea of shipwrecks or air crashes, said lamp being suitable for equipping life jackets on board aircraft.

Abstract: The invention relates to a beacon lamp which includes a substantially point source of light F surrounded by a transparent cap (1) which forms a lens (8). In accordance with the invention, said lens is chosen so that the emerging beam (9) occupies the nappe or sheet of a cone (10) having its apex at F. Application to air spotting survivors at sea of an air crash or a ship wreck, the survivors being equipped for example with life jackets including such lamps.