GB418567A - Improvements relating to light projectors with total occultation - Google Patents

Abstract

418,567. Electric incandescent lamps. GUICHERD, L., 9, Boulevard de Villiers, Neuilly-sur-Seine, France. March 29, 1934, No. 9871. Convention date, March 30, 1933. Addition to 398,398. [Classes 39 (ii) and 75 (iv).] The light projector according to the parent Specification is provided with an electric incandescent lamp 2, Fig. 2, having a spherical bulb which is silvered over its lower portion, the silvering 1 being wholly or partly limited by a plane X-X downwardly displaced from the centre of the bulb, preferably in such manner that after mounting in the projector this plane coincides with that passing through the upper and lower edges of the lower mask 4, Fig. 1, and upper mask 5 respectively of the lamp casing. In a modification only those parts of the silvered edge 3-3 above which the rays must pass to reach the surface of the reflector lie in the plane X-X, the remaining parts of the edge then lying in the diametrical plane Y-Y. Alternatively, instead of silvering the bulb a separate part-spherical reflecting- surface may be associated therewith. To avoid an image of the filament supports upon the reflector, the axis of the filament 6, Fig. 5, and the axes of its supports 7, 8 are situated in the same plane, which is preferably vertical and perpendicular to that passing through the edge of the silvering.