| 摘要 |
884,000. Projection lamps. GENERAL ELECTRIC CO. June 2, 1959 [June 16, 1958], No. 18797/59. Class 39(2) [Also in Group XX] An electric lamp for projection comprises a sealed envelope containing the light source and a reflector consisting of a portion of an ellipsoid unsymmetrical to the axis of the ellipsoid, with the light source at one of the foci, the second focus lying outside the lamp. In use, the second focus lies between the film gate and the lens system of the projector. The reflector 15 may be of glass with a reflecting coating of silver or aluminium and may have a supporting ledge 17 surrounding the reflecting area. The reflector is carried by the filament supporting wires 5, 6 and a wire 14 which also supports a baffle 13 mounted above the filament 7 to prevent this from being coded by convection currents and to collect tungsten vapours from the filament, thereby reducing blackening of the top of the envelope. The baffle may be of tungsten or aluminium. A coiled coil filament or one consisting of straight segments of coiled wire generally in two planes may be used.
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