| 摘要 |
484,565. Kinematograph projectors. GARDNER, J. Aug. 10, 1937, No. 23888. [Class 97 (i)] The current supply to the light source is interrupted or reduced during the times the projection beam is cut off by a shutter comprising a masking blade and a single flicker blade symmetrically disposed in relation to the masking blade and of a size not exceeding that of the masking blade. The current may be controlled by a commutator 9 having two groups of contact segments respectively engaging a brush 11 in the circuit of the projector light source 13 and a brush 12 in the circuit of an auxiliary source. The auxiliary source may be a lamp 14 disposed outside the projector lamp house in a circuit including a resistance 15, or may be a lamp 16 floodlighting the projection screen. Arc lamps, mercury vapour lamps, or gaseous discharge lamps, may be used, and the current supply may bo rectified A.C. with an interrupter in circuit, or may be chopped D.C. |
