| 摘要 |
782,219. Automatic control systems for arc lamps. VITARAMA CORPORATION. June 22, 1955 [July 21, 1954], No. 18123/55. Class 38 (4). [Also in Group XL (a)] In a system for automatically controlling the colour of light from an arc lamp, particularly when the latter is one of several used in the projection of a motion picture mosaic, feed of colour modifying material to the are is controlled in response to the colour of the light. In Fig. 1 a consumable carbon electrode 11 of a motion picture projector are lamp is automatically fed by an electric motor 17 controlled in dependence on are current in known manner. Light from the are 14 passes to the film 34. through a two-blade projector shutter 32 which also reflects some of the light back to hooded light-sensitive electric cells 40, 41, 42, 43. The outputs of cells 40, 41, 43 which are made sensitive to red, yellow and blue light respectively 'by filters 45, 46, 47, are each compared with a portion of the output of cell 42, sensitive to white light, and any difference, indicating a fall in the proportion of coloured light is applied through an amplifier, 56, 66 or 76 to run a twophase motor 51, 61 or 71 feeding consumable colour-modifying strip 52, 62 or 72 to the are. Motors 51, 61, 71 may be operated reversibly may feed the colour-modifying strips through a longitudinal passage in one of the electrodes, or may regulate pumps or valves controlling the supply of colour-modifying gases to the arc. |
