| 摘要 |
861,916. Exposure meters. MEOPTA NARODNI PODNIK PREROV ZAVOD MODRANY. Aug. 8, 1958, No. 25504/58. Class 40(3) In a photo electric exposure meter fitted in a motion picture camera the photosensitive surface is formed on the face of the camera rotary shutter on which the light is incident. Light passing through the camera objective lens 3 falls alternately on the shutter surface 5 or on the film F via the shutter aperture. The photoelectric layer 4 (e.g. selenium) is connected via conductive frame 6 to the collector ring 7 and thence via the brush 8 to the transistor amplifier 11. The transistor output is registered on the galvanometer 15 placed in the camera viewfinder. Resistor 12, shunted when the camera is operative by the switch 13, compensates for the difference in photocell output when the camera is at rest (steady D.C. output) and when the camera is running (trapezoidal shaped pulsed output). Resistor 16 adjusts the sensitivity of the circuit for the differing film speeds and frame repetition rates. Specification 400,906, German Specification 804,485, Italian Specification 505,233 and Swiss Specification 219,160 are referred to. |
