Improvements in or relating to optical systems for photographic recording of the waveform of electric currents such as those influenced by sound waves

摘要

365,559. Recording sound and electric currents optically. CASTELLAIN, A. P., 8, Clydesdale Mansions, Bayswater, London. Oct. 15, 1930, No. 30785. [Class 40 (ii).] Apparatus for recording electric current variations, which may be due to modulation by sound, comprises a light source 1 focused by lens 4 on a slit 5 the beam from which is focused by lens 6 to pass through a lens 9 on to an oscillograph mirror 2 whereby the slitimage is reflected through lens 9, lens 7, and cylindrical lens 8 on to a travelling sensitized film 3. The exterior surface of the lens 9 is normal to both the incident and reflected beam.