A New Method of Counteracting Noise in Sound Film Reproduction

Reproduction of the sound recorded on sound film is usually accomplished by means of a narrow beam of light thrown upon the film in a direction perpendicular to that in which the sound track is moving. The fluctuations in the light flux passed through are converted into sound. With this method a noise results which is caused by the fact that part of the light passed through is intercepted by specks of dust, scratches, etc., on the sound track, especially when the film has already been used several times. This article describes a method of counteracting this noise in cases where the sound is recorded as so-called amplitude writing. The beam of light is replaced by a series of equidistant light spots moving with great velocity perpendicular to the sound track. In addition to the theoretical fundamentals of the method, a practical form of application is also discussed.

Print ISSN

0097-5834

Published

1946-11

Content type

Original Research

DOI

10.5594/J12769