Etusivulle | Back to main text
The invention concerns a process for the reproduction of sound recordings, which have been made optically onto film bands or such. According to the invention, the process consists in the following: a band with recordings covered with a substance resistant to rays is moved in between a source of ionised rays and a transition point (air-bridge) that is in a telephone electric circuit or such and exposed to rays and conductive by the measure of radiation exposure. As source of radiation, a radium source is preferable and the sound wave on the film band should be covered with a layer impenetrable to radium rays so that the rays reaching the air-bridge between the electrodes are more or less deflected and the resistance at the transition point, and thus also in the telephone electric circuit, are variable.
In the drawing (Illustration) the invention is presented in a sample application and shows:
In a shell a made from lead or another material impenetrable to radium rays, a radium source b is placed. The rays emanating from the shell can leave through a slit c. Before the slit the film d can be moved, and on it a sound wave has been recorded by optical means. Underneath the wave, the segment greyed out in the drawing e is covered with a radiumimpenetrable layer.
Behind the film are two broad electrodes f, and the air-bridge g between them is parallel to the slit c and arranged diametrically so that it can be reached by the radium rays. The electrodes are within the telephone circuit h which feeds on a battery i.
When the film d is moved before the slit c, the impenetrable part e covers, depending on the sound wave, the slit to larger or lesser extent, so that the air-bridge g, which ideally is in a vacuum, is removed more or less from the radium rays, and is not conductive in those places. At the non-protected places the radium rays are ionising. There follows accordingly a change in the intensity of the electric current in the telephone circuit h and thus no influence on the telephone. If the modulations in the intensity are too low to have may also be used, or ultraviolet light and such with ionising effect.
Patent claim:
Procedure for rendering sound recordings characterised by a tape with recordings under a layer of a radiation-impenetrable substance between a source for ionised rays and a telephone circuit or such, where the transition point (air-bridge) is – depending on the exposure to rays – more or less conductive depending on radiation exposure.
