Method and apparatus for transferring wide-band sound signals
AssigneeInternational Standard Electric Corporation
InventorHans Reiber
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Abstract
The invention provides a system for developing sync pulses when PICOR is used on sound film systems. The sprocket holes in the feed track of the film are used in conjunction with a light source and a photocell to develop sync pulses which are required to synchronize a rotating electronic switch with periodic sequential information recorded on the sound track of the film.
Claims15
A method for providing synchronization, in a system for transferring wide-band sound signals of the type wherein at the input end of the system the sound signal is divided into a lower and a higher frequency range, the signal of the lower frequency range is transferred directly while the signal of the higher frequency range is divided into partial higher frequency ranges, the amplitude of each of said partial higher frequency ranges being detected and used to sequentially modulate a single subcarrier frequency which is thereafter transferred to a reproducing end where the subcarrier frequency is demodulated to obtain the amplitude information of each partial high frequency range said sequential amplitude information being separated by a time selection operating electronic switch said amplitude information being used to modulate an equivalent signal lying approximately in the center of the individual partial high frequency ranges, said modulated equivalent sound signal being added to the directly transferred lower frequency range signal for reproduction of the wide-band sound signal, comprising the steps of:
- recording the lower frequency range signal and the sequentially modulated subcarrier signal on the sound track of a sound film;
- providing periodic information on another track of the sound film;
- detecting the periodic information at the reproducing end;
- and
- synchronizing said electronic time selection switch with said periodic information at the reproducing end, so that the amplitude information of each partial high frequency range is provided to the proper equivalent sound signal.
A receiver for use in an information transfer system of the type wherein a number of information signals are sampled and thereafter sequentially and cyclically recorded on a first track of an elongated storage means and a periodic sync signal corresponding to the cyclic repetition is recorded on a separate track of said elongated storage means, comprising:
- means for sensing and reproducing the periodic sync signal;
- means for sensing and reproducing the recorded sequential information signals;
- means for storing a like number of information signals;
- electronic rotary switch means for receiving the sequential information signals from said sensing and reproducing means and for distributing said signals to the information storing means;
- synchronizing means responsive to the periodic sync signal for synchronizing the electronic rotary switch means so that the proper information signal is stored in the proper information storage means.
Dependencies are inferred from the claim text.