Wireless speaker system using infra-red link

Claim 1

A communication system for developing and translating an information signal to an information reproducer, said system comprising: a transmitter comprising an oscillator, for developing a carrier signal of a predetermined center frequency, means for coupling said information signal to said oscillator for frequency modulating said carrier signal in accordance with said information signal to deviate said carrier over a super wide band of frequencies such that the peak deviation of the carrier is of the same order of magnitude as the frequency of the carrier itself and the modulation index of said transmitter is substantially greater than the modulation index of a standard FM broadcasting service, means responsive to the modulated output of said oscillator for generating a train of pulses of substantially constant width and height, a light source, responsive to said train of pulses, for producing and transmitting a modulated beam of light energy, and a negative feedback system coupled between the output of said pulse generating means and the input of said oscillator, said feedback system comprising a de-emphasis network for stabilizing the center frequency of the oscillator and for linearizing the voltage v. frequency characteristic of the oscillator over said super wide range of frequency deviation; receiver means comprising a photodetector responsive to said modulated beam of light energy for deriving an electrical signal, means responsive to said electrical signal for reconstituting a replica of said original train of pulses, demodulation means responsive to said reconstituted train of pulses for deriving said information signal therefrom, and means for applying said information signal to said information reproducer.