Abstract: An acousto-optic modulator beam switching device for use in recording and display systems comprises a source of collimated light; an acousto-optic modulator; said source being capable of being beamed at said modulator; a radio-frequency oscillator capable of providing outputs at a plurality of frequencies; and a switching device coupled to said modulator and to said oscillator means; said switching device allowing each of said plurality of frequencies to be coupled to said modulator in succession, according to a predetermined sequence; the application to the modulator of each of said frequencies causing a corresponding deflection in the angle of the beam exiting from said modulator; said deflected beam having a predetermined power versus time characteristic; said predetermined sequence allowing a first frequency to be coupled to said modulator followed by a second frequency being coupled to said modulator at a time before the deflected beam exiting from said modulator, as a consequence of the application of s

Abstract: This invention relates to information transmission systems and in one embodiment comprises apparatus and methods for generating facsimile signals that are compatible with devices in general use for sequential printing of alphanumeric characters, whereby the number of data bits required to transmit such facsimile signals may be reduced, and facsimile images or alphanumeric images may be printed interchangeably in sequence from the same data stream.