Carrier control method by using phase-pulse signals

Claim 1

A carrier control method using phase-pulse signals comprising forming a plurality of terminal-selection channels, a plurality of figure-selection channels, and a plurality of returning channels having a respective predetermined phase width in one cycle of an alternating-current carrier wave; each of said returning channels being assigned a particular figure value; inserting a terminal-selection phase-pulse signal comprising a coded combination of the existence and the non-existence of a phase pulse of each terminal-selection channel in the terminal-selection channels of the alternating current carrier wave, corresponding to a code assigned to each terminal equipment at the center; inserting a figure-selection phase-pulse signal comprising a coded combination of the existence and the non-existence of a phase pulse of each figure-selection channel in the figure-selection channels of the alternating-current carrier wave, corresponding to a code which designates a figure of a datum of a plural number of figures stored in the terminal in the electrically readable state, also at the center; receiving the terminal-selection phase-pulse signal at the terminal equipment; inserting a returning phase-pulse signal comprising the existence and the non-existence of a phase pulse on only one of the returning channels of the alternating-current carrier wave at the terminal equipment, corresponding to the value of the designated figure of the datum memorized in the terminal, when a code of the terminal-selection phase-pulse signal coincides with the code of the terminal equipment; and receiving said returning phase-pulse signal at the center; the transmission of said terminal-selection phase-pulse signal and said figure-selection phase-pulse signal and the return of the returning phase-pulse signal being made for every figure of the datum stored in the terminal.