Compact hand-operated data input keyboard - has limited number of keys to facilitate high speed input of information with less fatigue

摘要

The compact hand-operated keyboard has a limited number of keys so arranged to facilitate the high-speed input of information using the fingers of one hand. The necessary number of switches (1, 3, 5) activate a recording circuit which prepares a control signal if an electrical signal associated with a symbol is at the output lines. The output terminals of the switches are simultaneously connected with the input terminals of a control circuit (25) which produce a first output signal when all switches are open and a second signal when one of the switches is closed. The output of this circuit is coupled to the input of a differentiating stage (27). A rectifier (31) is interposed between the output of the differentiator and the control line (37) which prepares the control signal.