Keyboard printer with continuously rotating type member

Claim 2

A keyboard printer for use as a peripheral element of a computer comprising a character wheel, means for continuously rotating said character wheel and for selectively printing the characters without stopping of the wheel, means for distributing onto a plurality of start and character terminals a start pulse and character pulses, each character being defined by the delay between the start pulse and the character pulse, a plurality of touch-operated character keys each including first and second electrodes, connections between the first of said electrodes and said character terminals, an annular electrode a rotating electrode sequentially and capacitatively coupling said annular electrode to each one of a plurality of character electrodes each constituting one of said character terminals, connections between the second of said electrodes and an output terminal, said key electrodes exhibiting with each other a large capacitance when the operator''s finger tip is on the key and a small capacitance when it is out of the key, whereby a character pulse is produced at said output terminal when the operator touches the corresponding key.

Claim 3

A keyboard printer as set forth in claim 1 in which the start and character pulse distributing means comprise a first rotative wheel with one magnetic tooth and a first electromagnet cooperating therewith, a second rotative wheel with a plurality of equally spaced magnetic teeth and a second electromagnet cooperating therewith and having a winding with a grounded center tap, a dielectric cylinder coaxial with said first and second rotative wheel, an annular common electrode disposed around said cylinder and a plurality of character electrodes radially and equiangularly spaced on said cylinder and connected to the character keys, and electrode-carrying rotative arm forming with said annular common electrode and said character electrodes a capacitor means for connecting said annular common electrode to the first terminal of the winding of the second electromagnet, a compensation capacitor, means for connecting in parallel the second key electrodes to a terminal of said compensation capacitor and means for connecting the other terminal of said compensation capacitor to the second terminal of said second electromagnet.

Claim 4

A keyboard printer as set forth in claim 1, in which the start and character pulses distributing means comprise a first rotative wheel with one magnetic tooth and a first electromagnet cooperating therewith, a second rotative wheel with a plurality of equally spaced magnetic teeth and a second electromagnet cooperating therewith and having a winding with a grounded center tap, a dielectric plane sheet parallel to said first and second rotative wheels, three annular coaxial electrode rings disposed on said plane sheet and a plurality of character electrodes radially and equiangularly spaced apart on said plane sheet and connected to the character keys, a rotative arm carrying two mobile electrodes, the first mobile electrode forming with the first annular electrode ring and said character electrodes a first capacitor and the second mobile electrode forming with the second and third annular electrode rings a second compensation capacitor, means for connecting said first annular electrode ring to the first terminal of the winding of the second electromagnet, means for connecting said second annular electrode ring to the second terminal of the winding of the second electromagnet and means for connecting in parallel the second key electrode to the third annular elecTrode ring.

Claim 5

A keyboard printer as set forth in claim 1 in which the start and character pulse distributing means comprises a first rotative wheel with one magnetic tooth and a first electromagnet cooperating therewith, a second rotative wheel with a plurality of equally spaced magnetic teeth and a second electromagnet cooperating therewith, a dielectric plane sheet parallel to said first and second rotative wheels, an annular electrode ring disposed on said plane sheet and a plurality of character electrodes radially disposed and equiangularly spaced on said plane sheet, a rotative arm carrying a mobile electrode and forming with the annular electrode ring and the character electrodes a capacitor, an oscillator with two output terminals, a plurality of transformers having primary and secondary windings, means for connecting the character electrodes respectively to the first key electrodes through the primary windings of said transformers, means for connecting one output terminal of the oscillator to said annular electrode ring, means for connecting in parallel the second key electrodes to the second output terminal of the oscillator and means for connecting the windings of the first and second electromagnets on the one hand and the secondary windings of the transformers in series on the other hand to the output terminal of the printer.