Abstract A contactfree data input device for an electronic calculator which is not limited by the finger size of the operator. The input device includes an input stylus having an element on the end thereof which will initiate an electrical input signal when it is brought into close proximity to a cooperating input circuit means located at a value input location in the input field. According to one embodiment an electret is provided on the stylus and the input circuit means comprises a pair of spaced electrodes. According to a further embodiment, the stylus is provided with a permanent magnet and the input circuit means comprises a ferrite core which is continuously being switched between its magnetization states and which has a separate readout winding.
Apparatus for the manual contactfree input of data into a miniature electronic data processing device comprising in combination: an input field for the data processing device having a plurality of discrete input locations each of which is associated with a different input value; an input circuit at each of said input locations including a pair of spaced electrodes; signal evaluating means; means directly connecting each said electrode to said signal evaluating means; an input stylus; and an electret located on the tip of said stylus for initiating an electrical signal in one of said input circuits when the tip of said stylus is brought in close proximity to the input circuit associated with said one of of said input locations.
Claim 2
Dependent Claim
120 words
Apparatus for the manual contactfree input of data into a miniature electronic data processing device comprising in combination: an input field for the data processing device having a plurality of discrete input locations each of which is associated with a different input value; an input circuit at each of said input locations including a pair of spaced electrodes; signal evaluating means; means directly connecting each said electrode to said signal evaluating means; an input stylus; and an electret located on the tip of said stylus for initiating an electrical signal in one of said input circuits when the tip of said stylus is brought in close proximity to the input circuit associated with said one of of said input locations.