Telegraphy – Systems – Position coordinate determination for writing
Patent
1980-03-19
1981-09-15
Robinson, Thomas A.
Telegraphy
Systems
Position coordinate determination for writing
G08C 2100
Patent
active
042899265
ABSTRACT:
The invention improves the signal-to-noise ratio of a telewriter transmitter without requiring a change in preexisting telewriter transmission equipment. The individual crosspoints of an orthogonal matrix of wires are identified by high-frequency X and Y signals having phase-shifted characteristics which identify individual crosspoints by phase angles. The use of high frequencies reduces coupling impedance, especially when moisture is present or humidity is high. The high frequency signals are picked up by an electrostatic coupling between the point of a pen and any selected crosspoint which the pen happens to be near. The picked-up signal is amplitude modulated to increase its strength and then fed back to the identified crosspoint, thereby enhancing the strength of the picked-up signal. The enhanced signal is again picked-up and demodulated to recover the original phase-shifted characteristics of the signal which individually identified a crosspoint selected by the pick up means. The demodulated signals are then converted into the form of crosspoint identification signal which is used by the preexisting telewriter transmission system.
REFERENCES:
patent: 3342935 (1967-09-01), Leifer et al.
patent: 3636258 (1972-01-01), Brumbach
patent: 3767858 (1973-10-01), Rodgers
patent: 3865977 (1975-02-01), Hiraki et al.
Nippon Electric Co. Ltd.
Robinson Thomas A.
LandOfFree
Transmitter for a telewriter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transmitter for a telewriter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transmitter for a telewriter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-391949