发明名称 |
Transmitter for a telewriter |
摘要 |
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.
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申请公布号 |
US4289926(A) |
申请公布日期 |
1981.09.15 |
申请号 |
US19800131654 |
申请日期 |
1980.03.19 |
申请人 |
NIPPON ELECTRIC CO., LTD. |
发明人 |
KOBAYASHI, MASAHISA |
分类号 |
G06F3/045;G06F3/033;G06F3/041;G06F3/044;G06K11/00;G06K11/06;(IPC1-7):G08C21/00 |
主分类号 |
G06F3/045 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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