Control circuit for a telephone system for the control of visual and audible signals
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United States of America Patent
Stats
-
May 5, 1981
Grant Date -
N/A
app pub date -
Jul 18, 1979
filing date -
Jul 18, 1979
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A telephone switching system, such as a private branch exchange, incorporates a centrally controlled control unit for controlling operation of visual and audible station instrument display device, without interfering with the voice communication line circuits, and without requiring external circuits and equipment.
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Family
International Classification(s)
Cited Art Landscape
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