Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1981-09-21
1983-11-08
Rubinson, G. Z.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
179 81B, 179100L, 358 85, H04M 1108
Patent
active
044144326
ABSTRACT:
A television/telephone loudspeaker system is disclosed wherein feedback oscillation caused by having a speaker phone system simultaneously in the transmit and receive mode is minimized. Improved separation of transmit and receive signals is accomplished by microprocessor-controlled dynamic balancing of a bridge network coupled to a telephone isolation transformer to which the incoming and outgoing calls are provided. In addition, by microprocessor sampling of the television receiver's loudspeaker drive voltage from the telephone input line, dynamic proportional attenuation of microphone gain (AGC) is digitally accomplished in simulating full duplex operation. Bridge balancing is accomplished by means of test signals output by the microprocessor during quiet periods with various other audio signal refinements, such as room background noise cancellation, available with the constant monitoring of the microphone signal. Audio and visual indications of an incoming telephone call are provided by the television receiver's tuning system microcomputer which detects and decodes user remote commands and activates a phone relay and phone light emitting diode (LED) drivers.
REFERENCES:
patent: 2766378 (1956-10-01), Sundin et al.
patent: 3899643 (1975-08-01), Tabalba
patent: 3908094 (1975-09-01), Deluegue
patent: 3987254 (1976-10-01), Pipitone
patent: 4087636 (1978-05-01), Akiyama et al.
patent: 4113996 (1978-09-01), Sanderson
patent: 4192978 (1980-03-01), Vincent
patent: 4225754 (1980-09-01), Bernard et al.
patent: 4251689 (1981-02-01), Hastings-James et al.
patent: 4338492 (1982-07-01), Snopko
"MN 1400 Series: 4-Bit One-Chip Microcomputer" published by Matsushita Electronics Corporation.
"2920-16 Signal Processor" published by Intel Corporation.
Skerlos Peter C.
Zato Thomas J.
George Keith E.
Rubinson G. Z.
Zenith Radio Corporation
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