|
GB1406243A
(en)
*
|
1971-10-28 |
1975-09-17 |
Gen Electric Co Ltd |
Loudspeaking telephone instruments
|
|
US3860756A
(en)
*
|
1973-03-23 |
1975-01-14 |
Nitsuko Ltd |
Automatic voice-path switching circuit for a speaker phone telephone set
|
|
US3889059A
(en)
*
|
1973-03-26 |
1975-06-10 |
Northern Electric Co |
Loudspeaking communication terminal apparatus and method of operation
|
|
JPS49123706A
(xx)
*
|
1973-03-30 |
1974-11-27 |
|
|
|
US3909548A
(en)
*
|
1973-12-07 |
1975-09-30 |
Jacobson Sava |
Speaker telephone
|
|
US4028506A
(en)
*
|
1973-12-12 |
1977-06-07 |
Nippon Electric Company, Ltd. |
Maximum value tracing circuit for digitized voice signals
|
|
JPS5411203B2
(xx)
*
|
1974-05-02 |
1979-05-12 |
|
|
|
US3963868A
(en)
*
|
1974-06-27 |
1976-06-15 |
Stromberg-Carlson Corporation |
Loudspeaking telephone hysteresis and ambient noise control
|
|
US3970786A
(en)
*
|
1974-06-27 |
1976-07-20 |
Stromberg-Carlson Corporation |
Loudspeaking telephone with improved receive sensitivity
|
|
ZA755743B
(en)
*
|
1974-09-27 |
1976-08-25 |
Gen Electric |
Improvements in or relating to loudspeaking telephone instruments
|
|
NO134477C
(xx)
*
|
1974-10-29 |
1976-10-13 |
Manus Max |
|
|
US3953676A
(en)
*
|
1974-12-12 |
1976-04-27 |
Northern Electric Company, Limited |
Digital control of a loudspeaking telephone system
|
|
CA1058340A
(en)
*
|
1975-06-30 |
1979-07-10 |
International Standard Electric Corporation |
Two-way loudspeaking device for telephone stations
|
|
US4115658A
(en)
*
|
1977-04-11 |
1978-09-19 |
Williams Richard W |
Two way telephone amplifier
|
|
US4115659A
(en)
*
|
1977-06-16 |
1978-09-19 |
Abram N. Spanel |
Electroacoustical telephone adapter
|
|
DE2842369A1
(de)
*
|
1978-09-28 |
1980-04-10 |
Siemens Ag |
Schaltungsanordnung fuer eine sprachgesteuerte lautfernsprechstation in fernmelde-, insbesondere fernsprechanlagen
|
|
IL63653A
(en)
*
|
1980-08-29 |
1984-05-31 |
Western Electric Co |
Line powered transformer-less loudspeaking telephone
|
|
US4378603A
(en)
*
|
1980-12-23 |
1983-03-29 |
Motorola, Inc. |
Radiotelephone with hands-free operation
|
|
US4536888A
(en)
*
|
1981-08-21 |
1985-08-20 |
Plantronics, Inc. |
Voice communication instrument system with line-powered receiver conditioning circuit
|
|
US4763349A
(en)
*
|
1981-12-31 |
1988-08-09 |
Howard Siegel |
Monitoring apparatus using telephone link
|
|
US4400584A
(en)
*
|
1982-04-05 |
1983-08-23 |
Motorola, Inc. |
Speakerphone for radio and, landline telephones
|
|
US4490582A
(en)
*
|
1983-02-18 |
1984-12-25 |
At&T Information Systems Inc. |
Speakerphone control circuit
|
|
JPS6412649A
(en)
*
|
1987-07-06 |
1989-01-17 |
Nec Corp |
Variable gain circuit for loudspeaker telephone set
|
|
US4786329A
(en)
*
|
1987-09-09 |
1988-11-22 |
The Dow Chemical Company |
Asphalt compositions containing anti-stripping additives prepared from amines or polyamines and phosphonates
|
|
US4879746A
(en)
*
|
1987-12-30 |
1989-11-07 |
Plantronics, Inc. |
Voice communication link interface apparatus
|
|
US4959857A
(en)
*
|
1988-12-28 |
1990-09-25 |
At&T Bell Laboratories |
Acoustic calibration arrangement for a voice switched speakerphone
|
|
US5187741A
(en)
*
|
1990-11-30 |
1993-02-16 |
At&T Bell Laboratories |
Enhanced acoustic calibration procedure for a voice switched speakerphone
|
|
US5594784A
(en)
*
|
1993-04-27 |
1997-01-14 |
Southwestern Bell Technology Resources, Inc. |
Apparatus and method for transparent telephony utilizing speech-based signaling for initiating and handling calls
|
|
JPH06338934A
(ja)
*
|
1993-05-25 |
1994-12-06 |
Exar Corp |
事象駆動型制御回路を有するスピーカーホーン
|
|
US5649008A
(en)
*
|
1994-08-02 |
1997-07-15 |
Motorola, Inc. |
Circuit and method of reducing sidetone in a receive signal path
|
|
US5692042A
(en)
*
|
1995-05-31 |
1997-11-25 |
Casio Phonemate, Inc. |
Speakerphone controlled by a comparator with hysteresis
|
|
CN1141552A
(zh)
*
|
1995-05-31 |
1997-01-29 |
尾电话伴侣公司 |
软件扬声器电话系统与操作扬声器电话的方法
|