JPS57148452A - Control system for transmitting and receiving line of hand-free telephone set - Google Patents

Control system for transmitting and receiving line of hand-free telephone set

Info

Publication number
JPS57148452A
JPS57148452A JP3376381A JP3376381A JPS57148452A JP S57148452 A JPS57148452 A JP S57148452A JP 3376381 A JP3376381 A JP 3376381A JP 3376381 A JP3376381 A JP 3376381A JP S57148452 A JPS57148452 A JP S57148452A
Authority
JP
Japan
Prior art keywords
transmitting
line
receiving line
switch
telephone set
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP3376381A
Other languages
Japanese (ja)
Other versions
JPS6324584B2 (en
Inventor
Shigeru Sutani
Takahiro Kudo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
YUNIDEN KK
Uniden Corp
Original Assignee
YUNIDEN KK
Uniden Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by YUNIDEN KK, Uniden Corp filed Critical YUNIDEN KK
Priority to JP3376381A priority Critical patent/JPS57148452A/en
Publication of JPS57148452A publication Critical patent/JPS57148452A/en
Publication of JPS6324584B2 publication Critical patent/JPS6324584B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)

Abstract

PURPOSE:To prevent various characteristics from being spoiled by increasing a howling margin, by comparing the outputs of detectors provided to a transmitting and a receiving line. CONSTITUTION:On a transmitting line Lt, a level detector 19 is provided in front of a transmitting line switch 16, and on a receiving line Lr, a level detector 20 is provided behind a receiving line switch 17. The outputs of those detectors 19 and 20 are connected to a comparator 21 to make a comparison between the two inputs 21a and 21b; when the out-of-phase input 21a is equal to or greater than the in-phase input 21b, an output 21c having a high level as the 2nd one is generated and when not, the output has a high level as the 2nd one. When it has the low level, the switch 16 opens the line Lt and the switch 17 closes the line Lr. Namely, while a telephone set is in a waiting state, control is so exercised that the output 21c of the comparator 21 has the low level securely.
JP3376381A 1981-03-11 1981-03-11 Control system for transmitting and receiving line of hand-free telephone set Granted JPS57148452A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3376381A JPS57148452A (en) 1981-03-11 1981-03-11 Control system for transmitting and receiving line of hand-free telephone set

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3376381A JPS57148452A (en) 1981-03-11 1981-03-11 Control system for transmitting and receiving line of hand-free telephone set

Publications (2)

Publication Number Publication Date
JPS57148452A true JPS57148452A (en) 1982-09-13
JPS6324584B2 JPS6324584B2 (en) 1988-05-21

Family

ID=12395466

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3376381A Granted JPS57148452A (en) 1981-03-11 1981-03-11 Control system for transmitting and receiving line of hand-free telephone set

Country Status (1)

Country Link
JP (1) JPS57148452A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5951646A (en) * 1982-09-16 1984-03-26 Fujitsu Ltd Loudspeaker telephone set
JPH01253353A (en) * 1988-03-31 1989-10-09 Fujitsu Ten Ltd Howling canceler system for hand-free telephone
US5138651A (en) * 1989-02-23 1992-08-11 Fujitsu Limited Cordless loud speaking telephone
SG82584A1 (en) * 1997-08-06 2001-08-21 Calsonic Corp Telephone hand-free apparatus

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5951646A (en) * 1982-09-16 1984-03-26 Fujitsu Ltd Loudspeaker telephone set
JPS6340061B2 (en) * 1982-09-16 1988-08-09 Fujitsu Ltd
JPH01253353A (en) * 1988-03-31 1989-10-09 Fujitsu Ten Ltd Howling canceler system for hand-free telephone
US5138651A (en) * 1989-02-23 1992-08-11 Fujitsu Limited Cordless loud speaking telephone
SG82584A1 (en) * 1997-08-06 2001-08-21 Calsonic Corp Telephone hand-free apparatus

Also Published As

Publication number Publication date
JPS6324584B2 (en) 1988-05-21

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