JPS5567267A - Hand-free telephone set - Google Patents

Hand-free telephone set

Info

Publication number
JPS5567267A
JPS5567267A JP14034278A JP14034278A JPS5567267A JP S5567267 A JPS5567267 A JP S5567267A JP 14034278 A JP14034278 A JP 14034278A JP 14034278 A JP14034278 A JP 14034278A JP S5567267 A JPS5567267 A JP S5567267A
Authority
JP
Japan
Prior art keywords
circuit
sound
microphone
speaker
supplied
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
JP14034278A
Other languages
Japanese (ja)
Other versions
JPS6217424B2 (en
Inventor
Hisashi Fujisaki
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.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
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 NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP14034278A priority Critical patent/JPS5567267A/en
Publication of JPS5567267A publication Critical patent/JPS5567267A/en
Publication of JPS6217424B2 publication Critical patent/JPS6217424B2/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

Abstract

PURPOSE:To prevent generation of echo and singing without interference in normal conversation by using only the half of a sound spectrum band. CONSTITUTION:Receiving sound signal a from receiver or two wire-four wire converter 6 has the sound spectrum band divided into narrow bands at, for example, an interval of 100Hz by receiving circuit 7, and only even-numbered narrow band spectrums are supplied to speaker 1. Meanwhile, voice of a talking person is converted to signal c by microphone 2, and only odd-numbered narrow band spectrums are supplied to transmitter or converter 6 by transmission circuit 8 having a characteristic complementary for receiving circuit 7. Consequently, sound radiated from speaker 1 is prevented from being transmitted to the transmission system through microphone 2 and circuit 8, so that complete simultaneous services can be performed.
JP14034278A 1978-11-14 1978-11-14 Hand-free telephone set Granted JPS5567267A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14034278A JPS5567267A (en) 1978-11-14 1978-11-14 Hand-free telephone set

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14034278A JPS5567267A (en) 1978-11-14 1978-11-14 Hand-free telephone set

Publications (2)

Publication Number Publication Date
JPS5567267A true JPS5567267A (en) 1980-05-21
JPS6217424B2 JPS6217424B2 (en) 1987-04-17

Family

ID=15266591

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14034278A Granted JPS5567267A (en) 1978-11-14 1978-11-14 Hand-free telephone set

Country Status (1)

Country Link
JP (1) JPS5567267A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60214144A (en) * 1984-03-21 1985-10-26 エヌ・ベー・フイリツプス・フルーイランペンフアブリケン Loudspeaking telephone set

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4990007A (en) * 1972-12-27 1974-08-28

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4990007A (en) * 1972-12-27 1974-08-28

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60214144A (en) * 1984-03-21 1985-10-26 エヌ・ベー・フイリツプス・フルーイランペンフアブリケン Loudspeaking telephone set
JPH0319747B2 (en) * 1984-03-21 1991-03-15 Fuiritsupusu Furuuiranpenfuaburiken Nv

Also Published As

Publication number Publication date
JPS6217424B2 (en) 1987-04-17

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