JPS5787657A - Loudspeaker telephone system - Google Patents

Loudspeaker telephone system

Info

Publication number
JPS5787657A
JPS5787657A JP16337580A JP16337580A JPS5787657A JP S5787657 A JPS5787657 A JP S5787657A JP 16337580 A JP16337580 A JP 16337580A JP 16337580 A JP16337580 A JP 16337580A JP S5787657 A JPS5787657 A JP S5787657A
Authority
JP
Japan
Prior art keywords
call
loudspeaker
handset
power failure
circuit
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.)
Pending
Application number
JP16337580A
Other languages
Japanese (ja)
Inventor
Yutaka Nishino
Makoto Yoshitoshi
Shinichi Shibata
Shigenori Okamoto
Taiji Sato
Yoshiichi Sano
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.)
Toshiba Corp
NTT Inc
Original Assignee
Toshiba Corp
Nippon Telegraph and Telephone Corp
Tokyo Shibaura 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 Toshiba Corp, Nippon Telegraph and Telephone Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP16337580A priority Critical patent/JPS5787657A/en
Publication of JPS5787657A publication Critical patent/JPS5787657A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
    • H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets

Landscapes

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

Abstract

PURPOSE:To avoid disabled communication due to mis-operation and to hold the telephone line even at power failure, by automatically restoring a loudspeaker switch at the end of call. CONSTITUTION:When a handset 3 is disconnected, hook switches HS1, HS2 are changed over and normal telephone call can be made with a telephone set circuit 2. When a start switch in a control circuit 8 is depressed, a relay is activated, contacts S1-S3 are selected, and loudspeaker call can be made through a loudspeaker telephone circuit 5, speaker 6 and microphone 7. At the end of call, a hook switch is off-hooked once for on-hook again or another start switch can be depressed for the end of call. If power failure takes place during the loudspeaker call, an alarm takes place through the operation of power failure detection and an alarm circuit (not shown). In this case, when the handset is off- hooked, the relay is restored and the handset call is obtained.
JP16337580A 1980-11-21 1980-11-21 Loudspeaker telephone system Pending JPS5787657A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16337580A JPS5787657A (en) 1980-11-21 1980-11-21 Loudspeaker telephone system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16337580A JPS5787657A (en) 1980-11-21 1980-11-21 Loudspeaker telephone system

Publications (1)

Publication Number Publication Date
JPS5787657A true JPS5787657A (en) 1982-06-01

Family

ID=15772681

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16337580A Pending JPS5787657A (en) 1980-11-21 1980-11-21 Loudspeaker telephone system

Country Status (1)

Country Link
JP (1) JPS5787657A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61208951A (en) * 1985-03-13 1986-09-17 Sharp Corp Loudspeaker telephone set
US11395575B2 (en) 2016-10-31 2022-07-26 Flint Group IP Holdings Limited Lint removing device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5012910A (en) * 1973-04-05 1975-02-10

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5012910A (en) * 1973-04-05 1975-02-10

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61208951A (en) * 1985-03-13 1986-09-17 Sharp Corp Loudspeaker telephone set
US11395575B2 (en) 2016-10-31 2022-07-26 Flint Group IP Holdings Limited Lint removing device

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