JPS5551375B2 - - Google Patents

Info

Publication number
JPS5551375B2
JPS5551375B2 JP5749476A JP5749476A JPS5551375B2 JP S5551375 B2 JPS5551375 B2 JP S5551375B2 JP 5749476 A JP5749476 A JP 5749476A JP 5749476 A JP5749476 A JP 5749476A JP S5551375 B2 JPS5551375 B2 JP S5551375B2
Authority
JP
Japan
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.)
Expired
Application number
JP5749476A
Other languages
Japanese (ja)
Other versions
JPS52141104A (en
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 filed Critical
Priority to JP5749476A priority Critical patent/JPS52141104A/en
Publication of JPS52141104A publication Critical patent/JPS52141104A/en
Priority to US05/967,017 priority patent/US4254306A/en
Publication of JPS5551375B2 publication Critical patent/JPS5551375B2/ja
Granted 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
    • H04M1/68—Circuit arrangements for preventing eavesdropping

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Sub-Exchange Stations And Push- Button Telephones (AREA)
JP5749476A 1975-12-26 1976-05-19 Private talk system for telephone unit Granted JPS52141104A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP5749476A JPS52141104A (en) 1976-05-19 1976-05-19 Private talk system for telephone unit
US05/967,017 US4254306A (en) 1975-12-26 1978-12-06 Key telephone system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5749476A JPS52141104A (en) 1976-05-19 1976-05-19 Private talk system for telephone unit

Publications (2)

Publication Number Publication Date
JPS52141104A JPS52141104A (en) 1977-11-25
JPS5551375B2 true JPS5551375B2 (en) 1980-12-24

Family

ID=13057269

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5749476A Granted JPS52141104A (en) 1975-12-26 1976-05-19 Private talk system for telephone unit

Country Status (1)

Country Link
JP (1) JPS52141104A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56149158A (en) * 1980-04-21 1981-11-18 Nitsuko Ltd Key telephone set
JPS5725786A (en) * 1980-07-22 1982-02-10 Iwatsu Electric Co Ltd Changeover talking circuit during service interruption
JPS5725767A (en) * 1980-07-22 1982-02-10 Iwatsu Electric Co Ltd Telephone device

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS494962A (en) * 1972-04-27 1974-01-17
JPS4996604A (en) * 1973-01-13 1974-09-12

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS494962A (en) * 1972-04-27 1974-01-17
JPS4996604A (en) * 1973-01-13 1974-09-12

Also Published As

Publication number Publication date
JPS52141104A (en) 1977-11-25

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