JPS5652972A - Automatic frequency control unit - Google Patents

Automatic frequency control unit

Info

Publication number
JPS5652972A
JPS5652972A JP12860779A JP12860779A JPS5652972A JP S5652972 A JPS5652972 A JP S5652972A JP 12860779 A JP12860779 A JP 12860779A JP 12860779 A JP12860779 A JP 12860779A JP S5652972 A JPS5652972 A JP S5652972A
Authority
JP
Japan
Prior art keywords
aft
signal
changed
mode
control unit
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
JP12860779A
Other languages
Japanese (ja)
Inventor
Akinobu Masuko
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
Original Assignee
Toshiba 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, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP12860779A priority Critical patent/JPS5652972A/en
Publication of JPS5652972A publication Critical patent/JPS5652972A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/50—Tuning indicators; Automatic tuning control

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Television Receiver Circuits (AREA)

Abstract

PURPOSE:To expand the AFT leading-in range, by detecting the existence of both the synchronous signal but also the AFT signal as a signal detecting signal, and operating the AFT signal detecting circuit for a fixed time, in case the operation state has been changed to the AFT mode from the PLL mode. CONSTITUTION:When the switching unit 24 has been changed to the AFT mode, even in case there is no output from only the AFT signal detecting circuit 44, the frequency dividing ratio of the variable divider 13 in a PLL loop operation state is changed low by a fixed value, and the frequency dividing ratio of the variable divider 13 is fixed at the position where the synchronous signal has been detected.
JP12860779A 1979-10-05 1979-10-05 Automatic frequency control unit Pending JPS5652972A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12860779A JPS5652972A (en) 1979-10-05 1979-10-05 Automatic frequency control unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12860779A JPS5652972A (en) 1979-10-05 1979-10-05 Automatic frequency control unit

Publications (1)

Publication Number Publication Date
JPS5652972A true JPS5652972A (en) 1981-05-12

Family

ID=14988953

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12860779A Pending JPS5652972A (en) 1979-10-05 1979-10-05 Automatic frequency control unit

Country Status (1)

Country Link
JP (1) JPS5652972A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4731871A (en) * 1985-11-18 1988-03-15 Casio Computer Co., Ltd. Tuning device for liquid crystal television

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4731871A (en) * 1985-11-18 1988-03-15 Casio Computer Co., Ltd. Tuning device for liquid crystal television

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