GB1471384A - Facsimile apparatus - Google Patents

Facsimile apparatus

Info

Publication number
GB1471384A
GB1471384A GB3304774A GB3304774A GB1471384A GB 1471384 A GB1471384 A GB 1471384A GB 3304774 A GB3304774 A GB 3304774A GB 3304774 A GB3304774 A GB 3304774A GB 1471384 A GB1471384 A GB 1471384A
Authority
GB
United Kingdom
Prior art keywords
signals
frequency
controlled oscillator
phase
frequencies
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.)
Expired
Application number
GB3304774A
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.)
ExxonMobil Technology and Engineering Co
Original Assignee
Exxon Research and Engineering Co
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 Exxon Research and Engineering Co filed Critical Exxon Research and Engineering Co
Publication of GB1471384A publication Critical patent/GB1471384A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/00095—Systems or arrangements for the transmission of the picture signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
    • H04L27/14—Demodulator circuits; Receiver circuits

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Facsimiles In General (AREA)

Abstract

1471384 Copying by scanning EXXON RESEARCH & ENG CO 26 July 1974 33047/74 Heading H4F Frequency-modulated signals representative of a scanned original are demodulated by a phase-locked loop having a voltage controlled oscillator 324 and a phase detector which may be a balanced modulator 326; the phase-locked loop inherently doubles (or triples or quadruples) the fundamental frequencies of the frequencymodulated signals, these multiplied frequencies being removed by a filter 328. The signals derived from a scanned original may be fed to a voltage controlled oscillator 304, block signals being transmitted as a signal of frequency 2400 Hz and white signals as a signal of frequency 1500 Hz, filter 328 removing frequencies in the range 3000-4800 Hz. A transceiver (Fig. 3, not shown) may use one voltage-controlled oscillator instead of two separate oscillators 304 and 324, switches being provided at the input and output of the oscillator to correctly connect it for use in a transmitting mode or a receiving mode.
GB3304774A 1974-06-12 1974-07-26 Facsimile apparatus Expired GB1471384A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19742428481 DE2428481A1 (en) 1974-06-12 1974-06-12 FACSIMILE SYSTEM

Publications (1)

Publication Number Publication Date
GB1471384A true GB1471384A (en) 1977-04-27

Family

ID=5918001

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3304774A Expired GB1471384A (en) 1974-06-12 1974-07-26 Facsimile apparatus

Country Status (2)

Country Link
DE (1) DE2428481A1 (en)
GB (1) GB1471384A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3237239A1 (en) * 1981-10-08 1983-04-28 Canon K.K., Tokyo IMAGE TRANSFER SYSTEM

Also Published As

Publication number Publication date
DE2428481A1 (en) 1976-01-02

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee