JPS5623074A - Modulator for facsimile - Google Patents

Modulator for facsimile

Info

Publication number
JPS5623074A
JPS5623074A JP9846079A JP9846079A JPS5623074A JP S5623074 A JPS5623074 A JP S5623074A JP 9846079 A JP9846079 A JP 9846079A JP 9846079 A JP9846079 A JP 9846079A JP S5623074 A JPS5623074 A JP S5623074A
Authority
JP
Japan
Prior art keywords
waveform
signal
circuit
supplied
waveforms
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
JP9846079A
Other languages
Japanese (ja)
Inventor
Masaru Yamaguchi
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 JP9846079A priority Critical patent/JPS5623074A/en
Publication of JPS5623074A publication Critical patent/JPS5623074A/en
Pending 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
    • H04N1/41—Bandwidth or redundancy reduction

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Image Signal Circuits (AREA)

Abstract

PURPOSE:To realize a high-degree band compression by forming the modulation signal via the signal whose polarity is reversed with every minimum and maximum points of the facsimile signal. CONSTITUTION:Base band facsimile signal A supplied through input terminal 1 is supplied to minimum point detecting circuit 2 and maximum point detecting circuit 3 each to deliver rectangular wave type signals C and D which hold the value up to the polarity inversion with every polar point. And signal A and output C are supplied to waveform processing circuit 4 to obtain signal B. Then the output of circuit 4 plus outputs C and D are supplied to waveform separating circuit 5. Circuit 5 holds waveform B during time T0-T1 and the value at time T1 during T1-T2 each. Thus separation waveform E which varies like the waveform produced by subtracting waveform B from the held value during T2-T3 is produced along with separation waveform F from waveforms E and B respectively. Then the orthogonal modulation is given to the carrier wave by waveforms E and F and through orthogonal modulating circuit 10 to carry out the transmission. Waveforms E and F have the band compressed to 1/4 in comparison with signal A.
JP9846079A 1979-07-31 1979-07-31 Modulator for facsimile Pending JPS5623074A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9846079A JPS5623074A (en) 1979-07-31 1979-07-31 Modulator for facsimile

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9846079A JPS5623074A (en) 1979-07-31 1979-07-31 Modulator for facsimile

Publications (1)

Publication Number Publication Date
JPS5623074A true JPS5623074A (en) 1981-03-04

Family

ID=14220302

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9846079A Pending JPS5623074A (en) 1979-07-31 1979-07-31 Modulator for facsimile

Country Status (1)

Country Link
JP (1) JPS5623074A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4949657A (en) * 1987-11-06 1990-08-21 Janome Sewing Machine Co. Ltd. Sewing machine with a device for amending thread tightening by needle positions

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4949657A (en) * 1987-11-06 1990-08-21 Janome Sewing Machine Co. Ltd. Sewing machine with a device for amending thread tightening by needle positions

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