GB375892A - Process and apparatus for the transmission of half-tone pictures by wireless telegraphy - Google Patents

Process and apparatus for the transmission of half-tone pictures by wireless telegraphy

Info

Publication number
GB375892A
GB375892A GB1030831A GB1030831A GB375892A GB 375892 A GB375892 A GB 375892A GB 1030831 A GB1030831 A GB 1030831A GB 1030831 A GB1030831 A GB 1030831A GB 375892 A GB375892 A GB 375892A
Authority
GB
United Kingdom
Prior art keywords
picture
april
intervals
transmitted
modulating frequency
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
GB1030831A
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.)
Telefunken AG
Original Assignee
Telefunken AG
Telefunken Gesellschaft fuer Drahtlose Telegraphie mbH
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 Telefunken AG, Telefunken Gesellschaft fuer Drahtlose Telegraphie mbH filed Critical Telefunken AG
Publication of GB375892A publication Critical patent/GB375892A/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

Landscapes

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

Abstract

375,892. Copying-telegraphy. TELEFUNKEN GES. FœR DRAHTLOSE TELEGRAPHIE, 12, Hallesches Ufer, Berlin. April 8, 1931, No. 10308. Convention date, April 8, 1930. [Classes 40 (iii) and 40 (v).] In a system for the telegraphic transmission of pictures, the amplitude range of the picture current is divided into a number of intervals, each of which is represented by and transmitted as a separate modulating frequency. At the receiving end the picture is reproduced in gradations of tone corresponding to the different frequencies. An oscillograph mirror 1, oscillated by the picture currents passed through an amplifier and rectifier 21, reflects a lightbeam from a source 2 as a light spot 4 which, in accordance with current amplitude, falls upon one of a number of photo-electric cells 5, 6, 7 connected through resistances 8, 9, 10 in the grid circuits of thermionic valves 11, 12,13 respectively. The valve rendered operative causes one of the A.C. generators 14, 15, 16 to transmit a corresponding modulating frequency w1, w2 or w3 to the line. One of the intervals of the picture current amplitude may be transmitted as unmodulated carrier frequency. The system is stated to reduce the effects of fading since the output of the receiving device selectively operated by any of the frequencies is arranged to be of constant strength. Specification 360,263 is referred to.
GB1030831A 1930-04-09 1931-04-08 Process and apparatus for the transmission of half-tone pictures by wireless telegraphy Expired GB375892A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE563071T 1930-04-09

Publications (1)

Publication Number Publication Date
GB375892A true GB375892A (en) 1932-07-07

Family

ID=34559077

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1030831A Expired GB375892A (en) 1930-04-09 1931-04-08 Process and apparatus for the transmission of half-tone pictures by wireless telegraphy

Country Status (4)

Country Link
DE (1) DE563071C (en)
FR (1) FR714841A (en)
GB (1) GB375892A (en)
NL (1) NL31570C (en)

Also Published As

Publication number Publication date
NL31570C (en)
DE563071C (en) 1932-11-03
FR714841A (en) 1931-11-20

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