GB341818A - Improvements in or relating to picture telegraph apparatus - Google Patents

Improvements in or relating to picture telegraph apparatus

Info

Publication number
GB341818A
GB341818A GB13364/30A GB1336430A GB341818A GB 341818 A GB341818 A GB 341818A GB 13364/30 A GB13364/30 A GB 13364/30A GB 1336430 A GB1336430 A GB 1336430A GB 341818 A GB341818 A GB 341818A
Authority
GB
United Kingdom
Prior art keywords
cell
beams
scanned
current
curve
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
GB13364/30A
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 GB341818A publication Critical patent/GB341818A/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
    • H04N1/024—Details of scanning heads ; Means for illuminating the original
    • H04N1/028—Details of scanning heads ; Means for illuminating the original for picture information pick-up
    • H04N1/029—Heads optically focused on only one picture element at a time

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Scanning Arrangements (AREA)

Abstract

341,818. Copying telegraphy. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE, 12, Hallesches Ufer, Berlin. April 30, 1930, No. 13364. Convention date, April 30, 1929. [Class 40 (iii).] A photo-electric cell is alternately illuminated by two beams of light, one of constant intensity and the other of an intensity varying in accordance with the tone values of a scanned picture so that the electrical variations of the cell are inversely proportional to the brightness of the point scanned. The two light beams 3, 9 are derived from a source 1 and pass through the apertures 2, 11 in a disc 16 which allows the beams to pass alternately. The beam 3 is modulated by the picture 6 while the beam 9 remains constant in intensity. The fluctuations in the current through the cell 8 caused by the two beams are represented by the curves a, b, respectively in Fig. 3. The tinted wedges 15, Fig. 1, are adjusted so that when the point scanned is white a constant current, curve c1, passes through the cell. When a dark portion is being scanned, the curve a assumes the form in the lower portion of Fig. 3 and the resultant curve c2, and therefore the current through the cell, becomes oscillatory, the variations in the current being inversely proportional to the brightness of the point scanned. A reflector 7, Fig. 1, is used to concentrate light upon the cell 8.
GB13364/30A 1929-04-30 1930-04-30 Improvements in or relating to picture telegraph apparatus Expired GB341818A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE341818X 1929-04-30

Publications (1)

Publication Number Publication Date
GB341818A true GB341818A (en) 1931-01-22

Family

ID=6236015

Family Applications (1)

Application Number Title Priority Date Filing Date
GB13364/30A Expired GB341818A (en) 1929-04-30 1930-04-30 Improvements in or relating to picture telegraph apparatus

Country Status (1)

Country Link
GB (1) GB341818A (en)

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