US1884288A - Facsimile transmission - Google Patents

Facsimile transmission Download PDF

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Publication number
US1884288A
US1884288A US420330A US42033030A US1884288A US 1884288 A US1884288 A US 1884288A US 420330 A US420330 A US 420330A US 42033030 A US42033030 A US 42033030A US 1884288 A US1884288 A US 1884288A
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US
United States
Prior art keywords
picture
frequency
transmission
carrier
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 - Lifetime
Application number
US420330A
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English (en)
Inventor
Schroter Fritz
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
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 filed Critical Telefunken AG
Application granted granted Critical
Publication of US1884288A publication Critical patent/US1884288A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
    • H04N1/06—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using cylindrical picture-bearing surfaces, i.e. scanning a main-scanning line substantially perpendicular to the axis and lying in a curved cylindrical surface
    • H04N1/0671—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using cylindrical picture-bearing surfaces, i.e. scanning a main-scanning line substantially perpendicular to the axis and lying in a curved cylindrical surface with sub-scanning by translational movement of the main-scanning components
    • H04N1/0678—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using cylindrical picture-bearing surfaces, i.e. scanning a main-scanning line substantially perpendicular to the axis and lying in a curved cylindrical surface with sub-scanning by translational movement of the main-scanning components using a lead-screw or worm
    • 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
    • H04N1/00103—Systems or arrangements for the transmission of the picture signal specially adapted for radio transmission, e.g. via satellites
    • 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
    • H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
    • H04N1/203—Simultaneous scanning of two or more separate pictures, e.g. two sides of the same sheet
    • 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
    • H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
    • H04N1/203—Simultaneous scanning of two or more separate pictures, e.g. two sides of the same sheet
    • H04N1/2036—Simultaneous scanning of two or more separate pictures, e.g. two sides of the same sheet of a plurality of pictures corresponding to a single side of a plurality of media
    • H04N1/2038—Simultaneous scanning of two or more separate pictures, e.g. two sides of the same sheet of a plurality of pictures corresponding to a single side of a plurality of media lying in the same plane
    • 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
    • H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
    • H04N1/06—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa using cylindrical picture-bearing surfaces, i.e. scanning a main-scanning line substantially perpendicular to the axis and lying in a curved cylindrical surface

Definitions

  • This invention proposes arsolution which does away with the described deficiency by adaptation to the peculiarities-of short-wave transmission and permits an undiminished speed of transmission.
  • the news or documents to be facsimiled are mounted on a number of reduced-speed transmitting and receiving drums and to eachfcombination of this kind is assigned a separate transf mission channel with a frequency band of correspondingly diminished width; withthis arrangement the total widthof the frequency band employed is not vgreater than if a single drum were used at ⁇ a correspondingly:higher velocity, although the transmitting capacity, measured, vfor instance, in Words'per minute is notchanged.
  • the separate transmission channels may consist in this case. of frequency bands, limitable and separable by electrical filters and Similar to those used Lin the A. C. multipletelegraphy (sound telegraphy) Consequently the side band or bands of the usual carrier wave modulation of a transmitter would consist, in thiscase, of several ksections andeach section would be assigned a transmissionl channel..
  • sevor BERLIN, GERMANY, A ⁇ CORPORATION or
  • the first-mentioned case it is of advan- Y tage :to apply the one-sideband-method with suppressed carrier oscillation.
  • thetotalpower given off by the transmitter is applied only to the frequencies needed iforthe transmission. If it were, forinstance, neces ⁇ sary vto reduce theY speed of transmission, in view of the describedv disturbances to onethirdof its present value, thel transmitted band would vhave to consist of three sections, each containing Athe picture frequencies for one of the separate transmissions.vv Hereby only one-third of. the transmitting power'fis givenfoff through each channel, thus reducing the' intensity of reception.
  • Fig. 1 illustrates 'the transmittingand by which Fig. 2 yillustrates the receiving device.
  • Three picture drums l, 2, 3, drivenby the same'operating mechanismand covered with the documents to ybe transmitted are spotted, that is, scanned over by a'spot-photographing device.
  • the driving forceI may bebfurnislied by an electro-motor 4, directly coupled to a synchronous motor 5 of constant speed, supplied with a current of normal lfrequency. This speed is reduced by means of a system of gears 6 to the 'value desired for the drums 1, 2, 3.
  • the same mechanism drives, by means of the bevel gears 7, 8, the perforated disks 9, l0, 11 provided with a varying number of holes.
  • the purpose of thesedisks is'to interrupt the spotting light at various frequencies.
  • the perforated disk 9.1,nay-.generate alight to secure a helical scanning or spotting of the drums 1, 2, 3 the latter are, during the rotation, gradually advanced along their axis by means of a Worm gear 21, 22.
  • the input tubes of the three amplifiers 23, 24, 25 are subjected to modulated oscillations of a carrier frequency of 1500, 3000 and 4500 periods, With side bands Whose width depends on the spotting velocity and on the distribution of light and darkness on the documents to be transmitted.
  • the modulation Width is kept within the permissible limits foreach channel.
  • filter chains or filter circuits 26, 27, 28 are provided, each of Which has to transmit only one side band of the modulation of the three carrier 4frequencies.
  • filter 26 maytransmit the frequency band 1500 to 2500, filter 27-the band 3000 to 4000, filter 28-the band 4500 to 5500., In certain cases it is, however,
  • the high frequency received by the short- Wave receiver 31 is at firstdemodulated in a known manner and the amplified low frequency, which is a combination of the three transmission-frequency bands, is filtered by Way of three filters 33, 34, 35. If both side bands of each carrier voscillation are passed by the filters 33, 34, 35, it is onlyvnecessary to effect by rectification a second demodulation in the amplifiers 36, 37, 38 in order to obtain directly the picture-recording frequency. If, however, only one sideband of each perforated-disk frequency is transmitted to the receiver, While the carrier oscillation is suppressed, it is necessary to generate these perforated-disk frequencies artificially. To this end frequency generators are provided, of known constrction, f.
  • the interrupters 51, 52, 53 which are included in the circuit of a D. C. source 54 and are driven at constant speed over a bevel gear by a synchronous motor set 49, corresponding to the set 4, 5 at the transmitting end.
  • the picture frequencies obtained at the outlet of the ampli- ⁇ fieis 36, 37, 38 are now transmitted to three separate recording devices. l
  • the recorder in this case is assumed-to ⁇ consist of an electro-chemical recording device, three recording points 39, 40, 41 gliding along a moistened, specially prepared paper which is mounted on the three receiving drums 42, 43, 44.
  • the amplifiers thus serve the double purpose of reestablishing and rectifying the picture frequencies.
  • the three drums 42, 43, 44 are driven by means of a system of gears 47 at a proper speed and advanced axially by means of aI Worm gear 45, 46 similar in construction to the operating mechanism at the transmitting end.
  • a system for simultaneously transmitting a plurality of picture record messages which comprises a plurality of supporting carriers for carrying said messages, a single driving element for rotating said carriersat identical speeds relative to predetermined points positioned in like relationship With respect to each record carrier, means for illuminating related elemental areas of each of said record carriers from a plurality of light sources, means for interrupting the light from each of said light sources directed toward said record carriers at different frequencies bearing preestablished relationship one With the other, light translating means associated With each of said record carriers for converting the varying intensities of light and shadow thereon as illuminated by said light sources into proportionately modulated electric current impulses of different frequencies, means for combining the output energies of all of said light translating elements, a transmitter for transmitting said signals, means for modulating said transmitter simultaneously by all of said signals, receiving means, and means at the point of reception for separating said receivedsignals one from the other for reproducing a plurality of images corresponding to the records carried by each record carrier.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • General Physics & Mathematics (AREA)
  • Facsimiles In General (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Optical Communication System (AREA)
US420330A 1929-01-16 1930-01-13 Facsimile transmission Expired - Lifetime US1884288A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DET36295D DE559838C (de) 1929-01-16 1929-01-16 Verfahren zur telegraphischen Bild- und Faksimile-UEbertragung
DE342857X 1929-01-16

Publications (1)

Publication Number Publication Date
US1884288A true US1884288A (en) 1932-10-25

Family

ID=25823533

Family Applications (1)

Application Number Title Priority Date Filing Date
US420330A Expired - Lifetime US1884288A (en) 1929-01-16 1930-01-13 Facsimile transmission

Country Status (4)

Country Link
US (1) US1884288A (de)
DE (1) DE559838C (de)
FR (1) FR687979A (de)
GB (1) GB342857A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4870504A (en) * 1986-12-02 1989-09-26 Dainippon Screen Mfg. Co., Ltd. Image scanning apparatus including means for selecting one of a plurality of scanning drums to be scanned

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1034213B (de) * 1954-08-04 1958-07-17 Emi Ltd Sendeanordnung fuer die UEbertragung des Bild- und Tonkanals eines Fernsehsenders
DE977779C (de) * 1954-10-19 1970-03-26 Bundesrep Deutschland Fernschreiber zum drahtlosen Unterwasserfernschreiben
GB907790A (en) * 1959-09-16 1962-10-10 Muirhead & Co Ltd Improvements in or relating to facsimile telegraphy

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4870504A (en) * 1986-12-02 1989-09-26 Dainippon Screen Mfg. Co., Ltd. Image scanning apparatus including means for selecting one of a plurality of scanning drums to be scanned

Also Published As

Publication number Publication date
FR687979A (fr) 1930-08-18
DE559838C (de) 1932-09-24
GB342857A (en) 1931-02-12

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