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US2301375A - Facsimile photo transmission and reception - Google Patents

Facsimile photo transmission and reception Download PDF

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Publication number
US2301375A
US2301375A US364617A US36461740A US2301375A US 2301375 A US2301375 A US 2301375A US 364617 A US364617 A US 364617A US 36461740 A US36461740 A US 36461740A US 2301375 A US2301375 A US 2301375A
Authority
US
United States
Prior art keywords
subject
drum
facsimile
cycle
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 - Lifetime
Application number
US364617A
Other languages
English (en)
Inventor
John W Cox
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.)
RCA Corp
Original Assignee
RCA Corp
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 RCA Corp filed Critical RCA Corp
Priority to US364617A priority Critical patent/US2301375A/en
Priority to CH233314D priority patent/CH233314A/de
Priority to GB14326/41A priority patent/GB551034A/en
Application granted granted Critical
Publication of US2301375A publication Critical patent/US2301375A/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
    • H04N1/17—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa the scanning speed being dependent on content of picture

Definitions

  • An object of this invention is to transmit sig- .Qnalshavinga frequency varying with the shad- 2 ing of the subject and tomove the drum, or other scanning and recording surface, relatively past the analyzing member-.iat a rate vthat varies with theirequencyzfoithe signal.
  • FIG. 2 is an illustration of the receiving ap- Fig. 3 is a plan of the pinion and release catch o! the scanner and recording drum.
  • Fig. .4 is an elevation of the detent and pinion shown in Fig. 3.
  • Fig. 5 is a series of graphs used in explaining the operation of the invention.
  • the scanner l at the transmitter maybe of any type for producing relative motion between the pick-up and the picture or subject to be transmitted, but I have illustrated it, by way of example. as consisting of a drum 2 rotated by motor l, energized from direct current mains 4. 'This motor has a suitable resistance 5, so that it can be stopped with the current on without injury to the windings. The motor can either be geared to the drum or connected directly thereto. For simplicity of illustration I have shown the latter.
  • the pick-upl l2 is moved axially ofthe -drum by the usual threaded'shaft I3,"rotated by gear il meshing with a pinion I5 on the dnunshaft.
  • the gears in the scanner may have any desired pitch, as the invention is not limited to any line advance 'or circumferential speed ofthe drum.
  • the Ydrum 2 will be moved circumferentially oneiii'tieth of an inch and the pick-up l2 ⁇ wili'move to the right one-ilitieth of an inch for each complete revolution of the drum. That is, the line advance will be one-ftieth of an inch.
  • the scanning device of the recorder will be the same as that shown at the transmitter, except.
  • the element i2 instead of having a photoelectric cell for conversion of varying illumination into electric currents, will have a device for converting current into either illumination or mechanical motion to produce a record.
  • This may be produced in any of the well-known ways. but merelyby way of example it is assumed that the element 2 at the receiver contains a neon or other suitable lamp I8 for converting the sig- ⁇ nal pulses into illumination and that the drum supports a light sensitive surface for producing a picture in a suitable darkroom.
  • the pick-up I2 at the transmitter is adjustably connected by conductor i1 to a potentiometer resistance Il joined to the terminals of battery or other source of voltage Il. While the voltage variations produced by the photocell o the pick-up l1 can be used either to reduce or to increase the potential applied to the grid of the tube, Lhave illustrated it, by way of example. as increasing the potential.
  • the negative terminal of the battery I9 is thus connected to the cathode of this tube.
  • the cathode o! tube 20 is also connected through a suitable resistance 2l is madeadjustable, as shown.
  • a condenser 2l is connected across the neon tube and the primary of transformer 24 for producing oscillations, though it could be connected in other ways to the elements illustrated without materially changing its operation.
  • the secondary of transformer 24 is connected to suitable amplifier stages 21 and this is connected to any type of modulator 28 for modulating the radio frequency carrier produced in transmitting apparatus 29 having an antenna 3U.
  • the amplifier, modulator and transmitting apparatus may be of any type and hence are not illustrated in detail, since they are well known in the art.
  • the amplifier 21 also has connected across its output terminals a load resistance 3l and a halfwave rectifier 32. To'produce momentary energization of the magnet Il, a transformer 33 and rectifier 34, like rect ber 32 but illustrated diagrammatically, are used to energize magnet ii.l By connecting the coil Il through the rectifier 34 to the secondary of the transformer, it is energized only by a pulse induced at the beginning of the signal. This permits the dog toreturn soon after the pinion 'i starts its rotation. Ofcourse, the pulse induced in the secondary may be amplined up to any desired value for operating the magnet.
  • the receiving antenna 35 is connected to receiving, amplifying and detecting apparatus 38 of any well-known form and the 'audio alternating output of the receiving apparatus is fed intotransformer 31.
  • 'I'he primary of this transformer has connected across its terminals a load resistance 38 and a half-wave rectifier 39.- It has also connected across its terminals a fullsingle-wave rectifier-may also be used, if desired;
  • the neon lamp I6 is adjustably connected across resistance 4I.
  • the light reected from the square is converted into electric current by the pick-up l2. This will produce a certain positive potential across the 'input of vacuum tube 20, producinga given mutual conductance in the tube and causing condenser 26 tocharge at a certain rate.
  • This pulse energizes magnet Il and releases dogl 9.
  • the speed of the motor is such that the pinion makes a revolution before the completion of a cycle of the highest frequency that lcan be generated in scanning the subject.
  • the pinion therefore. is always ready to be released at the beginning of each cycle.
  • the drum at the transmitter isstepped -along one element at a time and the time between the individual steps of the drum depends upon the shading of the element beneath th pick-up.
  • 'I'he frequency generated by the condenser 28 and neon tube 23 is used to modulate' the transmitter 22 and the modulated radio current is radiated by the antenna 30.
  • 'I'he wave is re- ,ceived at the distance receiving station and ampiified and the audio frequency is extracted.
  • the apparatus at the recorder is like that at the transmitter and therefore the recorder drum is stepped along in timed relation with the drum modulating current, this also aids in varying the shades at the recorder.
  • Graph 42 of Fig. 5 indicates the signal frequency produced by the oscillator and transmitted to the receiver.
  • Graph 43 indicates the E. M. F. in resistance 3
  • Graph 45 indicates the form of the E. M. F. after rectification at 34, assuming that the negative half wave is utilized.
  • an optical unit having means for producing a light beam, means for causing relative movement between the subject and said beam to bring the elements of the subject successively thereinto, and means for causing said movement to be .intermittent with periods of rest varying with the density ofthe elements passing into said beam.
  • an optical unit having means for producing a light beam, means for causing relative movement between the subject and said beam to bring the elements of the subject successively thereinto, and means for causing said movement to be intermittent with constant periods of movement and periods of rest varying with the density of the elements passing into said beam.
  • a support for the subject being scanned.
  • an optical unit having means for projecting a light beam onto said subject, means for producing relative movev ment between the support and the beam to bring the elements'of the subject successively thereinto, means for producing alternating current of frequency varying with the intensity of the light leaving .the elements when in said beam and means for stopping said movement during4 each cycle of said frequency.
  • a support for the subject being scanned an optical unit having means for projecting a light beam onto said subject, means for producing relative movement between the support and the beam to bring the elements of the subject successively thereinto, means for producing alternating current of frequency varying with the intensity of the light leaving the elements when in said beamand means for stopping said movement during the greater part of the time period of ,each cycle of said frequency.
  • a support for the subject being scanned an optical unit having means for projecting a light beam onto said subject, means for producing relative movement between the support and the beam to bring the elements of the subject successively thereinto, means for producing alternating current of frequency varying with the. intensity of the light leaving the elements when in said beam, means for stopping said movement during each cycle of said frequency and means for translating the last-mentioned light beam into electrical potentials.
  • a support for the subject being scanned van optical unit having means for projecting a light beam onto said subject.
  • means for producing relative movement between the support and the beam to bringl the elements of the subject successively thereinto means for producing alternating current of frequency varying with the intensity of the light. leaving the elements when in said beam, meansfor stopping said movement during each cycle oi' said frequency and means for producing electrical potentials varying with the intensity of the lastmentioned light beam.
  • an A optical unit means for producing intermittent relative movement between theisubject and the optical unit, the period of immobility varying with the intensity ⁇ ot ⁇ the light from said unit leaving said subject, means for producing an alternating current having a cycle for each cycle of said intermittent movement, a recorder having a support for a light sensitive surface, means for projecting a light beam onto said surface,
  • an optical unit means for producing'intermittent relative movement between the subject and the optical unit,- the period of immobility varying with the intensity of the light from said unit leaving said subject, means for producing an alternating current having a cycle for each cycle of said intermittent movement,A a recorder having a support for a. light sensitive surface, means for projecting a light beam oi' constant intensity onto said surface, means for producing relative movement oi' said support and said beam and means for stopping the movement of said support during the greater frequency;

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
US364617A 1940-11-07 1940-11-07 Facsimile photo transmission and reception Expired - Lifetime US2301375A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US364617A US2301375A (en) 1940-11-07 1940-11-07 Facsimile photo transmission and reception
CH233314D CH233314A (de) 1940-11-07 1941-11-05 Verfahren zur Übertragung von stehenden Bildern.
GB14326/41A GB551034A (en) 1940-11-07 1941-11-06 Transmission of picture telegraphy and like signals

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US364617A US2301375A (en) 1940-11-07 1940-11-07 Facsimile photo transmission and reception

Publications (1)

Publication Number Publication Date
US2301375A true US2301375A (en) 1942-11-10

Family

ID=23435319

Family Applications (1)

Application Number Title Priority Date Filing Date
US364617A Expired - Lifetime US2301375A (en) 1940-11-07 1940-11-07 Facsimile photo transmission and reception

Country Status (3)

Country Link
US (1) US2301375A (de)
CH (1) CH233314A (de)
GB (1) GB551034A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2467950A (en) * 1943-09-21 1949-04-19 Nea Service Inc Facsimile receiving system
US2976357A (en) * 1957-01-22 1961-03-21 Robert L Hammett Television slide projector

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2467950A (en) * 1943-09-21 1949-04-19 Nea Service Inc Facsimile receiving system
US2976357A (en) * 1957-01-22 1961-03-21 Robert L Hammett Television slide projector

Also Published As

Publication number Publication date
GB551034A (en) 1943-02-04
CH233314A (de) 1944-07-15

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