US1892371A - Method of picture transmission - Google Patents

Method of picture transmission Download PDF

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Publication number
US1892371A
US1892371A US487117A US48711730A US1892371A US 1892371 A US1892371 A US 1892371A US 487117 A US487117 A US 487117A US 48711730 A US48711730 A US 48711730A US 1892371 A US1892371 A US 1892371A
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US
United States
Prior art keywords
picture
currents
current
light
disk
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
US487117A
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English (en)
Inventor
Tuczek Franz
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.)
Siemens and Halske AG
Siemens Corp
Original Assignee
Siemens 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 Siemens Corp filed Critical Siemens Corp
Application granted granted Critical
Publication of US1892371A publication Critical patent/US1892371A/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
    • H04N5/00—Details of television systems
    • H04N5/30—Transforming light or analogous information into electric information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems

Definitions

  • Such an arrangement is further adapted to regulate the degree of modulation both in sending positive as well as n'egative'pictures. This is not only desirable :in frequent in stances, but even imperative," if theincoming stancyin the properties of the cell.
  • Thephase can be so adjusted in this scheme that the currents'corresponding to white surfaces or spots are wholly or partly compensated for positive pictures or else so that their amplitudes are augmented by cooperation with'the acoustic wheel for negative pictures.
  • the added currents and the carrier currents have constantly and permanently the same frequency, an aim which is attained in the 1 -perforated-disk method by drivingthe per-' forated disk and the tone-wheel by one and the same motor, most preferably. by seating them upon thesame spindle.
  • the tonewheel mustbe driven from a motor running in synchronism with the sending-outfit motor, for, example, the motor driving the cylinder-of the incoming picture. Adjustmentof the correct phase relations maybe'efi'ected by turning the stator of the tone-wheel, or else by shifting theoptical' means parallel to'the circumference of the perforated disk.
  • the arrangement can be made'particularly simple-if the perforated or serrated disk is made of iron, and if the teeth which periodically mask the lightare' at the same time used for 'the generation of the alternating current magnetic flux.
  • This form of construction offers this advantage that, upon exchanging the perforated disksye. g., for changing over to another carrier frequency, not only the freangularly upon the requency of the compensating current will automatically be made equal to the carrier frequency, but that also the phase relations are preserved. It is also easily possible in this scheme to make the wave shapes of the two cooperating currents identical in that the cross-sectional shape of the magnetic flux is adapted to the cross-section of the pencil of light rays.
  • Regulation of the desired amplitude conditions can be accomplished by regulation of the filament current, by the use of variable resistances or attenuating means, or by regulation of the exciting current used for the tonewheel. It may be recommendable in this connection in addition to adj ustability of the amplitudes of both currents, to provide a certain interrelationship, say, betweenthe exciting current and the tube (lamp) current in such a manner that, when the picture currents become smaller owing to decrease of the lamp current, also the current of the tone wheel becomes simultaneously smaller so that the degree of modulation or compensation is preserved.
  • an electric filter for smoothing for instance, a coil low-pass filter.
  • the combination of the two currents may be efiected at different places.
  • the tonewheel should be as small as feasible in order to save expense. Hence, if a relatively large output power is required, for instance, in radio or air-line operation, such combination most suitably is to be effected between two tubes of the amplifier, while in the case of low output powers such as needed in telegraph work, it is most suitably effected at the output end of the transmitting amplifier. If the tone-wheel is mounted at the receiving end, the currents most conveniently are combined at the input end of the amplifier.
  • Fig. 1 illustrates one form of alternator
  • Fig. 2 illustrates a modification
  • Fig. 3 illustrates a system for producing the reversing action at the receiver in combination with the arrangement shown by either Fig. 1 or Fig. 2.
  • alternator may be chosen the same as that of any ordinary alternating current machine.
  • sirene type of alternator Fig. 1 in which the rotor 1 has no winding, while the stator 2 consists of a sim-' ple magnetic yoke comprising two poles 3 and 4.
  • FIG. 2 Another embodiment is shown in Fig. 2.
  • the teeth mask the light periodically, thereby effecting the optical analyzing.
  • a complete system is shown wherein at the transmission point a synchronous motor or the like 8 is driven from an a. c. line and arranged to rotate the chopping disk 9 which is placed immediately in front of the photo tube 10.
  • the picture record 11 is illuminated from a light source 12 and the light signals brought to act upon the photo cell 10 are periodically interrupted by means of the rotary disk 9.
  • the receiver recording device is driven by means of a synchronous motor 13 which can, if desired, be connected to the same a. 0. supply line.
  • a generator 1 for example, of the type shown by Fig. 1, and by suitable arrangement of the pick-up device generally designated as 14, the amplitude and phase of the locally generated signals may be determined, The phase is determined by shifting the pick-up device to the right or left as shown, and the amplitude may be controlled b moving the pick-up device radially inwar or outward from the tone generator.
  • the method of producing picture reversal and regulating the modulation in picture telegraph apparatus which comprises generating carrier currents and modulating said currents by currents representing the varying intensities of light and shadow of the picture elements of the transmitted record, simultaneously generating at the receiving point other currents of the same frequency as the carrier current generated, and adding the two generated currentsin predetermined phase relationship so as to produce either positive or negative picture reproduction at the receiving point.
  • the method of producing picture reversal in picture telegraph apparatus which comprises generating a carrier frequency, modulating the carrier frequency by signal ios impulses correspondin tothe varying in- 1 tensities of light and s adow of the picture elements, generating at a receiving point a, second frequency corresponding to that of 5 the carrier frequency, and regulating both I currentsin size and in phase so as to selectively create at the receiving point positive or negative pictures and control the picture modulation, 7 i 10 r In testimony whereof Iafiix my si ature, FRANZ TU ZEK.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Multimedia (AREA)
  • Brushless Motors (AREA)
US487117A 1929-09-06 1930-10-08 Method of picture transmission Expired - Lifetime US1892371A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1892371X 1929-09-06

Publications (1)

Publication Number Publication Date
US1892371A true US1892371A (en) 1932-12-27

Family

ID=7747936

Family Applications (1)

Application Number Title Priority Date Filing Date
US487117A Expired - Lifetime US1892371A (en) 1929-09-06 1930-10-08 Method of picture transmission

Country Status (2)

Country Link
US (1) US1892371A (fr)
FR (1) FR701206A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2711495A (en) * 1950-06-06 1955-06-21 Smitsvonk Nv Method and apparatus for supplying low voltage current to low voltage spark plugs, more particularly for an ignition device for internal combustion engines
US2978599A (en) * 1957-11-20 1961-04-04 Rca Corp Indicating system
US3225285A (en) * 1962-07-16 1965-12-21 Advanced Kinetics Inc Brushless generator for high-powered electrical pulses
US3564313A (en) * 1969-08-08 1971-02-16 Trans Sonics Inc Self-compensating tachometer generator
US3676765A (en) * 1970-06-30 1972-07-11 Trans Sonics Inc Tachometer generator
US3782136A (en) * 1971-08-10 1974-01-01 Stoll & Co H Pulse generator for an electrical control system of a machine
US4071246A (en) * 1976-08-18 1978-01-31 Bally Manufacturing Corporation Magnetic reel reading device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2711495A (en) * 1950-06-06 1955-06-21 Smitsvonk Nv Method and apparatus for supplying low voltage current to low voltage spark plugs, more particularly for an ignition device for internal combustion engines
US2978599A (en) * 1957-11-20 1961-04-04 Rca Corp Indicating system
US3225285A (en) * 1962-07-16 1965-12-21 Advanced Kinetics Inc Brushless generator for high-powered electrical pulses
US3564313A (en) * 1969-08-08 1971-02-16 Trans Sonics Inc Self-compensating tachometer generator
US3676765A (en) * 1970-06-30 1972-07-11 Trans Sonics Inc Tachometer generator
US3782136A (en) * 1971-08-10 1974-01-01 Stoll & Co H Pulse generator for an electrical control system of a machine
US4071246A (en) * 1976-08-18 1978-01-31 Bally Manufacturing Corporation Magnetic reel reading device

Also Published As

Publication number Publication date
FR701206A (fr) 1931-03-13

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