US1890558A - Television or like system and apparatus - Google Patents

Television or like system and apparatus Download PDF

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Publication number
US1890558A
US1890558A US353632A US35363229A US1890558A US 1890558 A US1890558 A US 1890558A US 353632 A US353632 A US 353632A US 35363229 A US35363229 A US 35363229A US 1890558 A US1890558 A US 1890558A
Authority
US
United States
Prior art keywords
commutator
relay
receiver
brushes
signal
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
US353632A
Other languages
English (en)
Inventor
Baird John Logie
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.)
Baird Television Ltd
Original Assignee
Baird Television Ltd
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 Baird Television Ltd filed Critical Baird Television Ltd
Application granted granted Critical
Publication of US1890558A publication Critical patent/US1890558A/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
    • H04N5/04—Synchronising
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising
    • H04N5/12—Devices in which the synchronising signals are only operative if a phase difference occurs between synchronising and synchronised scanning devices, e.g. flywheel synchronising
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/7605—Television signal recording on discs or drums

Definitions

  • a maintaining synchronism between a transmitter and a receiver which consists in transmitting a distinctive signal, receiving it on the circuit of the receiver, coupling the re DC circuit by a synchronizing switch to a correcting device in such manner that when the receiver is out of phase the signal operates the correcting device but when the receiver is in phase the signal is not applied to the correcting device.
  • a further feature of the invention is a method of the kind above set forth which is characterized by the fact that the distinctive signal is obtained by the contrast of the picture signal with a signal which is weak compared with the picture signal or is of zero value.
  • the invention comprises also as a feature, a synchronizing mechanism in a television system or the like, which mechanism comprises devices (including for example a commutator or a light-sensitive cell) for transmitting periodically to the receiver a distinctive signal, and means (for example, a commutator) running in synchronism with the receiver and operating by reason of said distinctive signal, if the receiver is not in synchronism with the transmitter, to feed current to a device (for example a winding of a relay or the like or a winding on the field magnet of a motor), by the action of which device the synchronism of the receiver is restored.
  • a synchronizing mechanism in a television system or the like, which mechanism comprises devices (including for example a commutator or a light-sensitive cell) for transmitting periodically to the receiver a distinctive signal, and means (for example, a commutator) running in synchronism with the receiver and operating by reason of said distinctive signal, if the receiver is not in synchronism with the transmitter, to
  • Figure 1 shows one form of synchronizing mechanism including a commutator at a transmitting station
  • Figure 3 shows a third form of such mechanism, also at a transmitting station
  • Figure 13 illustrates the application of a form of the invention similar to-that shown in Figure 7 to a receiving circuit
  • the image current is amplified by a suitable amplifier 12 from which the current passes to the receiving station.
  • a distinct synchronizing signal is transmitted at a frequency of repetition definitely related to the scanning frequency. This signal may be utilized to actuate any suitable mechanism at the receiving station for controlling the scanning speed.
  • FIG 3 illustrates'the case where a large positive bias is applied to the valve.
  • the brushes 28 bear upon a commutator 30, which, like the commutator 14 of Figure 2, has its segments narrow relatively to the insulation between them.
  • the brushes 28 are in a circuit'which includes the grid and filament of a valve 32 together with a source of potential 34 to produce the necessary positive bias.
  • a relay 60 is connected between the filament and plate of a valve 62 and in series with the relay are two brushes 64 which are short-circuited by a commutator 66, which is driven in synchronism with the exploring disc, at a position corresponding to the hottom of each line of the picture.
  • the plate of the valve 62 is connectedto the varying light-source 68, which if a glow-discharge lamp should be shunted with a high resistance so that in darkness there is still current passing.
  • the relay is periodically connected to the receiving circuit so as to be affected by received signals, the periodicity of this connection coinciding with or hearing a definite timed relation to the line scanning frequency of the receiver exploring disc.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Microscoopes, Condenser (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Control Of Electric Motors In General (AREA)
  • Toys (AREA)
  • Control Of Turbines (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Motor Or Generator Current Collectors (AREA)
  • Dc Machiner (AREA)
US353632A 1928-04-16 1929-04-08 Television or like system and apparatus Expired - Lifetime US1890558A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5173/29A GB320627A (en) 1928-04-16 1928-04-16 Improvements in or relating to television apparatus and the like

Publications (1)

Publication Number Publication Date
US1890558A true US1890558A (en) 1932-12-13

Family

ID=9791061

Family Applications (1)

Application Number Title Priority Date Filing Date
US353632A Expired - Lifetime US1890558A (en) 1928-04-16 1929-04-08 Television or like system and apparatus

Country Status (5)

Country Link
US (1) US1890558A (ru)
BE (2) BE359858A (ru)
DE (1) DE595289C (ru)
FR (3) FR672965A (ru)
GB (4) GB320627A (ru)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3061730A (en) * 1960-10-19 1962-10-30 Barnes Eng Co High resolution tracker

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE763191C (de) * 1933-05-20 1954-12-13 Opta Radio A G Anordnung zur Aussendung von Synchronisierimpulsen waehrend der Abtastpausen des Fernsehsenders
DE743481C (de) * 1936-09-10 1943-12-27 Opta Radio Ag Anordnung zur Herstellung von Bildzerlegerscheiben

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3061730A (en) * 1960-10-19 1962-10-30 Barnes Eng Co High resolution tracker

Also Published As

Publication number Publication date
FR673042A (fr) 1930-01-09
BE359858A (ru)
FR673495A (fr) 1930-01-15
GB320628A (en) 1929-10-16
GB320639A (en) 1929-10-16
GB320909A (en) 1929-10-25
BE359857A (ru)
FR672965A (fr) 1930-01-09
DE595289C (de) 1934-04-10
GB320627A (en) 1929-10-16

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