US2282992A - Television receiver - Google Patents

Television receiver Download PDF

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Publication number
US2282992A
US2282992A US334531A US33453140A US2282992A US 2282992 A US2282992 A US 2282992A US 334531 A US334531 A US 334531A US 33453140 A US33453140 A US 33453140A US 2282992 A US2282992 A US 2282992A
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US
United States
Prior art keywords
tube
voltage
television receiver
resistance
cathode
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
US334531A
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English (en)
Inventor
Deserno Peter
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.)
Alcatel Lucent Deutschland AG
C Lorenz AG
Original Assignee
Standard Elektrik Lorenz 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 Standard Elektrik Lorenz AG filed Critical Standard Elektrik Lorenz AG
Application granted granted Critical
Publication of US2282992A publication Critical patent/US2282992A/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
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/57—Control of contrast or brightness

Definitions

  • Television pictures should be adjusted not only as regardstheir brightness but should be adjusted also with a viewto obtaining the greatest possible sharpness of contrasts.
  • the adjustment is proper if .the black value of the mixture of picture and synchronizing signals acts to control the cathode ray tube to just dark. Withthe working point of the cathode ray tube positioned too far in the negative region the intensity of the dark details of the picture'is impaired thereby, whereas if the working point is too far in the positive region a dim picture is obtained. Proper adjustment is hence difficult especially to those not skilled in the art. It is therefore desirable to provide for means whereby the contrast effects of a picture are automatically given the best intensity.
  • This invention relates to a method for the filter chain, this filter chain segregating the synchronizing signals.
  • the filter chain which comprises a number of choke coils connected in series, may be arranged to segregate the synchronizing impulses while at the same time separating them into the well known picture change and line change impulses.
  • An arrangement particularly adapted for this purpose comprises means whereby the control voltage is caused to change the potentials of the Braun tube and-also those of its voltage source.
  • the control voltage may be taken from a con-v denser which is charged over a rectifier and a of amplitudes.
  • a means is used which has a time constant and is connected to the filter chain througha rectifier path.
  • Fig. l is a circuit diagram showing one embodiment of the invention, while Fig. 2 is a graphical representation referred to in explaining the function of 'this embodiment.
  • An electron tube R serves to rectify' the received amplified frequency mixture.
  • a tap m of a coupling resistance RK the Wehnelt cylinder- H of the Braun tube K is 'coupled to the tubeR.
  • the control voltage that corresponds to the black value arises at condenser C1.
  • This condenser is charged over a filter chain which comprises choke coils Di, T1 and T2 and condensers C2, C3, and over a dual diode I.
  • This diode here acts by means of that discharge path which in the drawing is shown to constitute the leithand half thereof.
  • the cathode of this discharge path is connected to a tap n of the resistance RK.
  • the respective voltage conditions will appear from 2.
  • the upper line represents the anode potential.
  • the voltage arising at condenser C1 corresponds to the distance A.- This voltage is conveyed to the negative'pole of a voltage source N, G for the Braun tube. Any, change in the control voltage therefore causes the potentials of the Braun tube and of its voltage means of the condensers C2, 73 are so tuned that from T1 the picture change impulses and from T2 the line change impulses are derived by a secondary coils u and 12, respectively.
  • Curve E, Fig. 2 illustrates the current con tions peculiar to the lefthand discharge path or system of the diode I.
  • the voltage between the anode thereof and earth only containsthe synchronizing impulses, the picture impulses not being contained therein. This voltage acts through coupling condenser 05 on the cathode of that discharge path or system which in the vdrawing forms the righthand half of diode I.
  • the cathode of this system is also joined through i a high ohmic resistance to the negative grounded pole of the anode voltage source.
  • the voltage As the voltage is negative with respect to earth it may serve directly for controlling the input voltage, thus enabling an automatic amplitude regulation thereof over line Q.
  • a circuit arrangement comprising 9. rectifier tube operativelyconnected to a source of amplified signals, a load comprising a resistance connecting the anode of said tube with a source of positive potential, a Braun tube, a tap on said resistance connected to the Wehnelt electrode of said tube to cause variation in the acceleration of electrons in said tube in accordance with signals across said resistance, a double diode tube, a circuit connected between a point on said resistance more negative than said tap and a cathode of said diode tube, a chain of tunedinductances comprising two transformers and a condenser shunted by a resistance connected between the anode associated with said cathode of the double diode and the positive terminal of said load resistance and a circuit connecting the cathode of said Braun tube to the more negative side of said condenser, the arrangement being such that the operating characteristics of
  • a television receiver in which the second cathode of the double diode is connected through a condenser to the anode of the first diode, and the second anode and the second cathode are shunted by a resistance and also acondenser comprising a. time constant device, the arrangement being such that the anode being negative in respect to ground provides a volume control voltage.
  • a television receiver in which the chain of tuned inductances include the primaries of two transformers, said transformers being so tuned that picture frame impulses are derived from the secondary of one and line impulses .from the. secondary of the other.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Details Of Television Scanning (AREA)
US334531A 1939-05-13 1940-05-11 Television receiver Expired - Lifetime US2282992A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE213518X 1939-05-13

Publications (1)

Publication Number Publication Date
US2282992A true US2282992A (en) 1942-05-12

Family

ID=5813659

Family Applications (1)

Application Number Title Priority Date Filing Date
US334531A Expired - Lifetime US2282992A (en) 1939-05-13 1940-05-11 Television receiver

Country Status (4)

Country Link
US (1) US2282992A (enrdf_load_stackoverflow)
BE (1) BE438854A (enrdf_load_stackoverflow)
CH (1) CH213518A (enrdf_load_stackoverflow)
FR (1) FR868486A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426419A (en) * 1942-12-23 1947-08-26 Du Mont Allen B Lab Inc Return trace blanking and mixing
US2745037A (en) * 1951-12-18 1956-05-08 Rca Corp Keying arrangement for single beam color tube

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426419A (en) * 1942-12-23 1947-08-26 Du Mont Allen B Lab Inc Return trace blanking and mixing
US2745037A (en) * 1951-12-18 1956-05-08 Rca Corp Keying arrangement for single beam color tube

Also Published As

Publication number Publication date
FR868486A (fr) 1941-12-31
BE438854A (enrdf_load_stackoverflow)
CH213518A (de) 1941-02-15

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