US2519911A - Selection of first interruption pulse for synchronization of vertical sweep generators - Google Patents

Selection of first interruption pulse for synchronization of vertical sweep generators Download PDF

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Publication number
US2519911A
US2519911A US761050A US76105047A US2519911A US 2519911 A US2519911 A US 2519911A US 761050 A US761050 A US 761050A US 76105047 A US76105047 A US 76105047A US 2519911 A US2519911 A US 2519911A
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United States
Prior art keywords
voltage
impulses
image
control
interruption
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Expired - Lifetime
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US761050A
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English (en)
Inventor
Kuperus Jan
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising
    • H04N5/08—Separation of synchronising signals from picture signals
    • H04N5/10—Separation of line synchronising signal from frame synchronising signal or vice versa
    • 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
    • H04N5/123—Devices in which the synchronising signals are only operative if a phase difference occurs between synchronising and synchronised scanning devices, e.g. flywheel synchronising whereby the synchronisation signal directly commands a frequency generator

Definitions

  • This mixture is supplied, after the image signal is cut off, to an integrating network, the output voltage of which is fed to a control electrode of a discharge system and the signal voltage being supplied, if necessary after the image signal is cut off, to the same or to another control electrode of this system, the output electrode of the discharge system having taken from it a voltage, with the aid of which the image is synchronized.
  • the above described circuit-arrangement has the disadvantage that the selected signal for the synchronisation of the image time-base generator is built up from a series of impulses which are derived from the series of interrupting impulses. It is, in general, desirable that for synchronisation purposes only one interrupting impulse should be used, since a plurality of impulses may give rise to interference.
  • the image time-base generator comprises a gasfilled discharge tube, it may be possible for this tube to be opened at all impulses of the series after the first impulse of this series has already brought about the discharge of the condenser included in the sawtooth generator.
  • the beginning of the image sawtooth voltage is, in this case, governed by the last impulse of the series, which for example in the case of interlaced reproduction, may lead to irregularities.
  • the principal object of the invention is to provide a circuit arrangement in which these disadvantages are obviated.
  • Figure 1 is a schematic diagram of a circuit arrangement according to the invention
  • - i Fig. 2 are graphs illustrating the wave form of advantages.
  • Fig. 3 is a schematic diagram of a circuit arrangement in accordance with another embodiment of the invention.
  • Fig. 1 shows, partly in block diagram, one embodiment of the circuit-arrangement according to the invention.
  • a control electrode of a discharge tube 2 a voltage V1 and, in addition, a fixed bias voltage.
  • Voltage V1 is illustrated in Fig. 2.
  • the voltage V1 is formed from the incoming television signal by cutting off the image signal and, consequently, merely consists of a mixture of synchronizing impulses, viz. line synchronizing pulses a, image synchronizing pulses b and interrupting impulses c. In the present television transmitting systems these interrupting impulses have double the frequency of the line synchronizing pulses.
  • Fig. 2 illustrates two image synchronizing impulses, one of which is associated with the even image raster, the other with the odd image raster.
  • Voltage V1 has derived from it, with the aid of a phase-reversing device 3 and an integrating network 4, a voltage V2, which, so far as it exceeds a threshold voltage which has also been applied and the value of which is shown in Fig. 2 by a dotted line 01, is fed to a control electrode 5 of the discharge tube. Due to the said applied voltage, the discharge tube 2 will conduct only for the time periods ii to t2 or is to 754 respectively, so that across the anode resistance 6 is set up a voltage V3 in which only the interrupting impulses occur. This voltage is converted, with the aid of a differentiating network 1, into a voltage having a shape V4. Voltage V4 is fed to the image saw-tooth generator 8.
  • the voltage set up across the resistance ll! has 'a shape Vs, the maximum voltage occurring being consequently reached more gradually, i. e. with a smallerslope than in the case of voltage V5.
  • Vs the maximum voltage occurring being consequently reached more gradually, i. e. with a smallerslope than in the case of voltage V5.
  • V the total voltage of the shape V: which is substantially equal to the sum of the voltages V1 and V6.
  • the shape of the first interrupting impulse is not deformed to any appreciable extent. This is in contradistinction to the second interrupting impulse, for example, which falls Within the fly-back time of the timebase generator and is thus superimposed on a very steep portion of the curve.
  • voltage V2 exceeds the threshold value and thevoltage onthe con.-
  • trol electrode i is sufiiciently high so that the. tube is alive and the first interrupting impulseoccurs in the output circuit,
  • the voltage V2 still exceeds the threshold Value, it is true, but the voltage on the control electrode I has decreased to an extent such that the tube does not conduct and hencev these impulses are 1 allowed to-pass. as; a result, .a voltage haw in a. shape Va is. set. up across.- the anode resistance G.
  • This voltage is fed via the differentiating network I to thein'iagesaw-tooth gen.- era tor whichiis, consequently, synchronized with theaidof thefirst interrupting impulse, without thesubsequent. interrupting impulses being capable of actinguponthe image time-base genenator.-
  • Fig. 3 shows .af-urther embodiment of the circuit-arrangement according to the invention.
  • A. grid l2. of the hexode part of the discharge system of a. tube l3 has fed to it, via a bias voltage supply battery 5, a voltage theshape of which is similar tothat of V1 illustrated in Fig. 2, but which is of opposite polarity.
  • This voltage is reversed in sensewiththeaid of the hexode partof the discharge system'and integrated, because anode [5 is practically earthedthrough condenser l6, resistance if being small, so that the-voltageset up across it is negligible relatively-to that set up across condenser H5.
  • the integrated voltage issupplied through a condenser wand-a resistance!
  • the integrated voltage is transferred at thesame time b-y-I-neans of: the coupling condenser 2
  • the control-grid 23 is connected through resistances 24 and: ll 1 to the bias voltage battery 25.
  • the resistance I forms part of" the anode circuit. of the. hexode-part and not shunted'by a condenser, so that there is set up 7 at the control-grid a voltage .of the shape V1. As soon asthe grid voltage becomes negative, under.
  • interruption impulses means toapplysaid diner.- .entiated: interruption impulses .to an. image saw.- tooth generator toaproduce .a sawtooth. voltage, means to derive a. secpndcontrol voltage from said sawtooth, voltage, .and:means to apply said second controlivoltage toisaid transmission path to transmitonIy the first of. said interruption impulses 2.
  • the anode 1 of said tube meansto nififerentiaiesaid-interruption impulses; means-to :flaDDlYvsSil-iik difierentiatedinterruption impulses to an image sawtooth generator to produce a sawtooth voltage, means to differentiate said sawtooth voltage to derive a second control voltage from said sawtooth generator, and means to apply said second control voltage to the first control grid of said tube to produce only the first or said interruption impulses at the anode of said tube.
  • a synchronizing circuit arrangement for a television receiver responsive to signals comprising line synchronizing pulses and image synchronizing pulses comprising a plurality of interruption impulses occurring within the period of said image synchronizing pulses and appearing in fixed time relationship with respect to said line synchronizing pulses comprising an electron discharge tube having a first electron discharge system having a first output electrode, a second electron discharge system having a second output electrode, electron emitting means and input electrode means for said first and said second electron discharge systems, means to apply said signals to said input electrode means, means coupling the output electrodes of said electron discharge systems, means coupled to said first output electrode to produce a potential reversed in phase and proport' nal to said signals, means to integrate potential to produce a first control voltage, means to apply said first control voltage to said input electrode to produce an output potential on said second output electrode, means to differentiate said output potential to produce a second control voltage, a sawtooth voltage generator, means to apply said second control voltage to said sawtooth generator to produce therefrom sawtooth output voltage, means to differentiate said sawt

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Electrotherapy Devices (AREA)
  • Details Of Television Scanning (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
US761050A 1946-06-15 1947-07-15 Selection of first interruption pulse for synchronization of vertical sweep generators Expired - Lifetime US2519911A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL126515A NL76305C (en)) 1946-06-15 1946-06-15

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US2519911A true US2519911A (en) 1950-08-22

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US (1) US2519911A (en))
BE (1) BE474571A (en))
CH (1) CH258157A (en))
DE (1) DE976180C (en))
ES (1) ES178896A1 (en))
FR (2) FR927118A (en))
GB (1) GB654154A (en))
NL (1) NL76305C (en))

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2632050A (en) * 1950-04-03 1953-03-17 Avco Mfg Corp Keyed automatic frequency control system for television receivers
US2725424A (en) * 1950-02-10 1955-11-29 Bell Telephone Labor Inc Error-voltage-sensitive differential amplifier
US2802046A (en) * 1950-03-24 1957-08-06 Emi Ltd Television receiving apparatus
US3517127A (en) * 1966-03-21 1970-06-23 Fowler Allan R Sync generator and recording system including same
US3535451A (en) * 1967-12-21 1970-10-20 Webb James E Means for generating a sync signal in an fm communication system

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE518188A (en)) * 1952-03-06
DE1268193B (de) * 1960-08-10 1968-05-16 Philips Patentverwaltung Schaltungsanordnung zum Synchronisieren eines Kippgeraetes
DE2651677C3 (de) * 1976-11-12 1981-04-30 Norddeutsche Mende Rundfunk Kg, 2800 Bremen Schaltungsanordnung zur Erzeugung einer sägezahnförmigen Spannung

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR847675A (en)) * 1937-12-17
US2242633A (en) * 1935-11-27 1941-05-20 Rca Corp Synchronizing system, particularly for television purposes
US2358545A (en) * 1941-07-31 1944-09-19 Rca Corp Television system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2242633A (en) * 1935-11-27 1941-05-20 Rca Corp Synchronizing system, particularly for television purposes
FR847675A (en)) * 1937-12-17
US2358545A (en) * 1941-07-31 1944-09-19 Rca Corp Television system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2725424A (en) * 1950-02-10 1955-11-29 Bell Telephone Labor Inc Error-voltage-sensitive differential amplifier
US2802046A (en) * 1950-03-24 1957-08-06 Emi Ltd Television receiving apparatus
US2632050A (en) * 1950-04-03 1953-03-17 Avco Mfg Corp Keyed automatic frequency control system for television receivers
US3517127A (en) * 1966-03-21 1970-06-23 Fowler Allan R Sync generator and recording system including same
US3535451A (en) * 1967-12-21 1970-10-20 Webb James E Means for generating a sync signal in an fm communication system

Also Published As

Publication number Publication date
NL76305C (en)) 1954-11-15
FR927118A (fr) 1947-10-21
FR56855E (fr) 1952-10-08
DE976180C (de) 1963-05-09
GB654154A (en) 1951-06-06
CH258157A (de) 1948-11-15
ES178896A1 (es) 1947-11-01
BE474571A (en))

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