US2196364A - Television receiving connection system - Google Patents

Television receiving connection system Download PDF

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Publication number
US2196364A
US2196364A US47788A US4778835A US2196364A US 2196364 A US2196364 A US 2196364A US 47788 A US47788 A US 47788A US 4778835 A US4778835 A US 4778835A US 2196364 A US2196364 A US 2196364A
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US
United States
Prior art keywords
grid
tube
image
cathode
potential
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
US47788A
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English (en)
Inventor
Schlesinger Kurt
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.)
LOEWE RADIO Inc
Original Assignee
LOEWE RADIO Inc
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 LOEWE RADIO Inc filed Critical LOEWE RADIO Inc
Application granted granted Critical
Publication of US2196364A publication Critical patent/US2196364A/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
    • 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
    • H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
    • H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
    • H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
    • H04N3/24—Blanking circuits

Definitions

  • I is the lead proceedin from the anode of thefinal receiving rectifier'Z, the construction of which is not of interest for the present purpose; this lead is connected directly to the first control grid 3 of the cathode ray tube 4.
  • This line supplies positive potential values to the grid if white points should occur in the image.
  • the television tube 4 is furnished with a second control grid5, which has the specific object of blocking the ray during the return lines, but which, however, except in the relaxation moments, should not participatevin the control of the ray.
  • the grid 5 may at the same time assume an electronoptical function; For example it may, as a condenser, perform the task of reproducing sharply on theapertureof the diaphragm the'stream 55 ofelectrons proceeding from the cathodetiliIn ground, which interferes considerably with the a singlethe case of present-day television tubes with extreme light intensity, a condenser of this kind is necessary in any case, and the inclusion of the electrode 5- does not, therefore, represent any particular complication.
  • the in- 5 according to the invention which anode is led nected to earth through the medium of the high charge which have leaked off through I9 during out preferably. at the top. This valve is preferably' furnished with.
  • an intercepting grid I3 and screening grid I4 and agrees fully otherwise in construction with the pentodes employed in the present-day radio art with good mutual conductance'(gm v3 mA per volt) andindirectly heated cathode I5.
  • the cathode is con 20 nected 'throughthe medium of a resistance I6 of approximately 500 ohms with a positive potential with respect to earth adjustable at the potentiometer I1, whilst the control grid I8 is conohmic resistance I 9 of approximately 2-3 megohms;
  • the wiping contact of the potentiometer I'I is'e'arthed dynamically through the condenser 20 of 0.01 mf.
  • the control grid iii of 'thefilter valve I2 is connected with theimage current lead I through the medium of the blocking condenser 2i of 0.01 mf.- There then occurs the following: So long as the positive potential peaks occurring at the grid I8 are not equal to,"or greater than, the biasof the cathode I 5 adjusted at I'I no current of any kind is able to flow through the valve I2. If, however, sufficiently strong potential peaks occur, a powerful grid current passes to I3.
  • the grid'current ensures that the'bias of I8 in the limiting case becomes exactly to the same extent negative as the cathode I5 is positive at the highest peak amplitude, so thatlinthe limiting case no more current passes to I8 than is employed for supplementing the portions of the 5 the signal intervals.
  • potential peaks will, therefore, be able to liberate electrons from the cathode l5.
  • the bias of l8 may be utilised throughthe medium of a filter'chain 22, 23 (0.1
  • the intercept ing grid, of the pentodes employed in the receiving amplifier In this manner thereis obtained an effective regulation of the receiving potential supplied to the television tube.
  • the extreme potential peaks produce in the cathode resistance 16 of approximately 500 ohms small positive potential impulses. These may be divided in simple fashion by means of a CR or RC filter 24 or 25 into short and long signals, and these may be supplied separately at the terminals 26 to the line relaxation apparatus and to the terminal 21 of the image relaxation apparatus.
  • a false actuation of the relaxation apparatus in the case of very big signals is rendered impossible by the utilisation, in accordance with the invention, of the grid D. C. potential efiect, which ensures that only the extreme peaks of the signals, i. e., only a definite proportion of the total amplitude, is capable of producing a cathodic current.
  • a state of constancy of the intensity of the synchronisation signals is effectively assisted by the fading compensation effect, according to the invention, via the circuit 2223.
  • the blocking of the ray results from utilisation of the anode circuit ll.
  • This circuit is obviously traversed by amplified impulses which have become negative.
  • the connection between the anode II and the electrode 5 is made so poor in capacity that the tube [2 has a good h gh frequency amplification.
  • the amplification in accordance with the invention, is made at least of such extent as prescribed by the reciprocal of the control sensitivity of the blocking electrode 5 compared with that of the main control grid 3 in the tube 4. This degree of amplification cannot be accomplished solely by making the lead 363 and the resistance 9 low in capacity, but also involves the selection of the valve [2 with particularly great mutual conductance and possibly resonance chokes 29.
  • the strength of the impulse reaching the blocking electrode 5 is adjusted by the screening grid I6 independently of the adjustments of the gird circuit l5, l8. It is, therefore, possible to adjust the responding potential for the filter independently at the potentiometer I1, and to determine at the screening grid [4 without interference to the occurrences at the grid-cathode circuit what amounts of current are to be allowed to reach the blocking electrode.
  • the coupling of the grid I8 with the image current circuit I does not take place in ptu'ely capacitative fashion through the medium of a condenser 2!, but additionally in galvanic fashion by way of the resistance 28.
  • the latter is made highly ohmic
  • the transmitter oyperates with black impulses, and if it transmits a uniformly black area, the differences in amplitude between the impulse and the mean value of the image is merely small. If a pure condenser coupling were provided between grid !8 and line I, the bias of the grid I 8 would be much too high to permit of a regulation of the tube [2 with these small differences in amplitude. By reason of the galvanic coupling, however, the bias of the grid is decreased to such extent in the desired direction that the small differences in amplitude are sufficient for removing the blocking effect on the tube 12.
  • a cathode ray tube having at least a cathode, a main control electrode and an auxiliary control electrode, a grid controlled tube for filtering the synchronizing signals from said mixture, and at least one deflecting voltage generator, the output of said amplifier being connected on the one hand to said main control electrode and on the other hand to the grid of said filter tube, the anode of said filtering tube being connected to said auxiliary control electrode, the cathode of said filter tube being connected on the one hand via a resistance to a fixed potential and on the other hand to said deflecting voltage generators.
  • a cathode ray tube having at least a cathode, a main control electrode, and an auxiliary control electrode, a grid controlled tube for filtering the synchronizing signals from said mixture, and at least one defiecting voltage generator, the output of said amplifier being connected on the one hand to said main control electrode and on the other hand to the grid of said filter tube, the anode of said filtering tube being connected to said auxiliary control electrode, the cathode of said filter tube being connected on the one hand via a resistance to a fixed potential and on the other hand to said deflecting voltage generator, said filtering tube being a pentode, the screen grid of which being biased independently on the cathode potential.
  • an amplifier for amplifying the received modulated high frequency, an amplifier amplifying the mixture of demodulated image and synchronizing signals, a cathode ray tube having at least a main control electrode and an auxiliary control electrode, a grid controlled tube for filtering the synchronizing signals from said mixture and at least one de' fleeting voltage generator, the output of said second mentioned amplifier being connected on the one hand to said maincontrol electrode and.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Picture Signal Circuits (AREA)
  • Television Receiver Circuits (AREA)
US47788A 1934-11-06 1935-11-01 Television receiving connection system Expired - Lifetime US2196364A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE465141X 1934-11-06

Publications (1)

Publication Number Publication Date
US2196364A true US2196364A (en) 1940-04-09

Family

ID=6540351

Family Applications (1)

Application Number Title Priority Date Filing Date
US47788A Expired - Lifetime US2196364A (en) 1934-11-06 1935-11-01 Television receiving connection system

Country Status (3)

Country Link
US (1) US2196364A (fr)
FR (1) FR797328A (fr)
GB (1) GB465141A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2481045A (en) * 1945-03-12 1949-09-06 Rca Corp Automatic volume control and sync separator for television receivers
US2652450A (en) * 1948-05-29 1953-09-15 Rca Corp Sync separation and automatic gain control

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2481045A (en) * 1945-03-12 1949-09-06 Rca Corp Automatic volume control and sync separator for television receivers
US2652450A (en) * 1948-05-29 1953-09-15 Rca Corp Sync separation and automatic gain control

Also Published As

Publication number Publication date
GB465141A (en) 1937-05-03
FR797328A (fr) 1936-04-24

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