US2582014A - Scanning device for television transmitters - Google Patents

Scanning device for television transmitters Download PDF

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Publication number
US2582014A
US2582014A US91242A US9124249A US2582014A US 2582014 A US2582014 A US 2582014A US 91242 A US91242 A US 91242A US 9124249 A US9124249 A US 9124249A US 2582014 A US2582014 A US 2582014A
Authority
US
United States
Prior art keywords
scanning
tube
voltage
scanning device
electron
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
US91242A
Other languages
English (en)
Inventor
France Henri Georges De
Ernyei Herbert
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.)
Radio Ind S A Soc
Society "la Radio-Industrie " S A
Original Assignee
Radio Ind S A Soc
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 Radio Ind S A Soc filed Critical Radio Ind S A Soc
Application granted granted Critical
Publication of US2582014A publication Critical patent/US2582014A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/56—Arrangements for controlling cross-section of ray or beam; Arrangements for correcting aberration of beam, e.g. due to lenses
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/021—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof arrangements for eliminating interferences in the tube
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/80—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching
    • 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
    • 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
    • H04N3/22—Circuits for controlling dimensions, shape or centering of picture on screen
    • H04N3/23—Distortion correction, e.g. for pincushion distortion correction, S-correction
    • H04N3/233—Distortion correction, e.g. for pincushion distortion correction, S-correction using active elements

Definitions

  • Our invention relates to. electron scanning devices for television transmitters.
  • .Its..chief..object. is to providea deviceof this kind which is .betteradapted to .meet the requirements of practice than those usedv up to this time for. the same purpose.
  • correcting means capable of modifyingthe direction of the scanning beam .in.order-to correct defects of the image to be analyzed.
  • ..Fig.l1- shows, in diagrammatic section, a television. analyzer tubev to which the invention may .beapplied;
  • FIG. 2 shows, at aand. 1), vertical and horizontal stripsbelonging to the picture to be repro- ..duced;
  • Fig. 3 shows, at-a. and b,...the same strips subjected.tothedeformation effect which the invention is to eliminate.
  • Figs. 4. and 5 show .embodimentsof meansfor correcting scanning ina tube of this .kind shown by Fig. l.
  • the .analyzer tube shown by Fig. 1 is of conventional construction. Animage of the object 'tocbe televised is projected through an optical system 2 ontoa photocathode 3 included in tube 4. Thisphotocathode releases. electronsproportionally to illumination, and the resulting emission-is focused by electron means 5 upon'a target 6 where the coil image thus formed produces acharge image with respect to a metal plate 1 through a process of secondary emission.
  • scanningof the electron image is performed in accordance with the deformation thereof, so as to permit of. creating, at the output of the tube, the same voltages as ifthisdeformation did not exist.
  • the desired correction can be obtained by superimposing on the line scanning deflecting voltages or currents an approximately sinusoidal voltage or current of a frequency equal to the frame scanning frequency, say periods per second.
  • these correcting voltages or currents may be applied either to the existing deflecting coils II), II or to coils, or other deflecting means, distinct from coils I0, I i.
  • the means for obtaining the correcting voltages or currents may be devised in many ways, advantageously by making use of the scanning saw teeth which are modified in suitable circuits so as to transform them into sinusoidal voltages, in'particular as follows.
  • the frame scanningsaw-tooth signal i3 is supplied through a. coupling capacitor Manda high resistor. iii to thelgrid of a tube ifi'which is'biased for-instance by acathode resistor i! and a grid rleak resistor i8.
  • Resistor i5 rounds off the shape --of: the.sauctoothpwherebya somewhat sinusoidal signal is obtained across a load resistor-such as v: I 9.-1This "signal: iseappliedto-tubeiiithrou'gh a phase changing system 2
  • the plate of this tube 20 is connected with the high voltage whereas there is inserted on the cathode a low-pass filter 24 which determines the necessary rate of harmonics.
  • the circuit of this tube is closed on cathode resistor 25, and a potentiometer 26 of high resistance permits of coupling the value of the voltage thus obtained.
  • This correction voltage is then injected for instance in series with a leak resistor 21 belonging to the line scanning 28 (not shown).
  • the plate of this cell is connected with a circuit 35 tuned to the line frequency.
  • the sinusoidal voltage thus obtained is amplifled in a tube 36 and a potentiometer 3! permits of adjusting its value.
  • a condenser 38 acts as connection and a resistor 39 supplies bias.
  • the useful plate voltage is obtained across a low load resistor 4
  • the frame scanning tube is then subjected to the action of the cathode of said tube 44,,through a capacitor 42.
  • capacitor 40 acts as a connection whereas resistor 43 serves to the supply of the plate of tube 36.
  • a television camera tube including a, photocathode, a target, electron optics means for directing the electrons released by said photocathode onto said target to form an electron image thereon, and an electron beam scanning device including means for defiecting the electron beam in the horizontal direction, means for deflecting the electron beam in the vertical direction and means for supplying each of said deflecting means with respective periodically varying voltages, means for superimposing on the voltage supplied to the means for deflecting the beam in one of said directions in at least substantially sinusoidal correcting voltage of a frequency equal to that of the voltage supplied to the means for deflecting the beam in the other direction and of a phase adjusted to tube including a photocathode, a target, electron optics means for directing the electrons released by said photocathode onto said target to form an electron image thereon and an electron beam scanning device including line scanning means, frame scanning means and means for producing saw-tooth voltage variations to operate each of said scanning means respectively, means responsive to one of said saw-tooth voltage variations for
  • a television camera tube including a photocathode, a target, electron optics means for directing the electrons released by said photocathode onto said target to form an electron image thereon and an electron beam scanning device including line scanning means, frame scanning means and means for producing saw-tooth voltage variations to operate each of obtain at least partial compensation of the S dissaid scanning means respectively, means responsive to frame scanning saw-tooth voltage variations for producing a substantially sinusoidal voltage variation and superimposin it on the line scanning saw-tooth voltage variation in correct phase relation to compensate for S distortion of said electron image.
  • a combination according to claim 3 in which the last mentioned means include a capacitor and resistor device for flattening the saw-tooth signal wave-form, a tube connected with the output of said device so as to receive on its grid said flattened signal and means connected with said tube for changing the phase of the substantially sinusoidal signal supplied by said tube.
  • a television camera tube including a photocathode, a target, electron optics means for directing the electrons released by said photocathode onto said target to form an electron image thereon and an electron beam scanning device including line scanning means, frame scanning means, means for producing voltage pulses to control said line scanning means, and means for producing said tooth voltage variations to operate said frame scanning means, means responsive to said pulses for producing a substantially sinusoidal voltage variation and superimposing it on said saw tooth voltage variation in correct phase relation to compensate for S distortion of said electron image.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
US91242A 1948-05-08 1949-05-04 Scanning device for television transmitters Expired - Lifetime US2582014A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR673368X 1948-05-08

Publications (1)

Publication Number Publication Date
US2582014A true US2582014A (en) 1952-01-08

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ID=9018076

Family Applications (1)

Application Number Title Priority Date Filing Date
US91242A Expired - Lifetime US2582014A (en) 1948-05-08 1949-05-04 Scanning device for television transmitters

Country Status (3)

Country Link
US (1) US2582014A (enrdf_load_stackoverflow)
GB (1) GB673368A (enrdf_load_stackoverflow)
NL (2) NL142081B (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2682012A (en) * 1952-09-08 1954-06-22 Rca Corp Television raster distortion correction
US2700742A (en) * 1951-08-07 1955-01-25 Rca Corp Deflection system for cathode-ray tubes
US2726351A (en) * 1952-07-16 1955-12-06 Pye Ltd Television pick-up tubes
US2906919A (en) * 1955-12-27 1959-09-29 Gen Electric Deflection circuit

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1773980A (en) * 1927-01-07 1930-08-26 Television Lab Inc Television system
US2047533A (en) * 1931-10-06 1936-07-14 Loewe Opta Gmbh Television method
US2100702A (en) * 1932-11-04 1937-11-30 Schlesinger Kurt Arrangement for producing relaxation oscillations
US2248556A (en) * 1937-06-21 1941-07-08 Loewe Radio Inc Interlaced line method
US2310197A (en) * 1940-12-21 1943-02-02 Rca Corp Television system
US2425491A (en) * 1943-06-22 1947-08-12 Rca Corp Deflection circuit
US2477557A (en) * 1945-08-11 1949-07-26 Rca Corp Power conservation system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1773980A (en) * 1927-01-07 1930-08-26 Television Lab Inc Television system
US2047533A (en) * 1931-10-06 1936-07-14 Loewe Opta Gmbh Television method
US2100702A (en) * 1932-11-04 1937-11-30 Schlesinger Kurt Arrangement for producing relaxation oscillations
US2248556A (en) * 1937-06-21 1941-07-08 Loewe Radio Inc Interlaced line method
US2310197A (en) * 1940-12-21 1943-02-02 Rca Corp Television system
US2425491A (en) * 1943-06-22 1947-08-12 Rca Corp Deflection circuit
US2477557A (en) * 1945-08-11 1949-07-26 Rca Corp Power conservation system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2700742A (en) * 1951-08-07 1955-01-25 Rca Corp Deflection system for cathode-ray tubes
US2726351A (en) * 1952-07-16 1955-12-06 Pye Ltd Television pick-up tubes
US2682012A (en) * 1952-09-08 1954-06-22 Rca Corp Television raster distortion correction
US2906919A (en) * 1955-12-27 1959-09-29 Gen Electric Deflection circuit

Also Published As

Publication number Publication date
NL142081B (nl)
GB673368A (en) 1952-06-04
NL78390C (enrdf_load_stackoverflow)

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