US2608666A - Braun tube for use in television - Google Patents

Braun tube for use in television Download PDF

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Publication number
US2608666A
US2608666A US133504A US13350449A US2608666A US 2608666 A US2608666 A US 2608666A US 133504 A US133504 A US 133504A US 13350449 A US13350449 A US 13350449A US 2608666 A US2608666 A US 2608666A
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US
United States
Prior art keywords
aperture
electron beam
electron
tube
plane
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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
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US133504A
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English (en)
Inventor
Gier Johannes De
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.)
Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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Filing date
Publication date
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
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    • 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
    • H01J29/84—Traps for removing or diverting unwanted particles, e.g. negative ions, fringing electrons; Arrangements for velocity or mass selection

Definitions

  • Said device may comprise a cylindrical electrode through which the electron beam passes and which collects a beamof negative ions separated from the electron beam by deflection.
  • This electrode which may be referred to as a negative ion collector, has a transverse wall (collecting plate) which is provided with an aperture to allow the passage of electrons.
  • the cylindrical part of the ion collector may be a metal body arranged in the tube and is not necessarily of cir-'" cular cross-section; as an alternative, it may be constituted by a conductive coating or a metal part of the tube wall.
  • the invention relates to Braun tubes for television reception comprising a negative ion collector, in which tubes the negative ions are deilected from their original path and are brought outside the electron beam.
  • Brainun tubes for use in television receivers which comprise an ion collector, in which the ion beam retains its original direction and the electrons are deflected from this directionby a magnetic field.
  • a tube is described, for example, in British patent specification No. 538,684.
  • the collecting plate of an ion collector is arranged at or near a point at which the cross-sectional area of the electron beam exhibits a minimum value; the small aperture in the collecting plate is projected by an electron-optical lens onto the image screen.
  • the present invention does not relate to such tubes butconcerns only tubesin which the col-l.
  • lecting plate lies within the object distance from the projecting lens, suchyfor example, as the tubes towhich Figs. 16 and'17 on pages 375 and 376 of Reviewsof Modern Physics," vol. 18, No. 3.01 July 1946 refer. I. l
  • The'plane passing through the axes of "the ion collector and the deflected ion beam will be reterredtoas the meridian plane, the plane passing through the axis of the ion collector atright 3 Claims. (01.313-86) angles to the meridian plane will be-referred to as the equatorialplane.
  • the aperture in the ion collector for passage or: the electron beam is circular "and-concentric with the axis of the ion collector.
  • a Braun tube for use in television receivers comprising a negative ion collector for intercepting a beam of negative ionswhich is deflected and thus separated.
  • the collector being constituted by a cylindrical electrodecomprising'a collecting plate, which plate is not located at or near apoint at which the cross-sectional area of the electron beam exhibits a minimum value, ischaracterized in that'the, aperture in the collecting plate for passage of the electronsis not both circular and; concentric with the cylindrical electrode.”
  • the aperture is asymmetrical with respectfito'the equatorial plane, the plane figure it forms has its centre of gravity on that side 01 the equatorial plane opposite thaton which the deflected negative ion beam is located.
  • the aperture may be circular.
  • the: aperture may -be symmetrical with respectt'o the equatorial plane, but in this case itis not circular.
  • Fig. 1 is an axial sectional view taken on the meridian plane of an ion collector of known con structionwhich collects a beam of negative ions deflected from itsinitial direction
  • Fig. 2 is a cross-sectional view of the same body taken on the planeIL-II
  • Figs. 3 to 7 are cross-sectional views, similarto that of Fig. 2, of ion collectors for use in a Braun tube according to the invention.
  • Figs. 8, 9 and 10 are graphs themeaning oi which will be apparent from the description.
  • a negative ion collector comprises a right circular cylindricalpart and a diaphragm 2 which constitutes the collecting plate.
  • the end plane at the left-hand end of I cylinder I is at an angle with the axis 301? the cylinder.
  • an electric field which, in the region associated with the beam, has a constant component at right angles to the axis 3, parallel to the plane of the figure.
  • the negative ion collector coincides with the ax-is. 3 of the cylinder I.
  • Fig. 2 shows the circular apertureintlie: dia: n
  • the radius of this aperture deter mines the diameter of the electron beam Sallowed to pass.
  • the aperture is not necessarily circular. It may extend as far as the cylinder wall. This results in constructions of which Figs. 4 and 5 are examples.
  • the full line curve illustrates the relationship between the bright-v ness B, measured in mK./cm. of the image spot in a tube having a circular central aperture and the current strength i in ,u amps absorbed by the tube.
  • the broken line curve illustrates the corresponding. relationshipior'fa tubeicorhpi'ising a diaphragm as shown inFig; 41 It will-be seen that the effect of the increase in size of the aperture in the diaphragm increases with increase instrengthoi. thecurrent.
  • a collecting plate as shownih Fig.2 cuts off a greater part of the electron: heam.
  • the aperture is asshowninEig; 4", the cen' tring; operation may be carried out" as follows? With; the beam stationary, an unfocused light spot is caused to appear on. the image screen. The brightest partof thetspot isat its centre, but ithasa-largesurface area andit's boundaries are- I'IOt ShaI'PIYidBfiIIBdL In: addition; since the object plane of the. electronxlens ise nearerthe collectingplatefthan. with .a focused beam, an undefined reproduction of the edge :of the col lectingplate iSTObSBITVBdL In".these circumstances,' the-light spot may readily be" caused toiiappear from behind: the.
  • the device for removing the negative ions may be rendered more effective without incurring a corresponding loss in electrons.
  • the centre of the electron beam may without objection be With a diaphragm having a central cirbeam than is the case under similar conditions slightly moved away from the edge so as to wholly V avoid the loss of light which might be produced by reduction of the depth of the recess or by provision of a local elevation to mark the centre of the edge.
  • This movement which is effected by magnetic means, does not result in any shift of the negative ion beam, Instead of collecting fewer negative ions, as might be expected, the use of a collecting plate in the form shown in Fig. 4 yields a better result.
  • Fig. 6 illustrates that with a tube according to the invention a non-circular aperture arranged symmetrically with respect to the equatorial plane may be provided.
  • an ion trap for separating negative ions from electrons in said electron beam comprising a cylindrical electrode adapted to receive therein said focused beam, a masking element arranged transverse to said longitudinal axis and within the object distance of said initial focus, and means to deflect the negative ions from said longitudinal axis along an axis intercepted by said masking element and forming with the longitudinal axis a meridian plane, said masking element having a split aperture which is symmetrical about the meridian plane and an equatorial plane perpendicular to the meridian plane and containing said longitudinal axis, said aperture having a dimension in the equatorial plane which is greater than the largest dimension of the aperture in the meridian plane thereby permitting a greater degree of lateral movement of the electrons in said beam about the longitudinal axis in the said equatorial plane than in
  • an ion trap for separating negative ions from electrons in said electron beam comprising a cylindrical electrode adapted to receive therein said focused beam, a masking element arranged transverse to said longitudinal axis and within the object distance of said initial focus, and means to deflect the negative ions from said longitudinal axis along an axis intercepted by said masking element and forming with the longitudinal axis a meridian plane, said masking element having a rectangular aperture arranged symmetrically about the longitudinal axis, said aperture having a dimension in an equatorial plane perpendicular to the meridian plane and containing the longitudinal axis which is greater than the largest dimension of the aperture in the meridian plane, thereby permitting a greater degree of lateral movement of the electrons in said beam about the longitudinal axis in the said equatorial plane than said meridian plane.
  • a cathode-ray tube having an electron gun for directing an electron beam along a longitudinal axis to a point of initial focus, an ion ammo;

Landscapes

  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Electrodes For Cathode-Ray Tubes (AREA)
US133504A 1948-12-21 1949-12-17 Braun tube for use in television Expired - Lifetime US2608666A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL282229X 1948-12-21

Publications (1)

Publication Number Publication Date
US2608666A true US2608666A (en) 1952-08-26

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Application Number Title Priority Date Filing Date
US133504A Expired - Lifetime US2608666A (en) 1948-12-21 1949-12-17 Braun tube for use in television

Country Status (7)

Country Link
US (1) US2608666A (fr)
BE (1) BE492805A (fr)
CH (1) CH282229A (fr)
DE (1) DE862168C (fr)
FR (1) FR1002873A (fr)
GB (1) GB670152A (fr)
NL (1) NL143970B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2717322A (en) * 1952-11-01 1955-09-06 Rca Corp Cathode ray tube guns
US2836752A (en) * 1953-02-19 1958-05-27 Int Standard Electric Corp Beam generating system for cathoderay tubes employing an ion trap

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL185006B (nl) * 1953-02-13 Sentralinst For Ind Forskning Bestuurbaar onderstel.

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2181850A (en) * 1936-07-25 1939-11-28 Emi Ltd Cathode ray tube
US2188579A (en) * 1933-05-27 1940-01-30 Loewe Radio Inc Cathode ray tube, more particularly for television purposes
US2211614A (en) * 1936-08-14 1940-08-13 Hygrade Sylvania Corp Cathode ray tube and the like
US2274586A (en) * 1939-02-25 1942-02-24 Philco Radio & Television Corp Cathode ray tube
US2456474A (en) * 1946-07-02 1948-12-14 Gen Electric Electric discharge device
US2472766A (en) * 1944-12-28 1949-06-07 Cossor Ltd A C Cathode-ray tube
US2496127A (en) * 1947-02-05 1950-01-31 Rca Corp Electron gun for cathode-ray tubes
US2515305A (en) * 1946-01-24 1950-07-18 Rca Corp Electromagnet

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB458270A (en) * 1935-06-24 1936-12-16 Robert Vaughan Whelpton Improvements in high speed cathode ray recording oscillographs

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2188579A (en) * 1933-05-27 1940-01-30 Loewe Radio Inc Cathode ray tube, more particularly for television purposes
US2181850A (en) * 1936-07-25 1939-11-28 Emi Ltd Cathode ray tube
US2211614A (en) * 1936-08-14 1940-08-13 Hygrade Sylvania Corp Cathode ray tube and the like
US2274586A (en) * 1939-02-25 1942-02-24 Philco Radio & Television Corp Cathode ray tube
US2472766A (en) * 1944-12-28 1949-06-07 Cossor Ltd A C Cathode-ray tube
US2515305A (en) * 1946-01-24 1950-07-18 Rca Corp Electromagnet
US2456474A (en) * 1946-07-02 1948-12-14 Gen Electric Electric discharge device
US2496127A (en) * 1947-02-05 1950-01-31 Rca Corp Electron gun for cathode-ray tubes

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2717322A (en) * 1952-11-01 1955-09-06 Rca Corp Cathode ray tube guns
US2836752A (en) * 1953-02-19 1958-05-27 Int Standard Electric Corp Beam generating system for cathoderay tubes employing an ion trap

Also Published As

Publication number Publication date
DE862168C (de) 1953-01-08
NL143970B (nl)
GB670152A (en) 1952-04-16
FR1002873A (fr) 1952-03-11
BE492805A (fr)
CH282229A (de) 1952-04-15

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