US2836752A - Beam generating system for cathoderay tubes employing an ion trap - Google Patents

Beam generating system for cathoderay tubes employing an ion trap Download PDF

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Publication number
US2836752A
US2836752A US409195A US40919554A US2836752A US 2836752 A US2836752 A US 2836752A US 409195 A US409195 A US 409195A US 40919554 A US40919554 A US 40919554A US 2836752 A US2836752 A US 2836752A
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United States
Prior art keywords
generating system
ion trap
beam generating
lens
tubes employing
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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
Application number
US409195A
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English (en)
Inventor
Berthold Wolfgang
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.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
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 International Standard Electric Corp filed Critical International Standard Electric Corp
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Publication of US2836752A publication Critical patent/US2836752A/en
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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
    • H01J29/845—Traps for removing or diverting unwanted particles, e.g. negative ions, fringing electrons; Arrangements for velocity or mass selection by means of magnetic systems

Definitions

  • This invention relates to systems in generating electron beams for cathode ray tubes particularly of the type in which ions are trapped and prevented from impinging on the fluorescent screen.
  • An object of the present invention is to improve the arrangement described in said application.
  • the purpose of this improvemen is to produce a substantially larger angle of deflection of the electron beam away from the axis' This enables the use of a shorter-necked tube and is particularly advantageous with strong beam currents.
  • the foregoing advantages are obtained by arching the asymmetrical lens within the beam generating system towards the cathode in accordance with a further improvement of the above arrangement, the lens which is arched towards the cathode is made elliptical or oval instead of circular. in this way it will be possible to change the shape of the focal point on the fluorescent screen.
  • the focal point or focusing spot may have either an oblong or a circular shape.
  • the ion trap magnet whose deflecting field is generally insufiiciently homogeneous, an originally circular spot will be extended in the longitudinal direction (astigmatism).
  • This distortion, or any other distortion which is caused by the system can be compensated by the oval shape of the lens aperture, because generally a circular spot is to be preferred, since it has the smallest cross-section.
  • any other oblong shape of the focal point or focusing spot can be determined by the shape of the lens aperture, in which case the direction of the axis of the ellipse (oval) is decisive for the direction of the major axes of the oblong or longitudinal focusing spot.
  • Fig. 1 is a schematic diagram of a tetrode electron gun system
  • Fig. 2 is a view of the apertures taken along the line A. .AofFig. 1,
  • Fig. 3 is a diagram illustrating the operation of the gun
  • Fig. 4 is a diagram showing the position of the ion trap magnet.
  • a cathode 1 a control electrode 2, a first lens electron 3 and an anode 4.
  • the anode aperture 5 is arched towards the cathode.
  • Fig. 2 there is depicted the asymmetrical lens that is arched towards the cathode.
  • the lens aperture is designed either oval or in the shape of an ellipse and the relation of the long semi-axis a to the short semi-axis b is approximately 1.15 to 1.0.
  • the ion trap magnet is so arranged that the long semiaxis a points in the direction of the magnetic field lines of the ion trap magnet as shown in Fig. 1.
  • the electron beam 5e will be re-directed to the beam axis by means of the magnetic field 9.
  • Fig. 3 of the commercial type ion trap magnet 10, Fig 4 consisting of a permanent magnet and two pole-shoes, while the ions 5i are further trapped by the aperture 11.
  • a beam generating system for a cathode ray tube comprising a cathode electrode, a control electrode adjacent said cathode electrode, a first accelerating electrode adjacent said control electrode and an anode electrode, said control, accelerating, and anode electrodes being mounted serially along a given longitudinal axis and symmetrically disposed thereabout, said accelerating electrode and anode electrode each having an electron lens aperture through which the beam passes, one of said lenses being concentric with the longitudinal axis, the other of said lenses being eccentric with respect thereto, the lens of the anode electrode being arched towards the accelerating electrode, the aperture of the arched anode lens being elliptical.
  • a beam generating system in which the long semi-axis of the ellipse of said elliptical aperture bears the ratio of 1.15:0.1 to l.
  • a beam generating system further including a magnet for redirecting the deflected electrons while permitting the ions to be trapped, said long semi-axis of the ellipse pointing in the same direction as the magnetic field lines of said magnet.

Landscapes

  • Electron Sources, Ion Sources (AREA)
  • Physical Vapour Deposition (AREA)
US409195A 1953-02-19 1954-02-09 Beam generating system for cathoderay tubes employing an ion trap Expired - Lifetime US2836752A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE766158X 1953-02-19

Publications (1)

Publication Number Publication Date
US2836752A true US2836752A (en) 1958-05-27

Family

ID=6673293

Family Applications (1)

Application Number Title Priority Date Filing Date
US409195A Expired - Lifetime US2836752A (en) 1953-02-19 1954-02-09 Beam generating system for cathoderay tubes employing an ion trap

Country Status (4)

Country Link
US (1) US2836752A (de)
BE (1) BE526615A (de)
DE (1) DE1073638B (de)
GB (1) GB766158A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3579010A (en) * 1968-10-31 1971-05-18 Philco Ford Corp Elongated aperture electron gun structure for flat cathode-ray tube
US4075533A (en) * 1976-09-07 1978-02-21 Tektronix, Inc. Electron beam forming structure utilizing an ion trap
US4924138A (en) * 1987-04-10 1990-05-08 U.S. Philips Corporation Device comprising a vacuum ion arc source

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1067949B (it) * 1976-08-27 1985-03-21 Valente D Apparecchio a palette atto a concretizzare la rotazione dell asta di valvole a farfalla e simili

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
US2562242A (en) * 1950-06-06 1951-07-31 Du Mont Allen B Lab Inc Split anode for bent gun ion trap cathode-ray tubes
US2565533A (en) * 1950-05-19 1951-08-28 Rauland Corp Cathode-ray tube
US2604599A (en) * 1949-09-17 1952-07-22 Sylvania Electric Prod Cathode-ray tube
US2608666A (en) * 1948-12-21 1952-08-26 Hartford Nat Bank & Trust Co Braun tube for use in television
US2617060A (en) * 1950-05-02 1952-11-04 Hartford Nat Bank & Trust Co Cathode-ray tube
US2637828A (en) * 1949-11-25 1953-05-05 Du Mont Allen B Lab Inc Ion-trap cathode-ray tube
US2658161A (en) * 1952-01-09 1953-11-03 Rauland Corp Image-reproducing device
US2673305A (en) * 1951-05-31 1954-03-23 Rauland Corp Image-reproducing device
US2733365A (en) * 1956-01-31 hoagland

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE480334A (de) * 1942-03-14
FR1021531A (fr) * 1950-07-05 1953-02-19 Radiotechnique Perfectionnements aux tubes à rayons cathodiques

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2733365A (en) * 1956-01-31 hoagland
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
US2608666A (en) * 1948-12-21 1952-08-26 Hartford Nat Bank & Trust Co Braun tube for use in television
US2604599A (en) * 1949-09-17 1952-07-22 Sylvania Electric Prod Cathode-ray tube
US2637828A (en) * 1949-11-25 1953-05-05 Du Mont Allen B Lab Inc Ion-trap cathode-ray tube
US2617060A (en) * 1950-05-02 1952-11-04 Hartford Nat Bank & Trust Co Cathode-ray tube
US2565533A (en) * 1950-05-19 1951-08-28 Rauland Corp Cathode-ray tube
US2562242A (en) * 1950-06-06 1951-07-31 Du Mont Allen B Lab Inc Split anode for bent gun ion trap cathode-ray tubes
US2673305A (en) * 1951-05-31 1954-03-23 Rauland Corp Image-reproducing device
US2658161A (en) * 1952-01-09 1953-11-03 Rauland Corp Image-reproducing device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3579010A (en) * 1968-10-31 1971-05-18 Philco Ford Corp Elongated aperture electron gun structure for flat cathode-ray tube
US4075533A (en) * 1976-09-07 1978-02-21 Tektronix, Inc. Electron beam forming structure utilizing an ion trap
US4924138A (en) * 1987-04-10 1990-05-08 U.S. Philips Corporation Device comprising a vacuum ion arc source

Also Published As

Publication number Publication date
DE1073638B (de) 1960-01-21
GB766158A (en) 1957-01-16
BE526615A (de)

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