US3663907A - Beam convergence exciter for shadow mask color picture tube - Google Patents

Beam convergence exciter for shadow mask color picture tube Download PDF

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Publication number
US3663907A
US3663907A US96003A US3663907DA US3663907A US 3663907 A US3663907 A US 3663907A US 96003 A US96003 A US 96003A US 3663907D A US3663907D A US 3663907DA US 3663907 A US3663907 A US 3663907A
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United States
Prior art keywords
coils
exciter
convergence
pole pieces
neck section
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
US96003A
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English (en)
Inventor
William Henry Barkow
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RCA Licensing Corp
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RCA Corp
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Filing date
Publication date
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Publication of US3663907A publication Critical patent/US3663907A/en
Assigned to RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE reassignment RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: RCA CORPORATION, A CORP. OF DE
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Expired - Lifetime legal-status Critical Current

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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
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/70—Arrangements for deflecting ray or beam
    • H01J29/701—Systems for correcting deviation or convergence of a plurality of beams by means of magnetic fields at least
    • H01J29/702—Convergence correction arrangements therefor
    • H01J29/705—Dynamic convergence systems
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/0007—Elimination of unwanted or stray electromagnetic effects
    • H01J2229/0046—Preventing or cancelling fields within the enclosure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/56—Correction of beam optics
    • H01J2229/563—Aberrations by type
    • H01J2229/5637—Colour purity
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/56—Correction of beam optics
    • H01J2229/568—Correction of beam optics using supplementary correction devices
    • H01J2229/5681—Correction of beam optics using supplementary correction devices magnetic
    • H01J2229/5687—Auxiliary coils

Definitions

  • the exciter mounted closely behind the deflection yoke on the neck of the tube, has three pairs of external coils which are respectively associated with three pairs of internal pole pieces and are enveloped by a ferromagnetic core.
  • the beam convergence exciter of this invention comprises a pair of coils, external of the picture tube neck, associated with each pair of convergence pole pieces, internal of the tube neck, and through each of which an electron beam passes.
  • the coils are enveloped by a ferromagnetic core which shields the electron beams from extraneous magnetic fields and so concentrates the convergence fields for the respective beams between the associated pole pieces that interaction between the different convergence fields is minimized.
  • FIG. 1 is a diagrammatic view of a shadow mask color picture tube showing the general positions of the beam convergence exciter of this invention in relation to other adjuncts used in the operation of the tube;
  • FIG. 2 is a sectional view of the neck section of the picture tube taken on the line 2-2 of FIG. I and showing the general structure of the exciter;
  • FIGS. 3 and 4 are plan and side views respectively of one of the coils included in the exciter.
  • FIG. 5 is a schematic diagram showing the electrical con nections of the exciter coils.
  • the three beam shadow mask-type of color picture tube ll with which the beam convergence exciter is used, has a relatively large flared front section I2 and a relatively small cylindrical rear neck section 13.
  • the face plate 14 at the front of the flared section 12 has formed on its rear surface a fluorescent screen 15 comprising a plurality of triads of phosphor dots which are excitable by respective electron beams to produce light of three different colors such as red, green and blue.
  • a shadow mask 16 having a plurality of apertures aligned with the triads of phosphor dots of the screen 15 is mounted in back of the screen and functions, in cooperation with other elements of the tube, to direct the three electron beams to their respective phosphor dots.
  • Three electron guns of which only the blue gun l7 and the red gun 18 are visible, are mounted in the neck section 13 of the picture tube 11 to produce, when suitably energized, the three electron beams for excitation of the screen 15.
  • the green electron gun is mounted directly on the same horizontal line with the red electron gun so that it is not visible in this figure.
  • a deflection yoke 19 is mounted externally of the tube 11 in the region in which the neck section 13 merges with the flared section 12.
  • the beam convergence exciter 21, comprising this invention, is indicated diagrammatically as surrounding the neck section 13 immediately to the rear of the deflection yoke 19. Still further to the rear on the neck section 13 there are located a color purity device 22 and a lateral magnet 23 behind it.
  • the color picture tube 11 and the various adjuncts referred to are generally known and used and hence, except for the convergence exciter 21, need no additional description or explanation.
  • the beam convergence exciter 21 is shown in its relation to the neck section 13 of the picture tube 11 and to the blue, red and green electron beams 17a, 18a and 240 respectively emanating from the blue and red electron guns 17 and 18 and from the green gun (not shown).
  • the three beams are symmetrically disposed about the longitudinal axis 25 of the picture tube 11.
  • the blue, red and green electron beams 17a, 18a and 24a pass respectively between the internal pole pieces 26a-26b, 27a-27b and 28a-28b which are suitably mounted on the inside of the tube neck section 13.
  • the beam convergence exciter 21, comprising this invention, is mounted on the outside of the picture tube neck section 13.. It includes three pairs of coils 29a-29b, 3la-3lb and 320-32 associated respectively with the internal pole pieces 26a-26, 27a-27b and 28a-28b.
  • a ferromagnetic core 33 envelopes the three pairs of exciter coils.
  • the core may be formed of several convolutions of a strip of suitable material such as Allegheny-Ludlum No. 4750 nickel steel having a thickness of approximately 0.003 inches.
  • Each coil such as the coil 29a, is fabricated as illustrated in FIGS. 3 and 4 by first winding a suitable number of turns, such as 220 for example, upon a substantially rectangular mandrel. The coils are then assembled in equally spaced positions around a forming tube (not shown) having an outside diameter only slightly greater than the outside diameter of the neck section 13 of the picture tube 11. In this operation each coil, whose thickness is small relative to its length and width, is shaped to conform generally to the curvature of the forming tube and thus to that of the picture tube neck section 13.
  • a suitable number of turns such as 220 for example
  • the core 33 is then applied and the coils securely afiixed thereto by suitable means.
  • the completed assembly is removed from the forming tube and is ready for mounting on the picture tube neck 13.
  • the core 33 When the beam convergence exciter as described is mounted on the picture tube neck section 13 closely adjacent the deflection yoke as shown in FIG. 1, the core 33 functions as an effective shield to prevent any substantial component of the deflection field from affecting the electron beams while they are traversing the convergence region including the internal pole pieces 26a-26b, 27a-27b and 28a-28b. At the same time the core 33 also serves to so concentrate the three convergence fields between each pair of pole pieces that there is a minimum of interaction between the convergence fields.
  • the beam convergence exciter of this invention enables the convergence region to be close to the deflection yoke, thereby minimizing any degrouping of the three beams when convergence is effected. It also enables the production of a deflection field which is sufficiently long to provide wide angle beam deflection with optimum astigmatism characteristics. These factors contribute to a desired shortening of the neck section 13 of the picture tube 1 1.
  • a beam convergence exciter for mounting on the tubular neck section of a shadow mask color picture tube having three electron beams symmetrically disposed about the longitudinal axis of said tube and traversing a convergence region between three respective pairs of internal pole pieces, said exciter com-,
  • each of said coils comprising a plurality of convolutions of a conductor about a central axis, and each of said coils being mounted in close roximity to the curved outer surface of said tubular neck section, with each coil axis in alignment with a respectively different one of said internal pole pieces and with the conductor convolutions of each coil arcuately bent relative to the axis thereof in such manner as to present to said neck a curved coil surface substantially conforming in curvature to the proximate neck surface;
  • a ferromagnetic core circumferentially enveloping said coils to concentrate over said pole pieces electromagnetic fields produced by energizing said coils and to shield said electron beams from extraneous magnetic fields.
  • a color picture tube enclosing three electron beam paths symmetrically disposed about the longitudinal axis of a tubular neck section of said tube, each of said beam paths traversing a convergence region within said neck section between three respective pairs of internal pole pieces of magnetizable material, said color picture tube having a display screen; and (b) a deflection yoke for establishing magnetic fields to deflect electron beams traversing said paths over a wide deflection angle, said magnetic fields being subject to pincushion correcting modulation to ensure development of a substantially undistorted raster of scanning lines on said display screen despite the wideness of said deflection angle, said deflection yoke encircling said picture tube and positioned along the longitudinal axis thereof in such manner as to place the rear of said yoke in the immediate vicinity of said convergence region; (c) a beam convergence exciter, mounted on said neck section, and comprising:
  • each of said coils comprising a plurality of convolutions of a conductor about a central axis, and each of said coils being mounted in close proximity to the curved outer surface of said tubular neck section, with each coil axis in alignment with a respectively different one of said internal pole pieces and with the conductor convolutions of each coil arcuately bent relative to the axis thereof in such manner as to present to said neck a curved coil surface substantially conforming in curvature to the proximate neck surface; and means, comprising an annular band of ferromagnetic material circumferentially enveloping said arcuately bent coils, for providing said coils with a ferromagnetic core concentrating over each pole piece pair the electromagnetic fields produced by energizing the respectively associated coil pair and for concomitantly shielding said coils and the aligned pole pieces in said convergence region from the modulated magnetic fields produced by said deflection
  • said coils are affixed to the inside of said annular ferromagnetic band.

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  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Manufacturing Of Steel Electrode Plates (AREA)
US96003A 1970-12-08 1970-12-08 Beam convergence exciter for shadow mask color picture tube Expired - Lifetime US3663907A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US9600370A 1970-12-08 1970-12-08

Publications (1)

Publication Number Publication Date
US3663907A true US3663907A (en) 1972-05-16

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ID=22254602

Family Applications (1)

Application Number Title Priority Date Filing Date
US96003A Expired - Lifetime US3663907A (en) 1970-12-08 1970-12-08 Beam convergence exciter for shadow mask color picture tube

Country Status (10)

Country Link
US (1) US3663907A (es)
JP (1) JPS5114403B1 (es)
AU (1) AU473396B2 (es)
CA (1) CA988140A (es)
DE (1) DE2160883C3 (es)
ES (1) ES397752A1 (es)
FR (1) FR2117235A5 (es)
GB (1) GB1369076A (es)
IT (1) IT941956B (es)
NL (1) NL7116793A (es)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6097163A (en) * 1997-02-22 2000-08-01 Deutsche Thomson-Brandt Gmbh Electron beam deflection apparatus using an auxiliary deflection coil and a compensation coil
WO2001073811A1 (en) * 2000-03-28 2001-10-04 Koninklijke Philips Electronics N.V. Color display device with a deflection-dependent distance between outer beams
US20060226714A1 (en) * 2005-01-24 2006-10-12 Naoki Miura Electromagnetic exciter

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2949593A (en) * 1957-05-09 1960-08-16 Reynolds Metals Co Electrical coil formed from multilayer strip conductor
US3088046A (en) * 1960-05-20 1963-04-30 Sol L Reiches Color convergence assembly
US3268753A (en) * 1962-07-06 1966-08-23 Rca Corp Plural electron gun assembly and magnetic convergence cage
US3294999A (en) * 1962-08-06 1966-12-27 Rca Corp Cathode ray tube
US3325758A (en) * 1965-12-08 1967-06-13 Varian Associates Negative temperature coefficient shunt means for magnetic structures

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2949593A (en) * 1957-05-09 1960-08-16 Reynolds Metals Co Electrical coil formed from multilayer strip conductor
US3088046A (en) * 1960-05-20 1963-04-30 Sol L Reiches Color convergence assembly
US3268753A (en) * 1962-07-06 1966-08-23 Rca Corp Plural electron gun assembly and magnetic convergence cage
US3294999A (en) * 1962-08-06 1966-12-27 Rca Corp Cathode ray tube
US3325758A (en) * 1965-12-08 1967-06-13 Varian Associates Negative temperature coefficient shunt means for magnetic structures

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6097163A (en) * 1997-02-22 2000-08-01 Deutsche Thomson-Brandt Gmbh Electron beam deflection apparatus using an auxiliary deflection coil and a compensation coil
WO2001073811A1 (en) * 2000-03-28 2001-10-04 Koninklijke Philips Electronics N.V. Color display device with a deflection-dependent distance between outer beams
US20060226714A1 (en) * 2005-01-24 2006-10-12 Naoki Miura Electromagnetic exciter
US7436088B2 (en) * 2005-01-24 2008-10-14 Citizen Electronics Co., Ltd. Electromagnetic exciter

Also Published As

Publication number Publication date
JPS5114403B1 (es) 1976-05-10
ES397752A1 (es) 1975-06-16
DE2160883A1 (de) 1972-06-22
AU473396B2 (en) 1973-05-31
NL7116793A (es) 1972-06-12
GB1369076A (en) 1974-10-02
CA988140A (en) 1976-04-27
AU3604571A (en) 1973-05-31
IT941956B (it) 1973-03-10
DE2160883C3 (de) 1974-05-30
FR2117235A5 (es) 1972-07-21
DE2160883B2 (de) 1973-11-08

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AS Assignment

Owner name: RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, P

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:RCA CORPORATION, A CORP. OF DE;REEL/FRAME:004993/0131

Effective date: 19871208