GB1459656A - Cathode-ray tube having magnetic shield - Google Patents

Cathode-ray tube having magnetic shield

Info

Publication number
GB1459656A
GB1459656A GB5026974A GB5026974A GB1459656A GB 1459656 A GB1459656 A GB 1459656A GB 5026974 A GB5026974 A GB 5026974A GB 5026974 A GB5026974 A GB 5026974A GB 1459656 A GB1459656 A GB 1459656A
Authority
GB
United Kingdom
Prior art keywords
shields
mask
internal
beams
external
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
Application number
GB5026974A
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.)
RCA Corp
Original Assignee
RCA 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 RCA Corp filed Critical RCA Corp
Publication of GB1459656A publication Critical patent/GB1459656A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/06Screens for shielding; Masks interposed in the electron stream
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/003Arrangements for eliminating unwanted electromagnetic effects, e.g. demagnetisation arrangements, shielding coils
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/86Vessels; Containers; Vacuum locks
    • H01J29/867Means associated with the outside of the vessel for shielding, e.g. magnetic shields
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00Details of cathode ray tubes or electron beam tubes
    • H01J2229/0007Elimination of unwanted or stray electromagnetic effects
    • H01J2229/003Preventing or cancelling fields entering the enclosure
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00Details of cathode ray tubes or electron beam tubes
    • H01J2229/0007Elimination of unwanted or stray electromagnetic effects
    • H01J2229/0046Preventing or cancelling fields within the enclosure
    • H01J2229/0053Demagnetisation

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Electrodes For Cathode-Ray Tubes (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)

Abstract

1459656 Colour television tubes RCA CORPORATION 20 Nov 1974 [29 Nov 1973] 50269/74 Heading H1D [Also in Division H4] In a shadow mask colour tube 12, the electron beams are shielded from external magnetic field and the magnetizable shadow mask may be degaussed by external coil-carrying magnetic shields 40 at the sides of the mask, magnetically continued through internal magnetic shields 44, 48, running back down the cone of the tube from the top and bottom of the mask. The internal shields form a lens shaped opening 50 for the passage of the beams, and are cut away in a wedge shape (Fig. 2, not shown) opposite coils 42 to force the flux into the mask. The external shields are each made in two overlapping parts 56, 58, surrounded by coils 42 which are extended round the shields. In tubes with non-in-line guns the shields may need to be set off horizontal. Degaussing is performed by decreasing A.C. The internal shields attached to the mask-frame prevent extreme beams from passing the edges, but to capture reflected or secondary electrons a grooved ring is placed on the mask-mounting frame adjacent to the shields (Figs. 8, 9, not shown).
GB5026974A 1973-11-29 1974-11-20 Cathode-ray tube having magnetic shield Expired GB1459656A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US420324A US3867668A (en) 1973-11-29 1973-11-29 Cathode-ray tube having an internal-external magnetic shield and degaussing combination

Publications (1)

Publication Number Publication Date
GB1459656A true GB1459656A (en) 1976-12-22

Family

ID=23665997

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5026974A Expired GB1459656A (en) 1973-11-29 1974-11-20 Cathode-ray tube having magnetic shield

Country Status (12)

Country Link
US (1) US3867668A (en)
JP (1) JPS5426418B2 (en)
BE (1) BE822727A (en)
BR (1) BR7409924A (en)
CA (1) CA1017400A (en)
DE (1) DE2456315A1 (en)
ES (1) ES432172A1 (en)
FR (1) FR2253267B1 (en)
GB (1) GB1459656A (en)
IT (1) IT1027576B (en)
NL (1) NL7415534A (en)
PL (1) PL100481B1 (en)

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5527957Y2 (en) * 1974-05-20 1980-07-04
JPS52120518U (en) * 1976-03-02 1977-09-13
JPS5413253A (en) * 1977-07-01 1979-01-31 Hitachi Ltd Color receiving tube
JPS5569938A (en) * 1978-11-21 1980-05-27 Toshiba Corp Color picture tube device
US4243913A (en) * 1979-08-29 1981-01-06 Rca Corporation Color picture tube magnetic shielding and degaussing structure
US4556821A (en) * 1984-03-15 1985-12-03 Rca Corporation Color image display system having an improved external magnetic shield
GB2177539B (en) * 1985-05-20 1989-07-05 Mitsubishi Electric Corp Magnetic shielding system in color television receiver
JPH07107831B2 (en) * 1986-12-26 1995-11-15 ソニー株式会社 Cathode ray tube
JPS63221790A (en) * 1987-03-11 1988-09-14 Sony Corp Cathode-ray tube
US4767969A (en) * 1987-05-26 1988-08-30 Honeywell, Inc. RF emission shield for CRT displays
US4996461A (en) * 1989-09-07 1991-02-26 Hughes Aircraft Company Closed loop bucking field system
US5081392A (en) * 1990-09-11 1992-01-14 Rca Thomson Licensing Corporation Color picture tube having an internal magnetic shield
US5097174A (en) * 1990-11-23 1992-03-17 Thomson Consumer Electronics, Inc. Color picture tube having an improved internal magnetic shield
ATE142047T1 (en) * 1991-03-08 1996-09-15 Philips Electronics Nv COLOR IMAGE REVIEW TUBE WITH INTERNAL MAGNETIC SHIELD CAP
US5180947A (en) * 1991-04-23 1993-01-19 Alliant Techsystems Inc. Shielded cathode ray tube
US5229689A (en) * 1991-05-14 1993-07-20 Apple Computer, Inc. Electrostatic shield for nearfield alternating electrical field emission reduction in a CRT display
KR100234168B1 (en) * 1997-06-28 1999-12-15 손욱 Inner shield for color cathode-ray tube
KR20030010096A (en) * 2001-07-25 2003-02-05 엘지.필립스디스플레이(주) Structure for shielding external magnetism in color cathode ray tube
US6686695B2 (en) * 2001-10-16 2004-02-03 Samsung Sdi Co., Ltd. Cathode ray tube having degaussing coil for minimizing variations in landing of electron beam
US11177114B1 (en) * 2020-09-15 2021-11-16 ICT Integrated Circuit Testing Gesellschaft für Halbleiterprüftechnik mbH Electrode arrangement, contact assembly for an electrode arrangement, charged particle beam device, and method of reducing an electrical field strength in an electrode arrangement

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3317781A (en) * 1963-12-19 1967-05-02 Rca Corp Television degaussing apparatus
US3322998A (en) * 1964-08-31 1967-05-30 Rca Corp Color purity correcting apparatus for colored television picture tubes
US3431454A (en) * 1967-07-31 1969-03-04 Zenith Radio Corp Cathode-ray tube magnetic shield and tube mount
US3564329A (en) * 1968-10-28 1971-02-16 Philco Ford Corp Shielding apparatus of metal plates strap-mounted on cathode ray tube for shielding against external magnetic fields
US3549932A (en) * 1969-04-04 1970-12-22 Motorola Inc Color television tube with shadow mask assembly provided with shield for reducing x-ray radiation and the effect of stray magnetic fields
US3571652A (en) * 1969-04-14 1971-03-23 Sony Corp Degaussing device for color picture tube having parallel-slitted beam-selecting grid
US3576395A (en) * 1969-05-21 1971-04-27 Sylvania Electric Prod Integral support and magentic shielding means for cathode-ray

Also Published As

Publication number Publication date
PL100481B1 (en) 1978-10-31
DE2456315A1 (en) 1975-06-05
JPS5426418B2 (en) 1979-09-04
BE822727A (en) 1975-03-14
FR2253267A1 (en) 1975-06-27
FR2253267B1 (en) 1979-07-06
CA1017400A (en) 1977-09-13
US3867668A (en) 1975-02-18
AU7567874A (en) 1976-05-27
ES432172A1 (en) 1976-09-16
JPS50114927A (en) 1975-09-09
NL7415534A (en) 1975-06-02
IT1027576B (en) 1978-12-20
BR7409924A (en) 1976-05-25

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee