US3873876A - Color cathode-ray tube with temperature equilization for plurality of electron gun filaments - Google Patents

Color cathode-ray tube with temperature equilization for plurality of electron gun filaments Download PDF

Info

Publication number
US3873876A
US3873876A US451285A US45128574A US3873876A US 3873876 A US3873876 A US 3873876A US 451285 A US451285 A US 451285A US 45128574 A US45128574 A US 45128574A US 3873876 A US3873876 A US 3873876A
Authority
US
United States
Prior art keywords
electron gun
cathode
connection member
heater
ray tube
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
US451285A
Other languages
English (en)
Inventor
Masaaki Yamauchi
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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 Hitachi Ltd filed Critical Hitachi Ltd
Application granted granted Critical
Publication of US3873876A publication Critical patent/US3873876A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • H01J29/48—Electron guns
    • H01J29/484—Eliminating deleterious effects due to thermal effects, electrical or magnetic fields; Preventing unwanted emission
    • 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
    • H01J29/48—Electron guns
    • H01J29/50—Electron guns two or more guns in a single vacuum space, e.g. for plural-ray tube
    • H01J29/503—Three or more guns, the axes of which lay in a common plane
    • 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
    • H01J29/82—Mounting, supporting, spacing, or insulating electron-optical or ion-optical arrangements

Definitions

  • the present invention relates to an electron gun assembly for color cathode-ray tube or more in particular to an in-line type of the electron gun assembly comprising three electron guns arranged approximately parallel in substantially the same plane.
  • electron gun assemblies for color cathoderay tube are classified into bipotential and unipotential types depending on the manner in which electrodes are arranged. Further, they are grouped into delta and inline types depending on the arrangement of the electron guns.
  • the conventional in-line type of electron gun assembly in which three electron guns each with a heater, a cathode and a plurality of electrodes are arranged approximately parallel in substantially the same plane has the disadvantage that the cathode belonging to the central electron gun is heated more than the cathodes belonging to the other electron guns since it receives radiation heat from the cathodes and heaters of the other electron guns. This fact adversely affects the activity of the cathodes in the manufacturing processes of the color cathode-ray tube, especially during the activation step thereof and also shortens the service life of the central cathode.
  • the cathode associated with the central electron gun is made larger than the cathodes associated with the other electron guns thereby to increase the thermal radiation and thermal conductivity of such a central cathode. According to such a method, however, the cathode for the central electron gun is likely to be mistaken for the cathode for one of the other electron guns on an assembly line for mass production.
  • an object of the present invention to provide an in-line type of electron gun assembly for a color cathode-ray tube comprising similar cathodes for the three electron guns which can be maintained at substantially the same temperature.
  • an electron gun assembly for a color cathode-ray tube comprising three electron guns which are arranged approximately parallel in the same plane and each of which includes a heater, a cathode and a plurality of electrodes, and at least one connection member to which the respective heaters are connected at substantially equal intervals, wherein the area of the connection member portion to which the heater belonging to the central one of the electron gun is connected is made larger than that of each of the areas of the connection member portions to which the heaters belonging to the other electron guns are connected.
  • FIG. 1 is a diagram schematically showing an example of a conventional electron gun assembly for color cathode-ray tube
  • FIG. 2 is a diagram schematically showing the construction of a heater connection member of the electron gun assembly of FIG. 1;
  • FIG. 3 is a diagram schematically showing the construction of a heater connection member of an electron gun assembly'for color cathode-ray tube according to the present invention.
  • FIG. 1 showing an example of a conventional in-line type of electron gun assembly for color cathode-ray tube
  • electron guns 2 and 4 among the electron guns 2, 3 and 4 for red, green and blue respectively supported on support members 1 of bead glass have their axes inclined by about l in such a manner as to intersect with each other at a point on a color selective electrode not shown.
  • connection members 8 and 9 connected to heaters 5, 6 and 7 associated respectively with the electron guns 2, 3 and 4 are fixedly supported by the support members 1 through legs 81, 82 and 83 extending from the connection members 8 and 9.
  • Cathodes 10, 11 and 12 into which the heaters 5, 6 and 7 are inserted are contained respectively in the first grid electrodes 13 which constitute the electron guns.
  • the conventional electron gun assembly of the above-mentioned construction has the disadvantage that the radiation heat received by the central cathode 11 from the heaters 5 and 7 are the other cathodes 10 and 12 causes the cathode 11 to be increased in temperature more than the other cathodes l0 and 12.
  • This phenomenon has a great adverse effect on the initial characteristics of the cathodes in the manufacturing processes of cathode-ray tubes, especially on the activation step thereof, and also shortens the service life of the cathode 11 compared with those of the other cathodes 10 and 12.
  • FIG. 3 showing schematically the construction of an electron gun assembly for a color cathode-ray tube according to the present invention, especially the connection members thereof, the reference numerals same as those inserted in FIG. 2 show the same elements.
  • the central portions 80a and 90a of the connection members 80 and 90 to which the heater 6 is connected are made larger.
  • the cathode 11 positioned at the center tends to be increased in temperature more than the other cathodes 10 and 12 due to the aforementioned reason.
  • the central portions 800 and 90a of the connection members connecting the heaters have a larger area than the other portions thereof and hence radiate more heat
  • the temperature of the heater 6 secured to the particular portions is maintained as low as the other heaters due to the higher radiation efficiency thereof coupled with small thermal conduction of the leads 61.
  • the cathode 11 is maintained at the temperature same as the other cathodes l and 12.
  • the areas of the central portions 80a and 90a of the connection members 80 and 90 are required to be selected such that the rise in temperature of the cathode 11 is maintained the same as those of the cathodes l0 and 12.
  • connection members employ two connection members
  • the present invention may be applied with equal effect, employing a single connection member comprising an insulator secured to at least one support member and separate conductors connected respectively to the leads of the heaters of the respective electron guns, the area of the central conductor being made larger than each of those of the other conductors.
  • each conductor is divided such that the portions of the conductor to which a couple of loads of the heater are connected are electrically insulated from each other.
  • the present invention has been described in the case where three heaters are connected in parallel, the invention may be applied with equal effect, employing three heaters connected in series. Also, in place of three electron guns separated completely for the respective colors, an integrally formed electron gun may be employed in the invention.
  • the area of that portion of the connection member to which the central heater is connected is'made larger for an increase in heat radiation therefrom, so that the temperature of the central heater does not rise to an undesirably high level, thus maintaining all the cathodes at the same temperature.
  • the activity of the cathodes is not adversely affected and the shortened life of the central cathode as compared with those of the other cathodes is successfully prevented. resulting in a longer useful life of the electron gun assembly as a whole.
  • An electron gun assembly for a color cathodc-ray tube comprising three electron guns which are arranged approximately parallel in the same plane and each ofwhich includes a heater, a cathode and a plurality of electrodes, at least one connection member to which the respective heaters are connected at substantially equal intervals, wherein the area of the connection member portion to which the heater belonging to the central one of the electron gun is connected is made larger than that of each of the areas of the connection member portions to which the heaters belonging to the other electron guns are connected, the area of the connection member portion to which the heater belonging to the central electron gun is connected being selected so as to maintain the rise in temperature of the cathode belonging to the central electron gun substantially the same as those of the cathodes belonging to the other electron guns.

Landscapes

  • Electrodes For Cathode-Ray Tubes (AREA)
US451285A 1973-09-21 1974-03-14 Color cathode-ray tube with temperature equilization for plurality of electron gun filaments Expired - Lifetime US3873876A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10603573A JPS5624983B2 (ja) 1973-09-21 1973-09-21

Publications (1)

Publication Number Publication Date
US3873876A true US3873876A (en) 1975-03-25

Family

ID=14423369

Family Applications (1)

Application Number Title Priority Date Filing Date
US451285A Expired - Lifetime US3873876A (en) 1973-09-21 1974-03-14 Color cathode-ray tube with temperature equilization for plurality of electron gun filaments

Country Status (5)

Country Link
US (1) US3873876A (ja)
JP (1) JPS5624983B2 (ja)
DE (1) DE2412529C3 (ja)
FR (1) FR2245078B1 (ja)
GB (1) GB1430702A (ja)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4044278A (en) * 1976-01-07 1977-08-23 Westinghouse Electric Corporation Electron gun cathode heater filament electrical connection and support system
US4063128A (en) * 1976-07-02 1977-12-13 Rca Corporation Cathode support structure for color picture tube guns to equalize cutoff relation during warm-up
WO1998059358A1 (en) * 1997-06-25 1998-12-30 Koninklijke Philips Electronics N.V. Picture display device having an improved bandwidth

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59175542A (ja) * 1983-03-24 1984-10-04 Mitsubishi Electric Corp 電子銃のヒ−タ組立構体
JPS59176801A (ja) * 1983-03-28 1984-10-06 Fujitsu Ltd 電源供給回路
JPS62145255U (ja) * 1986-03-07 1987-09-12
JPS6391178A (ja) * 1986-10-06 1988-04-21 品川白煉瓦株式会社 ２基の篩分け装置を具備する粒度管理機

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4044278A (en) * 1976-01-07 1977-08-23 Westinghouse Electric Corporation Electron gun cathode heater filament electrical connection and support system
US4063128A (en) * 1976-07-02 1977-12-13 Rca Corporation Cathode support structure for color picture tube guns to equalize cutoff relation during warm-up
WO1998059358A1 (en) * 1997-06-25 1998-12-30 Koninklijke Philips Electronics N.V. Picture display device having an improved bandwidth
US6310434B1 (en) * 1997-06-25 2001-10-30 U.S. Philips Corporation Picture display device having an improved bandwidth

Also Published As

Publication number Publication date
FR2245078B1 (ja) 1976-12-17
GB1430702A (en) 1976-04-07
JPS5624983B2 (ja) 1981-06-09
DE2412529A1 (de) 1975-04-17
DE2412529C3 (de) 1976-05-20
DE2412529B2 (de) 1975-10-09
FR2245078A1 (ja) 1975-04-18
JPS5057772A (ja) 1975-05-20

Similar Documents

Publication Publication Date Title
US2690518A (en) Color picture tube
US3928785A (en) Single gun, multi-screen, multi-beam, multi-color cathode ray tube
US2755405A (en) Color television tube
US3873876A (en) Color cathode-ray tube with temperature equilization for plurality of electron gun filaments
US4337409A (en) Color display tube with control grid positioning feature
US4403169A (en) Cathode suspension means for cathode ray tube electron gun
US2638559A (en) Electrostatic lens for cathode-ray tubes
US2712087A (en) Plural beam electron discharge devices
US3265920A (en) Electron-discharge device cathode assembly with radiation shield
US2459792A (en) Beam type electron discharge device
US3560779A (en) Shadow mask type color picture tube with a fine mesh flexible particle shield between the gun and target portions
US6271625B1 (en) Picture display device provided with an electron gun, and electron gun for use in such a device
US2130281A (en) Electron discharge tube
US3745397A (en) Pyramidal gun array having resilient member contacting corresponding supports of each of three guns
US3575626A (en) Electrode mounting brackets producing shorter electron gun mounts in cathode-ray tubes
US3732450A (en) Electron gun assembly having cathodes insulatively mounted in metallic plate
US3465401A (en) Electron-discharge devices
US4095138A (en) Electron gun having an arc-inhibiting electrode
CA1069166A (en) Electron gun support structure and method
US4523124A (en) Cathode-ray tube having multiplate cathode unit
US4609848A (en) Color cathode-ray tube with insulating rod support for electron gun
US3626231A (en) Thermal shunt for a cathode structure
US4100453A (en) Electrical connection of electrodes in multiple gun electrode structure
US3517242A (en) Potential gradiant stabilized cathode-ray tube
US4305018A (en) Electron gun structure with electrical contact spring for color television display tube