EP0237005A2 - Tube image couleur - Google Patents

Tube image couleur Download PDF

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Publication number
EP0237005A2
EP0237005A2 EP87103329A EP87103329A EP0237005A2 EP 0237005 A2 EP0237005 A2 EP 0237005A2 EP 87103329 A EP87103329 A EP 87103329A EP 87103329 A EP87103329 A EP 87103329A EP 0237005 A2 EP0237005 A2 EP 0237005A2
Authority
EP
European Patent Office
Prior art keywords
electrode
electron
diameter
groove
facing
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.)
Withdrawn
Application number
EP87103329A
Other languages
German (de)
English (en)
Other versions
EP0237005A3 (fr
Inventor
Hiroshi Suzuki
Koichi Sugahara
Hidekuni Fujisawa.
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electronics 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
Priority claimed from JP5291786A external-priority patent/JPS62211836A/ja
Priority claimed from JP24456286A external-priority patent/JPS6398941A/ja
Application filed by Matsushita Electronics Corp filed Critical Matsushita Electronics Corp
Publication of EP0237005A2 publication Critical patent/EP0237005A2/fr
Publication of EP0237005A3 publication Critical patent/EP0237005A3/fr
Withdrawn legal-status Critical Current

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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
    • H01J29/50—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
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/48—Electron guns
    • H01J2229/4844—Electron guns characterised by beam passing apertures or combinations
    • H01J2229/4848—Aperture shape as viewed along beam axis
    • H01J2229/4858—Aperture shape as viewed along beam axis parallelogram
    • H01J2229/4865—Aperture shape as viewed along beam axis parallelogram rectangle
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/48—Electron guns
    • H01J2229/4844—Electron guns characterised by beam passing apertures or combinations
    • H01J2229/4848—Aperture shape as viewed along beam axis
    • H01J2229/4872—Aperture shape as viewed along beam axis circular

Definitions

  • the present invention relates generally to a cathode ray tube for color display, and more particularly to a cathode ray tube for displaying high resolution color images irrespective of variation of luminance thereof.
  • a resolution of a cathode ray tube for color display is influenced by a diameter and shape of a beam spot which lands on a fluorescent screen. Therefore, it is important to form the beam spot as small as possible and to reduce distortion of shape in order to obtain a high resolution image.
  • the diameter of the beam spot generally increases with increase of a beam current, and hence, the resolution is apt to be lowered in a high luminance display which is resulted by a large beam current.
  • FIG.11 shows a prior art.
  • an electron beam 2a which is emitted from a central portion of an electron emission plane of a cathode 1 and is adjacent to an axis of an electron gun is converged by a cathode lens 4, which is formed between the cathode 1 and a G 1 electrode 3, and produces a crossover 5a.
  • electron beam 2b which is emitted from a peripheral portion of the electron emission plane of the cathode 1 and is apart from the axis of the electron gun are subject to comparatively strong convergence by the cathode lens 4, and a crossover 5b is formed at a position nearer to the cathode I than the crossover 5a of the electron beam adjacent to the axis of the electron gun. Then, a difference of the positions of the crossover 5a and 5b causes the difference of the diameter of the beam spot on a hypothetical object point, and magnifies the diameter of the images produced on the fluorescent screen, and as a result it deteriorates the resolution.
  • a conventional example of methods for improving the above-mentioned problem in the prior art is that: the intensity of the electric field on the axis of the electron gun between the G 2 electrode 6 and the G 3 electrode 7 is selected within a range of 5x10 4-- 5xi0 5 V/cm, and the intense prefocus lens 8 is formed adjacent to the crossover 5a, then the electron beam component 2b which is apart from the axis of the electron gun in the area of the prefocus lens 8 is converged more than the electron beam component 2a which is near the axis of the electron gun.
  • the difference of divergence angles of both the electron beam components 2a and 2b after the crossover becomes small, thereby decreasing the diameter of the hypothetical object point under the large beam current and the resultant diameter of the beam spot.
  • Object of the present invention is to maintain a small diameter beam spot under a large beam current, and prevent the diameter of the beam spot becoming too small under a small beam current.
  • the cathode lay tube for color display in accordance with the present invention comprises:
  • each electron gun between the G 2 electrode and the G 3 electrode is selected in a range of 5x10 4 --5x10 5 V/cm, and when a distance from a surface facing the G 2 electrode of the G l electrode to the face of the electron emitter is g k1 and a distance from a surface facing the G 3 electrode of the G 2 electrode to the emitter is g k2 , the respective values have the following relation:
  • FIG.I A sectional view of a cathode ray tube of a first embodiment in accordance with the present invention is shown in FIG.I.
  • an electron gun 9 is an in-line type gun wherein cathodes 10a, 10b and 10c are disposed on a horizontal line which is perpendicular to an axis of the electron gun 9, and is provided with a G 1 electrode 11 as a control grid, a G 2 electrode 12 as an accelerating grid, a G 3 electrode 13 as a focusing grid and a G 4 electrode 14 as a final accelerating grid (anode).
  • Cathode lenses l5a, 15b and 15c are formed between the G 1 electrode 11 and the cathodes 10a, 10b and 10c, respectively.
  • Prefocus lenses 16a, 16b and 16c are formed between the G 2 electrode 12 and the G 3 electrode 13.
  • Main lenses 17a, 17b and 17c are formed between the G 3 electrode 13 and the G 4 electrode 14.
  • the G 1 electrode 11 has three circular apertures 18 having a diameter of d 1 as electron beam paths.
  • the G 2 electrode 12 has an oblong groove 19 of width W and length L on its surface facing the G 1 electrode 11, and circular apertures 20 for passing the electron beam having a diameter of d 2 are disposed on the bottom of the groove 19.
  • the G 2 electrode 12 is composed by combination of an electrode plate 12a having three apertures 20 and an electrode plate 12b having an oblong rectangular opening of width W and length L.
  • the G 3 electrode 13 is provided with round apertures for passing the electron beams having a diameter of d 3 on a member opposite to the G 2 electrode 12.
  • a distance from a surface of the G 1 electrode 11 facing the G 2 electrode to an electron emission surface of the cathode 10 is designated g kl
  • a distance from a surface of the G 2 electrode 12 facing the G 3 electrode to the electron emission surface of the cathode 10 is designated g k2
  • a distance between the G 2 electrode 12 and the G 3 electrode 13 is designated g 23
  • the respective values in a cathode ray tube for color display of 90° deflection type of 21 inches are shown as follows:
  • the voltages which are applied to the respective electrodes are to be selected as follows:
  • FIG.3 A cross-sectional plan view of the electron gun 9 is shown in FIG.3 and a cross-sectional elevation view thereof is shown in FIG.4.
  • the electron beams adjacent to the axis of the electron guns do not receive lens effect by the prefocus lens, and thus, a total magnification of the lenses including the main lenses 17a, 17b and 17c is comparatively small. Furthermore, since the diameter of the electron beam in the main lens is not so large, an aberration is small.
  • electron beams 24h and 24v which are emitted from a peripheral portion of the electron emission surface of the cathode 10 and are passing apart from the axis of the electron gun form crossovers 25h and 25v at positions adjacent to the cathode 10.
  • the beam current is about 4 mA
  • the beam spot having a diameter as small as 35--45 X of the prior art can be obtained.
  • FIG.5 shows a horizontal cross-sectional view
  • FIG.6 shows a vertical cross-sectional view of the electron gun.
  • the electron beam 26h as shown in the horizontal cross-sectional view does not receive the effect of the groove 19 which is provided on the G 2 electrode 12, and forms two crossovers 27a and 27b and produces a beam spot of excessively small diameter in horizontal direction on the fluorescent screen.
  • the smallness of the beam spot is in only in the horizontal direction, the moire image interference fringes are not produced.
  • the electron beam 26v in vertical cross-sectional view as shown in FIG.6 receives strong effect of a divergence electric field 28 due to the groove 19, a single crossover 27c is formed.
  • a vertical diameter of the beam spot which is formed on the fluorescent screen under the low beam current of about 50 pA does not become too small.
  • the vertical diameter of the beam spot can be made as large as 1.0 mm which is twice the size in the prior art, and the moire image interference fringes are prevented to appearance.
  • the diameters d 2 and d 3 and a distance between the electrodes g k1 and g k2 are selected to comparatively short and an intensity of electric field on the axis of the electron gun between the G 2 electrode 12 and the G 3 electrode 13 is selected within the range of 5x10 4 --5x10 5 V/cm, and that, the diameter d 2 is made smaller than or equal to the diameter d l and the diameter d 3 is made larger than or equal to the diameter d 2 .
  • the diameter d 3 is smaller than the diameter d 2 , since a part of the electron beam is liable to be cut, the diameters d 2 and d 3 are selected to be in the following relation:
  • Deviation of the respective distances g k2 and g 23 from the above-mentioned ranges obstructs good arrangement of the crossover location in conjunction with a prefocus lens.
  • the width W of the groove 19 is recommended to be equal to the diameter d 2 or to be slightly larger than that.
  • the groove 19 is made to be a single oblong rectangular groove covering the three apertures 20 for passing the beam, each one independent small groove may be disposed on the respective apertures 20.
  • the length of the groove are made longer than 1.75 d 2 , and the apertures 20 for passing the electron beam are to be disposed on central portions of the bottom of the respective grooves.
  • FIG.7 is a graph showing relation of the electric potential (V) on the axis of the electron gun and its second order differential coefficient (V") in the electron gun in accordance with the present invention, and a distance (Z) from the electron emission surface of the cathode is shown on an abscissa.
  • a positive maximum value of the second order differential coefficient (V") exists at a position of the distance Z 1
  • a negative maximum value (V") thereof exists at a position of the distance Z 2 .
  • the distances Z l and Z 2 are selected in the range as shown by the following relation:
  • a constitution of the electrode of the main lens is a bi- potential type, but a uni-potential type or multi- potential type are usable.
  • the G 2 electrode 12 is has a horizontally long groove 19b on a surface which faces the G 1 electrode 11 of width W and length L, and furthermore, a groove 19c which is similar to the groove 19b is provided on the surface which faces the G 3 electrode 13.
  • the width W' of the groove 19c can be set in a rang shown by the following inequity: and when the width of W of the groove 19b is 0.7 mm, the width W' of the groove 19c can be made 1.0 mm.
  • the electron beam 24V in the vertical cross-sectional view of FIG.10 which is for the component apart from the axis of the electron gun, forms a crossover at a position adjacent to the prefocus lens, which position is nearer than a crossover of the electron beam 24h in the horizontal cross-sectional view of FIG.9 which is for the component apart from the axis of the electron gun.
  • the electron beam 24h is greatly converged in the vertical direction by intense converging electric field of the focusing lens induced by the groove 19c. Therefore, a vertical diameter of the electron beam in the deflection magnetic field after passing the main lens can be kept to be small, and hence a distortion of the beam spot which is focused on a peripheral portion of the fluorescent screen can be minimized.

Landscapes

  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Electrodes For Cathode-Ray Tubes (AREA)
EP87103329A 1986-03-11 1987-03-09 Tube image couleur Withdrawn EP0237005A3 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP5291786A JPS62211836A (ja) 1986-03-11 1986-03-11 カラ−受像管装置
JP52917/86 1986-03-11
JP244562/86 1986-10-15
JP24456286A JPS6398941A (ja) 1986-10-15 1986-10-15 カラ−受像管装置

Publications (2)

Publication Number Publication Date
EP0237005A2 true EP0237005A2 (fr) 1987-09-16
EP0237005A3 EP0237005A3 (fr) 1988-10-12

Family

ID=26393582

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87103329A Withdrawn EP0237005A3 (fr) 1986-03-11 1987-03-09 Tube image couleur

Country Status (1)

Country Link
EP (1) EP0237005A3 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8902679A (nl) * 1988-11-02 1990-06-01 Samsung Electronic Devices Elektronenkanon voor kleurenbeeldbuis met unipotentiaal type focusseringslenzen.
FR2644628A1 (fr) * 1989-03-17 1990-09-21 Videocolor Grille de focalisation pour canon a electrons en ligne pour tube de television en couleurs et canon a electrons en ligne utilisant une telle grille
EP0441486A2 (fr) * 1990-02-08 1991-08-14 Hitachi, Ltd. Canon à électrons et tube à rayons cathodiques
EP0691672A1 (fr) * 1994-07-07 1996-01-10 Goldstar Co. Ltd. Canon à électrons pour tubes à rayons cathodiques de grandes dimensions
WO1996035224A1 (fr) * 1995-05-02 1996-11-07 Philips Electronics N.V. Tube image couleur
KR100418934B1 (ko) * 2002-02-28 2004-02-14 엘지.필립스디스플레이(주) 칼라 음극선관용 전자총

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2020092A (en) * 1978-04-12 1979-11-07 Rca Corp High potential, low magnification electron gun
JPS5519730A (en) * 1978-07-27 1980-02-12 Matsushita Electronics Corp Electron gun
FR2437062A1 (fr) * 1978-09-25 1980-04-18 Rca Corp Perfectionnements apportes aux canons electroniques, notamment pour recepteurs de television
EP0111872A1 (fr) * 1982-12-16 1984-06-27 Matsushita Electronics Corporation Dispositif de tube à rayons cathodiques
EP0117475A1 (fr) * 1983-02-14 1984-09-05 Matsushita Electronics Corporation Tube à rayons cathodiques

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2020092A (en) * 1978-04-12 1979-11-07 Rca Corp High potential, low magnification electron gun
JPS5519730A (en) * 1978-07-27 1980-02-12 Matsushita Electronics Corp Electron gun
FR2437062A1 (fr) * 1978-09-25 1980-04-18 Rca Corp Perfectionnements apportes aux canons electroniques, notamment pour recepteurs de television
EP0111872A1 (fr) * 1982-12-16 1984-06-27 Matsushita Electronics Corporation Dispositif de tube à rayons cathodiques
EP0117475A1 (fr) * 1983-02-14 1984-09-05 Matsushita Electronics Corporation Tube à rayons cathodiques

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 4, no. 48 (E-6)[530], 12th April 1980, page 107 E 6; & JP-A-55 019 730 (MATSUSHITA DENSHI KOGYO K.K.) 12-02-1980 *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8902679A (nl) * 1988-11-02 1990-06-01 Samsung Electronic Devices Elektronenkanon voor kleurenbeeldbuis met unipotentiaal type focusseringslenzen.
FR2644628A1 (fr) * 1989-03-17 1990-09-21 Videocolor Grille de focalisation pour canon a electrons en ligne pour tube de television en couleurs et canon a electrons en ligne utilisant une telle grille
WO1990011612A1 (fr) * 1989-03-17 1990-10-04 Videocolor S.A. Grille de focalisation pour canon a electrons en ligne pour tube de television en couleurs et canon a electrons en ligne utilisant une telle grille
EP0441486A2 (fr) * 1990-02-08 1991-08-14 Hitachi, Ltd. Canon à électrons et tube à rayons cathodiques
EP0441486A3 (en) * 1990-02-08 1992-01-29 Hitachi, Ltd. Electron gun and cathode-ray tube
EP0691672A1 (fr) * 1994-07-07 1996-01-10 Goldstar Co. Ltd. Canon à électrons pour tubes à rayons cathodiques de grandes dimensions
WO1996035224A1 (fr) * 1995-05-02 1996-11-07 Philips Electronics N.V. Tube image couleur
KR100418934B1 (ko) * 2002-02-28 2004-02-14 엘지.필립스디스플레이(주) 칼라 음극선관용 전자총

Also Published As

Publication number Publication date
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Inventor name: SUZUKI, HIROSHI