US3846658A - Post acceleration type cathode ray tube with perforated hollow collector electrode adjacent shadow mask - Google Patents

Post acceleration type cathode ray tube with perforated hollow collector electrode adjacent shadow mask Download PDF

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Publication number
US3846658A
US3846658A US00311679A US31167972A US3846658A US 3846658 A US3846658 A US 3846658A US 00311679 A US00311679 A US 00311679A US 31167972 A US31167972 A US 31167972A US 3846658 A US3846658 A US 3846658A
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US
United States
Prior art keywords
electrode
cathode ray
collector electrode
ray tube
funnel
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
US00311679A
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English (en)
Inventor
M Kasai
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
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Filing date
Publication date
Priority claimed from JP11181171U external-priority patent/JPS5127726Y2/ja
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
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Publication of US3846658A publication Critical patent/US3846658A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/20—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours
    • H01J31/201—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours using a colour-selection electrode
    • 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
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/06—Screens for shielding; Masks interposed in the electron stream
    • 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
    • H01J29/80—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching
    • 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
    • H01J29/80—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching
    • H01J29/803—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching for post-acceleration or post-deflection, e.g. for colour switching
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/20—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours
    • H01J31/201—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours using a colour-selection electrode
    • H01J31/203—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes for displaying images or patterns in two or more colours using a colour-selection electrode with more than one electron beam

Definitions

  • This invention relates to a post acceleration type cathode ray tube capable of efficiently collecting the secondary electrons generated in the tube.
  • the well known post acceleration type cathode ray tube, a post acceleration type colour picture tube for example, schematically shown in FIG. 1, comprises a panel 1, a funnel 2 and a neck 3 which are sealed with each other to form an evacuated envelope.
  • a fluorescent screen 4 is formed on the inner surface of the panel and a shadow mask electrode 5 supplied with an intermediate potential is mounted a predetermined distance apart from the fluorescent screen 4.
  • the shadow mask electrode 5 is secured to the inner wall of the envelope by means of holders 6, generally in the form of leaf springs.
  • An electron gun 7 is contained in the neck 3 and a funnel electrode 8 is applied on the inner surface of the funnel 2.
  • a cylindrical inner shield electrode 9 having a construction shown in FIG. 2 is supported by the holders 6 in concentric relationship with the funnel electrode 8.
  • a source of getter 10 is provided near the joint between the funnel and the neck.
  • the purpose of the inner shield electrode 9 is to prevent the getter material evaporated from the getter source 10 from depositing upon the fluorescent screen 4 and the shadow mask electrode 5 mounted on the panel thereby decreasing electric insulation strength between these members and thence causing unstable operation of the cathode ray tube and to accomplish the following object.
  • the speed of the electron beam passing through a passage between the electron gun 7 and the shadow mask electrode 5 is smaller than that of a colour picture tube not incorporated with the feature of post acceleration so that the electron beam is liable to be affected by magnetism or external magnetic field.
  • the inner shield electrode 9 functions to eliminate such adverse affect of the magnetism or external field.
  • the inner shield electrode 9 functions to prevent a portion of the electron beam emanated from the electron gun from impinging upon the surface of the shadow mask electrode 5 that faces to the neck 3 thereby generating secondary electrons. A portion of such secondary electrons collides upon the funnel 2 to generate additional secondary electrons. These two types of secondary electrons impinge upon the fluorescent screen thereby causing undesired phosphor spots to luminesce thus decreasing the quality of the reproduced image.
  • the surfaces of the shadow mask electrode 5, the inner shielding electrode 9 and the funnel electrode 8 are coated with a material that prevents the generation of the secondary electrons. Even with these various measures, secondary electrons are still generated thereby causing nonuniform luminescence and colour shading.
  • Another object of this invention is to provide an improved post acceleration type cathode ray tube used for oscilloscope and utilizing a collector electrode of a novel construction thereby preventing the secondary electrons generated by the collector electrode from impinging upon the fluorescent screen thus preventing deterioration of the picture quality.
  • Still another object of this invention is to provide a post acceleration type colour picture tube utilizing a perforated or mesh shaped inner shield electrode.
  • a further object of this invention is to provide an improved post acceleration type cathode ray tube used for oscilloscope which utilizes a perforated or wire mesh shaped collector electrode.
  • a post acceleration type cathode ray tube of the class comprising a panel, a fluorescent screen coated on the inner surface of the panel, a funnel, an auxiliary electrode formed on the inner surface of the funnel, an electrode maintained at an intermediate potential and positioned to face the fluorescent screen for transmitting an electron beam, and a secondary electron electrode disposed close to the auxiliary electrode, characterized in that the secondary electron collector electrode is constructed to transmit trodes of the tube.
  • FIG. I shows a diagrammatic longitudinal sectional view of a prior art post acceleration type colour picture tube
  • FIG. 2 is a perspective view of the inner shield electrode shown in FIG. 1;
  • FIG. 3 is a perspective view of one example of the inner shield electrode utilized in the post acceleration type cathode ray tube of this invention and FIG. 4 shows a diagrammatic longitudinal sectional view of another embodiment of the novel post acceleration type cathode ray tube.
  • FIG. 3 of the accompanying drawing there is shown an inner shield electrode 11 especially suitable for use in a post acceleration type colour picture tube.
  • the inner shield electrode 11 has generally the same configuration as that shown in FIG. 2 but provided with a plurality of perforations I2.
  • the inner shield electrode 11 acts as a suppression grid. Under these conditions, the percentage of the secondary electrons will be decreased to a low value which is nearly equal to (l -l)d,. Accordigly, under these conditions, it is advantageous to use a wire mesh shaped inner shield electrode having a high percentage of transmission of the secondary electrons.
  • FIG. 4 illustrates a modified embodiment of the post acceleration type cathode ray tube which is especially suitable for oscilloscope in which the same or corresponding elements to those shown in FIG. 1 are designated by the same reference numerals.
  • a cylindrical perforated collector electrode 15 a mesh electrode 16 mounted on the collector electrode 16 at one end thereof facing the fluorescent screen 14 and a helical electrode 17 applied on the inner surface of the funnel, these electrodes corresponding to the inner shield electrode, the shadow mask electrode and the funnel electrode, respectively of the previous embodiment.
  • the collector electrode 15 is provided with a plurality of perforations.
  • the collector electrode may take the form of a wire mesh with this construction the secondary electrons generated are absorbed by the cooperation of the collector electrode 15 and the helical electrode 17 at extremely higher efficiencies than the prior art cathode ray tube.
  • substantially the same object can also be accomplished by providing such perforations only at the portions of the collector electrode close to the electrode at the intermediate potential.
  • a post acceleration type cathode raytube of the class comprising a panel, a fluorescent screen coated on the inner surface of said panel, a funnel, an auxiliary electrode coated on the inner surface of said funnel, a neck, at least one electron gun positioned within said neck, said panel, funnel and neckcooperating to form a sealed envelope, an electrode having perforations for transmitting an electron beam maintained at a potential below the post acceleration potential and positioned in front of said fluorescent screen, and a hollow secondary electron collector electrode positioned within the envelope and having open ends, said collector electrode forming an enclosure surrounding the path of the electron beam directed toward the fluorescent screen from the electron gun, the improvement in which said secondary electron collector electrode is constructed to have perforations for transmitting a portion of the secondary electrons generated by other electrodes of said tube to said auxiliary electrode.

Landscapes

  • Electrodes For Cathode-Ray Tubes (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
US00311679A 1971-11-30 1972-12-04 Post acceleration type cathode ray tube with perforated hollow collector electrode adjacent shadow mask Expired - Lifetime US3846658A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP1181171 1971-11-30
JP11181171U JPS5127726Y2 (de) 1971-11-30 1971-11-30
JP1118171 1971-11-30

Publications (1)

Publication Number Publication Date
US3846658A true US3846658A (en) 1974-11-05

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Family Applications (1)

Application Number Title Priority Date Filing Date
US00311679A Expired - Lifetime US3846658A (en) 1971-11-30 1972-12-04 Post acceleration type cathode ray tube with perforated hollow collector electrode adjacent shadow mask

Country Status (4)

Country Link
US (1) US3846658A (de)
CA (1) CA959911A (de)
DE (1) DE2258720C3 (de)
FR (1) FR2162065B1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4019085A (en) * 1973-05-02 1977-04-19 Mitsubishi Denki Kabushiki Kaisha Internal magnetic shield for cathode ray tube

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2639033C3 (de) * 1976-08-30 1981-07-23 Gkss - Forschungszentrum Geesthacht Gmbh, 2000 Hamburg Bauteil in mit Ladungsträgerstrahlen arbeitenden elektrischen Vakuumgeräten und Verfahren zu dessen Herstellung
JPS6032304B2 (ja) * 1978-02-17 1985-07-27 日本電気株式会社 カラ−受像管
KR940011935B1 (ko) * 1992-03-03 1994-12-27 삼성전관 주식회사 칼라 음극선관용 새도우마스크 프레임과 인너시일드의 조립구조

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2037711A (en) * 1928-11-26 1936-04-21 Television Lab Inc Method and apparatus for television
US2185590A (en) * 1937-06-18 1940-01-02 Rca Corp Cathode ray tube
US2230134A (en) * 1936-05-09 1941-01-28 Firm Fernseh Ag Image analyzing tube
US2569654A (en) * 1948-11-19 1951-10-02 John M Cage Cathode-ray tube
US2795720A (en) * 1955-09-15 1957-06-11 Rca Corp Post-accelerated color-kinescopes
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

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2037711A (en) * 1928-11-26 1936-04-21 Television Lab Inc Method and apparatus for television
US2230134A (en) * 1936-05-09 1941-01-28 Firm Fernseh Ag Image analyzing tube
US2185590A (en) * 1937-06-18 1940-01-02 Rca Corp Cathode ray tube
US2569654A (en) * 1948-11-19 1951-10-02 John M Cage Cathode-ray tube
US2795720A (en) * 1955-09-15 1957-06-11 Rca Corp Post-accelerated color-kinescopes
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

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4019085A (en) * 1973-05-02 1977-04-19 Mitsubishi Denki Kabushiki Kaisha Internal magnetic shield for cathode ray tube

Also Published As

Publication number Publication date
DE2258720C3 (de) 1978-03-16
CA959911A (en) 1974-12-24
DE2258720A1 (de) 1973-06-28
FR2162065A1 (de) 1973-07-13
FR2162065B1 (de) 1977-08-26
DE2258720B2 (de) 1977-07-21

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