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US3873343A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming secondary electron emission preventing layer for post-deflection acceleration type color picture tube

Assignee: Hitachi Ltd
•
Filing: 1972-09-07
•
Granted: 1975-03-25
•
Expires: 1992-09-07
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Abstract

Abstract A method of forming a secondary electron emission preventing layer for a post-deflection acceleration type color picture tube, wherein a layer made of a mixture consisting of particles of a secondary electron emission preventing material, an organic binder and fine metal grains is formed on those surfaces of constituting parts inside the tube, at least a shadow mask, on which primary electrons impinge, or an inorganic binder layer made of an inorganic compound is formed on the surfaces and a mixed layer of particles of a secondary electron emission preventing material and an organic binder is formed on the inorganic binder layer, or the surfaces of the constituting parts are roughened and a mixed layer of particles of a secondary electron emission preventing material and an organic binder is formed on the roughened surfaces, the organic binder being thereafter burnt away by heat treatment. Alternatively, a mixed layer of an inorganic binder consisting of an inorganic compound and particles of a secondary electron emission preventing material is formed on the surfaces and a surface layer made of the secondary electron emission preventing material is formed on the mixed layer.

Inventors

  • 👤 Akira Misumi
  • 👤 Toshiaki Kasai
  • 👤 Kenji Fukuda
  • 👤 Hiromitu Nakai

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:01
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/14; H01J9/142; H01J9/146; H01J29/00; H01J29/46; H01J29/80; H01J29/81; Y; Y10; Y10T; Y10T428/00; Y10T428/25

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 94 words
A METHOD OF FORMING A SECONDARY ELECTRON EMISSION PREVENTING LAYER FOR A POST-DEFLECTION ACCELERATION TYPE COLOR PICTURE TUBE, COMPRISING: FORMING A FIRST LAYER OF WATER GLASS AT LEAST ON A SURFACE AT WHICH THE FORMATION OF SECONDARY ELECTRON EMISSIONS IS TO BE PREVENTED IN A COLOR PICTURE TUBE ON AN ELECTRON GUN SIDE, FORMING A SECOND LAYER OF AN ORGANIC BINDER CONTAINING GRAPHITE PARTICLES ON SAID FIRST LAYER, AND THEREAFTER BURNING AWAY SAID ORGANIC BINDER IN SAID SECOND LAYER BY A HEAT TREATMENT, TO FORM A SECONDARY ELECTRON EMISSION PREVENTING LAYER ON SAID SURFACE.
Claim 2
Independent Claim 94 words
A METHOD OF FORMING A SECONDARY ELECTRON EMISSION PREVENTING LAYER FOR A POST-DEFLECTION ACCELERATION TYPE COLOR PICTURE TUBE, COMPRISING: FORMING A FIRST LAYER OF WATER GLASS AT LEAST ON A SURFACE AT WHICH THE FORMATION OF SECONDARY ELECTRON EMISSIONS IS TO BE PREVENTED IN A COLOR PICTURE TUBE ON AN ELECTRON GUN SIDE, FORMING A SECOND LAYER OF AN ORGANIC BINDER CONTAINING GRAPHITE PARTICLES ON SAID FIRST LAYER, AND THEREAFTER BURNING AWAY SAID ORGANIC BINDER IN SAID SECOND LAYER BY A HEAT TREATMENT, TO FORM A SECONDARY ELECTRON EMISSION PREVENTING LAYER ON SAID SURFACE.
Claim 3
Dependent Claim 21 words
The method according to claim 1, wherein said first layer is formed to a thickness of 1 to 2 Mu .
Claim 4
Dependent Claim 21 words
The method according to claim 1, wherein said second layer is formed to a thickness of 3 to 30 Mu .
Claim 5
Dependent Claim 21 words
The method according to claim 1, wherein said second layer is formed to a thickness of 5 to 10 Mu .
Claim 6
Dependent Claim 19 words
The method according to claim 1, wherein said graphite particles have a particle size of at most several microns.
Claim 7
Dependent Claim 31 words
The method according to claim 1, wherein fine powder of a material which exerts no adverse influence on the picture tube is added to said water glass of said first layer.
Claim 8
Dependent Claim 28 words
The method according to claim 6, wherein said material exerting no adverse influence on the picture tube is one selected from the group consisting of graphite and silver.
Claim 9
Dependent Claim 25 words
The method according to claim 1, wherein said first layer is of a potash water glass material which does not burn away by heat treatment.
Claim 10
Dependent Claim 54 words
The method according to claim 1, wherein said surface at which the formation of secondary electron emission is prevented in a color picture tube on the electron gun side is a surface of at least one of a shadow mask, the inner wall of the glass bulb, a mask support, or a shield electrode.
Claim 11
Dependent Claim 21 words
The method according to claim 1, wherein said surface is the surface of the shadow mask on the electron gun side.
Claim 12
Dependent Claim 18 words
The method according to claim 1, wherein said second layer contains 6.6 percenT by weight of flake graphite.
Claim 13
Dependent Claim 17 words
The method according to claim 1, wherein said flake graphite has a particle size of 1 micron.

References Cited (Backward Citations)

US2518434A Cited
US2829295A Cited
US2942130A Cited
US3093501A Cited
US3010092A Cited
US3475639A Cited
US3604970A Cited
US3600213A Cited
US3703401A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-03-24 1978-09-23 1979-03-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-03-24 1982-09-23 1983-03-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-03-24 1986-09-23 1987-03-25 $7700.00 Window Closed / Lapsed

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