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US4558252A Expired / Lapsed US ⏱️ 0.0 years remaining

Color cathode ray tube with frame, mask or shield having an oxidized layer

Assignee: Toshiba Corp
•
Filing: 1982-11-03
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Granted: 1985-12-10
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Expires: 2002-11-03
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Abstract

Abstract A color cathode ray tube having a mask frame, a shadow mask attached to the mask frame and inner shield attached to the mask frame. At least one of these parts is made substantially of iron (Fe) and has a oxidized layer on its surface. That part further includes silicon (Si), aluminum (Al) and chromium (Cr) as impurity elements in weight amounts satisfying the following relation: Cr≧1/3(Al+Si).

Inventors

  • 👤 Masaharu Kanto
  • 👤 Hisato Kihara
  • 👤 Koichi Teshima
  • 👤 Michihiko Inaba

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:51
CPC Classifications
C; C07; C07D; C07D275/00; C07D275/04; C07D275/06; H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J2229/00; H01J2229/07; H01J2229/0727; H01J2229/0733; H01J2229/0777; H01J2229/0783

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 152 words
A color cathode ray tube comprising: an envelope having a face plate, a funnel portion joined to said face plate and a neck portion joined to said funnel portion; an electron gun disposed within said neck portion; a phosphor screen formed on said inner surface of said face plate; a mask frame mounted to said face plate; a shadow mask attached to said mask frame, said shadow mask having a plurality of apertures therein and which faces said phosphor screen; and an inner shield attached to said mask frame; wherein at least one part of said mask frame, said shadow mask and said inner shield is made substantially of iron and has an oxidized layer on a surface thereof, said iron part further including silicon, aluminum and chromium as impurity elements in weight amounts satisfying the following relation: Cr≧1/3(Al+Si) wherein Cr+Al+Si≦0.44 percent by weight, to enhance the adhesion of the oxidized layer.
Claim 2
Dependent Claim 152 words
A color cathode ray tube comprising: an envelope having a face plate, a funnel portion joined to said face plate and a neck portion joined to said funnel portion; an electron gun disposed within said neck portion; a phosphor screen formed on said inner surface of said face plate; a mask frame mounted to said face plate; a shadow mask attached to said mask frame, said shadow mask having a plurality of apertures therein and which faces said phosphor screen; and an inner shield attached to said mask frame; wherein at least one part of said mask frame, said shadow mask and said inner shield is made substantially of iron and has an oxidized layer on a surface thereof, said iron part further including silicon, aluminum and chromium as impurity elements in weight amounts satisfying the following relation: Cr≧1/3(Al+Si) wherein Cr+Al+Si≦0.44 percent by weight, to enhance the adhesion of the oxidized layer.
Claim 3
Dependent Claim 23 words
A color cathode ray tube according to claim 1, wherein the weight amounts of silicon, aluminum and chromium satisfy the following relation: Cr≧(Al+Si).
Claim 4
Dependent Claim 17 words
A color cathode ray tube according to claim 1, wherein said iron part is said shadow mask.

References Cited (Backward Citations)

US3647572A Cited
US3838985A Cited
US4019085A Cited
FR2231101A1 Cited
US4306172A Cited
US4292565A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-12-09 1989-06-10 1989-12-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-12-09 1993-06-10 1993-12-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-12-09 1997-06-10 1997-12-10 $7700.00 Window Closed / Lapsed

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