Patent US4540914A successfully refreshed from Google Patents.
US4540914A
Expired / Lapsed
US
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Absorbing graded nitride film for high contrast display devices
Assignee: Lockheed Martin Corp
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Filing: 1982-12-17
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Granted: 1985-09-10
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Expires: 2002-12-17
Abstract
Abstract A faceplate of a cathode ray tube is shown wherein a cathodoluminescent phosphor material 1 is deposited on glass faceplate 2. A metal nitride metal absorbing inhomogeneous film 3, where the metal is aluminum or silicon, is deposited on the back side of the phosphor material 1. To avoid unwanted reflections at the interface between the glass 2 and the phosphor 1, a homogeneous film 4 is optionally deposited on glass plate 2 prior to deposition of the phosphor film 1. Additionally, an anti-reflection coating 5 may also be optionally applied to the exterior of the glass plate 2 to eliminate reflection that would otherwise occur at the air-glass interface.
Inventors
- 👤 T. Grant Maple
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:13
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/185; C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; H01J29/26; H01J29/28
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
122 words
In a viewing screen for a luminescent display device, a transparent viewing portion, a luminescent phosphor layer on the interior surface of said viewing portion and a light absorbing inhomogeneous film covering and adherent to said phosphor layer, said film characterized by having a tapered composition varying continuously from a metal nitride at a point remote from said interface at the phosphor-film interface to the metal constituent of said nitride such that said film exhibits a continuous gradient of refractive index from an index of said phosphor at the phosphor-film interface to an index approximating the index of said metal at said remote point, and said metal nitride being selected from the group of nitrides consisting of aluminum nitride and silicon nitride.
Claim 2
Dependent Claim
122 words
In a viewing screen for a luminescent display device, a transparent viewing portion, a luminescent phosphor layer on the interior surface of said viewing portion and a light absorbing inhomogeneous film covering and adherent to said phosphor layer, said film characterized by having a tapered composition varying continuously from a metal nitride at a point remote from said interface at the phosphor-film interface to the metal constituent of said nitride such that said film exhibits a continuous gradient of refractive index from an index of said phosphor at the phosphor-film interface to an index approximating the index of said metal at said remote point, and said metal nitride being selected from the group of nitrides consisting of aluminum nitride and silicon nitride.
Claim 3
Dependent Claim
90 words
A viewing screen in accordance with claim 1 wherein said phosphor has the formula Ln 2 O 2 SiRE, where Ln is at least one trivalent rare earth host ion selected from the group consisting of lanthanum, gadolinium yttrium and lutetium and RE is at least one trivalent activator ion selected from the group consisting of rare earth ions having atomic numbers 59 through 70 and in which from about 0.001 percent to 20 percent of the trivalent host ions have been replaced by at least one said activator ion.
Claim 4
Dependent Claim
12 words
A viewing screen in accordance with claim 2 wherein Ln is lanthanum.
Claim 5
Dependent Claim
17 words
A viewing screen in accordance with claim 1 wherein said display device is a cathode ray tube.
Claim 6
Dependent Claim
26 words
A viewing screen in accordance with claim 1 wherein said phosphor layer consists of multiple phosphor films, each film capable of luminescing at a different color.
Claim 7
Dependent Claim
123 words
In a luminescent display device, a transparent viewing portion, a phosphor layer on the interior surface of said viewing portion, a light absorbing inhomogeneous film covering and adherent to said phosphor layer and excitation means for causing said phosphor layer to luminesce, said inhomogeneous film characterized by having a tapered composition varying continuously from a metal nitride at the phosphor-film interface to the metal constituent of said nitride facing said excitation means such that said film exhibits a continuous gradient of refractive index from an index approximating the index of said phosphor at the phosphor-film interface to an index approximating the index of said metal, and said metal nitride being selected from the group of nitrides consisting of aluminum nitride and silicon nitride.
Claim 8
Dependent Claim
123 words
In a luminescent display device, a transparent viewing portion, a phosphor layer on the interior surface of said viewing portion, a light absorbing inhomogeneous film covering and adherent to said phosphor layer and excitation means for causing said phosphor layer to luminesce, said inhomogeneous film characterized by having a tapered composition varying continuously from a metal nitride at the phosphor-film interface to the metal constituent of said nitride facing said excitation means such that said film exhibits a continuous gradient of refractive index from an index approximating the index of said phosphor at the phosphor-film interface to an index approximating the index of said metal, and said metal nitride being selected from the group of nitrides consisting of aluminum nitride and silicon nitride.
Claim 9
Dependent Claim
16 words
A display device in accordance with claim 6 wherein said device is a cathode ray tube.
Claim 10
Dependent Claim
90 words
A display device in accordance with claim 6 wherein said phosphor has the formula Ln 2 O 2 S:RE, where Ln is at least one trivalent rare earth host ion selected from the group consisting of lanthanum, gadolinium, yttrium and lutetium and RE is at least one trivalent activator ion selected from the group consisting of rare earth ions having atomic numbers 59 through 70 and in which from about 0.001 percent to 20 percent of the trivalent host ions have been replaced by at least one said activator ion.
Claim 11
Dependent Claim
12 words
A display device in accordance with claim 8 wherein Ln is lanthanum.
Claim 12
Dependent Claim
26 words
A display device in accordance with claim 6 wherein said phosphor layer consists of multiple phosphor films, each film capable of luminescing at a different color.
Claim 13
Dependent Claim
122 words
In a method for making a viewing screen for luminescent display devices, the steps of forming a luminescent phosphor layer on a transparent substrate, and forming a light absorbing inhomogeneus film on said phosphor substrate, said film characterized by having a tapered composition varying continuously from a metal nitride at the phosphor-film interface to the metal constituent of said nitride at a point remote from said interface such that said film exhibits a continuous gradient of refractive index from an index approximating the index of said phosphor at the phosphor-film interface to an index approximating the index of said metal at said remote point and said metal nitride being selected from the group of nitrides consisting of aluminum nitride and silicon nitride.
Claim 14
Dependent Claim
122 words
In a method for making a viewing screen for luminescent display devices, the steps of forming a luminescent phosphor layer on a transparent substrate, and forming a light absorbing inhomogeneus film on said phosphor substrate, said film characterized by having a tapered composition varying continuously from a metal nitride at the phosphor-film interface to the metal constituent of said nitride at a point remote from said interface such that said film exhibits a continuous gradient of refractive index from an index approximating the index of said phosphor at the phosphor-film interface to an index approximating the index of said metal at said remote point and said metal nitride being selected from the group of nitrides consisting of aluminum nitride and silicon nitride.
Claim 15
Dependent Claim
89 words
A method in accordance with claim 11 wherein said phosphor has the formula Ln 2 O 2 S:RE, where Ln is at least one trivalent rare earth host ion selected from the group consisting of lanthanum, gadolinium, yttrium and lutetium and RE is at least one trivalent activator ion selected from the group consisting of rare earth ions having atomic numbers 59 through 70 and in which from about 0.001 percent to 20 percent of the trivalent host ions have been replaced by at least one said activator ion.
Claim 16
Dependent Claim
11 words
A method in accordance with claim 12 wherein Ln is lanthanum.
Claim 17
Dependent Claim
16 words
A method in accordance with claim 11 wherein said display device is a cathode ray tube.
Claim 18
Dependent Claim
25 words
A method in accordance with claim 11 wherein said phosphor layer consists of multiple phosphor films, each film capable of luminescing at a different color.
References Cited (Backward Citations)
US3108904A
Cited
US3347603A
Cited
US3560784A
Cited
US3825436A
Cited
US4275326A
Cited
US4132919A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-09 | 1989-03-11 | 1989-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-09 | 1993-03-11 | 1993-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-09 | 1997-03-11 | 1997-09-10 | $7700.00 | Window Closed / Lapsed |