US4132919A
Expired / Lapsed
US
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Absorbing inhomogeneous film for high contrast display devices
Assignee: Lockheed Martin Corp
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Filing: 1977-12-12
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Granted: 1979-01-02
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Expires: 1997-12-12
Abstract
Abstract This invention relates to light absorbing inhomogeneous films and their use in luminescent display devices such as cathode ray tubes and electroluminescent panels to achieve high contrast ratio and minimal halation effect, and more particularly to an inhomogeneous film having a composition varying continuously from metal oxide to metal, and the method of making same. The metal is selected from the group consisting of tantalum and vanadium.
Inventors
- 👤 T. Grant Maple
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:14
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/26; C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; H01J29/185; H01J29/86; H01J29/89; H01J2229/00; H01J2229/89; H01J2229/8913; Y; Y10; Y10S; Y10S428/00; Y10S428/913
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
123 words
A viewing screen for a luminescent display device comprising 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 having a tapered composition varying continuously from a metal oxide at a point remote from said interface at the phosphor-film interface to the metal constituent of said oxide 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 oxide being selected from the group of oxides consisting of tantalum oxide and vanadium oxide.
Claim 2
Dependent Claim
123 words
A viewing screen for a luminescent display device comprising 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 having a tapered composition varying continuously from a metal oxide at a point remote from said interface at the phosphor-film interface to the metal constituent of said oxide 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 oxide being selected from the group of oxides consisting of tantalum oxide and vanadium oxide.
Claim 3
Dependent Claim
90 words
A viewing screen in accordance with claim 1 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 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
121 words
A luminescent display device comprising 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 having a tapered composition varying continuously from a metal oxide at the phosphor-film interface to the metal constituent of said oxide 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 oxide being selected from the group of oxides consisting of tantalum oxide and vanadium oxide.
Claim 8
Dependent Claim
121 words
A luminescent display device comprising 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 having a tapered composition varying continuously from a metal oxide at the phosphor-film interface to the metal constituent of said oxide 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 oxide being selected from the group of oxides consisting of tantalum oxide and vanadium oxide.
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
89 words
A display device in accordance with claim 6 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
Independent Claim
122 words
A method for making a viewing screen for luminescent display devices consisting essentially of the steps of: forming a luminescent phosphor layer on a transparent substrate, and forming a light absorbing inhomogeneous film on said phosphor substrate, said film having a tapered composition varying continuously from a metal oxide at the phosphor-film interface to the metal constituent of said oxide 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 oxide being selected from the group of oxides consisting of tantalum oxide and vanadium oxide.
Claim 14
Independent Claim
122 words
A method for making a viewing screen for luminescent display devices consisting essentially of the steps of: forming a luminescent phosphor layer on a transparent substrate, and forming a light absorbing inhomogeneous film on said phosphor substrate, said film having a tapered composition varying continuously from a metal oxide at the phosphor-film interface to the metal constituent of said oxide 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 oxide being selected from the group of oxides consisting of tantalum oxide and vanadium oxide.
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.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-01 | 1982-07-03 | 1983-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-01 | 1986-07-03 | 1987-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-01 | 1990-07-03 | 1991-01-02 | $7700.00 | Window Closed / Lapsed |