EP0125731A1
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Luminescent screen
Assignee: Koninklijke Philips NV
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Filing: 1984-05-10
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Granted: —
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Expires: 2004-05-10
Abstract
Abstract A luminescent screen provided with a luminescent layer (4) formed on a carrier (1), which layer comprises an aluminate and/or a gallate of strontium and/or barium activated by bivalent europium or by trivalent chromium. The aluminate and/ or gallate has an orthorhombic crystal structure with a space group Pnnm and has a composition defined by the formula Me2:xEuxA6-yCryO11 (Me = Sr, Ba and A = AI, Ga).An advantageous application of such a luminescent screen is found in low-pressure mercury vapour discharge lamps.
Inventors
- 👤 Joseph Rutten
- 👤 Gerardus Petrus Franciscus Hoeks
- 👤 Johannes Trudo Cornelis Van Kemenade
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:07
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/38; H01J61/42; H01J61/44; C; C09; C09K; C09K11/00; C09K11/08; C09K11/67; C09K11/671; C09K11/673; C09K11/77; C09K11/7728; C09K11/7734
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
180 words
A luminescent screen provided with a carrier on which is formed a luminescent layer which comprises a luminescent material activated by bivalent europium or by trivalent chromium, which material is an aluminate and/or a gallate of strontium and/or barium, characterized in that the aluminate and/or gallate has an orthorhombic crystal structure with a space group P nnm and has a composition defined by the formula Me 2-x Eu x A 6-y Cr y O 11 , in which Me is mainly strontium or mainly barium, in that, when Me is mainly strontium, the Me is strontium of which up to 25 mol.% can be replaced by barium, while A is aluminium of which up to 25 mol.% can be replaced by gallium, where 0.001 ≤ x ≤ 0.25 and y = 0, and in that, when Me is mainly barium, the Me is barium of which up to 50 mol.% can be replaced by strontium, while A is gallium of which up to 25 mol.% can be replaced by aluminium, where 0.001 ≤ y ≤ 0.10 and x = 0.
Claim 2
Dependent Claim
180 words
A luminescent screen provided with a carrier on which is formed a luminescent layer which comprises a luminescent material activated by bivalent europium or by trivalent chromium, which material is an aluminate and/or a gallate of strontium and/or barium, characterized in that the aluminate and/or gallate has an orthorhombic crystal structure with a space group P nnm and has a composition defined by the formula Me 2-x Eu x A 6-y Cr y O 11 , in which Me is mainly strontium or mainly barium, in that, when Me is mainly strontium, the Me is strontium of which up to 25 mol.% can be replaced by barium, while A is aluminium of which up to 25 mol.% can be replaced by gallium, where 0.001 ≤ x ≤ 0.25 and y = 0, and in that, when Me is mainly barium, the Me is barium of which up to 50 mol.% can be replaced by strontium, while A is gallium of which up to 25 mol.% can be replaced by aluminium, where 0.001 ≤ y ≤ 0.10 and x = 0.
Claim 3
Dependent Claim
42 words
A luminescent screen as claimed in Claim 1, characterized in that the luminescent material corresponds to the formula Sr 2-p-x Ba p Eu x Al 6 O 11 , in which O ≤ p ≤ 0.50 and 0.001 ≤ x ≤ 0.25.
Claim 4
Dependent Claim
40 words
A luminescent screen as claimed in Claim 1, characterized in that the luminescent material corresponds to the formula Ba 2-q Sr Ga 6 Cr O 11 , in which O ≤ q ≤ 1.00 and 0.001 ≤ y ≤ 0.10.
Claim 5
Dependent Claim
19 words
A low-pressure mercury vapour discharge lamp provided with a luminescent screen as claimed in Claim 1, 2 or 3.
Claim 6
Dependent Claim
41 words
A lamp as claimed in Claim 4, characterized in that the luminescent material is activated by bivalent europium. 6. A lamp as claimed in Claim 5, characterized in that the lamp further comprises a green luminescing material and a red-lumimescing material.
Claim 7
Dependent Claim
31 words
A lamp as claimed in Claim 6, characterized in that the green-luminescing material is activated by terbium and the red-luminescing material is a rare earth metal oxide activated by trivalent europium.
References Cited (Backward Citations)
FR1597747A
Cited
US4047069A
Cited
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