US4684846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Luminescent screen having restored cavities and display tube having such a screen
Assignee: US Philips Corp
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Filing: 1985-06-24
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Granted: 1987-08-04
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Expires: 2005-06-24
Abstract
Abstract The invention relates to luminescent screen comprising an optical fibre plate formed by the reunion of elementary optical fibres constituted by bars of core glass (10) enveloped by a cladding glass (12), the optical fibre plate being provided with cavities obtained after having hollowed out partially the core glass. The bottom of the cavities is covered by a deposit of a restoring material (30) which is transparent to the luminous flux, improving the surface state and the flatness of the bottom of the cavities and tending to minimize the break (32) at the intersection between the bottom and the wall of each cavity. The restoring material preferably has an optical index near that of the core glass in order to ensure the optical continuity. Said screen of high resolution and high luminous efficiency is used in display tubes such as night-vision tubes, X-ray converter tubes, slid scanning tubes, cathode ray tubes used in oscilloscopy or in television.
Inventors
- 👤 Valere Duchenois
- 👤 Michele Fouassier
- 👤 Hugues Baudry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:17
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/24; G; G02; G02B; G02B6/00; G02B6/04; G02B6/06; G02B6/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
198 words
A luminescent screen comprising an optical fibre plate formed by the reunion of elementary optical fibres constituted by bars of core glass surrounded by one or several cladding glasses, the optical fibre plate being provided with cavities disposed substantially perpendicularly to one of its faces, the cavities being obtained after having partially hollowed out one or several glasses, including the core glass, while preserving at least the cladding glass farthest remote from the core glass, the surfaces thus exposed constituting the walls of the cavities for the part substantially parallel to the axis of the elementary optical fibres, and the bottom of said cavities for the remaining part, the cavities being then filled by a luminescent product emitting a fluminous flux under the influence of an electron bombardment, characterized in that the bottom of the cavities is covered by a deposit of a restoring material which is transparent to the luminous flux to improve the surface state and the flatness of the bottom of the cavities, and tending to minimize the break at the intersection between the bottom and the wall of each cavity, thereby to improve the luminous flux between the luminescent product and the core glass.
Claim 2
Dependent Claim
198 words
A luminescent screen comprising an optical fibre plate formed by the reunion of elementary optical fibres constituted by bars of core glass surrounded by one or several cladding glasses, the optical fibre plate being provided with cavities disposed substantially perpendicularly to one of its faces, the cavities being obtained after having partially hollowed out one or several glasses, including the core glass, while preserving at least the cladding glass farthest remote from the core glass, the surfaces thus exposed constituting the walls of the cavities for the part substantially parallel to the axis of the elementary optical fibres, and the bottom of said cavities for the remaining part, the cavities being then filled by a luminescent product emitting a fluminous flux under the influence of an electron bombardment, characterized in that the bottom of the cavities is covered by a deposit of a restoring material which is transparent to the luminous flux to improve the surface state and the flatness of the bottom of the cavities, and tending to minimize the break at the intersection between the bottom and the wall of each cavity, thereby to improve the luminous flux between the luminescent product and the core glass.
Claim 3
Dependent Claim
25 words
A luminescent screen as claimed in claim 1, characterized in that the restoring material has an optical index close to that of the core glass.
Claim 4
Dependent Claim
32 words
A luminescent screen as claimed in claims 1, characterized in that the restoring material is an enamel having a softening and coating temperature lower than the lowest softening temperature of the glasses.
Claim 5
Dependent Claim
83 words
A luminescent screen as claimed in claim 3, characterized in that the restoring material is an enamel of which the composition is chosen, as a function of the optical index and desired softening and coating temperatures in the range of the following molar compositions: PbO: a=40 to 70%-SiO 2 : b=5 to 30%-Al 2 O 3 : c=0 to 10%-B 2 O 3 : d=10 to 35%-ZnO: e=0 to 15%-Bi 2 O 3 : f=0 to 3%, in such a manner that a+b+c+d+e+f=100%
Claim 6
Dependent Claim
43 words
An luminescent screen as claimed in claim 4, characterized in that the restoring material is an enamel which has the following molar composition: PbO: 60%; B 2 O 3 : 25%; SiO 2 : 10%; ZnO: 4%; Al 2 O 3 : 1%.
Claim 7
Dependent Claim
23 words
A luminescent screen as claimed in claim 1, characterized in that the restoring material is a mixture of aluminum phosphate and titanium phosphate.
Claim 8
Dependent Claim
21 words
A display tube characterized in that it comprises a luminescent screen as claimed in any of the claims 1 to 6.
References Cited (Backward Citations)
US4264408A
Cited
US4436366A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-03 | 1991-02-02 | 1991-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-03 | 1995-02-02 | 1995-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-03 | 1999-02-02 | 1999-08-04 | $7700.00 | Window Closed / Lapsed |