Patent US4002938A successfully refreshed from Google Patents.
US4002938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray or γ-ray image tube
Assignee: Thales SA
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Filing: 1975-07-08
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Granted: 1977-01-11
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Expires: 1995-07-08
Abstract
Abstract The input screen 5 of an X-ray or γ -ray image tube comprises a barrier layer 54 between scintillator 51 and photocathode 55, made of two sub-layers, one 52 of alumina, Al 2 O 3 , 50 to 150 angstrom units in thickness, and the other of silicon sesquioxide Si 2 O 3 , 200 to 1000 angstrom units in thickness. The photocathode is made of an alkaline antimonide and the scintillator of an alkaline halide.
Inventors
- 👤 Jean Pierre Pehe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:28
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/38; H01J29/385
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
163 words
An X-ray or γ ray image tube comprising an input screen receiving the incident radiation from the object, and a luminescent output screen, the two being separated by an evacuated space in which the electrons emitted in operation by said input screen under the effect of said radiation, are accelerated, their impact on said luminescent screen producing a visible image constituting the image of said object, said screen comprising a scintillator constituted by an alkaline halide, and a photocathode constituted by an alkaline antimonide, applied to either side of a barrier layer, characterised in that said barrier layer is constituted by two sub-layers applied one on top of the other, that applied to said scintillator and known as the first sub-layer, being constituted by alumina Al 2 O 3 and having a thickness ranging between 50 and 150 angstrom units, and that in contact with the photocathode, and known as the second sub-layer, being constituted by silicon sesquixoide Si 2 O 3 .
Claim 2
Dependent Claim
163 words
An X-ray or γ ray image tube comprising an input screen receiving the incident radiation from the object, and a luminescent output screen, the two being separated by an evacuated space in which the electrons emitted in operation by said input screen under the effect of said radiation, are accelerated, their impact on said luminescent screen producing a visible image constituting the image of said object, said screen comprising a scintillator constituted by an alkaline halide, and a photocathode constituted by an alkaline antimonide, applied to either side of a barrier layer, characterised in that said barrier layer is constituted by two sub-layers applied one on top of the other, that applied to said scintillator and known as the first sub-layer, being constituted by alumina Al 2 O 3 and having a thickness ranging between 50 and 150 angstrom units, and that in contact with the photocathode, and known as the second sub-layer, being constituted by silicon sesquixoide Si 2 O 3 .
Claim 3
Dependent Claim
27 words
An X-ray or γ ray image tube as claimed in claim 1, characterised in that said second sub-layer has a thickness between 200 and 1000 angstrom units.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |