US5519227A
Expired / Lapsed
US
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Structured scintillation screens
Assignee: UMass Memorial Medical Center
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Filing: 1994-08-08
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Granted: 1996-05-21
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Expires: 2014-08-08
Abstract
Abstract A method for fabricating x-ray-detecting structured screens using laser-based micro-machining techniques results in devices having improved spatial resolution. In one case, each pixel of the screen contains an optically active scintillating material surrounded with a optically inactive material having a relatively lower refractive index; following absorption of light, each pixel channels x-ray-induced phosphorescence to a small region of a detector. Alternatively, the optically active material can be a photoconducting material, such as selenium, and the surrounding optically inactive material is chosen to have a relatively high resistivity.
Inventors
- 👤 Andrew Karellas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:02
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/202; G21; G21K; G21K4/00
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
116 words
A process for making a structured scintillator for detecting x-rays comprising the steps of: providing a scintillation substrate comprising a scintillating material, exposing regions of said scintillating substrate to an electromagnetic radiation pattern, thereby substantially removing portions of said substrate in said exposed regions to form an array of pixel structures, and loading between said pixel structures a transparent, optically inactive interstitial material having a lower refractive index than said scintillation substrate, said interstitial material substantially surrounding said pixel structures such that following emission of radiation in response to x-ray radiation, said pixel structures internally reflect said radiation, thereby decreasing the area illuminated by a single pixel structure and increasing the resolution of said structured scintillator.
Claim 2
Dependent Claim
116 words
A process for making a structured scintillator for detecting x-rays comprising the steps of: providing a scintillation substrate comprising a scintillating material, exposing regions of said scintillating substrate to an electromagnetic radiation pattern, thereby substantially removing portions of said substrate in said exposed regions to form an array of pixel structures, and loading between said pixel structures a transparent, optically inactive interstitial material having a lower refractive index than said scintillation substrate, said interstitial material substantially surrounding said pixel structures such that following emission of radiation in response to x-ray radiation, said pixel structures internally reflect said radiation, thereby decreasing the area illuminated by a single pixel structure and increasing the resolution of said structured scintillator.
Claim 3
Dependent Claim
19 words
The process of claim 1, further comprising the step of using a laser to generate said electromagnetic radiation pattern.
Claim 4
Dependent Claim
12 words
The process of claim 2, wherein said laser is an excimer laser.
Claim 5
Dependent Claim
27 words
The process of claim 2, wherein said electromagnetic radiation pattern results in ablation of said portions of said scintillating substrate to form said array of pixel structures.
Claim 6
Dependent Claim
18 words
The process of claim 2, wherein said laser first illuminates a mask to form said electromagnetic radiation pattern.
Claim 7
Dependent Claim
27 words
The process of claim 5, wherein said electromagnetic radiation pattern results in ablation of said portions of said scintillating substrate to form said array of pixel structures.
Claim 8
Dependent Claim
15 words
The process of claim 1, wherein said array of pixel structures extends in two dimensions.
Claim 9
Dependent Claim
16 words
The process of claim 2, wherein the cross sections of said pixel structures are arbitrarily shaped.
Claim 10
Dependent Claim
14 words
The process of claim 8, wherein said cross sections are substantially circular in shape.
Claim 11
Dependent Claim
14 words
The process of claim 8, wherein said cross sections are substantially square in shape.
Claim 12
Dependent Claim
22 words
The process of claim 1, wherein said array of pixel structures comprises a pixel structure having tapered ends for focussing said radiation.
Claim 13
Dependent Claim
21 words
The process of claim 1, wherein neighboring pixel structures are separated by a distance of between 0.2 and 50.0 microns, inclusive.
Claim 14
Dependent Claim
18 words
The process of claim 12, wherein neighboring pixel structures are separated by a distance of about 0.5 microns.
Claim 15
Dependent Claim
64 words
The process of claim 1, wherein said scintillating material is selected from the group consisting of glass-based scintillating materials, CdWO 4 , thallium-activated sodium iodide, terbium-doped glass scintillators, transparent plastic scintillators, ceramic-based scintillating materials, Gd 2 O 3 , Gd 2 O 2 S:Pr,Ce,Cl, Gd 2 O 2 S:Pr,Ce,F, Gd 2 O 2 S:Pr, and Y 2 O 3 /Gd 2 O 3 .
Claim 16
Dependent Claim
13 words
The process of claim 14, wherein said scintillating material is CdWO 4 .
Claim 17
Dependent Claim
13 words
The process of claim 1, wherein said scintillating material is a single-crystalline material.
Claim 18
Dependent Claim
15 words
The process of claim 1, wherein said loading step consists of a thin-film deposition technique.
Claim 19
Dependent Claim
15 words
The process of claim 17, wherein said thin-film deposition technique is a vapor deposition technique.
Claim 20
Dependent Claim
24 words
The process of claim 1, wherein said transparent interstitial material comprises a material selected from the group consisting of optical glasses and polymeric materials.
Claim 21
Dependent Claim
14 words
The process of claim 19, wherein said transparent interstitial material is a polymeric material.
Claim 22
Dependent Claim
11 words
The process of claim 20, wherein said polymeric material is polyimide.
Claim 23
Dependent Claim
10 words
A structured scintillator made by the process of claim 1.
Claim 24
Dependent Claim
107 words
A structured scintillator for detecting x-rays comprising: a scintillation substrate comprising an array of pixel structures, each of said pixel structures comprising scintillating material throughout the entire pixel and having a diameter or width of between 0.5 and 100 μm, and a transparent optically inactive interstitial material disposed between said pixel structures, said interstitial material having a lower refractive index than said scintillation substrate and substantially surrounding said pixel structures such that following emission of radiation in response to x-ray radiation, said pixel structures internally reflect said emitted radiation, thereby decreasing the area illuminated by a single pixel structure and increasing the resolution of said structured scintillator.
Claim 25
Dependent Claim
107 words
A structured scintillator for detecting x-rays comprising: a scintillation substrate comprising an array of pixel structures, each of said pixel structures comprising scintillating material throughout the entire pixel and having a diameter or width of between 0.5 and 100 μm, and a transparent optically inactive interstitial material disposed between said pixel structures, said interstitial material having a lower refractive index than said scintillation substrate and substantially surrounding said pixel structures such that following emission of radiation in response to x-ray radiation, said pixel structures internally reflect said emitted radiation, thereby decreasing the area illuminated by a single pixel structure and increasing the resolution of said structured scintillator.
Claim 26
Dependent Claim
17 words
The structured scintillator of claim 23, wherein the cross sections of said pixel structures are arbitrarily shaped.
Claim 27
Dependent Claim
15 words
The structured scintillator of claim 24, wherein said cross sections are substantially circular in shape.
Claim 28
Dependent Claim
23 words
The structured scintillator of claim 23, wherein said array of pixel structures comprises a pixel structure having tapered ends for focussing said radiation.
Claim 29
Dependent Claim
22 words
The structured scintillator of claim 23, wherein neighboring pixel structures are separated by a distance of between 0.2 and 50.0 microns, inclusive.
Claim 30
Dependent Claim
19 words
The structured scintillator of claim 27, wherein neighboring pixel structures are separated by a distance of about 0.5 microns.
Claim 31
Dependent Claim
65 words
The structured scintillator of claim 23, wherein said scintillating material is selected from the group consisting of glass-based scintillating materials, CdWO 4 , thallium-activated sodium iodide, terbium-doped glass scintillators, transparent plastic scintillators, ceramic-based scintillating materials, Gd 2 O 3 , Gd 2 O 2 S:Pr,Ce,Cl, Gd 2 O 2 S:Pr,Ce,F, Gd 2 O 2 S:Pr, and Y 2 O 3 /Gd 2 O 3 .
Claim 32
Dependent Claim
14 words
The structured scintillator of claim 29, wherein said scintillating material is CdWO 4 .
Claim 33
Dependent Claim
17 words
The structured scintillator of claim 29, wherein said optically transparent or semi-transparent material is a single-crystalline material.
Claim 34
Dependent Claim
25 words
The structured scintillator of claim 23, wherein said transparent interstitial material comprises a material selected from the group consisting of optical glasses, and polymeric materials.
Claim 35
Dependent Claim
15 words
The structured scintillator of claim 32, wherein said transparent interstitial material is a polymeric material.
Claim 36
Dependent Claim
12 words
The structured scintillator of claim 33, wherein said polymeric material is polyimide.
Claim 37
Dependent Claim
17 words
The structured scintillator of claim 23, further comprising a highly absorbing material proximal to said interstitial material.
Claim 38
Dependent Claim
15 words
The structured scintillator of claim 23, wherein said highly absorbing material is a doped material.
Claim 39
Dependent Claim
11 words
The structured scintillator of claim 23, further comprising a detection device.
Claim 40
Dependent Claim
14 words
The structured scintillator of claim 37, wherein said detection device is a light-sensitive film.
Claim 41
Dependent Claim
14 words
The structured scintillator of claim 37, wherein said detection device is an electronic detector.
Claim 42
Dependent Claim
13 words
The structured scintillator of claim 39, wherein said electronic detector is a CCD.
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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) | 1999-05-21 | 1999-11-20 | 2000-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-21 | 2003-11-20 | 2004-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-21 | 2007-11-20 | 2008-05-21 | $7700.00 | Window Closed / Lapsed |