US4833698A
Expired / Lapsed
US
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Apparatus for three dimensional tomography utilizing an electro-optic x-ray detector
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1986-08-01
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Granted: 1989-05-23
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Expires: 2006-08-01
Abstract
Abstract The present invention is an apparatus for producing tomographic images of an object comprising: a beam of collimated radiation transmitted through the object in a plurality of rays, an imaging electro-optic detector for detecting the attenuated transmitted radiation after it has passed through the object, the detector including an energy convertor, image format altering device, and a readout device, wherein the detector has a detective quantum efficiency greater than 0.05, a total signal dependent background less than 10 percent of the signal from the unattenuated x-ray beam, a useful dynamic range greater than 10, a non-uniformity of response between adjacent active pixels of less than 75%, and deviations of geometric linearity that is less than 10 pixels in the recorded image, means for obtaining the attenuation coefficients from the transmitted radiation, and means for computing a reconstructed image of the object from the attenuation coefficients.
Inventors
- 👤 Brian P. Flannery
- 👤 Harry W. Deckman
- 👤 Peter M. Eisenberger
- 👤 Wayne G. Roberge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:50
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/04; G01N23/046; G01N2223/00; G01N2223/40; G01N2223/419; Y; Y10; Y10S; Y10S378/00; Y10S378/901
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
162 words
An apparatus for producing three dimensional tomographic images of an object irradiated by a plurality of rays of plane parallel collimated radiation (unattenuated beam) transmitted through said object comprising: (a) a two-dimensional electro-optical imaging detector having active pixels for simultaneously recording a two-dimensional image that measures attenuated transmitted radiation from multiple stacked planes after said plane parallel collimated radiation has passed through the object, said detector including an energy converter, an image format altering device, and a readout device, wherein said detector's active pixels have a detective quantum efficiency greater than 0.05, a total signal dependent background less than 10 percent of the signal from the unattenuated beam and a useful dynamic range greater than 10, and deviations of geometric linearity that are less than 10 pixels in the recorded image; (b) means for obtaining projection data from said attenuated transmitted radiation, and (c) means for computing a three dimensional reconstructed image of attenuation coefficients of said object from said projection data.
Claim 2
Independent Claim
162 words
An apparatus for producing three dimensional tomographic images of an object irradiated by a plurality of rays of plane parallel collimated radiation (unattenuated beam) transmitted through said object comprising: (a) a two-dimensional electro-optical imaging detector having active pixels for simultaneously recording a two-dimensional image that measures attenuated transmitted radiation from multiple stacked planes after said plane parallel collimated radiation has passed through the object, said detector including an energy converter, an image format altering device, and a readout device, wherein said detector's active pixels have a detective quantum efficiency greater than 0.05, a total signal dependent background less than 10 percent of the signal from the unattenuated beam and a useful dynamic range greater than 10, and deviations of geometric linearity that are less than 10 pixels in the recorded image; (b) means for obtaining projection data from said attenuated transmitted radiation, and (c) means for computing a three dimensional reconstructed image of attenuation coefficients of said object from said projection data.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein said detector's active pixels have a non-uniformity of response between adjacent active pixels of less than 75%.
Claim 4
Dependent Claim
11 words
The apparatus of claim 1 further including a source of radiation.
Claim 5
Dependent Claim
14 words
The apparatus of claim 3 wherein said source of radiation is an x-ray source.
Claim 6
Dependent Claim
17 words
The apparatus of claim 3 wherein said source of radiation is rigidly connected to said electro-optical detector.
Claim 7
Dependent Claim
23 words
The apparatus of claim 5 further comprising a means to rotate one of said object or said source of radiation about an axis.
Claim 8
Dependent Claim
13 words
The apparatus of claim 1 wherein said detector further comprises a gain element.
Claim 9
Dependent Claim
16 words
The apparatus of claim 1 wherein said detector has a detective quantum efficiency greater than 0.5.
Claim 10
Dependent Claim
16 words
The apparatus of claim 1 wherein said detector has a signal dependent background less than 2%.
Claim 11
Dependent Claim
15 words
The apparatus of claim 1 wherein said detector has a dynamic range greater than 50.
Claim 12
Dependent Claim
18 words
The apparatus of claim 1 wherein said detector has a deviation of geometric linearity less than 1 pixel.
Claim 13
Dependent Claim
14 words
The apparatus of claim 1 wherein said readout device is a charge coupled device.
Claim 14
Dependent Claim
22 words
The apparatus of claim 1 wherein the active pixels have a maximum non-uniformity of response across the detector of less than 10%.
Claim 15
Dependent Claim
22 words
The apparatus of claim 1 wherein the active pixels have a maximum non-uniformity of response across the detector of less than 2%.
Claim 16
Dependent Claim
13 words
The apparatus of claim 1 wherein said electro-optical detector includes a cellular phosphor.
Claim 17
Dependent Claim
10 words
The apparatus of claim 1 further including a display device.
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) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |