Patent US4211925A successfully refreshed from Google Patents.
US4211925A
Expired / Lapsed
US
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CT Scanner with anode scan monitor
Assignee: QED Intellectual Property Ltd
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Filing: 1978-04-19
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Granted: 1980-07-08
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Expires: 1998-04-19
Abstract
Abstract In a variant of the type of radiographic apparatus known as CT scanners a scanning X-ray tube is used to provide a planar fan-shaped distribution and to scan the distribution in its plane. Means are also provided to rotate the system about an axis perpendicular to the plane. In order to properly relate operation of the system, it is desirable to monitor the progress of the tube scan. This invention disposes a detector into the radiation and a pair of gratings acting together to modulate the radiation, incident on the detector, in relation to the scan position. The detector output is processed to give pulses which can be used to regulate the tube scan.
Inventors
- 👤 Ian A. Fairbairn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:59
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/032; A61B6/40; A61B6/4021; A61B6/4028; A61B6/42; A61B6/4291; G; G01; G01T; G01T1/00; G01T1/29; G01T1/2914; G01T1/2921; G01T1/295
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
95 words
A radiographic apparatus for examining a slice of the body of a patient, including a source of a substantially planar fan-shaped distribution of radiation originating from an anode included in the source, means for scanning the origin of the radiation in relation to the anode and a scan position indicator including means for detecting the intensity of the radiation and at least two gratings, disposed to shield the means for detecting, co-operating to modulate the intensity of the radiation incident on the means for detecting in a manner related to the position of said origin.
Claim 2
Dependent Claim
95 words
A radiographic apparatus for examining a slice of the body of a patient, including a source of a substantially planar fan-shaped distribution of radiation originating from an anode included in the source, means for scanning the origin of the radiation in relation to the anode and a scan position indicator including means for detecting the intensity of the radiation and at least two gratings, disposed to shield the means for detecting, co-operating to modulate the intensity of the radiation incident on the means for detecting in a manner related to the position of said origin.
Claim 3
Dependent Claim
44 words
An apparatus according to claim 1 in which the two gratings are of different pitches and the ratio of the pitches is substantially the same as the ratio of the distances of the gratings from the locus of the scanned origin of the radiation.
Claim 4
Dependent Claim
26 words
An apparatus according to claim 1 in which the means for detecting the intensity of the radiation includes a scintillator cooperating with at least one photomultiplier.
Claim 5
Dependent Claim
22 words
An apparatus according to claim 1 in which the means for detecting the intensity of the radiation includes a plurality of photodiodes.
Claim 6
Dependent Claim
24 words
An apparatus according to claim 4 in which one photodiode is provided for each of a plurality of apertures of one of the gratings.
Claim 7
Dependent Claim
25 words
An apparatus according to claim 4 in which the plurality of photodiodes co-operate with a plurality of scintillators to detect the intensity of the radiation.
References Cited (Backward Citations)
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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) | 1983-07-08 | 1984-01-07 | 1984-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-08 | 1988-01-07 | 1988-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-08 | 1992-01-07 | 1992-07-08 | $7700.00 | Window Closed / Lapsed |