US4511799A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual energy imaging
Assignee: American Science and Engineering Inc
•
Filing: 1982-12-10
•
Granted: 1985-04-16
•
Expires: 2002-12-10
Abstract
Abstract Dual energy imaging develops simultaneous signals from transmitted energy of different characteristics. The detector includes two serially arranged detectors. A first detector preferentially absorbs lower level radiant energy and the second detector preferentially absorbs higher radiant energy. The detectors may be identical in which case the preferential characteristic is developed by reason of the detector's position. Alternatively, the characteristics of the detectors may be selected to produce the desired effect, e.g. a gaseous detector may be pressurized in accordance with its function, a scintillating screen may be tilted or its length may be selected to produce the desired absorption characteristic.
Inventors
- 👤 Paul J. Bjorkholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:43
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/48; A61B6/482; A61B6/42; A61B6/4208; A61B6/4241; G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/2018; G01T1/20186
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
127 words
Apparatus for selectively imaging as a function of radiant energy levels, said apparatus comprising: a source of penetrating radiant energy, means for directing said radiant energy toward a target area, radiant energy detecting means located in a path of said radiant energy and including: a first scintillating screen detecting means with a surface having a normal at a first angle to said path of radiant energy for producing first signals corresponding to incident radiant energy, and a second scintillating screen detecting means, located in said path but beyond said first scintillating screen detecting means, with a surface having a normal at a second angle to said path of radiant energy for producing second signals corresponding to incident radiant energy, said second angle greater than said first angle.
Claim 2
Dependent Claim
127 words
Apparatus for selectively imaging as a function of radiant energy levels, said apparatus comprising: a source of penetrating radiant energy, means for directing said radiant energy toward a target area, radiant energy detecting means located in a path of said radiant energy and including: a first scintillating screen detecting means with a surface having a normal at a first angle to said path of radiant energy for producing first signals corresponding to incident radiant energy, and a second scintillating screen detecting means, located in said path but beyond said first scintillating screen detecting means, with a surface having a normal at a second angle to said path of radiant energy for producing second signals corresponding to incident radiant energy, said second angle greater than said first angle.
Claim 3
Dependent Claim
127 words
Apparatus for selectively imaging as a function of radiant energy levels, said apparatus comprising: a source of penetrating radiant energy, means for directing said radiant energy toward a target area, radiant energy detecting means, comprising a single scintillating crystal, located in a path of said radiant energy and including: first detecting means for producing first signals corresponding to incident radiant energy, said first detecting means including a dedicated transducer and a portion of said single scintillating crystal and second detecting means, located in said path of travel of said radiant energy but beyond said first detecting means for producing second signals corresponding to radiant energy incident on said second detecting means, said second detecting means including a dedicated transducer and another portion of said single scintillating crystal.
Claim 4
Dependent Claim
127 words
Apparatus for selectively imaging as a function of radiant energy levels, said apparatus comprising: a source of penetrating radiant energy, means for directing said radiant energy toward a target area, radiant energy detecting means, comprising a single scintillating crystal, located in a path of said radiant energy and including: first detecting means for producing first signals corresponding to incident radiant energy, said first detecting means including a dedicated transducer and a portion of said single scintillating crystal and second detecting means, located in said path of travel of said radiant energy but beyond said first detecting means for producing second signals corresponding to radiant energy incident on said second detecting means, said second detecting means including a dedicated transducer and another portion of said single scintillating crystal.
Claim 5
Dependent Claim
14 words
The device of claim 2 in which each of said portions are directly adjacent.
Claim 6
Dependent Claim
11 words
The device of claim 2 in which said portions are separated.
Claim 7
Dependent Claim
167 words
Apparatus useful in imaging comprising: a source of penetrating radiant energy, means for directing penetrating radiant energy emitted by said source to travel a path toward a target area, detector means located beyond said target area along the path of said radiant energy for producing signals representative of radiant energy reaching said detector means, said detector means including: first energy detector means for converting radiant energy to a first signal, said first energy detector means having a first detection efficiency as a function of radiant energy, and second energy detector means located in said path but beyond said first energy detector means, for converting radiant energy to a second signal, said second energy detector means having a second detection efficiency, as a function of radiant energy, different from said first detection efficiency, wherein said first detection efficiency has a lower sensitivity to radiant energy in a first energy range and said second detection efficiency has a lower sensitivity to radiant energy in a second, higher, energy range.
Claim 8
Dependent Claim
167 words
Apparatus useful in imaging comprising: a source of penetrating radiant energy, means for directing penetrating radiant energy emitted by said source to travel a path toward a target area, detector means located beyond said target area along the path of said radiant energy for producing signals representative of radiant energy reaching said detector means, said detector means including: first energy detector means for converting radiant energy to a first signal, said first energy detector means having a first detection efficiency as a function of radiant energy, and second energy detector means located in said path but beyond said first energy detector means, for converting radiant energy to a second signal, said second energy detector means having a second detection efficiency, as a function of radiant energy, different from said first detection efficiency, wherein said first detection efficiency has a lower sensitivity to radiant energy in a first energy range and said second detection efficiency has a lower sensitivity to radiant energy in a second, higher, energy range.
Claim 9
Dependent Claim
18 words
The device of claim 5 in which said first and second energy detectors are each gas filled detectors.
Claim 10
Dependent Claim
17 words
The device of claim 5 in which said first and second energy detectors are each scintillating screens.
Claim 11
Dependent Claim
17 words
The device of claim 5 in which said first and second energy detectors comprise a scintillating crystal.
References Cited (Backward Citations)
US2445305A
Cited
US3582651A
Cited
US3790799A
Cited
US3894181A
Cited
US3848130A
Cited
US3854049A
Cited
US3974386A
Cited
US3965358A
Cited
US4031401A
Cited
JPS522777A
Cited
US4029963A
Cited
US4242583A
Cited
US4204225A
Cited
US4204226A
Cited
US4317037A
Cited
US4247774A
Cited
US4260898A
Cited
US4413353A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-15 | 1988-10-15 | 1989-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-15 | 1992-10-15 | 1993-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-15 | 1996-10-15 | 1997-04-16 | $7700.00 | Window Closed / Lapsed |