Patent US2446810A successfully refreshed from Google Patents.
US4573185A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-Ray tube with low off-focal spot radiation
Assignee: General Electric Co
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Filing: 1984-06-27
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Granted: 1986-02-25
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Expires: 2004-06-27
Abstract
Abstract A tungsten focal track is placed on a graphite substrate in such a manner as to reduce off focal spot radiation while maintaining a fixed focal spot size. The radial width of the focal tract is made smaller than that of the electron beam from the cathode such that the electron beam overlap will allow for misalignments between the electron beam and the focal track without affecting the focal spot size or location.
Inventors
- 👤 Brian D. Lounsberry
- 👤 Robert W. Meade
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:51
CPC Classifications
H; H01; H01J; H01J35/00; H01J35/02; H01J35/04; H01J35/08; H01J35/10; H01J2235/00; H01J2235/08; H01J2235/083; H01J2235/084
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
86 words
An anode for a rotary X-ray tube of the type having a cathode for emitting a beam of electrons for bombardment of the focal track on the anode comprising: a substrate having a circular face adapted to be disposed generally toward the cathode such that the electron beam is projected over a given radial dimension; and a circular focal track disposed on said substrate's circular face, said focal track being comprised of a refractory metal and having a radial dimension less than said given radial dimension.
Claim 2
Dependent Claim
86 words
An anode for a rotary X-ray tube of the type having a cathode for emitting a beam of electrons for bombardment of the focal track on the anode comprising: a substrate having a circular face adapted to be disposed generally toward the cathode such that the electron beam is projected over a given radial dimension; and a circular focal track disposed on said substrate's circular face, said focal track being comprised of a refractory metal and having a radial dimension less than said given radial dimension.
Claim 3
Dependent Claim
17 words
An anode as set forth in claim 1 wherein said substrate is comprised of a graphite material.
Claim 4
Dependent Claim
18 words
An anode as set forth in claim 1 wherein said focal track is comprised of a tungsten material.
Claim 5
Dependent Claim
35 words
An anode as set forth in claim 1 and including a barrier layer between said substrate and said focal track, said barrier layer being comprised of a refractory material which is resistant to carbide formation.
Claim 6
Dependent Claim
27 words
An anode as set forth in claim 1 wherein said substrate has a coefficient of thermal expansion which is substantially equal to that of said focal track.
Claim 7
Dependent Claim
34 words
An anode as set forth in claim 1 wherein the difference in the radial dimension of said electron beam and that of said focal track is in the range of 0.002 to 0.250 inches.
Claim 8
Dependent Claim
82 words
An X-ray tube of the type having a rotating anode substrate with an associated annular focal track for receiving a beam of electrons from a cathode to produce X-rays, comprising: an anode substrate composed of a relatively low-density material; a focal track composed of a relatively high-density material attached to the substrate and having a predetermined radial dimension; and a cathode for producing a beam of electrons with a radial dimension slightly greater than said predetermined radial dimension of the focal track.
Claim 9
Dependent Claim
82 words
An X-ray tube of the type having a rotating anode substrate with an associated annular focal track for receiving a beam of electrons from a cathode to produce X-rays, comprising: an anode substrate composed of a relatively low-density material; a focal track composed of a relatively high-density material attached to the substrate and having a predetermined radial dimension; and a cathode for producing a beam of electrons with a radial dimension slightly greater than said predetermined radial dimension of the focal track.
Claim 10
Dependent Claim
19 words
An X-ray tube as set forth in claim 7 wherein said anode substrate is comprised of a graphite material.
Claim 11
Dependent Claim
19 words
An X-ray tube as set forth in claim 1 wherein said focal track is comprised of a tungsten material.
Claim 12
Dependent Claim
27 words
An X-ray tube as set forth in claim 7 wherein the coefficient of thermal expansion of said substrate is substantially equal to that of said focal track.
Claim 13
Dependent Claim
53 words
An improved X-ray tube of the type of having a rotating anode substrate with an associated annual focal track for receiving a beam of electrons from the cathode to produce X-rays, the improvement comprising a focal track with a radial dimension which is slightly less than the radial dimension of the electron beam.
Claim 14
Dependent Claim
53 words
An improved X-ray tube of the type of having a rotating anode substrate with an associated annual focal track for receiving a beam of electrons from the cathode to produce X-rays, the improvement comprising a focal track with a radial dimension which is slightly less than the radial dimension of the electron beam.
Claim 15
Dependent Claim
35 words
An X-ray tube as set forth in claim 11 wherein the difference in the radial dimension of the focal track and that of the electron beam is in the range of 0.002 to 0.250 inches.
Claim 16
Dependent Claim
18 words
An X-ray tube as set forth in claim 11 wherein said substrate is comprised of a graphite material.
Claim 17
Dependent Claim
19 words
An X-ray tube as set forth in claim 11 wherein said focal track is comprised of a tungsten material.
Claim 18
Dependent Claim
27 words
An X-ray tube as set forth in claim 11 wherein the coefficient of thermal expansion of the substrate is substantially equal to that of the focal track.
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) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |