US4581753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Translatively driven X-ray aperture mask
Assignee: Hologic Inc
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Filing: 1984-09-21
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Granted: 1986-04-08
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Expires: 2004-09-21
Abstract
Abstract Scatter is reduced in an X-ray system by a relatively large light- or X-radiation-opaque mask rotating on a first axis and carrying smaller, radiation-opaque masks rotating off the first axis. The smaller masks have elongate radiation windows which are held parallel to each other and to a fixed plane through the first axis by translative drive and driven wheels on the larger and smaller masks coupled by a flexible linkage belt.
Inventors
- 👤 Richard E. Rice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:04
CPC Classifications
G; G03; G03B; G03B42/00; G03B42/02; A; A61; A61B; A61B6/00; A61B6/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
In an X-ray system directing X-radiation on a path through a subject position to an X-ray receptor, an X-ray scatter reducing device comprising: a relatively large radiation-opaque mask in the path rotating on a first axis outside the path and having a radiation-transparent zone; a relatively small radiation-opaque mask with an elongate radiation window, the small mask being mounted in the zone of the large mask to rotate on a second axis spaced from the first axis so that the window is periodically moved through the radiation path; and translative drive means coupling the large and small masks to hold the window parallel to a fixed plane through and coincident with the first axis.
Claim 2
Dependent Claim
114 words
In an X-ray system directing X-radiation on a path through a subject position to an X-ray receptor, an X-ray scatter reducing device comprising: a relatively large radiation-opaque mask in the path rotating on a first axis outside the path and having a radiation-transparent zone; a relatively small radiation-opaque mask with an elongate radiation window, the small mask being mounted in the zone of the large mask to rotate on a second axis spaced from the first axis so that the window is periodically moved through the radiation path; and translative drive means coupling the large and small masks to hold the window parallel to a fixed plane through and coincident with the first axis.
Claim 3
Dependent Claim
32 words
A device according to claim 1 wherein a plurality of small masks are spaced equiangularly around the large mask and first axis, and coupled by translative drive means to the large mask.
Claim 4
Dependent Claim
17 words
A device according to claim 1 wherein the elongate window is of constant width throughout its length.
Claim 5
Dependent Claim
16 words
A device according to claim 1 wherein the small mask has a plurality of parallel windows.
Claim 6
Dependent Claim
28 words
A device according to claim 2 wherein each small mask has a plurality of windows, the windows of all masks being held parallel by the translative drive means.
Claim 7
Dependent Claim
38 words
A device according to claim 2 wherein each small mask comprises a driven wheel, the large mask having a drive wheel of the same diameter, and wherein the drive and driven wheels are coupled by a flexible linkage.
Claim 8
Dependent Claim
28 words
A system according to claim 1 wherein the small mask and large mask radiation-transparent zone are identical circularly so that the masks are continuously radio-opaque to the window.
Claim 9
Dependent Claim
24 words
A device according to claim 1 in combination with an X-ray source and X-ray receptor, the device being located between the source and receptor.
Claim 10
Dependent Claim
21 words
A combination according to claim 8 wherein the receptor comprises an X-ray responsive element producing light radiated on a secondary path.
Claim 11
Dependent Claim
28 words
A combination according to claim 9 including light responsive means on the secondary path and a light scatter reducing device between the X-ray receptor and light responsive device.
Claim 12
Dependent Claim
18 words
A combination according to claim 10 wherein the light scatter reducing device has small and large light-opaque masks.
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) | 1989-04-07 | 1989-10-07 | 1990-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-07 | 1993-10-07 | 1994-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-07 | 1997-10-07 | 1998-04-08 | $7700.00 | Window Closed / Lapsed |