Patent US4785471A successfully refreshed from Google Patents.
US4785471A
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Radioscopic image device
Assignee: Optische Industrie de Oude Delft NV
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Filing: 1986-10-22
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Granted: 1988-11-15
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Expires: 2006-10-22
Abstract
Abstract A radioscopic image former comprises a slit between an X-ray source and a subject to produce an X-ray fan beam to scan the subject. The transmission of the slit is adjusted locally during the scanning depending on local absorptions in the subject. The X-ray fan beam is cyclically modulated. The local modulation frequency depends on the coordinate in the longitudinal direction of the slit. The slit comprises a number of tongues each tongue being excited at or near its resonant frequency. Each tongue has its own frequency or phase and acts as a frequency-selective element.
Inventors
- 👤 Sipko L. Boersma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:43
CPC Classifications
H; H05; H05G; H05G1/00; H05G1/08; H05G1/60; A; A61; A61B; A61B6/00; A61B6/06; G; G21; G21K; G21K1/00; G21K1/02; G21K1/04; G21K1/043; H05G1/26; H05G1/30; H05G1/36
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
168 words
An apparatus for slit radiography, which comprises: an X-ray source; an X-ray detector for sensing radiation pasing through a body to be radiographed; a slit diaphragm positioned between said X-ray source and said body for forming a substantially planar X-ray beam; a plurality of attenuating elements positioned along said slit diaphragm forming corresponding number of attenuating sections; means to move said elements within said X-ray beam; means for scanning said body with said planar X-ray beam; detection means co-operating with said X-ray detector and being responsive to radiation sensed by said X-ray detector to prodice an electric signal representative of intensity of the sensed radiation; and means for controlling said means to move said attenuating elements during scanning of said body in response to said electric signal, such that the movement of each attenuating element modulates for each corresponding section, the intensity of X-ray radiation at a certain temporal frequency, wherein each attenuating element moves in response to a different frequency or phase than all other attenuating elements.
Claim 2
Independent Claim
168 words
An apparatus for slit radiography, which comprises: an X-ray source; an X-ray detector for sensing radiation pasing through a body to be radiographed; a slit diaphragm positioned between said X-ray source and said body for forming a substantially planar X-ray beam; a plurality of attenuating elements positioned along said slit diaphragm forming corresponding number of attenuating sections; means to move said elements within said X-ray beam; means for scanning said body with said planar X-ray beam; detection means co-operating with said X-ray detector and being responsive to radiation sensed by said X-ray detector to prodice an electric signal representative of intensity of the sensed radiation; and means for controlling said means to move said attenuating elements during scanning of said body in response to said electric signal, such that the movement of each attenuating element modulates for each corresponding section, the intensity of X-ray radiation at a certain temporal frequency, wherein each attenuating element moves in response to a different frequency or phase than all other attenuating elements.
Claim 3
Dependent Claim
46 words
The apparatus as defined in claim 1 wherein said attenuating elements comprises a plurality of tongues and wherein said means for controlling said attenuating elements to modulate the intensity of said X-ray radiation comprises means for exciting each tongue to vibrate at or near resonant frequency.
Claim 4
Dependent Claim
23 words
The apparatus as defined in claim 2 wherein said means for controlling the means to move said attenuating sections comprises frequency selective circuits.
Claim 5
Dependent Claim
15 words
The apparatus as defined in claim 3 wherein said frequency selective circuits include said tongues.
Claim 6
Dependent Claim
19 words
The apparatus as defined in claim 2 and further including means to control vibrational amplitudes of said vibrating tongues.
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) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |