US4755447A
Expired / Lapsed
US
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Enhanced radiographic image capture using a wide-dynamic-range film
Assignee: Agfa Gevaert NV
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Filing: 1986-10-03
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Granted: 1988-07-05
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Expires: 2006-10-03
Abstract
Abstract A wide-dynamic-range wide latitude silver halide film is used for X-ray intensifying screen exposure and subsequent computer enhancement of the images produced thereon. The enhanced image is equivalent to images produced by a host of individual films and screens.
Inventors
- 👤 Earle L. Kitts, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:43
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/16; G03C1/00; G03C1/005; G03C1/035; G03C2005/168; Y; Y10; Y10S; Y10S430/00; Y10S430/167
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
137 words
In a process wherein a photosensitive silver halide film is imagewise exposed to light emanating from an X-ray intensifying screen to form a latent image thereon, followed by developing said image and subsequently enhancing said developed image by analog or digital computer processing to provide additional contrast in selected regions of said image, the improvement comprising employing as the photosensitive silver halide film a wide-dynamic-range film with exposure latitude of ≧10:1 and within a useful density range of 0.3 to 3.0 having an essentially constant gradient of no greater than 2.0 and the maximum gradient never exceeds the minimum gradient by more than a factor of two within said density range and a ΔLog E between 1.0 and 3.0 for the essentially constant gradient, whereby visibility of the radiographic detail over a wide exposure latitude is obtained.
Claim 2
Dependent Claim
137 words
In a process wherein a photosensitive silver halide film is imagewise exposed to light emanating from an X-ray intensifying screen to form a latent image thereon, followed by developing said image and subsequently enhancing said developed image by analog or digital computer processing to provide additional contrast in selected regions of said image, the improvement comprising employing as the photosensitive silver halide film a wide-dynamic-range film with exposure latitude of ≧10:1 and within a useful density range of 0.3 to 3.0 having an essentially constant gradient of no greater than 2.0 and the maximum gradient never exceeds the minimum gradient by more than a factor of two within said density range and a ΔLog E between 1.0 and 3.0 for the essentially constant gradient, whereby visibility of the radiographic detail over a wide exposure latitude is obtained.
Claim 3
Dependent Claim
34 words
The process of claim 1 wherein three silver halide emulsions are mixed, and wherein the emulsion grain size distribution is such that their volume-weighted mean volumes are 0.06, 0.20, and 1.20 (μm) 3 .
Claim 4
Dependent Claim
10 words
The process of claim 1 wherein the optimum ΔLog E=1.7.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein the digital process uses a CRT screen for displaying the image.
Claim 6
Dependent Claim
27 words
The process of claim 1 wherein the specific analog process uses subtraction print film or duplicating film to enhance the image captured on the wide-dynamic-range film element.
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) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |