US4847686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiological installation using a camera television with low-remanence pick-up element
Assignee: General Electric CGR SA
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Filing: 1987-09-11
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Granted: 1989-07-11
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Expires: 2007-09-11
Abstract
Abstract An imaging installation, especially for digital type radiology, comprises a pick-up tube television camera with no remanence or low remanence with a non-linear element producing a remanence of the image signal given by the camera. The remanence varies with the level of the signal. When a recursive filter is used to obtain this remanence which is variable with the signal level, the modulation f 2 , introduced by the modulator connected to the output of this filter by a frames memory, is defined by the function: f 2 (x)=x[λ(1-g(x))+μg(x)], a formula in which x is the ratio between the signal applied at the input of this modulator and the maximum value of the input signal, λ and μ are constants, and g (x) is a linear function of x meeting the conditions: g (0) and g (1)=1.
Inventors
- 👤 Jean L. Ploix
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:52
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/30; H04N5/32
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
60 words
A radiological imaging installation, comprising: a television camera having a pickup device, said pickup device presenting no or low remanence; and non-linear means for producing a remanence of an image signal supplied by said television camera, said non-linear means connecting to said pickup device, and said remanence produced by said non-linear means varying with the level of said image signal.
Claim 2
Dependent Claim
60 words
A radiological imaging installation, comprising: a television camera having a pickup device, said pickup device presenting no or low remanence; and non-linear means for producing a remanence of an image signal supplied by said television camera, said non-linear means connecting to said pickup device, and said remanence produced by said non-linear means varying with the level of said image signal.
Claim 3
Dependent Claim
14 words
An installation according to claim 1, wherein: said non-linear means is a recursive filter.
Claim 4
Dependent Claim
25 words
An installation according to claim 2, wherein: the remanence produced by said non-linear means becomes high when the level of said image signal is low.
Claim 5
Dependent Claim
32 words
An installation according to claim 3, wherein: said non-linear means connecting to said pick-up device of said television camera results in a remanence behavior similar to a vidicon tube or chalnicon tube.
Claim 6
Dependent Claim
89 words
An installation according to claim 3 or 4, wherein: said non-linear means has an input signal modulator connected to a first input of an adder, an output of said adder forming an output of said recursive filter, said output of said adder connecting to a frame memory connected to a second modulator, said second modulator connecting to a second input of said adder, said input signal modulator and said second modulator being selected so as to produce said remanence which varies according to the level of said image signal.
Claim 7
Dependent Claim
20 words
An installation according to claim 5, wherein: a function f 1 of said input signal modulator contains a gamma correction.
Claim 8
Dependent Claim
64 words
An installation according to claim 5, wherein: said second modulator introduces a modulation defined by the function: f.sub.2 (x)=x[[(1-g(x))+μg(x)], a formula wherein x is the ratio between the signal applied to the input of the second modulator with the maximum value of the input signal, λ and μ are constants and g(x) is a linear function of x meeting the conditions: g(0)=0, and g(1)=1.
Claim 9
Dependent Claim
8 words
An installation according to claim 7 wherein: g(x)=x.
Claim 10
Dependent Claim
28 words
An installation according to claim 7 wherein the function g (x) is defined in the following manner: ##EQU10## x 1 , x 2 and y 2 being constants.
Claim 11
Dependent Claim
25 words
An installation according to claim 7 wherein the function g (x) is defined in the following manner: ##EQU11## x 1 and x 2 being constants.
Claim 12
Dependent Claim
20 words
An installation according to claims 1, 3 or 4 wherein: said pick-up device comprises a plumbicon tube or saticon tube.
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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) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |