Patent US5694448A successfully refreshed from Google Patents.
US5694448A
Expired / Lapsed
US
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Imaging apparatus
Assignee: Teledyne UK Ltd
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Filing: 1996-07-12
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Granted: 1997-12-02
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Expires: 2016-07-12
Abstract
Abstract In imaging apparatus particularly for use in intra-oral dental applications, a solid state imager is continually clocked out during a wait period prior to irradiation from an X-ray source. A signal derived from the CCD is compared with a threshold at to determine the onset of irradiation by the X-ray source which will appear as a rapid change in the signal level. The threshold conditions are varied to follow changes in ambient conditions and particularly temperature changes to allow for increase of dark current with a rise in temperature. This permits the threshold at which the CCD is triggered to begin image acquisition to be set at a relatively low level whilst minimising the risk of false triggering.
Inventors
- 👤 Christopher John Morcom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:21
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/50; A61B6/51; A61B6/512; G; G01; G01T; G01T1/00; G01T1/29; G01T1/2914; G01T1/2921; G01T1/2928; H; H04; H04N; H04N23/00; H04N23/30; H04N23/70; H04N23/73
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
53 words
Imaging apparatus comprising: a solid state imager device including radiation sensitive detector elements; means for carrying out a threshold test; means for varying a threshold condition of the threshold test in accordance with changes in ambient conditions; and means for initiating image acquisition by said imager device when said threshold test is satisfied.
Claim 2
Dependent Claim
53 words
Imaging apparatus comprising: a solid state imager device including radiation sensitive detector elements; means for carrying out a threshold test; means for varying a threshold condition of the threshold test in accordance with changes in ambient conditions; and means for initiating image acquisition by said imager device when said threshold test is satisfied.
Claim 3
Dependent Claim
22 words
Imaging apparatus as claimed in claim 1 includes means for comparing a signal derived from said detector elements with a threshold level.
Claim 4
Dependent Claim
43 words
Imaging apparatus as claimed in claim 2 wherein said means for varying a threshold condition includes comparison means for comparing a signal derived from said detector elements with a threshold level and changing said threshold level in accordance with changes in said signal.
Claim 5
Dependent Claim
50 words
Apparatus as claimed in claim 2 wherein said means for varying a threshold condition includes comparison means for comparing a signal derived from said detector elements with a previously obtained signal from said detector elements to give a difference value and said difference value being compared with a threshold level.
Claim 6
Dependent Claim
16 words
Apparatus as claimed in claim 1 wherein said solid state imager device is a CCD device.
Claim 7
Dependent Claim
17 words
Apparatus as claimed in claim 1 wherein said apparatus is adapted for use in an intra-oral arrangement.
Claim 8
Dependent Claim
15 words
Apparatus as claimed in claim 1 wherein said imager device, in use, detects X-ray radiation.
Claim 9
Dependent Claim
16 words
Apparatus as claimed in claim 3 wherein said solid state imager device is a CCD device.
Claim 10
Dependent Claim
16 words
Apparatus as claimed in claim 4 wherein said solid state imager device is a CCD device.
Claim 11
Dependent Claim
26 words
Apparatus as claimed in claim 1 and including an X-ray source for irradiating a subject behind which said solid state imager device is located during use.
Claim 12
Dependent Claim
24 words
Apparatus as claimed in claim 1 and including means for substantially continually clocking out charge from said detector elements prior to initiating image acquisition.
Claim 13
Dependent Claim
75 words
A dental X-ray imaging apparatus comprising: an X-ray source arranged in use to irradiate a subject; a solid state imager device for receiving X-ray radiation from said source after it has passed through said subject; means for initiating image acquisition when a threshold test is satisfied which incudes means for comparing a signal derived from said imager with a threshold condition; and means for varying said threshold condition in accordance with changes in ambient conditions.
Claim 14
Dependent Claim
75 words
A dental X-ray imaging apparatus comprising: an X-ray source arranged in use to irradiate a subject; a solid state imager device for receiving X-ray radiation from said source after it has passed through said subject; means for initiating image acquisition when a threshold test is satisfied which incudes means for comparing a signal derived from said imager with a threshold condition; and means for varying said threshold condition in accordance with changes in ambient conditions.
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) | 2000-12-01 | 2001-06-02 | 2001-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-01 | 2005-06-02 | 2005-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-01 | 2009-06-02 | 2009-12-02 | $7700.00 | Window Closed / Lapsed |