US5686732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray apparatus comprising a photoconductor and a charging device
Assignee: US Philips Corp
•
Filing: 1996-03-28
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Granted: 1997-11-11
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Expires: 2016-03-28
Abstract
Abstract An apparatus, including a photoconductor (1) for converting X-rays into a charge pattern, and a controllable charging device (3, 9) for charging the surface of the photoconductor to a defined potential. The service life of the charging device is prolonged in that there is provided a measuring device for measuring the potential on the surface of the photoconductor and for controlling the charging device in dependence on the potential.
Inventors
- 👤 Waldemar Lumma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:35
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5037; G03G15/02; G03G15/0266; G03G15/054
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
118 words
An X-ray apparatus, comprising a photoconductor for converting X-rays into a charge pattern, a controllable charging device for charging the surface of the photoconductor to a defined potential by a corona discharge, and a measuring device for measuring the potential on the surface of the photoconductor and for controlling the charging device in dependence on the measured potential in a manner that the corona discharge is stopped when a predetermined potential state is reached on the surface of the photoconductor, wherein the measuring device comprises a measuring electrode and a reference electrode, a charge on the measuring electrode being determined successively by the potential on the surface of the photoconductor and by the potential of the reference electrode.
Claim 2
Dependent Claim
118 words
An X-ray apparatus, comprising a photoconductor for converting X-rays into a charge pattern, a controllable charging device for charging the surface of the photoconductor to a defined potential by a corona discharge, and a measuring device for measuring the potential on the surface of the photoconductor and for controlling the charging device in dependence on the measured potential in a manner that the corona discharge is stopped when a predetermined potential state is reached on the surface of the photoconductor, wherein the measuring device comprises a measuring electrode and a reference electrode, a charge on the measuring electrode being determined successively by the potential on the surface of the photoconductor and by the potential of the reference electrode.
Claim 3
Dependent Claim
57 words
An X-ray apparatus as claimed in claim 1, wherein the measuring device is for measuring the potential on the surface of the photoconductor during successive measuring cycles, the charge on the measuring electrode during a measuring cycle being determined successively by the potential on the surface of the photoconductor and by the potential of the reference electrode.
Claim 4
Dependent Claim
40 words
An X-ray apparatus as claimed in claim 2, wherein the reference electrode is arranged between the photoconductor and the measuring electrode and the measuring device comprises a controlled switching device for alternately connecting the reference electrode to a reference potential.
Claim 5
Dependent Claim
61 words
An X-ray apparatus as claimed in claim 3, wherein the photoconductor comprises a photoconductor layer which is provided on the circumference of a carrier which rotates during charging, the switching device being controlled so that it connects the reference electrode to the reference potential n times during each revolution of the carrier, n being larger than 1 and not an integer.
Claim 6
Dependent Claim
65 words
An X-ray apparatus as claimed in claim 2, wherein the measuring device comprises an integrator circuit for generating an output signal which corresponds to a time integral of a current flowing across the measuring electrode, and a comparator device for comparing said output signal with a reference value which corresponds to a potential on the surface of the photoconductor at which renewed charging takes place.
Claim 7
Dependent Claim
67 words
An X-ray apparatus as claimed in claim 2, wherein the measuring device comprises an integrator circuit for generating an output signal which corresponds to a time integral of a current flowing across the measuring electrode, and a comparator device for comparing said output signal with a reference value which corresponds to a potential on the surface of the photoconductor in a fully charged state of the photoconductor.
Claim 8
Dependent Claim
77 words
An X-ray apparatus as claimed in claim 6, further comprising means for displacing the measuring electrode and the photoconductor relative to one another so that the measuring electrode will have measured the potential on the surface of the photoconductor once after n measuring cycles, and a counting device for determining a number of successive measuring cycles in which said reference value is reached, and means for switching off the charging device after m such cycles, where m>n.
References Cited (Backward Citations)
US3586908A
Cited
US3934141A
Cited
EP0109722A1
Cited
US4800337A
Cited
US4678317A
Cited
US4975935A
Cited
DE4015113A1
Cited
US5093851A
Cited
DE4333325A1
Cited
US5467378A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-11-10 | 2001-05-12 | 2001-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-10 | 2005-05-12 | 2005-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-10 | 2009-05-12 | 2009-11-11 | $7700.00 | Window Closed / Lapsed |