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US5467378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray apparatus comprising a photoconductor and a corona charging device
Assignee: US Philips Corp
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Filing: 1994-09-28
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Granted: 1995-11-14
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Expires: 2014-09-28
Abstract
Abstract An X-ray apparatus, includes a photoconductor for convening X-rays into a charge pattern and a corona charging device for charging the surface of the photoconductor to a defined potential prior to an X-ray exposure. Deposits of dust on the corona charging device, and the associated artefacts in the X-ray image, are avoided in that there is provided a control unit for operating the corona charging device in a charging mode and in a cleaning mode, a first voltage being applied to the corona charging device in the charging mode whereas in the cleaning mode a second voltage is applied thereto which has, at least temporarily, a polarity which opposes that of the first voltage.
Inventors
- 👤 Waldemar Lumma
- 👤 Heinz Haarmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:25
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0258; G03G15/0291
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
93 words
An X-ray apparatus, comprising a photoconductor (1) for convening X-rays into a charge pattern, and a corona charging device (3) for charging the surface of the photoconductor to a defined potential prior to an X-ray exposure, and a control unit (6) for operating the corona charging device (3) in a first mode and in a second mode, the corona charging device (3) receiving in the first mode a first voltage (U1) and in the second mode a second voltage (U2) of a polarity which opposes that of the first voltage at least temporarily.
Claim 2
Dependent Claim
93 words
An X-ray apparatus, comprising a photoconductor (1) for convening X-rays into a charge pattern, and a corona charging device (3) for charging the surface of the photoconductor to a defined potential prior to an X-ray exposure, and a control unit (6) for operating the corona charging device (3) in a first mode and in a second mode, the corona charging device (3) receiving in the first mode a first voltage (U1) and in the second mode a second voltage (U2) of a polarity which opposes that of the first voltage at least temporarily.
Claim 3
Dependent Claim
76 words
An X-ray apparatus as claimed in claim 1, further comprising a first direct voltage source (7) which is connected to the corona charging device (3) in the first mode, and a second direct voltage source (5) which is connected to the corona charging device (3) in the second mode, the voltage supplied by the second direct voltage source having a polarity opposing that of and being smaller than the voltage supplied by the first voltage source.
Claim 4
Dependent Claim
37 words
An X-ray apparatus as claimed in claim 2, characterized in that the photoconductor (1) comprises a photoconductor layer (1b) on an electrically conductive carrier (1a), said carrier (1a) being connected to the second direct voltage source (5).
Claim 5
Dependent Claim
74 words
An X-ray apparatus as claimed in claim 1, characterized in that the control unit (6) comprises a switching device (64) which is connected between a direct voltage source (7) and the corona charging device and which supplies the corona charging device (3) with the voltage supplied by the direct voltage source in the first mode with a first polarity and supplies this voltage with a polarity opposing the first polarity in the second mode.
Claim 6
Dependent Claim
46 words
An X-ray apparatus as claimed in claim 1, further comprising a direct voltage source which is connected to the corona charging device in the first mode, there also being provided an alternating voltage source which is connected to the corona charging device in the second mode.
Claim 7
Dependent Claim
25 words
An X-ray apparatus as claimed in claim 1, characterized in that operation in the first mode is always followed by operation in the second mode.
Claim 8
Dependent Claim
31 words
An X-ray apparatus as claimed in claim 1, characterized in that the duration of operation in the second mode is approximately equal to the duration of operation in the first mode.
Claim 9
Dependent Claim
41 words
An X-ray apparatus as claimed in claim 1, characterized in that at least one conductive surface (51, 71) is provided in the vicinity of the photoconductor (1), outside the corona discharging device, which surface is connected to a direct voltage source.
Claim 10
Dependent Claim
25 words
An X-ray apparatus as claimed in claim 2, characterized in that operation in the first mode is always followed by operation in the second mode.
Claim 11
Dependent Claim
25 words
An X-ray apparatus as claimed in claim 3, characterized in that operation in the first mode is always followed by operation in the second mode.
Claim 12
Dependent Claim
25 words
An X-ray apparatus as claimed in claim 4, characterized in that operation in the first mode is always followed by operation in the second mode.
Claim 13
Dependent Claim
25 words
An X-ray apparatus as claimed in claim 5, characterized in that operation in the first mode is always followed by operation in the second mode.
Claim 14
Dependent Claim
30 words
An X-ray apparatus as claimed claim 2, characterized in that the duration of operation in the second mode is approximately equal to the duration of operation in the first mode.
Claim 15
Dependent Claim
30 words
An X-ray apparatus as claimed claim 3, characterized in that the duration of operation in the second mode is approximately equal to the duration of operation in the first mode.
Claim 16
Dependent Claim
30 words
An X-ray apparatus as claimed claim 4, characterized in that the duration of operation in the second mode is approximately equal to the duration of operation in the first mode.
Claim 17
Dependent Claim
30 words
An X-ray apparatus as claimed claim 5, characterized in that the duration of operation in the second mode is approximately equal to the duration of operation in the first mode.
Claim 18
Dependent Claim
30 words
An X-ray apparatus as claimed claim 6, characterized in that the duration of operation in the second mode is approximately equal to the duration of operation in the first mode.
Claim 19
Dependent Claim
41 words
An X-ray apparatus as claimed in claim 2, characterized in that at least one conductive surface (51, 71) is provided in the vicinity of the photoconductor (1), outside the corona discharging device, which surface is connected to a direct voltage source.
References Cited (Backward Citations)
US5341409A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |