US4945389A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of cleaning a photoconductive element of an image recorder
Assignee: Ricoh Co Ltd
•
Filing: 1989-05-23
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Granted: 1990-07-31
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Expires: 2009-05-23
Abstract
Abstract A cleaning method applicable to a photoconductive element installed in an electrophotographic copier or similar image recorder of the type performing repetitive steps of charging, exposing, developing, transferring, discharging, cleaning and so forth. The method includes the steps of measuring the surface potential of the photoconductive element remaining after discharging which occurs prior to cleaning, comparing the measured potential with a reference potential, and controlling the output voltage of a discharging device to maintain the surface potential constant.
Inventors
- 👤 Noriyuki Usui
- 👤 Tsumori Satoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:19
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/0005; G03G21/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
121 words
A cleaning method for removing toner particles remaining on a photoconductive element which is installed in an image recorder, said method comprising the steps of: (a) producing a predetermined number of copies; then (b) measuring a potential being deposited on a surface of the photoconductive element after said surface has been discharged and prior to a cleaning step; then (c) comparing the measured potential of the surface of the photoconductive element with a predetermined reference potential; and then, still prior to the cleaning step, (d) adjusting an output voltage for discharging the surface of the photoconductive element on the basis of a result of the comparison such that the surface potential of the photoconductive element is controlled to a predetermined value.
Claim 2
Dependent Claim
121 words
A cleaning method for removing toner particles remaining on a photoconductive element which is installed in an image recorder, said method comprising the steps of: (a) producing a predetermined number of copies; then (b) measuring a potential being deposited on a surface of the photoconductive element after said surface has been discharged and prior to a cleaning step; then (c) comparing the measured potential of the surface of the photoconductive element with a predetermined reference potential; and then, still prior to the cleaning step, (d) adjusting an output voltage for discharging the surface of the photoconductive element on the basis of a result of the comparison such that the surface potential of the photoconductive element is controlled to a predetermined value.
Claim 3
Dependent Claim
25 words
A cleaning method as claimed in claim 1, and further comprising the step of controlling a bias voltage applied to a magnetic brush for cleaning.
Claim 4
Dependent Claim
36 words
A cleaning method as claimed in claim 2, wherein the output voltage for discharging the surface of the photoconductive element and the bias voltage applied to the magnetic brush are opposite in polarity to each other.
Claim 5
Dependent Claim
125 words
A cleaning method for removing toner particles remaining on a photoconductive element which is installed in an image recorder, said method comprising the steps of: (a) turning the main switch of the image recorder on; then, prior to producing copies, (b) discharging the surface of the photoconductive element; then (c) measuring a potential being deposited on the surface of the photoconductive element; then (d) comparing the measured potential of the surface of the photoconductive element with a predetermined reference potential; then (e) adjusting an output voltage for discharging the surface of the photoconductive element on the basis of a result of the comparison such that the surface potential of the photoconductive element is controlled to a predetermined value; and then (f) performing a cleaning step.
Claim 6
Dependent Claim
125 words
A cleaning method for removing toner particles remaining on a photoconductive element which is installed in an image recorder, said method comprising the steps of: (a) turning the main switch of the image recorder on; then, prior to producing copies, (b) discharging the surface of the photoconductive element; then (c) measuring a potential being deposited on the surface of the photoconductive element; then (d) comparing the measured potential of the surface of the photoconductive element with a predetermined reference potential; then (e) adjusting an output voltage for discharging the surface of the photoconductive element on the basis of a result of the comparison such that the surface potential of the photoconductive element is controlled to a predetermined value; and then (f) performing a cleaning step.
Claim 7
Dependent Claim
25 words
A cleaning method as claimed in claim 4, and further comprising the step of controlling a bias voltage applied to a magnetic brush for cleaning.
Claim 8
Dependent Claim
36 words
A cleaning method as claimed in claim 5, wherein the output voltage for discharging the surface of the photoconductive element and the bias voltage applied to the magnetic brush are opposite in polarity to each other.
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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) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |