Patent US5717979A successfully refreshed from Google Patents.
US5717979A
Expired / Lapsed
US
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Image forming apparatus with AC current controlled contact charging
Assignee: Canon Inc
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Filing: 1996-10-03
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Granted: 1998-02-10
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Expires: 2016-10-03
Abstract
Abstract An image forming apparatus includes an image bearing member; a charging member contactable the image bearing member to charge the image bearing member at a charging position; wherein an AC current applied to the charging member is constant-current-controlled when a region of the image bearing member which is going to be an image formation region is at the charging position, and wherein a current flowing through the charging member is detected when a region of the image bearing member which is going to be a non-image-formation region is at the charging position, and the AC current is determined on the basis of the detected current.
Inventors
- 👤 Hisaaki Senba, deceased
- 👤 Mitsuka Abe
- 👤 Keizo Takura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:11
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0208; G03G15/0216
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
105 words
An image forming apparatus comprising: an image bearing member; a charging member contactable said image bearing member to charge said image bearing member at a charging position; wherein an AC current applied to said charging member is constant-current-controlled when a region of said image bearing member which is going to be an image formation region is at said charging position, and wherein a current flowing through said charging member is detected when a region of said image bearing member which is going to be a non-image-formation region is at said charging position, and said AC current is determined on the basis of the detected current.
Claim 2
Dependent Claim
105 words
An image forming apparatus comprising: an image bearing member; a charging member contactable said image bearing member to charge said image bearing member at a charging position; wherein an AC current applied to said charging member is constant-current-controlled when a region of said image bearing member which is going to be an image formation region is at said charging position, and wherein a current flowing through said charging member is detected when a region of said image bearing member which is going to be a non-image-formation region is at said charging position, and said AC current is determined on the basis of the detected current.
Claim 3
Dependent Claim
24 words
An apparatus according to claim 1, wherein said AC current is determined on the basis of a DC current flowing through said charging member.
Claim 4
Dependent Claim
18 words
An apparatus according to claim 1, wherein said charging member is supplied with an AC biased DC voltage.
Claim 5
Dependent Claim
23 words
An apparatus according to claim 1, wherein when said current is detected, said charging member is supplied with an AC biased DC voltage.
Claim 6
Dependent Claim
30 words
An apparatus according to claim 1, wherein said charging member is provided with a resistance layer contactable the image bearing member and an electroconductive layer provided inside said resistance layer.
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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) | 2001-02-09 | 2001-08-11 | 2002-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-09 | 2005-08-11 | 2006-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-09 | 2009-08-11 | 2010-02-10 | $7700.00 | Window Closed / Lapsed |