Patent US4154770A successfully refreshed from Google Patents.
US5499080A
Expired / Lapsed
US
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Image forming apparatus having a voltage controlled contact charger
Assignee: Canon Inc
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Filing: 1993-12-23
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Granted: 1996-03-12
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Expires: 2013-12-23
Abstract
Abstract A charging apparatus includes a charging member for charging the member to be charged; a power source for supplying electric power to the charging member; a power source for supplying a constant small DC current to the charging member; and a device for determining a voltage to be applied to the charging member; wherein while the constant small DC current is supplied to the charging member, a voltage supplied to the charging member is detected and in response to the detected voltage, the voltage determining device determines the voltage to be applied to the charging member.
Inventors
- 👤 Tadashi Furuya
- 👤 Junji Araya
- 👤 Hideyuki Yano
- 👤 Harumi Kugoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:44
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0208; G03G15/0216
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
93 words
A charging apparatus comprising: a charging member for charging a member to be charged; a power source for supplying electric power to said charging member; means for supplying a constant small Dc current to said charging member; and means for determining a voltage to be applied to said charging member; wherein while the constant small DC current is supplied to said charging member, a voltage supplied to said charging member is detected and in response to said detected voltage, said voltage determining means determines the voltage to be applied to said charging member.
Claim 2
Dependent Claim
93 words
A charging apparatus comprising: a charging member for charging a member to be charged; a power source for supplying electric power to said charging member; means for supplying a constant small Dc current to said charging member; and means for determining a voltage to be applied to said charging member; wherein while the constant small DC current is supplied to said charging member, a voltage supplied to said charging member is detected and in response to said detected voltage, said voltage determining means determines the voltage to be applied to said charging member.
Claim 3
Dependent Claim
18 words
A charging apparatus according to claim 1, wherein said constant DC current is not more than 0.5 μA.
Claim 4
Dependent Claim
19 words
A charging apparatus according to claim 1, wherein said charging member is contactable to said member to be charged.
Claim 5
Dependent Claim
30 words
A charging apparatus according to claim 1, wherein said charging member is positioned such that a small gap is formed between said charging member and said member to be charged.
Claim 6
Dependent Claim
101 words
An image forming apparatus comprising: an image bearing member for bearing an image; a charging member for charging said image bearing member; a power source for supplying electric power to said charging member; means for supplying a constant small DC current to said charging member; and means for determining a voltage to be applied to said charging member; wherein while the constant small DC current is supplied to said charging member, a voltage supplied to said charging member is detected and in response to said detected voltage, said voltage determining means determines the voltage to be applied to said charging member.
Claim 7
Dependent Claim
101 words
An image forming apparatus comprising: an image bearing member for bearing an image; a charging member for charging said image bearing member; a power source for supplying electric power to said charging member; means for supplying a constant small DC current to said charging member; and means for determining a voltage to be applied to said charging member; wherein while the constant small DC current is supplied to said charging member, a voltage supplied to said charging member is detected and in response to said detected voltage, said voltage determining means determines the voltage to be applied to said charging member.
Claim 8
Dependent Claim
19 words
An image forming apparatus according to claim 5, wherein said constant DC current is not more than 0.5 μA.
Claim 9
Dependent Claim
26 words
An image forming apparatus according to claim 5 or 6, wherein said charging member is constant-voltage controlled using said voltage determined by said voltage determining means.
Claim 10
Dependent Claim
20 words
An apparatus according to any one of claim 7, wherein said charging member is contactable to said image bearing member.
Claim 11
Dependent Claim
47 words
An image forming apparatus according to claim 5, wherein a latent image can be formed on said image bearing member, with use of said charging member, and said voltage determined by said voltage determining means is applied to said charging member while the latent image is formed.
Claim 12
Dependent Claim
30 words
An image forming apparatus according to claim 9, wherein while the latent image is formed, said charging member is constant-voltage controlled using said voltage determined by said voltage determining means.
Claim 13
Dependent Claim
23 words
An image forming apparatus according to claim 9 or 10, wherein said constant DC current is supplied before the latent image is formed.
Claim 14
Dependent Claim
17 words
An apparatus according to claim 11, wherein said charging member is contactable to said image bearing member.
Claim 15
Dependent Claim
51 words
An image forming apparatus according to claim 5, wherein said voltage determined by said voltage determining means is substantially a sum of the voltage supplied to said charging member while said constant DC current is supplied and the potential to which said image bearing member is charged by said charging member.
Claim 16
Dependent Claim
19 words
An image forming apparatus according to claim 5, wherein said charging member is contactable to said image bearing member.
Claim 17
Dependent Claim
21 words
An image forming apparatus according to claim 5 or 14, wherein said charging member is in the form of a roller.
Claim 18
Dependent Claim
30 words
An image forming apparatus according to claim 5, wherein said charging member is positioned such that a small gap is formed between said charging member and said image bearing member.
Claim 19
Dependent Claim
35 words
An image forming apparatus according to claim 16, wherein said charging member is positioned such that it forms a micro-air gap of less than 1,000 μm between said charging member and said image bearing member.
Claim 20
Dependent Claim
126 words
An image forming apparatus comprising: an image bearing member for bearing an image; a charging member for charging said image bearing member in order to form a latent image on said image bearing member; a power source for supplying electric power to said charging member; means for supplying to said charging member, first and second voltages which are different from each other; and means for determining a third voltage to be applied to said charging member; wherein while said first and second voltages are supplied to said charging member, corresponding first and second currents flowing through said charging member are detected and in response to said detected first and second currents, said voltage determining means determines the third voltage to be applied to said charging member.
Claim 21
Dependent Claim
126 words
An image forming apparatus comprising: an image bearing member for bearing an image; a charging member for charging said image bearing member in order to form a latent image on said image bearing member; a power source for supplying electric power to said charging member; means for supplying to said charging member, first and second voltages which are different from each other; and means for determining a third voltage to be applied to said charging member; wherein while said first and second voltages are supplied to said charging member, corresponding first and second currents flowing through said charging member are detected and in response to said detected first and second currents, said voltage determining means determines the third voltage to be applied to said charging member.
Claim 22
Dependent Claim
30 words
An image forming apparatus according to claim 18, wherein said third voltage determined by said voltage determining means is applied to said charging member while the latent image is formed.
Claim 23
Dependent Claim
31 words
An image forming apparatus according to claim 18, wherein while the latent image is formed, said charging member is constant-voltage controlled using said third voltage determined by said voltage determining means.
Claim 24
Dependent Claim
21 words
An image forming apparatus according to claim 18, wherein said first and second currents are detected before the image is formed.
Claim 25
Dependent Claim
65 words
An image forming apparatus according to claim 18, wherein said third voltage determined by said voltage determining means is substantially equal to: V.sub.1 -I.sub.1 (V.sub.2 -V.sub.1)/(I.sub.2 -I.sub.1)+V.sub.d wherein V 1 is said first voltage; V 2 is second voltage; I 1 is first current; I 2 is second current; and V d is the potential of said image bearing member charged by said charging member.
Claim 26
Independent Claim
25 words
An apparatus according to any one of claims 6, 9, 10, 13, or 19-22, wherein said charging member is contactable to said image bearing member.
Claim 27
Dependent Claim
18 words
An image forming apparatus according to claim 18, wherein said charging member is contactable said image bearing member.
Claim 28
Dependent Claim
21 words
An image forming apparatus according to claim 18 or 24, wherein said charging member is in the form of a roller.
Claim 29
Dependent Claim
30 words
An image forming apparatus according to claim 18, wherein said charging member is positioned such that a small gap is formed between said charging member and said image bearing member.
Claim 30
Dependent Claim
35 words
An image forming apparatus according to claim 26, wherein said charging member is positioned such that it forms a micro-air gap of less than 1,000 μm between said charging member and said image bearing member.
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) | 1999-03-12 | 1999-09-11 | 2000-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-12 | 2003-09-11 | 2004-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-12 | 2007-09-11 | 2008-03-12 | $7700.00 | Window Closed / Lapsed |