US4456370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Charge control system
Assignee: Xerox Corp
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Filing: 1982-11-08
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Granted: 1984-06-26
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Expires: 2002-11-08
Abstract
Abstract An apparatus which controls the electrical charging of a photoconductive member used in an electrophotographic printing machine. The apparatus has a pair of corona generating devices. The second corona generating device detects the level of charge on the photoconductive surface after the charging thereof by the first corona generating device. In response to the detected charge level, the second corona generating device transmits a control signal to the first corona generating device so as to regulate the charge on the photoconductive member.
Inventors
- 👤 Thomas A. Hayes, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:09
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0266
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
98 words
An apparatus for controlling the charging of a photoconductive surface, including: first corona generating means for charging a portion of the photoconductive surface to a substantially uniform level; and second corona generating means for further charging the portion of the photoconductive surface charged by said first corona generating means, said second corona generating means detecting the level of charge on the portion of the photoconductive surface charged by said first corona generating means and transmitting a control signal to said first corona generating means to regulate the level that said first corona generating means charges the photoconductive surface.
Claim 2
Independent Claim
98 words
An apparatus for controlling the charging of a photoconductive surface, including: first corona generating means for charging a portion of the photoconductive surface to a substantially uniform level; and second corona generating means for further charging the portion of the photoconductive surface charged by said first corona generating means, said second corona generating means detecting the level of charge on the portion of the photoconductive surface charged by said first corona generating means and transmitting a control signal to said first corona generating means to regulate the level that said first corona generating means charges the photoconductive surface.
Claim 3
Dependent Claim
51 words
An apparatus according to claim 1, wherein said first corona generating means includes: a first coronode member; a first conductive shield member; first means, coupled to said first coronode member, for applying an alternating voltage thereto; and first means for electrically biasing said first conductive shield member to a constant voltage.
Claim 4
Dependent Claim
51 words
An apparatus according to claim 2, wherein said second corona generating means includes: a second coronode member; a second conductive shield member; second means, coupled to said second coronode member, for applying an alternating voltage thereto; and second means for electrically biasing said second conductive shield member to a constant voltage.
Claim 5
Dependent Claim
61 words
An apparatus according to claim 3, wherein said second corona generating means includes means, coupled to said second conductive shield member and said first electrical biasing means, for generating the control signal regulating the level of the constant voltage on said first conductive shield in response to the detected current flowing between said second conductive shield member and the photoconductive surface.
Claim 6
Dependent Claim
31 words
An apparatus according to claim 4, further including means, coupled to said second electrical biasing means, for adjusting the level of the constant voltage applied to said second conductive shield member.
Claim 7
Dependent Claim
108 words
An electrophotograhic printing machine of the type in which the charging of a photoconductive surface is controlled, wherein the improvement includes: first corona generating means for charging a portion of the photoconductive surface to a substantially uniform level; and second corona generating means for further charging the portion of the photoconductive surface charged by said first corona generating means, said second corona generating means detecting the level of charge on the portion of the photoconductive surface charged by said first corona generating means and transmitting a control signal to said first corona generating means to regulate the level that said first corona generating means charges the photoconductive surface.
Claim 8
Dependent Claim
108 words
An electrophotograhic printing machine of the type in which the charging of a photoconductive surface is controlled, wherein the improvement includes: first corona generating means for charging a portion of the photoconductive surface to a substantially uniform level; and second corona generating means for further charging the portion of the photoconductive surface charged by said first corona generating means, said second corona generating means detecting the level of charge on the portion of the photoconductive surface charged by said first corona generating means and transmitting a control signal to said first corona generating means to regulate the level that said first corona generating means charges the photoconductive surface.
Claim 9
Dependent Claim
52 words
A printing machine according to claim 6, wherein said first corona generating means includes: a first coronode member; a first conductive shield member; first means, coupled to said first coronode member, for applying an alternating voltage thereto; and first means for electrically biasing said first conductive shield member to a constant voltage.
Claim 10
Dependent Claim
52 words
A printing machine according to claim 7, wherein said second corona generating means includes: a second coronode member; a second conductive shield member; second means, coupled to said second coronode member, for applying an alternating voltage thereto; and second means for electrically biasing said second conductive shield member to a constant voltage.
Claim 11
Dependent Claim
62 words
A printing machine according to claim 8, wherein said second corona generating means includes means, coupled to said second conductive shield member and said first electrical biasing means, for generating the control signal regulating the level of the constant voltage on said first conductive shield in response to the detected current flowing between said second conductive shield member and the photoconductive surface.
Claim 12
Dependent Claim
32 words
A printing machine according to claim 9, further including means, coupled to said second electrical biasing means, for adjusting the level of the constant voltage applied to said second conductive shield member.
Claim 13
Dependent Claim
22 words
A printing machine according to claim 10, further including means for forming a sample patch of marking particles on the photoconductive surface.
Claim 14
Dependent Claim
57 words
A printing machine according to claim 11, wherein said adjusting means includes: means for sensing the density of the particles of the sample patch and generating an output signal indicative thereof; and means, responsive to the output signal from said sensing means, for regulating the level of the constant voltage applied to said second conductive shield 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) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |