Patent US264504A successfully refreshed from Google Patents.
Patent US5162850A successfully refreshed from Google Patents.
US5162850A
Expired / Lapsed
US
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Image forming apparatus using a linear equation to sense surface potential
Assignee: Ricoh Co Ltd
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Filing: 1991-07-22
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Granted: 1992-11-10
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Expires: 2011-07-22
Abstract
Abstract An image forming apparatus for uniformly charging the surface of a photoconductive element, exposing the charged surface of the photoconductive element imagewise to electrostatically form a latent image, and developing the latent image by a toner or similar developer. A linear equation is produced which is a reference representative of the input-output characteristic of a sensor responsive to the surface potential of the photoconductive element. The linear equation is used to calculate an accurate surface potential matching the output of the sensor. A bias voltage for development or similar image forming condition is controlled on the basis of the calculated surface potential.
Inventors
- 👤 Yoshihiro Nakashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5033; G03G15/5037; G03G15/06; G03G15/065
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
An image forming apparatus for uniformly charging the surface of a photoconductive element, comprising: voltage applying means for applying first and second predetermined voltages to the photoconductive element; surface potential sensing means for sensing first and second surface potentials on said photoconductive element based on said respective first and second applied voltages; calculating means for calculating a linear equation representing a reference input-output characteristic of said surface potential sensing means based on said sensed first and second surface potentials; and control means for controlling an image forming condition of said image forming means based on the calculated linear equation.
Claim 2
Dependent Claim
99 words
An image forming apparatus for uniformly charging the surface of a photoconductive element, comprising: voltage applying means for applying first and second predetermined voltages to the photoconductive element; surface potential sensing means for sensing first and second surface potentials on said photoconductive element based on said respective first and second applied voltages; calculating means for calculating a linear equation representing a reference input-output characteristic of said surface potential sensing means based on said sensed first and second surface potentials; and control means for controlling an image forming condition of said image forming means based on the calculated linear equation.
Claim 3
Dependent Claim
18 words
The image forming apparatus according to claim 1, further comprising a storage means for storing said linear equation.
Claim 4
Dependent Claim
15 words
The image forming apparatus according to claim 1, wherein said control means comprises a CPU.
Claim 5
Dependent Claim
20 words
The image forming apparatus according to claim 1, wherein said first predetermined voltage is lower than said second predetermined voltage.
Claim 6
Independent Claim
121 words
A method for uniformly charging a surface of a photoconductive element of an image forming apparatus, comprising the steps of: applying a first predetermined voltage to the photoconductive element; sensing a first surface potential of said photoconductive element by a surface potential sensing means based on said first applied voltage; applying a second predetermined voltage to the photoconductive element; sensing a second surface potential of said photoconductive element by the surface potential sensing means based on said second applied voltage; calculating a linear equation representing a reference input-output characteristic of said surface potential sensing means based on said sensed first and second surface potentials; and controlling an image forming condition of said image forming apparatus based on the calculated linear equation.
Claim 7
Independent Claim
121 words
A method for uniformly charging a surface of a photoconductive element of an image forming apparatus, comprising the steps of: applying a first predetermined voltage to the photoconductive element; sensing a first surface potential of said photoconductive element by a surface potential sensing means based on said first applied voltage; applying a second predetermined voltage to the photoconductive element; sensing a second surface potential of said photoconductive element by the surface potential sensing means based on said second applied voltage; calculating a linear equation representing a reference input-output characteristic of said surface potential sensing means based on said sensed first and second surface potentials; and controlling an image forming condition of said image forming apparatus based on the calculated linear equation.
Claim 8
Dependent Claim
19 words
The method according to claim 5, further comprising the step of: storing the calculated linear equation in a memory.
Claim 9
Dependent Claim
13 words
The method according to claim 5, wherein said controlling step uses a CPU.
Claim 10
Dependent Claim
18 words
The method according to claim 5, wherein said first predetermined voltage is lower than said second predetermined voltage.
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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) | 1995-11-10 | 1996-05-11 | 1996-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-10 | 2000-05-11 | 2000-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-10 | 2004-05-11 | 2004-11-10 | $7700.00 | Window Closed / Lapsed |