US3719169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plural electrode development apparatus
Assignee: Xerox Corp
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Filing: 1971-05-07
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Granted: 1973-03-06
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Expires: 1991-05-07
Abstract
Abstract Development electrode apparatus is provided in accordance with the teachings of the present invention wherein at least two development electrodes are employed at a developing station in electrophotographic apparatus. The first development electrode presented to a latent electrostatic image undergoing development displays characteristics which are optimum for high rates of developer flow and hence only reduced development of portions of a latent electrostatic image exhibiting low charge densities and extended areas is achieved but may be accompanied by optimum cleaning. The second development electrode presented to the latent electrostatic image to be developed displays characteristics which are optimized to complete low contrast and extended area development; however, as the majority of developer material is removed, no inhibition of the developer flow occurs at said second development electrode.
Inventors
- 👤 R Cade
- 👤 J Knapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:33
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0801
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
173 words
Apparatus for developing a latent electrostatic image associated with a surface comprising: means for cascading developer material over said surface at a high flow rate; first development electrode means disposed adjacent to said surface at a position at which said developer material is applied thereto, said first development electrode means being spaced a sufficient distance from said surface to allow substantial quantities of said developer material to pass between said surface and said first development electrode means at said high flow rate; and second development electrode means disposed adjacent to said surface in the vicinity of said first development electrode means and spaced a smaller distance from said surface than said first development electrode to thereby allow only reduced quantities of developer material to pass between said surface and said second development electrode means, said second development electrode means being spaced a sufficient distance from said first development electrode means to allow quantities of developer material equal to at least the difference between said substantial quantities and said reduced quantities to pass therebetween.
Claim 2
Dependent Claim
173 words
Apparatus for developing a latent electrostatic image associated with a surface comprising: means for cascading developer material over said surface at a high flow rate; first development electrode means disposed adjacent to said surface at a position at which said developer material is applied thereto, said first development electrode means being spaced a sufficient distance from said surface to allow substantial quantities of said developer material to pass between said surface and said first development electrode means at said high flow rate; and second development electrode means disposed adjacent to said surface in the vicinity of said first development electrode means and spaced a smaller distance from said surface than said first development electrode to thereby allow only reduced quantities of developer material to pass between said surface and said second development electrode means, said second development electrode means being spaced a sufficient distance from said first development electrode means to allow quantities of developer material equal to at least the difference between said substantial quantities and said reduced quantities to pass therebetween.
Claim 3
Dependent Claim
173 words
Apparatus for developing a latent electrostatic image associated with a surface comprising: means for cascading developer material over said surface at a high flow rate; first development electrode means disposed adjacent to said surface at a position at which said developer material is applied thereto, said first development electrode means being spaced a sufficient distance from said surface to allow substantial quantities of said developer material to pass between said surface and said first development electrode means at said high flow rate; and second development electrode means disposed adjacent to said surface in the vicinity of said first development electrode means and spaced a smaller distance from said surface than said first development electrode to thereby allow only reduced quantities of developer material to pass between said surface and said second development electrode means, said second development electrode means being spaced a sufficient distance from said first development electrode means to allow quantities of developer material equal to at least the difference between said substantial quantities and said reduced quantities to pass therebetween.
Claim 4
Dependent Claim
173 words
Apparatus for developing a latent electrostatic image associated with a surface comprising: means for cascading developer material over said surface at a high flow rate; first development electrode means disposed adjacent to said surface at a position at which said developer material is applied thereto, said first development electrode means being spaced a sufficient distance from said surface to allow substantial quantities of said developer material to pass between said surface and said first development electrode means at said high flow rate; and second development electrode means disposed adjacent to said surface in the vicinity of said first development electrode means and spaced a smaller distance from said surface than said first development electrode to thereby allow only reduced quantities of developer material to pass between said surface and said second development electrode means, said second development electrode means being spaced a sufficient distance from said first development electrode means to allow quantities of developer material equal to at least the difference between said substantial quantities and said reduced quantities to pass therebetween.
Claim 5
Dependent Claim
44 words
The apparatus according to claim 1 additionally comprising means for applying a reference potential to said first and second development electrode means to enable said first and second development electrode means to modify fields exhibited by said latent electrostatic image associated with said surface.
Claim 6
Dependent Claim
54 words
The apparatus according to claim 2 wherein the reference potential applied to at least said second development electrode means resides at a magnitude level appropriate to inhibit toner material present in said developer material from depositing on portions of said surface corresponding to background areas of said latent electrostatic image associated with said surface.
Claim 7
Dependent Claim
47 words
The apparatus according to claim 3 wherein said reference potential applied to said first development electrode means resides at a magnitude level appropriate to inhibit toner material from depositing on portions of said surface corresponding to background areas of said latent electrostatic image associated with said surface.
References Cited (Backward Citations)
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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) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |